From a0a373a8e1a5b2076ee685f47baff59f5e07410e Mon Sep 17 00:00:00 2001
From: baldurk <baldurk@baldurk.org>
Date: Fri, 29 May 2020 14:03:03 +0100
Subject: [PATCH] Fix handling of buffer truncation and zero-sized buffers

---
 qrenderdoc/Code/QRDUtils.cpp                  |   2 +-
 qrenderdoc/Windows/BufferViewer.cpp           |  92 +++++---
 .../Windows/ConstantBufferPreviewer.cpp       |   6 +-
 .../D3D12PipelineStateViewer.cpp              |  50 ++---
 qrenderdoc/Windows/TextureViewer.cpp          |   2 +-
 renderdoc/api/replay/common_pipestate.h       |   7 +-
 renderdoc/api/replay/control_types.h          |   4 +
 renderdoc/api/replay/pipestate.inl            |  34 +--
 renderdoc/driver/d3d11/d3d11_postvs.cpp       |   6 +
 renderdoc/driver/d3d12/d3d12_postvs.cpp       |   9 +-
 renderdoc/driver/d3d12/d3d12_rendermesh.cpp   |  12 +-
 renderdoc/driver/d3d12/d3d12_shaderdebug.cpp  |  22 +-
 renderdoc/driver/gl/gl_postvs.cpp             |   6 +
 renderdoc/driver/vulkan/vk_postvs.cpp         |   6 +
 .../vulkan/wrappers/vk_device_funcs.cpp       |   3 +
 renderdoc/replay/renderdoc_serialise.inl      |   4 +-
 util/test/demos/CMakeLists.txt                |   2 +
 .../demos/d3d11/d3d11_buffer_truncation.cpp   | 161 ++++++++++++++
 .../demos/d3d12/d3d12_buffer_truncation.cpp   | 198 ++++++++++++++++++
 util/test/demos/demos.vcxproj                 |   5 +-
 util/test/demos/demos.vcxproj.filters         |  15 +-
 util/test/demos/gl/gl_buffer_truncation.cpp   | 159 ++++++++++++++
 ...d_cbuffer.cpp => vk_buffer_truncation.cpp} |  92 ++++----
 util/test/demos/vk/vk_cbuffer_zoo.cpp         |  15 +-
 util/test/demos/vk/vk_secondary_cmdbuf.cpp    |  10 +-
 util/test/demos/vk/vk_shader_editing.cpp      |  15 +-
 util/test/demos/vk/vk_texture_zoo.cpp         |  12 +-
 util/test/rdtest/__init__.py                  |   1 +
 util/test/rdtest/analyse.py                   |  91 ++++++--
 util/test/rdtest/shared/Buffer_Truncation.py  | 161 ++++++++++++++
 util/test/rdtest/testcase.py                  |  18 +-
 .../tests/D3D11/D3D11_Buffer_Truncation.py    |   7 +
 .../tests/D3D12/D3D12_Buffer_Truncation.py    |   7 +
 util/test/tests/GL/GL_Buffer_Truncation.py    |   7 +
 .../test/tests/Vulkan/VK_Buffer_Truncation.py |   7 +
 .../test/tests/Vulkan/VK_Truncated_CBuffer.py |  32 ---
 36 files changed, 1038 insertions(+), 242 deletions(-)
 create mode 100644 util/test/demos/d3d11/d3d11_buffer_truncation.cpp
 create mode 100644 util/test/demos/d3d12/d3d12_buffer_truncation.cpp
 create mode 100644 util/test/demos/gl/gl_buffer_truncation.cpp
 rename util/test/demos/vk/{vk_truncated_cbuffer.cpp => vk_buffer_truncation.cpp} (60%)
 create mode 100644 util/test/rdtest/shared/Buffer_Truncation.py
 create mode 100644 util/test/tests/D3D11/D3D11_Buffer_Truncation.py
 create mode 100644 util/test/tests/D3D12/D3D12_Buffer_Truncation.py
 create mode 100644 util/test/tests/GL/GL_Buffer_Truncation.py
 create mode 100644 util/test/tests/Vulkan/VK_Buffer_Truncation.py
 delete mode 100644 util/test/tests/Vulkan/VK_Truncated_CBuffer.py

diff --git a/qrenderdoc/Code/QRDUtils.cpp b/qrenderdoc/Code/QRDUtils.cpp
index f7e584898..6037f7d7c 100644
--- a/qrenderdoc/Code/QRDUtils.cpp
+++ b/qrenderdoc/Code/QRDUtils.cpp
@@ -752,7 +752,7 @@ bool RichResourceTextMouseEvent(const QWidget *owner, const QVariant &var, QRect
             formatter = BufferFormatter::DeclareStruct(ptrType.descriptor.name, ptrType.members,
                                                        ptrType.descriptor.arrayByteStride);
 
-          IBufferViewer *view = ctx.ViewBuffer(ptr->offset, 0, ptr->base, formatter);
+          IBufferViewer *view = ctx.ViewBuffer(ptr->offset, ~0ULL, ptr->base, formatter);
 
           ctx.AddDockWindow(view->Widget(), DockReference::MainToolArea, NULL);
         }
diff --git a/qrenderdoc/Windows/BufferViewer.cpp b/qrenderdoc/Windows/BufferViewer.cpp
index ff08a32ae..fca37adbb 100644
--- a/qrenderdoc/Windows/BufferViewer.cpp
+++ b/qrenderdoc/Windows/BufferViewer.cpp
@@ -1522,16 +1522,23 @@ static void ConfigureMeshColumns(ICaptureContext &ctx, PopulateBufferData *bufda
 
       BoundVBuffer ib = ctx.CurPipelineState().GetIBuffer();
 
-      uint32_t bytesAvailable = 0;
+      uint32_t bytesAvailable = ib.byteSize;
 
-      BufferDescription *buf = ctx.GetBuffer(ib.resourceId);
-      if(buf)
+      if(bytesAvailable == ~0U)
       {
-        uint64_t offset = ib.byteOffset - draw->indexOffset * draw->indexByteWidth;
-        if(offset > buf->length)
-          bytesAvailable = 0;
+        BufferDescription *buf = ctx.GetBuffer(ib.resourceId);
+        if(buf)
+        {
+          uint64_t offset = ib.byteOffset - draw->indexOffset * draw->indexByteWidth;
+          if(offset > buf->length)
+            bytesAvailable = 0;
+          else
+            bytesAvailable = buf->length - offset;
+        }
         else
-          bytesAvailable = buf->length - offset;
+        {
+          bytesAvailable = 0;
+        }
       }
 
       // drawing more than this many indices will read off the end of the index buffer - which while
@@ -1548,12 +1555,25 @@ static void ConfigureMeshColumns(ICaptureContext &ctx, PopulateBufferData *bufda
         if(vb.byteStride == 0)
           continue;
 
-        BufferDescription *buf = ctx.GetBuffer(vb.resourceId);
-        if(buf)
+        uint32_t bytesAvailable = vb.byteSize;
+
+        if(bytesAvailable == ~0U)
         {
-          numRowsUpperBound = qMax(numRowsUpperBound,
-                                   uint32_t(buf->length - vb.byteOffset) / qMax(1U, vb.byteStride));
+          BufferDescription *buf = ctx.GetBuffer(vb.resourceId);
+          if(buf)
+          {
+            if(vb.byteOffset > buf->length)
+              bytesAvailable = 0;
+            else
+              bytesAvailable = buf->length - vb.byteOffset;
+          }
+          else
+          {
+            bytesAvailable = 0;
+          }
         }
+
+        numRowsUpperBound = qMax(numRowsUpperBound, bytesAvailable / qMax(1U, vb.byteStride));
       }
 
       // if there are no vertex buffers we can't clamp.
@@ -1596,8 +1616,18 @@ static void RT_FetchMeshData(IReplayController *r, ICaptureContext &ctx, Populat
 
   bytebuf idata;
   if(ib.resourceId != ResourceId() && draw && (draw->flags & DrawFlags::Indexed))
-    idata = r->GetBufferData(ib.resourceId, ib.byteOffset + draw->indexOffset * draw->indexByteWidth,
-                             draw->numIndices * draw->indexByteWidth);
+  {
+    uint64_t readBytes = draw->numIndices * draw->indexByteWidth;
+    uint32_t offset = draw->indexOffset * draw->indexByteWidth;
+
+    if(ib.byteSize > offset)
+      readBytes = qMin(ib.byteSize - offset, readBytes);
+    else
+      readBytes = 0;
+
+    if(readBytes > 0)
+      idata = r->GetBufferData(ib.resourceId, ib.byteOffset + offset, readBytes);
+  }
 
   if(data->vsinConfig.indices)
     data->vsinConfig.indices->deref();
@@ -1605,7 +1635,8 @@ static void RT_FetchMeshData(IReplayController *r, ICaptureContext &ctx, Populat
   data->vsinConfig.indices = new BufferData();
 
   if(draw && draw->indexByteWidth != 0 && !idata.isEmpty())
-    data->vsinConfig.indices->storage.resize(sizeof(uint32_t) * draw->numIndices);
+    data->vsinConfig.indices->storage.resize(
+        sizeof(uint32_t) * qMin(draw->numIndices, ((uint32_t)idata.size() / draw->indexByteWidth)));
   else if(draw && (draw->flags & DrawFlags::Indexed))
     data->vsinConfig.indices->storage.resize(sizeof(uint32_t));
 
@@ -1716,8 +1747,17 @@ static void RT_FetchMeshData(IReplayController *r, ICaptureContext &ctx, Populat
     BufferData *buf = new BufferData;
     if(used)
     {
-      buf->storage = r->GetBufferData(vb.resourceId, vb.byteOffset + offset * vb.byteStride,
-                                      qMax(maxIdx, maxIdx + 1) * vb.byteStride + maxAttrOffset);
+      uint64_t readBytes = qMax(maxIdx, maxIdx + 1) * vb.byteStride + maxAttrOffset;
+
+      offset *= vb.byteStride;
+
+      if(vb.byteSize > offset)
+        readBytes = qMin(vb.byteSize - offset, readBytes);
+      else
+        readBytes = 0;
+
+      if(readBytes > 0)
+        buf->storage = r->GetBufferData(vb.resourceId, vb.byteOffset + offset, readBytes);
 
       buf->stride = vb.byteStride;
     }
@@ -2410,12 +2450,8 @@ void BufferViewer::OnEventChanged(uint32_t eventId)
   }
   else
   {
-    uint64_t len = m_ByteSize;
-    if(len == UINT64_MAX)
-      len = 0;
-
     QString errors;
-    ShaderConstant constant = BufferFormatter::ParseFormatString(m_Format, len, true, errors);
+    ShaderConstant constant = BufferFormatter::ParseFormatString(m_Format, m_ByteSize, true, errors);
 
     UnrollConstant(constant, bufdata->vsinConfig.columns, bufdata->vsinConfig.props);
 
@@ -2487,8 +2523,6 @@ void BufferViewer::OnEventChanged(uint32_t eventId)
 
       uint64_t unclampedLen = m_ByteSize;
       if(unclampedLen == UINT64_MAX)
-        unclampedLen = 0;
-      if(unclampedLen == 0)
       {
         uint64_t bufLen = m_IsBuffer ? m_Ctx.GetBuffer(m_BufferID)->length : 0;
         uint64_t bufOffs = m_ByteOffset;
@@ -2505,7 +2539,8 @@ void BufferViewer::OnEventChanged(uint32_t eventId)
 
       if(m_IsBuffer)
       {
-        buf->storage = r->GetBufferData(m_BufferID, CurrentByteOffset(), clampedLen);
+        if(clampedLen > 0)
+          buf->storage = r->GetBufferData(m_BufferID, CurrentByteOffset(), clampedLen);
       }
       else
       {
@@ -2949,6 +2984,7 @@ void BufferViewer::UI_CalculateMeshFormats()
       BoundVBuffer ib = m_Ctx.CurPipelineState().GetIBuffer();
       m_VSInPosition.indexResourceId = ib.resourceId;
       m_VSInPosition.indexByteOffset = ib.byteOffset + draw->indexOffset * draw->indexByteWidth;
+      m_VSInPosition.indexByteSize = ib.byteSize;
 
       if((draw->flags & DrawFlags::Indexed) && m_VSInPosition.indexByteStride == 0)
         m_VSInPosition.indexByteStride = 4U;
@@ -2966,6 +3002,7 @@ void BufferViewer::UI_CalculateMeshFormats()
           m_VSInPosition.vertexByteStride = vbs[prop.buffer].byteStride;
           m_VSInPosition.vertexByteOffset = vbs[prop.buffer].byteOffset + el.byteOffset +
                                             draw->vertexOffset * m_VSInPosition.vertexByteStride;
+          m_VSInPosition.vertexByteSize = vbs[prop.buffer].byteSize;
         }
         else
         {
@@ -2993,6 +3030,7 @@ void BufferViewer::UI_CalculateMeshFormats()
           m_VSInSecondary.vertexByteStride = vbs[prop.buffer].byteStride;
           m_VSInSecondary.vertexByteOffset = vbs[prop.buffer].byteOffset + el.byteOffset +
                                              draw->vertexOffset * m_VSInSecondary.vertexByteStride;
+          m_VSInSecondary.vertexByteSize = vbs[prop.buffer].byteSize;
         }
         else
         {
@@ -3770,11 +3808,7 @@ void BufferViewer::processFormat(const QString &format)
 
   BufferConfiguration bufconfig;
 
-  uint64_t len = m_ByteSize;
-  if(len == UINT64_MAX)
-    len = 0;
-
-  ShaderConstant cols = BufferFormatter::ParseFormatString(format, len, true, errors);
+  ShaderConstant cols = BufferFormatter::ParseFormatString(format, m_ByteSize, true, errors);
 
   CalcColumnWidth(MaxNumRows(cols));
 
diff --git a/qrenderdoc/Windows/ConstantBufferPreviewer.cpp b/qrenderdoc/Windows/ConstantBufferPreviewer.cpp
index 8d8a8c03e..7b06c269f 100644
--- a/qrenderdoc/Windows/ConstantBufferPreviewer.cpp
+++ b/qrenderdoc/Windows/ConstantBufferPreviewer.cpp
@@ -136,7 +136,9 @@ void ConstantBufferPreviewer::OnEventChanged(uint32_t eventId)
   if(!m_formatOverride.type.members.empty())
   {
     m_Ctx.Replay().AsyncInvoke([this, offset, size, wasEmpty](IReplayController *r) {
-      bytebuf data = r->GetBufferData(m_cbuffer, offset, size);
+      bytebuf data;
+      if(size > 0)
+        data = r->GetBufferData(m_cbuffer, offset, size);
       rdcarray<ShaderVariable> vars = applyFormatOverride(data);
       GUIInvoke::call(this, [this, vars, wasEmpty] {
         RDTreeViewExpansionState state;
@@ -279,7 +281,7 @@ void ConstantBufferPreviewer::processFormat(const QString &format)
   {
     QString errors;
 
-    m_formatOverride = BufferFormatter::ParseFormatString(format, 0, false, errors);
+    m_formatOverride = BufferFormatter::ParseFormatString(format, ~0ULL, false, errors);
     ui->formatSpecifier->setErrors(errors);
   }
 
diff --git a/qrenderdoc/Windows/PipelineState/D3D12PipelineStateViewer.cpp b/qrenderdoc/Windows/PipelineState/D3D12PipelineStateViewer.cpp
index a7aa9222e..75e831caf 100644
--- a/qrenderdoc/Windows/PipelineState/D3D12PipelineStateViewer.cpp
+++ b/qrenderdoc/Windows/PipelineState/D3D12PipelineStateViewer.cpp
@@ -38,15 +38,17 @@
 struct D3D12VBIBTag
 {
   D3D12VBIBTag() { offset = 0; }
-  D3D12VBIBTag(ResourceId i, uint64_t offs, QString f = QString())
+  D3D12VBIBTag(ResourceId i, uint64_t offs, uint64_t sz, QString f = QString())
   {
     id = i;
     offset = offs;
+    size = sz;
     format = f;
   }
 
   ResourceId id;
   uint64_t offset;
+  uint64_t size;
   QString format;
 };
 
@@ -1384,13 +1386,10 @@ void D3D12PipelineStateViewer::setState()
   {
     if(ibufferUsed || ui->showUnused->isChecked())
     {
-      uint64_t length = 0;
+      uint64_t length = state.inputAssembly.indexBuffer.byteSize;
 
       BufferDescription *buf = m_Ctx.GetBuffer(state.inputAssembly.indexBuffer.resourceId);
 
-      if(buf)
-        length = buf->length;
-
       RDTreeWidgetItem *node = new RDTreeWidgetItem(
           {tr("Index"), state.inputAssembly.indexBuffer.resourceId, draw ? draw->indexByteWidth : 0,
            (qulonglong)state.inputAssembly.indexBuffer.byteOffset, (qulonglong)length, QString()});
@@ -1408,11 +1407,12 @@ void D3D12PipelineStateViewer::setState()
         iformat += lit(" indices[%1]").arg(RENDERDOC_NumVerticesPerPrimitive(draw->topology));
       }
 
-      node->setTag(
-          QVariant::fromValue(D3D12VBIBTag(state.inputAssembly.indexBuffer.resourceId,
-                                           state.inputAssembly.indexBuffer.byteOffset +
-                                               (draw ? draw->indexOffset * draw->indexByteWidth : 0),
-                                           iformat)));
+      uint32_t drawOffset = (draw ? draw->indexOffset * draw->indexByteWidth : 0);
+
+      node->setTag(QVariant::fromValue(
+          D3D12VBIBTag(state.inputAssembly.indexBuffer.resourceId,
+                       state.inputAssembly.indexBuffer.byteOffset + drawOffset,
+                       qMin(state.inputAssembly.indexBuffer.byteSize - drawOffset, 0U), iformat)));
 
       for(const D3D12Pipe::ResourceData &res : m_Ctx.CurD3D12PipelineState()->resourceStates)
       {
@@ -1455,11 +1455,12 @@ void D3D12PipelineStateViewer::setState()
         iformat += lit(" indices[%1]").arg(RENDERDOC_NumVerticesPerPrimitive(draw->topology));
       }
 
-      node->setTag(
-          QVariant::fromValue(D3D12VBIBTag(state.inputAssembly.indexBuffer.resourceId,
-                                           state.inputAssembly.indexBuffer.byteOffset +
-                                               (draw ? draw->indexOffset * draw->indexByteWidth : 0),
-                                           iformat)));
+      uint32_t drawOffset = (draw ? draw->indexOffset * draw->indexByteWidth : 0);
+
+      node->setTag(QVariant::fromValue(
+          D3D12VBIBTag(state.inputAssembly.indexBuffer.resourceId,
+                       state.inputAssembly.indexBuffer.byteOffset + drawOffset,
+                       qMin(state.inputAssembly.indexBuffer.byteSize - drawOffset, 0U), iformat)));
 
       for(const D3D12Pipe::ResourceData &res : m_Ctx.CurD3D12PipelineState()->resourceStates)
       {
@@ -1489,7 +1490,7 @@ void D3D12PipelineStateViewer::setState()
       {
         RDTreeWidgetItem *node =
             new RDTreeWidgetItem({i, tr("No Buffer Set"), lit("-"), lit("-"), lit("-"), QString()});
-        node->setTag(QVariant::fromValue(D3D12VBIBTag(ResourceId(), 0)));
+        node->setTag(QVariant::fromValue(D3D12VBIBTag(ResourceId(), 0, 0)));
 
         setEmptyRow(node);
         m_EmptyNodes.push_back(node);
@@ -1513,11 +1514,9 @@ void D3D12PipelineStateViewer::setState()
 
     if(showNode(usedSlot, filledSlot))
     {
-      qulonglong length = 0;
+      qulonglong length = v.byteSize;
 
       BufferDescription *buf = m_Ctx.GetBuffer(v.resourceId);
-      if(buf)
-        length = buf->length;
 
       RDTreeWidgetItem *node = NULL;
 
@@ -1528,8 +1527,8 @@ void D3D12PipelineStateViewer::setState()
         node =
             new RDTreeWidgetItem({i, tr("No Buffer Set"), lit("-"), lit("-"), lit("-"), QString()});
 
-      node->setTag(QVariant::fromValue(
-          D3D12VBIBTag(v.resourceId, v.byteOffset, m_Common.GetVBufferFormatString(i))));
+      node->setTag(QVariant::fromValue(D3D12VBIBTag(v.resourceId, v.byteOffset, v.byteSize,
+                                                    m_Common.GetVBufferFormatString(i))));
 
       for(const D3D12Pipe::ResourceData &res : m_Ctx.CurD3D12PipelineState()->resourceStates)
       {
@@ -1610,13 +1609,10 @@ void D3D12PipelineStateViewer::setState()
 
     if(showNode(usedSlot, filledSlot))
     {
-      qulonglong length = 0;
+      qulonglong length = s.byteSize;
 
       BufferDescription *buf = m_Ctx.GetBuffer(s.resourceId);
 
-      if(buf)
-        length = buf->length;
-
       RDTreeWidgetItem *node = new RDTreeWidgetItem(
           {i, s.resourceId, (qulonglong)s.byteOffset, length, s.writtenCountResourceId,
            (qulonglong)s.writtenCountByteOffset, QString()});
@@ -1975,7 +1971,7 @@ void D3D12PipelineStateViewer::resource_itemActivated(RDTreeWidgetItem *item, in
         {
           if(buf->resourceId == m_Ctx.CurD3D12PipelineState()->streamOut.outputs[i].resourceId)
           {
-            size -= m_Ctx.CurD3D12PipelineState()->streamOut.outputs[i].byteOffset;
+            size = m_Ctx.CurD3D12PipelineState()->streamOut.outputs[i].byteSize;
             offs += m_Ctx.CurD3D12PipelineState()->streamOut.outputs[i].byteOffset;
             break;
           }
@@ -2068,7 +2064,7 @@ void D3D12PipelineStateViewer::on_iaBuffers_itemActivated(RDTreeWidgetItem *item
 
     if(buf.id != ResourceId())
     {
-      IBufferViewer *viewer = m_Ctx.ViewBuffer(buf.offset, UINT64_MAX, buf.id, buf.format);
+      IBufferViewer *viewer = m_Ctx.ViewBuffer(buf.offset, buf.size, buf.id, buf.format);
 
       m_Ctx.AddDockWindow(viewer->Widget(), DockReference::AddTo, this);
     }
diff --git a/qrenderdoc/Windows/TextureViewer.cpp b/qrenderdoc/Windows/TextureViewer.cpp
index c93a91bd2..50a0d0baa 100644
--- a/qrenderdoc/Windows/TextureViewer.cpp
+++ b/qrenderdoc/Windows/TextureViewer.cpp
@@ -2067,7 +2067,7 @@ void TextureViewer::ViewTexture(ResourceId ID, bool focus)
   BufferDescription *buf = m_Ctx.GetBuffer(ID);
   if(buf)
   {
-    IBufferViewer *viewer = m_Ctx.ViewBuffer(0, 0, ID);
+    IBufferViewer *viewer = m_Ctx.ViewBuffer(0, ~0ULL, ID);
 
     m_Ctx.AddDockWindow(viewer->Widget(), DockReference::AddTo, this);
   }
diff --git a/renderdoc/api/replay/common_pipestate.h b/renderdoc/api/replay/common_pipestate.h
index 15ba67b67..ba630dc90 100644
--- a/renderdoc/api/replay/common_pipestate.h
+++ b/renderdoc/api/replay/common_pipestate.h
@@ -346,7 +346,8 @@ struct BoundVBuffer
 
   bool operator==(const BoundVBuffer &o) const
   {
-    return resourceId == o.resourceId && byteOffset == o.byteOffset && byteStride == o.byteStride;
+    return resourceId == o.resourceId && byteOffset == o.byteOffset && byteStride == o.byteStride &&
+           byteSize == o.byteSize;
   }
   bool operator<(const BoundVBuffer &o) const
   {
@@ -356,6 +357,8 @@ struct BoundVBuffer
       return byteOffset < o.byteOffset;
     if(byteStride != o.byteStride)
       return byteStride < o.byteStride;
+    if(byteSize != o.byteSize)
+      return byteSize < o.byteSize;
     return false;
   }
   DOCUMENT("A :class:`~renderdoc.ResourceId` identifying the buffer.");
@@ -364,6 +367,8 @@ struct BoundVBuffer
   uint64_t byteOffset = 0;
   DOCUMENT("The stride in bytes between the start of one element and the start of the next.");
   uint32_t byteStride = 0;
+  DOCUMENT("The size of the buffer binding, or 0xFFFFFFFF if the whole buffer is bound.");
+  uint64_t byteSize = 0;
 };
 
 DECLARE_REFLECTION_STRUCT(BoundVBuffer);
diff --git a/renderdoc/api/replay/control_types.h b/renderdoc/api/replay/control_types.h
index 3fa3301db..c76794fef 100644
--- a/renderdoc/api/replay/control_types.h
+++ b/renderdoc/api/replay/control_types.h
@@ -46,6 +46,8 @@ struct MeshFormat
   uint64_t indexByteOffset = 0;
   DOCUMENT("The width in bytes of each index. Valid values are 1 (depending on API), 2 or 4.");
   uint32_t indexByteStride = 0;
+  DOCUMENT("The number of bytes to use from the index buffer. Only valid on APIs that allow it.");
+  uint64_t indexByteSize = 0;
   DOCUMENT("For indexed meshes, a value added to each index before using it to read the vertex.");
   int32_t baseVertex = 0;
 
@@ -55,6 +57,8 @@ struct MeshFormat
   uint64_t vertexByteOffset = 0;
   DOCUMENT("The stride in bytes between the start of one vertex and the start of another.");
   uint32_t vertexByteStride = 0;
+  DOCUMENT("The number of bytes to use from the vertex buffer. Only valid on APIs that allow it.");
+  uint64_t vertexByteSize = 0;
 
   DOCUMENT("The :class:`ResourceFormat` describing this mesh component.");
   ResourceFormat format;
diff --git a/renderdoc/api/replay/pipestate.inl b/renderdoc/api/replay/pipestate.inl
index cc2b91c88..fd4707620 100644
--- a/renderdoc/api/replay/pipestate.inl
+++ b/renderdoc/api/replay/pipestate.inl
@@ -466,37 +466,36 @@ ResourceId PipeState::GetShader(ShaderStage stage) const
 
 BoundVBuffer PipeState::GetIBuffer() const
 {
-  ResourceId buf;
-  uint64_t ByteOffset = 0;
+  BoundVBuffer ret;
 
   if(IsCaptureLoaded())
   {
     if(IsCaptureD3D11())
     {
-      buf = m_D3D11->inputAssembly.indexBuffer.resourceId;
-      ByteOffset = m_D3D11->inputAssembly.indexBuffer.byteOffset;
+      ret.resourceId = m_D3D11->inputAssembly.indexBuffer.resourceId;
+      ret.byteOffset = m_D3D11->inputAssembly.indexBuffer.byteOffset;
+      ret.byteSize = ~0ULL;
     }
     else if(IsCaptureD3D12())
     {
-      buf = m_D3D12->inputAssembly.indexBuffer.resourceId;
-      ByteOffset = m_D3D12->inputAssembly.indexBuffer.byteOffset;
+      ret.resourceId = m_D3D12->inputAssembly.indexBuffer.resourceId;
+      ret.byteOffset = m_D3D12->inputAssembly.indexBuffer.byteOffset;
+      ret.byteSize = m_D3D12->inputAssembly.indexBuffer.byteSize;
     }
     else if(IsCaptureGL())
     {
-      buf = m_GL->vertexInput.indexBuffer;
-      ByteOffset = 0;    // GL only has per-draw index offset
+      ret.resourceId = m_GL->vertexInput.indexBuffer;
+      ret.byteOffset = 0;    // GL only has per-draw index offset
+      ret.byteSize = ~0ULL;
     }
     else if(IsCaptureVK())
     {
-      buf = m_Vulkan->inputAssembly.indexBuffer.resourceId;
-      ByteOffset = m_Vulkan->inputAssembly.indexBuffer.byteOffset;
+      ret.resourceId = m_Vulkan->inputAssembly.indexBuffer.resourceId;
+      ret.byteOffset = m_Vulkan->inputAssembly.indexBuffer.byteOffset;
+      ret.byteSize = ~0ULL;
     }
   }
 
-  BoundVBuffer ret;
-  ret.resourceId = buf;
-  ret.byteOffset = ByteOffset;
-
   return ret;
 }
 
@@ -562,6 +561,7 @@ rdcarray<BoundVBuffer> PipeState::GetVBuffers() const
         ret[i].resourceId = m_D3D11->inputAssembly.vertexBuffers[i].resourceId;
         ret[i].byteOffset = m_D3D11->inputAssembly.vertexBuffers[i].byteOffset;
         ret[i].byteStride = m_D3D11->inputAssembly.vertexBuffers[i].byteStride;
+        ret[i].byteSize = ~0ULL;
       }
     }
     else if(IsCaptureD3D12())
@@ -572,6 +572,7 @@ rdcarray<BoundVBuffer> PipeState::GetVBuffers() const
         ret[i].resourceId = m_D3D12->inputAssembly.vertexBuffers[i].resourceId;
         ret[i].byteOffset = m_D3D12->inputAssembly.vertexBuffers[i].byteOffset;
         ret[i].byteStride = m_D3D12->inputAssembly.vertexBuffers[i].byteStride;
+        ret[i].byteSize = m_D3D12->inputAssembly.vertexBuffers[i].byteSize;
       }
     }
     else if(IsCaptureGL())
@@ -582,6 +583,7 @@ rdcarray<BoundVBuffer> PipeState::GetVBuffers() const
         ret[i].resourceId = m_GL->vertexInput.vertexBuffers[i].resourceId;
         ret[i].byteOffset = m_GL->vertexInput.vertexBuffers[i].byteOffset;
         ret[i].byteStride = m_GL->vertexInput.vertexBuffers[i].byteStride;
+        ret[i].byteSize = ~0ULL;
       }
     }
     else if(IsCaptureVK())
@@ -592,6 +594,7 @@ rdcarray<BoundVBuffer> PipeState::GetVBuffers() const
         ret[i].resourceId = m_Vulkan->vertexInput.vertexBuffers[i].resourceId;
         ret[i].byteOffset = m_Vulkan->vertexInput.vertexBuffers[i].byteOffset;
         ret[i].byteStride = 0;
+        ret[i].byteSize = ~0ULL;
 
         // find the binding that corresponds to this VB to get the stride. Valid use suggests there
         // should be at most 1, so stop at first result. If there are 0 then the stride is just 0
@@ -964,6 +967,9 @@ BoundCBuffer PipeState::GetConstantBuffer(ShaderStage stage, uint32_t BufIdx, ui
             buf = b.resourceId;
             ByteOffset = b.byteOffset;
             ByteSize = b.byteSize;
+
+            if(ByteSize == 0)
+              ByteSize = ~0ULL;
           }
         }
       }
diff --git a/renderdoc/driver/d3d11/d3d11_postvs.cpp b/renderdoc/driver/d3d11/d3d11_postvs.cpp
index 0a0108811..cdc854a50 100644
--- a/renderdoc/driver/d3d11/d3d11_postvs.cpp
+++ b/renderdoc/driver/d3d11/d3d11_postvs.cpp
@@ -128,6 +128,7 @@ MeshFormat D3D11Replay::GetPostVSBuffers(uint32_t eventId, uint32_t instID, uint
   {
     ret.indexResourceId = ((WrappedID3D11Buffer *)s.idxBuf)->GetResourceID();
     ret.indexByteStride = s.idxFmt == DXGI_FORMAT_R16_UINT ? 2 : 4;
+    ret.indexByteSize = ~0ULL;
   }
   else
   {
@@ -136,9 +137,14 @@ MeshFormat D3D11Replay::GetPostVSBuffers(uint32_t eventId, uint32_t instID, uint
   }
 
   if(s.buf)
+  {
     ret.vertexResourceId = ((WrappedID3D11Buffer *)s.buf)->GetResourceID();
+    ret.vertexByteSize = ~0ULL;
+  }
   else
+  {
     ret.vertexResourceId = ResourceId();
+  }
 
   ret.vertexByteOffset = s.instStride * instID;
   ret.vertexByteStride = s.vertStride;
diff --git a/renderdoc/driver/d3d12/d3d12_postvs.cpp b/renderdoc/driver/d3d12/d3d12_postvs.cpp
index dcb400d0b..10262f719 100644
--- a/renderdoc/driver/d3d12/d3d12_postvs.cpp
+++ b/renderdoc/driver/d3d12/d3d12_postvs.cpp
@@ -400,7 +400,7 @@ void D3D12Replay::InitPostVSBuffers(uint32_t eventId)
     else    // drawcall is indexed
     {
       bytebuf idxdata;
-      if(rs.ibuffer.buf != ResourceId())
+      if(rs.ibuffer.buf != ResourceId() && rs.ibuffer.size > 0)
         GetBufferData(rs.ibuffer.buf, rs.ibuffer.offs + drawcall->indexOffset * rs.ibuffer.bytewidth,
                       RDCMIN(drawcall->numIndices * rs.ibuffer.bytewidth, rs.ibuffer.size), idxdata);
 
@@ -1361,6 +1361,7 @@ MeshFormat D3D12Replay::GetPostVSBuffers(uint32_t eventId, uint32_t instID, uint
   {
     ret.indexResourceId = GetResID(s.idxBuf);
     ret.indexByteStride = s.idxFmt == DXGI_FORMAT_R16_UINT ? 2 : 4;
+    ret.indexByteSize = ~0ULL;
   }
   else
   {
@@ -1371,9 +1372,15 @@ MeshFormat D3D12Replay::GetPostVSBuffers(uint32_t eventId, uint32_t instID, uint
   ret.baseVertex = 0;
 
   if(s.buf != NULL)
+  {
     ret.vertexResourceId = GetResID(s.buf);
+    ret.vertexByteSize = ~0ULL;
+  }
   else
+  {
     ret.vertexResourceId = ResourceId();
+    ret.vertexByteSize = 0;
+  }
 
   ret.vertexByteOffset = s.instStride * instID;
   ret.vertexByteStride = s.vertStride;
diff --git a/renderdoc/driver/d3d12/d3d12_rendermesh.cpp b/renderdoc/driver/d3d12/d3d12_rendermesh.cpp
index 076c12f03..1f9ab259f 100644
--- a/renderdoc/driver/d3d12/d3d12_rendermesh.cpp
+++ b/renderdoc/driver/d3d12/d3d12_rendermesh.cpp
@@ -328,7 +328,7 @@ void D3D12Replay::RenderMesh(uint32_t eventId, const rdcarray<MeshFormat> &secon
         D3D12_VERTEX_BUFFER_VIEW view;
         view.BufferLocation = vb->GetGPUVirtualAddress() + offs;
         view.StrideInBytes = fmt.vertexByteStride;
-        view.SizeInBytes = UINT(vb->GetDesc().Width - offs);
+        view.SizeInBytes = (UINT)fmt.vertexByteSize;
         list->IASetVertexBuffers(0, 1, &view);
 
         // set it to the secondary buffer too just as dummy info
@@ -348,7 +348,7 @@ void D3D12Replay::RenderMesh(uint32_t eventId, const rdcarray<MeshFormat> &secon
 
             D3D12_INDEX_BUFFER_VIEW iview;
             iview.BufferLocation = ib->GetGPUVirtualAddress() + fmt.indexByteOffset;
-            iview.SizeInBytes = UINT(ib->GetDesc().Width - fmt.indexByteOffset);
+            iview.SizeInBytes = (UINT)fmt.indexByteSize;
             iview.Format = fmt.indexByteStride == 2 ? DXGI_FORMAT_R16_UINT : DXGI_FORMAT_R32_UINT;
             list->IASetIndexBuffer(&iview);
 
@@ -380,7 +380,7 @@ void D3D12Replay::RenderMesh(uint32_t eventId, const rdcarray<MeshFormat> &secon
     D3D12_VERTEX_BUFFER_VIEW view;
     view.BufferLocation = vb->GetGPUVirtualAddress() + offs;
     view.StrideInBytes = cfg.position.vertexByteStride;
-    view.SizeInBytes = UINT(vb->GetDesc().Width - offs);
+    view.SizeInBytes = (UINT)cfg.position.vertexByteSize;
     list->IASetVertexBuffers(0, 1, &view);
 
     // set it to the secondary buffer too just as dummy info
@@ -413,7 +413,7 @@ void D3D12Replay::RenderMesh(uint32_t eventId, const rdcarray<MeshFormat> &secon
     D3D12_VERTEX_BUFFER_VIEW view;
     view.BufferLocation = vb->GetGPUVirtualAddress() + offs;
     view.StrideInBytes = cfg.second.vertexByteStride;
-    view.SizeInBytes = UINT(vb->GetDesc().Width - offs);
+    view.SizeInBytes = (UINT)cfg.second.vertexByteSize;
 
     list->IASetVertexBuffers(1, 1, &view);
   }
@@ -470,7 +470,7 @@ void D3D12Replay::RenderMesh(uint32_t eventId, const rdcarray<MeshFormat> &secon
 
         D3D12_INDEX_BUFFER_VIEW view;
         view.BufferLocation = ib->GetGPUVirtualAddress() + cfg.position.indexByteOffset;
-        view.SizeInBytes = UINT(ib->GetDesc().Width - cfg.position.indexByteOffset);
+        view.SizeInBytes = (UINT)cfg.position.indexByteSize;
         view.Format = cfg.position.indexByteStride == 2 ? DXGI_FORMAT_R16_UINT : DXGI_FORMAT_R32_UINT;
         list->IASetIndexBuffer(&view);
 
@@ -511,7 +511,7 @@ void D3D12Replay::RenderMesh(uint32_t eventId, const rdcarray<MeshFormat> &secon
 
       D3D12_INDEX_BUFFER_VIEW view;
       view.BufferLocation = ib->GetGPUVirtualAddress() + cfg.position.indexByteOffset;
-      view.SizeInBytes = UINT(ib->GetDesc().Width - cfg.position.indexByteOffset);
+      view.SizeInBytes = (UINT)cfg.position.indexByteSize;
       view.Format = cfg.position.indexByteStride == 2 ? DXGI_FORMAT_R16_UINT : DXGI_FORMAT_R32_UINT;
       list->IASetIndexBuffer(&view);
 
diff --git a/renderdoc/driver/d3d12/d3d12_shaderdebug.cpp b/renderdoc/driver/d3d12/d3d12_shaderdebug.cpp
index 6a787f84c..f0c717f37 100644
--- a/renderdoc/driver/d3d12/d3d12_shaderdebug.cpp
+++ b/renderdoc/driver/d3d12/d3d12_shaderdebug.cpp
@@ -1680,7 +1680,9 @@ void GatherConstantBuffers(WrappedID3D12Device *pDevice, const DXBCBytecode::Pro
                 pDevice->GetResourceManager()->GetCurrentAs<ID3D12Resource>(resId);
             cbufData.clear();
 
-            pDevice->GetDebugManager()->GetBufferData(pCbvResource, byteOffset, 0, cbufData);
+            if(cbv.SizeInBytes > 0)
+              pDevice->GetDebugManager()->GetBufferData(pCbvResource, byteOffset, cbv.SizeInBytes,
+                                                        cbufData);
             AddCBufferToGlobalState(program, global, sourceVars, refl, mapping, slot, cbufData);
 
             desc++;
@@ -1777,18 +1779,22 @@ ShaderDebugTrace *D3D12Replay::DebugVertex(uint32_t eventId, uint32_t vertid, ui
     {
       D3D12RenderState::VertBuffer &vb = rs.vbuffers[i];
       ID3D12Resource *buffer = m_pDevice->GetResourceManager()->GetCurrentAs<ID3D12Resource>(vb.buf);
-      GetDebugManager()->GetBufferData(buffer, vb.offs + vb.stride * (draw->vertexOffset + idx),
-                                       vb.stride, vertData[i]);
+
+      if(vb.stride * (draw->vertexOffset + idx) < vb.size)
+        GetDebugManager()->GetBufferData(buffer, vb.offs + vb.stride * (draw->vertexOffset + idx),
+                                         vb.stride, vertData[i]);
 
       for(UINT isr = 1; isr <= MaxStepRate; isr++)
       {
-        GetDebugManager()->GetBufferData(
-            buffer, vb.offs + vb.stride * (draw->instanceOffset + (instid / isr)), vb.stride,
-            instData[i * MaxStepRate + isr - 1]);
+        if((draw->instanceOffset + (instid / isr)) < vb.size)
+          GetDebugManager()->GetBufferData(
+              buffer, vb.offs + vb.stride * (draw->instanceOffset + (instid / isr)), vb.stride,
+              instData[i * MaxStepRate + isr - 1]);
       }
 
-      GetDebugManager()->GetBufferData(buffer, vb.offs + vb.stride * draw->instanceOffset,
-                                       vb.stride, staticData[i]);
+      if(vb.stride * draw->instanceOffset < vb.size)
+        GetDebugManager()->GetBufferData(buffer, vb.offs + vb.stride * draw->instanceOffset,
+                                         vb.stride, staticData[i]);
     }
   }
 
diff --git a/renderdoc/driver/gl/gl_postvs.cpp b/renderdoc/driver/gl/gl_postvs.cpp
index 2128b9195..745a27e5c 100644
--- a/renderdoc/driver/gl/gl_postvs.cpp
+++ b/renderdoc/driver/gl/gl_postvs.cpp
@@ -1946,6 +1946,7 @@ MeshFormat GLReplay::GetPostVSBuffers(uint32_t eventId, uint32_t instID, uint32_
   {
     ret.indexResourceId = m_pDriver->GetResourceManager()->GetID(BufferRes(ctx, s.idxBuf));
     ret.indexByteStride = s.idxByteWidth;
+    ret.indexByteSize = ~0ULL;
   }
   else
   {
@@ -1956,9 +1957,14 @@ MeshFormat GLReplay::GetPostVSBuffers(uint32_t eventId, uint32_t instID, uint32_
   ret.baseVertex = 0;
 
   if(s.buf)
+  {
     ret.vertexResourceId = m_pDriver->GetResourceManager()->GetID(BufferRes(ctx, s.buf));
+    ret.vertexByteSize = ~0ULL;
+  }
   else
+  {
     ret.vertexResourceId = ResourceId();
+  }
 
   ret.vertexByteOffset = s.instStride * instID;
   ret.vertexByteStride = s.vertStride;
diff --git a/renderdoc/driver/vulkan/vk_postvs.cpp b/renderdoc/driver/vulkan/vk_postvs.cpp
index 96c87a82a..bc9d5fc06 100644
--- a/renderdoc/driver/vulkan/vk_postvs.cpp
+++ b/renderdoc/driver/vulkan/vk_postvs.cpp
@@ -3037,6 +3037,7 @@ MeshFormat VulkanReplay::GetPostVSBuffers(uint32_t eventId, uint32_t instID, uin
       ret.indexByteStride = 1;
     else
       ret.indexByteStride = 2;
+    ret.indexByteSize = ~0ULL;
   }
   else
   {
@@ -3047,9 +3048,14 @@ MeshFormat VulkanReplay::GetPostVSBuffers(uint32_t eventId, uint32_t instID, uin
   ret.baseVertex = s.baseVertex;
 
   if(s.buf != VK_NULL_HANDLE)
+  {
     ret.vertexResourceId = GetResID(s.buf);
+    ret.vertexByteSize = ~0ULL;
+  }
   else
+  {
     ret.vertexResourceId = ResourceId();
+  }
 
   ret.vertexByteOffset = s.instStride * (instID + viewID * numInstances);
   ret.vertexByteStride = s.vertStride;
diff --git a/renderdoc/driver/vulkan/wrappers/vk_device_funcs.cpp b/renderdoc/driver/vulkan/wrappers/vk_device_funcs.cpp
index 227d3e52d..8379473c2 100644
--- a/renderdoc/driver/vulkan/wrappers/vk_device_funcs.cpp
+++ b/renderdoc/driver/vulkan/wrappers/vk_device_funcs.cpp
@@ -401,7 +401,10 @@ ReplayStatus WrappedVulkan::Initialise(VkInitParams &params, uint64_t sectionVer
   SAFE_DELETE_ARRAY(extscstr);
 
   if(ret != VK_SUCCESS)
+  {
+    RDCLOG("Instance creation returned %s", ToStr(ret).c_str());
     return ReplayStatus::APIHardwareUnsupported;
+  }
 
   RDCASSERTEQUAL(ret, VK_SUCCESS);
 
diff --git a/renderdoc/replay/renderdoc_serialise.inl b/renderdoc/replay/renderdoc_serialise.inl
index dbdf8feab..3b5e70c25 100644
--- a/renderdoc/replay/renderdoc_serialise.inl
+++ b/renderdoc/replay/renderdoc_serialise.inl
@@ -793,10 +793,12 @@ void DoSerialise(SerialiserType &ser, MeshFormat &el)
   SERIALISE_MEMBER(indexResourceId);
   SERIALISE_MEMBER(indexByteOffset);
   SERIALISE_MEMBER(indexByteStride);
+  SERIALISE_MEMBER(indexByteSize);
   SERIALISE_MEMBER(baseVertex);
   SERIALISE_MEMBER(vertexResourceId);
   SERIALISE_MEMBER(vertexByteOffset);
   SERIALISE_MEMBER(vertexByteStride);
+  SERIALISE_MEMBER(vertexByteSize);
   SERIALISE_MEMBER(format);
   SERIALISE_MEMBER(meshColor);
   SERIALISE_MEMBER(topology);
@@ -808,7 +810,7 @@ void DoSerialise(SerialiserType &ser, MeshFormat &el)
   SERIALISE_MEMBER(instanced);
   SERIALISE_MEMBER(showAlpha);
 
-  SIZE_CHECK(96);
+  SIZE_CHECK(128);
 }
 
 template <typename SerialiserType>
diff --git a/util/test/demos/CMakeLists.txt b/util/test/demos/CMakeLists.txt
index a1a2cbe2f..1118f7174 100644
--- a/util/test/demos/CMakeLists.txt
+++ b/util/test/demos/CMakeLists.txt
@@ -8,6 +8,7 @@ set(VULKAN_SRC
         vk/vk_helpers.cpp
         vk/vk_test.cpp
         vk/vk_adv_cbuffer_zoo.cpp
+        vk/vk_buffer_truncation.cpp
         vk/vk_cbuffer_zoo.cpp
         vk/vk_custom_border_color.cpp
         vk/vk_descriptor_index.cpp
@@ -51,6 +52,7 @@ set(OPENGL_SRC
         gl/gl_test.cpp
         gl/gl_test_linux.cpp
         gl/gl_buffer_spam.cpp
+        gl/gl_buffer_truncation.cpp
         gl/gl_buffer_updates.cpp
         gl/gl_callstacks.cpp
         gl/gl_cbuffer_zoo.cpp
diff --git a/util/test/demos/d3d11/d3d11_buffer_truncation.cpp b/util/test/demos/d3d11/d3d11_buffer_truncation.cpp
new file mode 100644
index 000000000..10d013ed2
--- /dev/null
+++ b/util/test/demos/d3d11/d3d11_buffer_truncation.cpp
@@ -0,0 +1,161 @@
+/******************************************************************************
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2019-2020 Baldur Karlsson
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ ******************************************************************************/
+
+#include "d3d11_test.h"
+
+RD_TEST(D3D11_Buffer_Truncation, D3D11GraphicsTest)
+{
+  static constexpr const char *Description =
+      "Tests using a constant buffer that is truncated by range (when supported), as well as "
+      "vertex/index buffers truncated by size.";
+
+  std::string vertex = R"EOSHADER(
+
+struct vertin
+{
+	float3 pos : POSITION;
+	float4 col : COLOR0;
+	float2 uv : TEXCOORD0;
+};
+
+struct v2f
+{
+	float4 svpos : SV_POSITION;
+	float4 pos : OUTPOSITION;
+	float4 col : OUTCOLOR;
+};
+
+v2f main(vertin IN)
+{
+	v2f OUT = (v2f)0;
+
+	OUT.svpos = OUT.pos = float4(IN.pos.xyz, 1);
+	OUT.col = IN.col;
+
+	return OUT;
+}
+
+)EOSHADER";
+
+  std::string pixel = R"EOSHADER(
+
+cbuffer consts : register(b0)
+{
+  float4 padding[16];
+  float4 outcol;
+};
+
+float4 main() : SV_Target0
+{
+	return outcol;
+}
+
+)EOSHADER";
+
+  int main()
+  {
+    // initialise, create window, create device, etc
+    if(!Init())
+      return 3;
+
+    const DefaultA2V OffsetTri[] = {
+        {Vec3f(7.7f, 0.0f, 0.0f), Vec4f(0.0f, 0.0f, 0.0f, 1.0f), Vec2f(0.0f, 0.0f)},
+        {Vec3f(7.7f, 0.0f, 0.0f), Vec4f(0.0f, 0.0f, 0.0f, 1.0f), Vec2f(0.0f, 0.0f)},
+        {Vec3f(7.7f, 0.0f, 0.0f), Vec4f(0.0f, 0.0f, 0.0f, 1.0f), Vec2f(0.0f, 0.0f)},
+
+        {Vec3f(9.9f, 0.0f, 0.0f), Vec4f(0.0f, 0.0f, 0.0f, 1.0f), Vec2f(0.0f, 0.0f)},
+
+        {Vec3f(-0.5f, -0.5f, 0.0f), Vec4f(0.0f, 1.0f, 0.0f, 1.0f), Vec2f(0.0f, 0.0f)},
+        {Vec3f(0.0f, 0.5f, 0.0f), Vec4f(0.0f, 1.0f, 0.0f, 1.0f), Vec2f(0.0f, 1.0f)},
+        {Vec3f(0.5f, -0.5f, 0.0f), Vec4f(0.0f, 1.0f, 0.0f, 1.0f), Vec2f(1.0f, 0.0f)},
+
+        {Vec3f(8.8f, 0.0f, 0.0f), Vec4f(0.0f, 0.0f, 0.0f, 1.0f), Vec2f(0.0f, 0.0f)},
+    };
+    uint16_t indices[] = {99, 99, 99, 1, 2, 3, 4, 5};
+    Vec4f cbufferdata[64] = {};
+    cbufferdata[32] = Vec4f(1.0f, 2.0f, 3.0f, 4.0f);
+
+    if(!opts.ConstantBufferOffsetting)
+      cbufferdata[16] = Vec4f(1.0f, 2.0f, 3.0f, 4.0f);
+
+    ID3DBlobPtr vsblob = Compile(vertex, "main", "vs_5_0");
+    ID3DBlobPtr psblob = Compile(pixel, "main", "ps_5_0");
+
+    CreateDefaultInputLayout(vsblob);
+
+    ID3D11VertexShaderPtr vs = CreateVS(vsblob);
+    ID3D11PixelShaderPtr ps = CreatePS(psblob);
+
+    ID3D11BufferPtr vb = MakeBuffer().Vertex().Data(OffsetTri);
+    ID3D11BufferPtr ib = MakeBuffer().Index().Data(indices);
+    ID3D11BufferPtr cb =
+        MakeBuffer()
+            .Constant()
+            .Data(cbufferdata)
+            .Size(opts.ConstantBufferOffsetting ? sizeof(cbufferdata) : sizeof(Vec4f) * 16);
+
+    ID3D11Texture2DPtr fltTex =
+        MakeTexture(DXGI_FORMAT_R32G32B32A32_FLOAT, screenWidth, screenHeight).RTV().SRV();
+    ID3D11RenderTargetViewPtr fltRT = MakeRTV(fltTex);
+
+    while(Running())
+    {
+      ClearRenderTargetView(bbRTV, {0.2f, 0.2f, 0.2f, 1.0f});
+
+      IASetVertexBuffer(vb, sizeof(DefaultA2V), sizeof(DefaultA2V) * 3);
+      ctx->IASetIndexBuffer(ib, DXGI_FORMAT_R16_UINT, sizeof(uint16_t) * 3);
+      ctx->IASetPrimitiveTopology(D3D11_PRIMITIVE_TOPOLOGY_TRIANGLELIST);
+      ctx->IASetInputLayout(defaultLayout);
+
+      ctx->VSSetShader(vs, NULL, 0);
+      ctx->PSSetShader(ps, NULL, 0);
+
+      if(opts.ConstantBufferOffsetting)
+      {
+        UINT offset = 16;
+        UINT count = 16;
+        ctx1->PSSetConstantBuffers1(0, 1, &cb.GetInterfacePtr(), &offset, &count);
+      }
+      else
+      {
+        setMarker("NoCBufferRange");
+        ctx->PSSetConstantBuffers(0, 1, &cb.GetInterfacePtr());
+      }
+
+      RSSetViewport({0.0f, 0.0f, (float)screenWidth, (float)screenHeight, 0.0f, 1.0f});
+
+      ctx->OMSetRenderTargets(1, &fltRT.GetInterfacePtr(), NULL);
+
+      ctx->DrawIndexed(6, 0, 0);
+
+      blitToSwap(fltTex);
+
+      Present();
+    }
+
+    return 0;
+  }
+};
+
+REGISTER_TEST();
diff --git a/util/test/demos/d3d12/d3d12_buffer_truncation.cpp b/util/test/demos/d3d12/d3d12_buffer_truncation.cpp
new file mode 100644
index 000000000..2f601a565
--- /dev/null
+++ b/util/test/demos/d3d12/d3d12_buffer_truncation.cpp
@@ -0,0 +1,198 @@
+/******************************************************************************
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2019-2020 Baldur Karlsson
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ ******************************************************************************/
+
+#include "d3d12_test.h"
+
+RD_TEST(D3D12_Buffer_Truncation, D3D12GraphicsTest)
+{
+  static constexpr const char *Description =
+      "Tests using a constant buffer that is truncated by range, as well as "
+      "vertex/index buffers truncated by size.";
+
+  std::string vertex = R"EOSHADER(
+
+struct vertin
+{
+	float3 pos : POSITION;
+	float4 col : COLOR0;
+	float2 uv : TEXCOORD0;
+};
+
+struct v2f
+{
+	float4 svpos : SV_POSITION;
+	float4 pos : OUTPOSITION;
+	float4 col : OUTCOLOR;
+};
+
+v2f main(vertin IN)
+{
+	v2f OUT = (v2f)0;
+
+	OUT.svpos = OUT.pos = float4(IN.pos.xyz, 1);
+	OUT.col = IN.col;
+
+	return OUT;
+}
+
+)EOSHADER";
+
+  std::string pixel = R"EOSHADER(
+
+cbuffer consts : register(b0)
+{
+  float4 padding[16];
+  float4 outcol;
+};
+
+float4 main() : SV_Target0
+{
+	return outcol;
+}
+
+)EOSHADER";
+
+  int main()
+  {
+    // initialise, create window, create device, etc
+    if(!Init())
+      return 3;
+
+    ID3DBlobPtr vsblob = Compile(vertex, "main", "vs_5_0");
+    ID3DBlobPtr psblob = Compile(pixel, "main", "ps_5_0");
+
+    const DefaultA2V OffsetTri[] = {
+        {Vec3f(7.7f, 0.0f, 0.0f), Vec4f(0.0f, 0.0f, 0.0f, 1.0f), Vec2f(0.0f, 0.0f)},
+        {Vec3f(7.7f, 0.0f, 0.0f), Vec4f(0.0f, 0.0f, 0.0f, 1.0f), Vec2f(0.0f, 0.0f)},
+        {Vec3f(7.7f, 0.0f, 0.0f), Vec4f(0.0f, 0.0f, 0.0f, 1.0f), Vec2f(0.0f, 0.0f)},
+
+        {Vec3f(9.9f, 0.0f, 0.0f), Vec4f(0.0f, 0.0f, 0.0f, 1.0f), Vec2f(0.0f, 0.0f)},
+
+        {Vec3f(-0.5f, -0.5f, 0.0f), Vec4f(0.0f, 1.0f, 0.0f, 1.0f), Vec2f(0.0f, 0.0f)},
+        {Vec3f(0.0f, 0.5f, 0.0f), Vec4f(0.0f, 1.0f, 0.0f, 1.0f), Vec2f(0.0f, 1.0f)},
+        {Vec3f(0.5f, -0.5f, 0.0f), Vec4f(0.0f, 1.0f, 0.0f, 1.0f), Vec2f(1.0f, 0.0f)},
+
+        {Vec3f(8.8f, 0.0f, 0.0f), Vec4f(0.0f, 0.0f, 0.0f, 1.0f), Vec2f(0.0f, 0.0f)},
+
+        {Vec3f(3.3f, 0.0f, 0.0f), Vec4f(0.0f, 0.0f, 0.0f, 1.0f), Vec2f(0.0f, 0.0f)},
+        {Vec3f(3.3f, 0.0f, 0.0f), Vec4f(0.0f, 0.0f, 0.0f, 1.0f), Vec2f(0.0f, 0.0f)},
+        {Vec3f(3.3f, 0.0f, 0.0f), Vec4f(0.0f, 0.0f, 0.0f, 1.0f), Vec2f(0.0f, 0.0f)},
+        {Vec3f(3.3f, 0.0f, 0.0f), Vec4f(0.0f, 0.0f, 0.0f, 1.0f), Vec2f(0.0f, 0.0f)},
+        {Vec3f(3.3f, 0.0f, 0.0f), Vec4f(0.0f, 0.0f, 0.0f, 1.0f), Vec2f(0.0f, 0.0f)},
+        {Vec3f(3.3f, 0.0f, 0.0f), Vec4f(0.0f, 0.0f, 0.0f, 1.0f), Vec2f(0.0f, 0.0f)},
+    };
+    uint16_t indices[] = {99, 99, 99, 1, 2, 3, 4, 5, 88, 88, 88, 88, 88};
+    Vec4f cbufferdata[64] = {};
+    cbufferdata[32] = Vec4f(1.0f, 2.0f, 3.0f, 4.0f);
+
+    ID3D12ResourcePtr vb = MakeBuffer().Data(OffsetTri);
+    ID3D12ResourcePtr ib = MakeBuffer().Data(indices);
+    ID3D12ResourcePtr cb = MakeBuffer().Data(cbufferdata);
+
+    ID3D12RootSignaturePtr sig = MakeSig({
+        tableParam(D3D12_SHADER_VISIBILITY_PIXEL, D3D12_DESCRIPTOR_RANGE_TYPE_CBV, 0, 0, 1),
+    });
+
+    ID3D12PipelineStatePtr pso = MakePSO().RootSig(sig).InputLayout().VS(vsblob).PS(psblob).RTVs(
+        {DXGI_FORMAT_R32G32B32A32_FLOAT});
+
+    ResourceBarrier(vb, D3D12_RESOURCE_STATE_COMMON, D3D12_RESOURCE_STATE_VERTEX_AND_CONSTANT_BUFFER);
+    ResourceBarrier(ib, D3D12_RESOURCE_STATE_COMMON, D3D12_RESOURCE_STATE_INDEX_BUFFER);
+    ResourceBarrier(cb, D3D12_RESOURCE_STATE_COMMON, D3D12_RESOURCE_STATE_VERTEX_AND_CONSTANT_BUFFER);
+
+    D3D12_CONSTANT_BUFFER_VIEW_DESC cbview;
+    cbview.BufferLocation = cb->GetGPUVirtualAddress() + sizeof(Vec4f) * 16;
+    cbview.SizeInBytes = sizeof(Vec4f) * 16;
+    dev->CreateConstantBufferView(&cbview, m_CBVUAVSRV->GetCPUDescriptorHandleForHeapStart());
+
+    ID3D12ResourcePtr rtvtex = MakeTexture(DXGI_FORMAT_R32G32B32A32_FLOAT, screenWidth, screenHeight)
+                                   .RTV()
+                                   .InitialState(D3D12_RESOURCE_STATE_RENDER_TARGET);
+
+    while(Running())
+    {
+      ID3D12GraphicsCommandListPtr cmd = GetCommandBuffer();
+
+      Reset(cmd);
+
+      ID3D12ResourcePtr bb = StartUsingBackbuffer(cmd, D3D12_RESOURCE_STATE_RENDER_TARGET);
+
+      D3D12_CPU_DESCRIPTOR_HANDLE bbrtv =
+          MakeRTV(bb).Format(DXGI_FORMAT_R8G8B8A8_UNORM_SRGB).CreateCPU(0);
+
+      ClearRenderTargetView(cmd, bbrtv, {0.2f, 0.2f, 0.2f, 1.0f});
+
+      D3D12_CPU_DESCRIPTOR_HANDLE offrtv = MakeRTV(rtvtex).CreateCPU(0);
+
+      ClearRenderTargetView(cmd, offrtv, {0.2f, 0.2f, 0.2f, 1.0f});
+
+      cmd->IASetPrimitiveTopology(D3D_PRIMITIVE_TOPOLOGY_TRIANGLELIST);
+
+      D3D12_VERTEX_BUFFER_VIEW vbview;
+      vbview.BufferLocation = vb->GetGPUVirtualAddress() + sizeof(DefaultA2V) * 3;
+      vbview.SizeInBytes = sizeof(DefaultA2V) * 5;
+      vbview.StrideInBytes = sizeof(DefaultA2V);
+      cmd->IASetVertexBuffers(0, 1, &vbview);
+
+      D3D12_INDEX_BUFFER_VIEW ibview;
+      ibview.BufferLocation = ib->GetGPUVirtualAddress() + sizeof(uint16_t) * 3;
+      ibview.SizeInBytes = sizeof(uint16_t) * 5;
+      ibview.Format = DXGI_FORMAT_R16_UINT;
+      cmd->IASetIndexBuffer(&ibview);
+
+      cmd->SetDescriptorHeaps(1, &m_CBVUAVSRV.GetInterfacePtr());
+
+      cmd->SetPipelineState(pso);
+      cmd->SetGraphicsRootSignature(sig);
+      cmd->SetGraphicsRootDescriptorTable(0, m_CBVUAVSRV->GetGPUDescriptorHandleForHeapStart());
+
+      RSSetViewport(cmd, {0.0f, 0.0f, (float)screenWidth, (float)screenHeight, 0.0f, 1.0f});
+      RSSetScissorRect(cmd, {0, 0, screenWidth, screenHeight});
+
+      OMSetRenderTargets(cmd, {offrtv}, {});
+
+      cmd->DrawIndexedInstanced(6, 1, 0, 0, 0);
+
+      ResourceBarrier(cmd, rtvtex, D3D12_RESOURCE_STATE_RENDER_TARGET,
+                      D3D12_RESOURCE_STATE_PIXEL_SHADER_RESOURCE);
+
+      blitToSwap(cmd, rtvtex, bb);
+
+      ResourceBarrier(cmd, rtvtex, D3D12_RESOURCE_STATE_PIXEL_SHADER_RESOURCE,
+                      D3D12_RESOURCE_STATE_RENDER_TARGET);
+
+      FinishUsingBackbuffer(cmd, D3D12_RESOURCE_STATE_RENDER_TARGET);
+
+      cmd->Close();
+
+      Submit({cmd});
+
+      Present();
+    }
+
+    return 0;
+  }
+};
+
+REGISTER_TEST();
diff --git a/util/test/demos/demos.vcxproj b/util/test/demos/demos.vcxproj
index 9281d22aa..f995c2073 100644
--- a/util/test/demos/demos.vcxproj
+++ b/util/test/demos/demos.vcxproj
@@ -123,6 +123,7 @@
     <ClCompile Include="d3d11\d3d11_1_many_uavs.cpp" />
     <ClCompile Include="d3d11\d3d11_array_interpolator.cpp" />
     <ClCompile Include="d3d11\d3d11_binding_hazards.cpp" />
+    <ClCompile Include="d3d11\d3d11_buffer_truncation.cpp" />
     <ClCompile Include="d3d11\d3d11_byte_address_buffers.cpp" />
     <ClCompile Include="d3d11\d3d11_cbuffer_zoo.cpp" />
     <ClCompile Include="d3d11\d3d11_counter_query_pred.cpp" />
@@ -168,6 +169,7 @@
     <ClCompile Include="d3d11\d3d11_untyped_backbuffer_descriptor.cpp" />
     <ClCompile Include="d3d11\d3d11_vertex_attr_zoo.cpp" />
     <ClCompile Include="d3d11\d3d11_video_textures.cpp" />
+    <ClCompile Include="d3d12\d3d12_buffer_truncation.cpp" />
     <ClCompile Include="d3d12\d3d12_cbuffer_zoo.cpp" />
     <ClCompile Include="d3d12\d3d12_draw_zoo.cpp" />
     <ClCompile Include="d3d12\d3d12_empty_capture.cpp" />
@@ -205,6 +207,7 @@
     </ClCompile>
     <ClCompile Include="3rdparty\glad\glad_wgl.c" />
     <ClCompile Include="gl\gl_buffer_spam.cpp" />
+    <ClCompile Include="gl\gl_buffer_truncation.cpp" />
     <ClCompile Include="gl\gl_buffer_updates.cpp" />
     <ClCompile Include="gl\gl_callstacks.cpp" />
     <ClCompile Include="gl\gl_cbuffer_zoo.cpp" />
@@ -275,7 +278,7 @@
     <ClCompile Include="vk\vk_spirv_13_shaders.cpp" />
     <ClCompile Include="vk\vk_texture_zoo.cpp" />
     <ClCompile Include="vk\vk_triangle_fan.cpp" />
-    <ClCompile Include="vk\vk_truncated_cbuffer.cpp" />
+    <ClCompile Include="vk\vk_buffer_truncation.cpp" />
     <ClCompile Include="vk\vk_vertex_attr_zoo.cpp" />
     <ClCompile Include="vk\vk_ext_buffer_address.cpp" />
     <ClCompile Include="vk\vk_cbuffer_zoo.cpp" />
diff --git a/util/test/demos/demos.vcxproj.filters b/util/test/demos/demos.vcxproj.filters
index 51a6f4da4..0b37082db 100644
--- a/util/test/demos/demos.vcxproj.filters
+++ b/util/test/demos/demos.vcxproj.filters
@@ -403,9 +403,6 @@
     <ClCompile Include="d3d12\d3d12_execute_indirect.cpp">
       <Filter>D3D12\demos</Filter>
     </ClCompile>
-    <ClCompile Include="vk\vk_truncated_cbuffer.cpp">
-      <Filter>Vulkan\demos</Filter>
-    </ClCompile>
     <ClCompile Include="d3d12\d3d12_parameter_zoo.cpp">
       <Filter>D3D12\demos</Filter>
     </ClCompile>
@@ -502,6 +499,18 @@
     <ClCompile Include="vk\vk_robustness2.cpp">
       <Filter>Vulkan\demos</Filter>
     </ClCompile>
+    <ClCompile Include="vk\vk_buffer_truncation.cpp">
+      <Filter>Vulkan\demos</Filter>
+    </ClCompile>
+    <ClCompile Include="gl\gl_buffer_truncation.cpp">
+      <Filter>OpenGL\demos</Filter>
+    </ClCompile>
+    <ClCompile Include="d3d12\d3d12_buffer_truncation.cpp">
+      <Filter>D3D12\demos</Filter>
+    </ClCompile>
+    <ClCompile Include="d3d11\d3d11_buffer_truncation.cpp">
+      <Filter>D3D11\demos</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <Filter Include="D3D11">
diff --git a/util/test/demos/gl/gl_buffer_truncation.cpp b/util/test/demos/gl/gl_buffer_truncation.cpp
new file mode 100644
index 000000000..09f8ae25f
--- /dev/null
+++ b/util/test/demos/gl/gl_buffer_truncation.cpp
@@ -0,0 +1,159 @@
+/******************************************************************************
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2019-2020 Baldur Karlsson
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ ******************************************************************************/
+
+#include "gl_test.h"
+
+RD_TEST(GL_Buffer_Truncation, OpenGLGraphicsTest)
+{
+  static constexpr const char *Description =
+      "Tests using a uniform buffer that is truncated by range, as well as "
+      "vertex/index buffers truncated by size.";
+
+  const std::string vertex = R"EOSHADER(
+#version 460 core
+
+layout(location = 0) in vec3 POSITION;
+layout(location = 1) in vec4 COLOR;
+
+layout(location = 0) out vec4 OUTPOSITION;
+layout(location = 1) out vec4 OUTCOLOR;
+
+void main()
+{
+	gl_Position = OUTPOSITION = vec4(POSITION.xyz, 1);
+	OUTCOLOR = COLOR;
+}
+
+)EOSHADER";
+
+  const std::string pixel = R"EOSHADER(
+#version 460 core
+
+layout(location = 0, index = 0) out vec4 Color;
+
+layout(binding = 0, std140) uniform constsbuf
+{
+  vec4 padding[16];
+  vec4 outcol;
+};
+
+void main()
+{
+	Color = outcol;
+}
+
+)EOSHADER";
+
+  int main()
+  {
+    // initialise, create window, create context, etc
+    if(!Init())
+      return 3;
+
+    const DefaultA2V OffsetTri[] = {
+        {Vec3f(7.7f, 0.0f, 0.0f), Vec4f(0.0f, 0.0f, 0.0f, 1.0f), Vec2f(0.0f, 0.0f)},
+        {Vec3f(7.7f, 0.0f, 0.0f), Vec4f(0.0f, 0.0f, 0.0f, 1.0f), Vec2f(0.0f, 0.0f)},
+        {Vec3f(7.7f, 0.0f, 0.0f), Vec4f(0.0f, 0.0f, 0.0f, 1.0f), Vec2f(0.0f, 0.0f)},
+
+        {Vec3f(9.9f, 0.0f, 0.0f), Vec4f(0.0f, 0.0f, 0.0f, 1.0f), Vec2f(0.0f, 0.0f)},
+
+        {Vec3f(-0.5f, -0.5f, 0.0f), Vec4f(0.0f, 1.0f, 0.0f, 1.0f), Vec2f(0.0f, 0.0f)},
+        {Vec3f(0.0f, 0.5f, 0.0f), Vec4f(0.0f, 1.0f, 0.0f, 1.0f), Vec2f(0.0f, 1.0f)},
+        {Vec3f(0.5f, -0.5f, 0.0f), Vec4f(0.0f, 1.0f, 0.0f, 1.0f), Vec2f(1.0f, 0.0f)},
+
+        {Vec3f(8.8f, 0.0f, 0.0f), Vec4f(0.0f, 0.0f, 0.0f, 1.0f), Vec2f(0.0f, 0.0f)},
+    };
+    uint16_t indices[] = {99, 99, 99, 1, 2, 3, 4, 5};
+    Vec4f cbufferdata[64] = {};
+    cbufferdata[32] = Vec4f(1.0f, 2.0f, 3.0f, 4.0f);
+
+    GLuint vao = MakeVAO();
+    glBindVertexArray(vao);
+
+    GLuint vb = MakeBuffer();
+    glBindBuffer(GL_ARRAY_BUFFER, vb);
+    glBufferStorage(GL_ARRAY_BUFFER, sizeof(OffsetTri), OffsetTri, 0);
+
+    glVertexAttribFormat(0, 3, GL_FLOAT, GL_FALSE, 0);
+    glVertexAttribFormat(1, 4, GL_FLOAT, GL_FALSE, sizeof(Vec3f));
+    glVertexAttribFormat(2, 2, GL_FLOAT, GL_FALSE, sizeof(Vec3f) + sizeof(Vec4f));
+
+    glVertexAttribBinding(0, 0);
+    glVertexAttribBinding(1, 0);
+    glVertexAttribBinding(2, 0);
+
+    glEnableVertexAttribArray(0);
+    glEnableVertexAttribArray(1);
+    glEnableVertexAttribArray(2);
+
+    GLuint ib = MakeBuffer();
+    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ib);
+    glBufferStorage(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, 0);
+
+    GLuint program = MakeProgram(vertex, pixel);
+
+    GLuint cb = MakeBuffer();
+    glBindBuffer(GL_UNIFORM_BUFFER, cb);
+    glBufferStorage(GL_UNIFORM_BUFFER, sizeof(cbufferdata), cbufferdata, GL_MAP_WRITE_BIT);
+
+    GLuint fbo = MakeFBO();
+    glBindFramebuffer(GL_FRAMEBUFFER, fbo);
+
+    // Color render texture
+    GLuint colattach = MakeTexture();
+
+    glBindTexture(GL_TEXTURE_2D, colattach);
+    glTexStorage2D(GL_TEXTURE_2D, 1, GL_RGBA32F, screenWidth, screenHeight);
+    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, colattach, 0);
+
+    while(Running())
+    {
+      glBindFramebuffer(GL_FRAMEBUFFER, 0);
+
+      float col[] = {0.2f, 0.2f, 0.2f, 1.0f};
+      glClearBufferfv(GL_COLOR, 0, col);
+
+      glBindFramebuffer(GL_FRAMEBUFFER, fbo);
+      glBindVertexArray(vao);
+
+      glBindBufferRange(GL_UNIFORM_BUFFER, 0, cb, 16 * sizeof(Vec4f), 16 * sizeof(Vec4f));
+
+      glUseProgram(program);
+
+      glViewport(0, 0, GLsizei(screenWidth), GLsizei(screenHeight));
+
+      glBindVertexBuffer(0, vb, sizeof(DefaultA2V) * 3, sizeof(DefaultA2V));
+
+      glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_SHORT, (void *)(sizeof(uint16_t) * 3));
+
+      blitToSwap(colattach);
+
+      Present();
+    }
+
+    return 0;
+  }
+};
+
+REGISTER_TEST();
diff --git a/util/test/demos/vk/vk_truncated_cbuffer.cpp b/util/test/demos/vk/vk_buffer_truncation.cpp
similarity index 60%
rename from util/test/demos/vk/vk_truncated_cbuffer.cpp
rename to util/test/demos/vk/vk_buffer_truncation.cpp
index abc97f816..8adc034aa 100644
--- a/util/test/demos/vk/vk_truncated_cbuffer.cpp
+++ b/util/test/demos/vk/vk_buffer_truncation.cpp
@@ -24,45 +24,31 @@
 
 #include "vk_test.h"
 
-RD_TEST(VK_Truncated_CBuffer, VulkanGraphicsTest)
+RD_TEST(VK_Buffer_Truncation, VulkanGraphicsTest)
 {
   static constexpr const char *Description =
-      "Draws using a cbuffer that is truncated by the descriptor range.";
-
-  std::string common = R"EOSHADER(
-
-#version 420 core
-
-struct v2f
-{
-	vec4 pos;
-	vec4 col;
-	vec4 uv;
-};
-
-)EOSHADER";
+      "Tests using a uniform buffer that is truncated by the descriptor range, as well as "
+      "vertex/index buffers truncated by size.";
 
   const std::string vertex = R"EOSHADER(
+#version 460 core
 
-layout(location = 0) in vec3 Position;
-layout(location = 1) in vec4 Color;
-layout(location = 2) in vec2 UV;
+layout(location = 0) in vec3 POSITION;
+layout(location = 1) in vec4 COLOR;
 
-layout(location = 0) out v2f vertOut;
+layout(location = 0) out vec4 OUTPOSITION;
+layout(location = 1) out vec4 OUTCOLOR;
 
 void main()
 {
-	vertOut.pos = vec4(Position.xyz*vec3(1,-1,1), 1);
-	gl_Position = vertOut.pos;
-	vertOut.col = Color;
-	vertOut.uv = vec4(UV.xy, 0, 1);
+	gl_Position = OUTPOSITION = vec4(POSITION.xyz, 1);
+	OUTCOLOR = COLOR;
 }
 
 )EOSHADER";
 
   const std::string pixel = R"EOSHADER(
-
-layout(location = 0) in v2f vertIn;
+#version 460 core
 
 layout(location = 0, index = 0) out vec4 Color;
 
@@ -93,6 +79,23 @@ void main()
     if(!Init())
       return 3;
 
+    const DefaultA2V OffsetTri[] = {
+        {Vec3f(7.7f, 0.0f, 0.0f), Vec4f(0.0f, 0.0f, 0.0f, 1.0f), Vec2f(0.0f, 0.0f)},
+        {Vec3f(7.7f, 0.0f, 0.0f), Vec4f(0.0f, 0.0f, 0.0f, 1.0f), Vec2f(0.0f, 0.0f)},
+        {Vec3f(7.7f, 0.0f, 0.0f), Vec4f(0.0f, 0.0f, 0.0f, 1.0f), Vec2f(0.0f, 0.0f)},
+
+        {Vec3f(9.9f, 0.0f, 0.0f), Vec4f(0.0f, 0.0f, 0.0f, 1.0f), Vec2f(0.0f, 0.0f)},
+
+        {Vec3f(-0.5f, -0.5f, 0.0f), Vec4f(0.0f, 1.0f, 0.0f, 1.0f), Vec2f(0.0f, 0.0f)},
+        {Vec3f(0.0f, 0.5f, 0.0f), Vec4f(0.0f, 1.0f, 0.0f, 1.0f), Vec2f(0.0f, 1.0f)},
+        {Vec3f(0.5f, -0.5f, 0.0f), Vec4f(0.0f, 1.0f, 0.0f, 1.0f), Vec2f(1.0f, 0.0f)},
+
+        {Vec3f(8.8f, 0.0f, 0.0f), Vec4f(0.0f, 0.0f, 0.0f, 1.0f), Vec2f(0.0f, 0.0f)},
+    };
+    uint16_t indices[] = {99, 99, 99, 1, 2, 3, 4, 5};
+    Vec4f cbufferdata[64] = {};
+    cbufferdata[32] = Vec4f(1.0f, 2.0f, 3.0f, 4.0f);
+
     VkDescriptorSetLayout setlayout = createDescriptorSetLayout(vkh::DescriptorSetLayoutCreateInfo({
         {0, VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, 1, VK_SHADER_STAGE_FRAGMENT_BIT},
     }));
@@ -111,38 +114,40 @@ void main()
     };
 
     pipeCreateInfo.stages = {
-        CompileShaderModule(common + vertex, ShaderLang::glsl, ShaderStage::vert, "main"),
-        CompileShaderModule(common + pixel, ShaderLang::glsl, ShaderStage::frag, "main"),
+        CompileShaderModule(vertex, ShaderLang::glsl, ShaderStage::vert, "main"),
+        CompileShaderModule(pixel, ShaderLang::glsl, ShaderStage::frag, "main"),
     };
 
     VkPipeline pipe = createGraphicsPipeline(pipeCreateInfo);
 
     AllocatedBuffer vb(
-        this, vkh::BufferCreateInfo(sizeof(DefaultTri), VK_BUFFER_USAGE_VERTEX_BUFFER_BIT |
-                                                            VK_BUFFER_USAGE_TRANSFER_DST_BIT),
+        this, vkh::BufferCreateInfo(sizeof(OffsetTri), VK_BUFFER_USAGE_VERTEX_BUFFER_BIT |
+                                                           VK_BUFFER_USAGE_TRANSFER_DST_BIT),
         VmaAllocationCreateInfo({0, VMA_MEMORY_USAGE_CPU_TO_GPU}));
 
-    vb.upload(DefaultTri);
+    vb.upload(OffsetTri);
 
-    Vec4f data[20];
+    AllocatedBuffer ib(this,
+                       vkh::BufferCreateInfo(sizeof(indices), VK_BUFFER_USAGE_INDEX_BUFFER_BIT |
+                                                                  VK_BUFFER_USAGE_TRANSFER_DST_BIT),
+                       VmaAllocationCreateInfo({0, VMA_MEMORY_USAGE_CPU_TO_GPU}));
 
-    data[16] = Vec4f(1.0f, 2.0f, 3.0f, 4.0f);
+    ib.upload(indices);
 
     AllocatedBuffer cb(
-        this, vkh::BufferCreateInfo(sizeof(Vec4f) * 20, VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT |
-                                                            VK_BUFFER_USAGE_TRANSFER_DST_BIT),
+        this, vkh::BufferCreateInfo(sizeof(cbufferdata), VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT |
+                                                             VK_BUFFER_USAGE_TRANSFER_DST_BIT),
         VmaAllocationCreateInfo({0, VMA_MEMORY_USAGE_CPU_TO_GPU}));
-
-    cb.upload(data);
+    cb.upload(cbufferdata);
 
     VkDescriptorSet descset = allocateDescriptorSet(setlayout);
 
     vkh::updateDescriptorSets(
-        device,
-        {
-            vkh::WriteDescriptorSet(descset, 0, VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER,
-                                    {vkh::DescriptorBufferInfo(cb.buffer, 0, sizeof(Vec4f) * 16)}),
-        });
+        device, {
+                    vkh::WriteDescriptorSet(descset, 0, VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER,
+                                            {vkh::DescriptorBufferInfo(
+                                                cb.buffer, sizeof(Vec4f) * 16, sizeof(Vec4f) * 16)}),
+                });
 
     while(Running())
     {
@@ -164,9 +169,10 @@ void main()
       vkCmdBindPipeline(cmd, VK_PIPELINE_BIND_POINT_GRAPHICS, pipe);
       vkCmdSetViewport(cmd, 0, 1, &mainWindow->viewport);
       vkCmdSetScissor(cmd, 0, 1, &mainWindow->scissor);
-      vkh::cmdBindVertexBuffers(cmd, 0, {vb.buffer}, {0});
+      vkCmdBindIndexBuffer(cmd, ib.buffer, sizeof(uint16_t) * 3, VK_INDEX_TYPE_UINT16);
+      vkh::cmdBindVertexBuffers(cmd, 0, {vb.buffer}, {sizeof(DefaultA2V) * 3});
       vkh::cmdBindDescriptorSets(cmd, VK_PIPELINE_BIND_POINT_GRAPHICS, layout, 0, {descset}, {});
-      vkCmdDraw(cmd, 3, 1, 0, 0);
+      vkCmdDrawIndexed(cmd, 6, 1, 0, 0, 0);
 
       vkCmdEndRenderPass(cmd);
 
diff --git a/util/test/demos/vk/vk_cbuffer_zoo.cpp b/util/test/demos/vk/vk_cbuffer_zoo.cpp
index fe5f10ad8..1efef36a1 100644
--- a/util/test/demos/vk/vk_cbuffer_zoo.cpp
+++ b/util/test/demos/vk/vk_cbuffer_zoo.cpp
@@ -716,20 +716,7 @@ float4 main() : SV_Target0
                                            VK_IMAGE_LAYOUT_GENERAL, img.image),
                });
 
-      VkImageBlit region = {};
-      region.srcSubresource.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
-      region.srcSubresource.layerCount = 1;
-      region.dstSubresource.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
-      region.dstSubresource.layerCount = 1;
-      region.srcOffsets[1].x = mainWindow->scissor.extent.width;
-      region.srcOffsets[1].y = mainWindow->scissor.extent.height;
-      region.srcOffsets[1].z = 1;
-      region.dstOffsets[1].x = mainWindow->scissor.extent.width;
-      region.dstOffsets[1].y = mainWindow->scissor.extent.height;
-      region.dstOffsets[1].z = 1;
-
-      vkCmdBlitImage(cmd, img.image, VK_IMAGE_LAYOUT_GENERAL, swapimg, VK_IMAGE_LAYOUT_GENERAL, 1,
-                     &region, VK_FILTER_LINEAR);
+      blitToSwap(cmd, img.image, VK_IMAGE_LAYOUT_GENERAL, swapimg, VK_IMAGE_LAYOUT_GENERAL);
 
       FinishUsingBackbuffer(cmd, VK_ACCESS_TRANSFER_WRITE_BIT, VK_IMAGE_LAYOUT_GENERAL);
 
diff --git a/util/test/demos/vk/vk_secondary_cmdbuf.cpp b/util/test/demos/vk/vk_secondary_cmdbuf.cpp
index 701c8399b..1e0d61f86 100644
--- a/util/test/demos/vk/vk_secondary_cmdbuf.cpp
+++ b/util/test/demos/vk/vk_secondary_cmdbuf.cpp
@@ -215,15 +215,7 @@ void main()
                                            VK_IMAGE_LAYOUT_GENERAL, img.image),
                });
 
-      region.srcOffsets[1].x = size.extent.width;
-      region.srcOffsets[1].y = size.extent.height;
-      region.srcOffsets[1].z = 1;
-      region.dstOffsets[1].x = mainWindow->scissor.extent.width;
-      region.dstOffsets[1].y = mainWindow->scissor.extent.height;
-      region.dstOffsets[1].z = 1;
-
-      vkCmdBlitImage(cmd, img.image, VK_IMAGE_LAYOUT_GENERAL, swapimg, VK_IMAGE_LAYOUT_GENERAL, 1,
-                     &region, VK_FILTER_LINEAR);
+      blitToSwap(cmd, img.image, VK_IMAGE_LAYOUT_GENERAL, swapimg, VK_IMAGE_LAYOUT_GENERAL);
 
       FinishUsingBackbuffer(cmd, VK_ACCESS_TRANSFER_WRITE_BIT, VK_IMAGE_LAYOUT_GENERAL);
 
diff --git a/util/test/demos/vk/vk_shader_editing.cpp b/util/test/demos/vk/vk_shader_editing.cpp
index 350dc8ed4..7aa24ca01 100644
--- a/util/test/demos/vk/vk_shader_editing.cpp
+++ b/util/test/demos/vk/vk_shader_editing.cpp
@@ -158,20 +158,7 @@ void main()
                                            VK_IMAGE_LAYOUT_GENERAL, img.image),
                });
 
-      VkImageBlit region = {};
-      region.srcSubresource.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
-      region.srcSubresource.layerCount = 1;
-      region.dstSubresource.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
-      region.dstSubresource.layerCount = 1;
-      region.srcOffsets[1].x = mainWindow->scissor.extent.width;
-      region.srcOffsets[1].y = mainWindow->scissor.extent.height;
-      region.srcOffsets[1].z = 1;
-      region.dstOffsets[1].x = mainWindow->scissor.extent.width;
-      region.dstOffsets[1].y = mainWindow->scissor.extent.height;
-      region.dstOffsets[1].z = 1;
-
-      vkCmdBlitImage(cmd, img.image, VK_IMAGE_LAYOUT_GENERAL, swapimg, VK_IMAGE_LAYOUT_GENERAL, 1,
-                     &region, VK_FILTER_LINEAR);
+      blitToSwap(cmd, img.image, VK_IMAGE_LAYOUT_GENERAL, swapimg, VK_IMAGE_LAYOUT_GENERAL);
 
       FinishUsingBackbuffer(cmd, VK_ACCESS_TRANSFER_WRITE_BIT, VK_IMAGE_LAYOUT_GENERAL);
 
diff --git a/util/test/demos/vk/vk_texture_zoo.cpp b/util/test/demos/vk/vk_texture_zoo.cpp
index 84c453b8b..7d919bc96 100644
--- a/util/test/demos/vk/vk_texture_zoo.cpp
+++ b/util/test/demos/vk/vk_texture_zoo.cpp
@@ -1464,17 +1464,7 @@ void main()
 
       vkCmdEndRenderPass(cmd);
 
-      VkImageBlit region = {};
-      region.srcSubresource.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
-      region.srcSubresource.layerCount = 1;
-      region.dstSubresource = region.srcSubresource;
-      region.srcOffsets[1].x = mainWindow->scissor.extent.width;
-      region.srcOffsets[1].y = mainWindow->scissor.extent.height;
-      region.srcOffsets[1].z = 1;
-      region.dstOffsets[1] = region.srcOffsets[1];
-
-      vkCmdBlitImage(cmd, fltTex.image, VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIMAL, swapimg,
-                     VK_IMAGE_LAYOUT_GENERAL, 1, &region, VK_FILTER_LINEAR);
+      blitToSwap(cmd, fltTex.image, VK_IMAGE_LAYOUT_GENERAL, swapimg, VK_IMAGE_LAYOUT_GENERAL);
 
       FinishUsingBackbuffer(cmd, VK_ACCESS_TRANSFER_WRITE_BIT, VK_IMAGE_LAYOUT_GENERAL);
 
diff --git a/util/test/rdtest/__init__.py b/util/test/rdtest/__init__.py
index 1d2cbcdb7..236612c04 100644
--- a/util/test/rdtest/__init__.py
+++ b/util/test/rdtest/__init__.py
@@ -7,3 +7,4 @@ from .shared.Texture_Zoo import *
 from .shared.Mesh_Zoo import *
 from .shared.Draw_Zoo import *
 from .shared.Overlay_Test import *
+from .shared.Buffer_Truncation import *
diff --git a/util/test/rdtest/analyse.py b/util/test/rdtest/analyse.py
index 1dada4667..7ecd64e2c 100644
--- a/util/test/rdtest/analyse.py
+++ b/util/test/rdtest/analyse.py
@@ -56,32 +56,52 @@ def open_capture(filename="", cap: rd.CaptureFile=None, opts: rd.ReplayOptions=N
 
 
 def fetch_indices(controller: rd.ReplayController, draw: rd.DrawcallDescription, mesh: rd.MeshFormat, index_offset: int, first_index: int, num_indices: int):
-    # Get the character for the width of index
-    index_fmt = 'B'
-    if mesh.indexByteStride == 2:
-        index_fmt = 'H'
-    elif mesh.indexByteStride == 4:
-        index_fmt = 'I'
 
     pipe = controller.GetPipelineState()
     restart_idx = pipe.GetStripRestartIndex() & ((1 << (mesh.indexByteStride*8)) - 1)
     restart_enabled = pipe.IsStripRestartEnabled() and rd.IsStrip(draw.topology)
 
-    # Duplicate the format by the number of indices
-    index_fmt = '=' + str(num_indices) + index_fmt
-
     # If we have an index buffer
     if mesh.indexResourceId != rd.ResourceId.Null():
+        offset = mesh.indexByteStride*(first_index + index_offset)
+
+        avail_bytes = mesh.indexByteSize
+        if avail_bytes > offset:
+            avail_bytes = avail_bytes - offset
+        else:
+            avail_bytes = 0
+
+        read_bytes = min([avail_bytes, mesh.indexByteStride*num_indices])
+
         # Fetch the data
-        ibdata = controller.GetBufferData(mesh.indexResourceId,
-                                          mesh.indexByteOffset + mesh.indexByteStride*(first_index + index_offset),
-                                          mesh.indexByteStride*num_indices)
+        if read_bytes > 0:
+            ibdata = controller.GetBufferData(mesh.indexResourceId,
+                                              mesh.indexByteOffset + offset,
+                                              read_bytes)
+        else:
+            ibdata = bytes()
+
+        # Get the character for the width of index
+        index_fmt = 'B'
+        if mesh.indexByteStride == 2:
+            index_fmt = 'H'
+        elif mesh.indexByteStride == 4:
+            index_fmt = 'I'
+
+        avail_indices = int(len(ibdata) / mesh.indexByteStride)
+
+        # Duplicate the format by the number of indices
+        index_fmt = '=' + str(min([avail_indices, num_indices])) + index_fmt
 
         # Unpack all the indices
         indices = struct.unpack_from(index_fmt, ibdata)
 
+        extra = []
+        if avail_indices < num_indices:
+            extra = [None] * (num_indices - avail_indices)
+
         # Apply the baseVertex offset
-        return [i if restart_enabled and i == restart_idx else i + mesh.baseVertex for i in indices]
+        return [i if restart_enabled and i == restart_idx else i + mesh.baseVertex for i in indices] + extra
     else:
         # With no index buffer, just generate a range
         return tuple(range(first_index, first_index + num_indices))
@@ -107,11 +127,14 @@ def get_vsin_attrs(controller: rd.ReplayController, vertexOffset: int, index_mes
         attr.name = a.name
         attr.mesh = rd.MeshFormat(index_mesh)
 
+        offs = a.byteOffset + vertexOffset * attr.mesh.vertexByteStride
+
         attr.mesh.vertexByteStride = vbs[a.vertexBuffer].byteStride
         attr.mesh.instStepRate = a.instanceRate
         attr.mesh.instanced = a.perInstance
         attr.mesh.vertexResourceId = vbs[a.vertexBuffer].resourceId
-        attr.mesh.vertexByteOffset = vbs[a.vertexBuffer].byteOffset + a.byteOffset + vertexOffset * attr.mesh.vertexByteStride
+        attr.mesh.vertexByteOffset = vbs[a.vertexBuffer].byteOffset + offs
+        attr.mesh.vertexByteSize = max([0, vbs[a.vertexBuffer].byteSize - offs])
 
         attr.mesh.format = a.format
 
@@ -205,6 +228,9 @@ def unpack_data(fmt: rd.ResourceFormat, data: bytes, data_offset: int):
     # We need to fetch compCount components
     vertex_format = '=' + str(fmt.compCount) + format_chars[fmt.compType][fmt.compByteWidth]
 
+    if data_offset >= len(data):
+        return None
+
     # Unpack the data
     try:
         value = struct.unpack_from(vertex_format, data, data_offset)
@@ -231,9 +257,29 @@ def unpack_data(fmt: rd.ResourceFormat, data: bytes, data_offset: int):
 
 def decode_mesh_data(controller: rd.ReplayController, indices: List[int], display_indices: List[int],
                      attrs: List[MeshAttribute], instance: int = 0, indexOffset: int = 0):
-    buffer_cache = {}
     ret = []
 
+    buffer_ranges = {}
+    for attr in attrs:
+        begin = attr.mesh.vertexByteOffset
+        end = min(begin + attr.mesh.vertexByteSize, 0xffffffffffffffff)
+
+        # This could be more optimal if we figure out the lower/upper bounds of any attribute and only fetch the
+        # data we need. For each referenced buffer, pick the attribute that references the largest range and fetch that
+        if attr.mesh.vertexResourceId in buffer_ranges:
+            buf_range = buffer_ranges[attr.mesh.vertexResourceId]
+
+            if buf_range[0] < begin:
+                begin = buf_range[0]
+            if buf_range[1] > end:
+                end = buf_range[1]
+
+        buffer_ranges[attr.mesh.vertexResourceId] = (begin, end)
+
+    buffer_data = {}
+    for buf, buf_range in buffer_ranges.items():
+        buffer_data[buf] = controller.GetBufferData(buf, buf_range[0], buf_range[1] - buf_range[0])
+
     # Calculate the strip restart index for this index width
     striprestart_index = None
     if controller.GetPipelineState().IsStripRestartEnabled() and attrs[0].mesh.indexResourceId != rd.ResourceId.Null():
@@ -245,18 +291,19 @@ def decode_mesh_data(controller: rd.ReplayController, indices: List[int], displa
 
         if striprestart_index is None or idx != striprestart_index:
             for attr in attrs:
-                offset = attr.mesh.vertexByteOffset + attr.mesh.vertexByteStride * idx
+                if idx is None:
+                    vertex[attr.name] = None
+                    continue
+
+                offset = attr.mesh.vertexByteStride * idx
 
                 if attr.mesh.instanced:
                     offset = (attr.mesh.vertexByteStride +
                               attr.mesh.vertexByteStride * int(instance / max(attr.mesh.instStepRate, 1)))
 
-                # This could be more optimal if we figure out the lower/upper bounds of any attribute and only fetch the
-                # data we need.
-                if attr.mesh.vertexResourceId not in buffer_cache:
-                    buffer_cache[attr.mesh.vertexResourceId] = controller.GetBufferData(attr.mesh.vertexResourceId, 0, 0)
-
-                vertex[attr.name] = unpack_data(attr.mesh.format, buffer_cache[attr.mesh.vertexResourceId], offset)
+                vertex[attr.name] = unpack_data(attr.mesh.format, buffer_data[attr.mesh.vertexResourceId],
+                                                attr.mesh.vertexByteOffset + offset -
+                                                buffer_ranges[attr.mesh.vertexResourceId][0])
 
         ret.append(vertex)
 
diff --git a/util/test/rdtest/shared/Buffer_Truncation.py b/util/test/rdtest/shared/Buffer_Truncation.py
new file mode 100644
index 000000000..4326fa92d
--- /dev/null
+++ b/util/test/rdtest/shared/Buffer_Truncation.py
@@ -0,0 +1,161 @@
+import renderdoc as rd
+import rdtest
+from typing import List, Tuple
+import time
+import os
+
+
+# Not a direct test, re-used by API-specific tests
+class Buffer_Truncation(rdtest.TestCase):
+    internal = True
+
+    def check_capture(self):
+        draw = self.find_draw("Draw")
+
+        self.check(draw is not None)
+
+        self.controller.SetFrameEvent(draw.eventId, False)
+
+        vsin_ref = {
+            0: {
+                'vtx': 0,
+                'idx': 1,
+                'POSITION': [-0.5, -0.5, 0.0],
+                'COLOR': [0.0, 1.0, 0.0, 1.0],
+            },
+            1: {
+                'vtx': 1,
+                'idx': 2,
+                'POSITION': [0.0, 0.5, 0.0],
+                'COLOR': [0.0, 1.0, 0.0, 1.0],
+            },
+            2: {
+                'vtx': 2,
+                'idx': 3,
+                'POSITION': [0.5, -0.5, 0.0],
+                'COLOR': [0.0, 1.0, 0.0, 1.0],
+            },
+            3: {
+                'vtx': 3,
+                'idx': 4,
+                'POSITION': [8.8, 0.0, 0.0],
+                'COLOR': [0.0, 0.0, 0.0, 1.0],
+            },
+            4: {
+                'vtx': 4,
+                'idx': 5,
+                'POSITION': None,
+                'COLOR': None,
+            },
+            5: {
+                'vtx': 5,
+                'idx': None,
+                'POSITION': None,
+                'COLOR': None,
+            },
+        }
+
+        self.check_mesh_data(vsin_ref, self.get_vsin(draw))
+
+        postvs_data = self.get_postvs(draw, rd.MeshDataStage.VSOut, 0, draw.numIndices)
+
+        postvs_ref = {
+            0: {
+                'vtx': 0,
+                'idx': 1,
+                'OUTPOSITION': [-0.5, -0.5, 0.0, 1.0],
+                'OUTCOLOR': [0.0, 1.0, 0.0, 1.0],
+            },
+            1: {
+                'vtx': 1,
+                'idx': 2,
+                'OUTPOSITION': [0.0, 0.5, 0.0, 1.0],
+                'OUTCOLOR': [0.0, 1.0, 0.0, 1.0],
+            },
+            2: {
+                'vtx': 2,
+                'idx': 3,
+                'OUTPOSITION': [0.5, -0.5, 0.0, 1.0],
+                'OUTCOLOR': [0.0, 1.0, 0.0, 1.0],
+            },
+            3: {
+                'vtx': 3,
+                'idx': 4,
+                'OUTPOSITION': [8.8, 0.0, 0.0, 1.0],
+                'OUTCOLOR': [0.0, 0.0, 0.0, 1.0],
+            },
+            4: {
+                'vtx': 4,
+                'idx': 5,
+                # don't rely on any particular OOB behaviour for postvs, as this may come from the driver/API
+            },
+            5: {
+                'vtx': 5,
+                'idx': None,
+                # don't rely on any particular OOB behaviour for postvs, as this may come from the driver/API
+            },
+        }
+
+        self.check_mesh_data(postvs_ref, postvs_data)
+
+        rdtest.log.success("vertex/index buffers were truncated as expected")
+
+        pipe: rd.PipeState = self.controller.GetPipelineState()
+
+        stage = rd.ShaderStage.Pixel
+
+        cbuf: rd.BoundCBuffer = pipe.GetConstantBuffer(stage, 0, 0)
+
+        if self.find_draw('NoCBufferRange') == None:
+            self.check(cbuf.byteSize == 256)
+
+        variables = self.controller.GetCBufferVariableContents(pipe.GetGraphicsPipelineObject(),
+                                                               pipe.GetShader(stage),
+                                                               pipe.GetShaderEntryPoint(stage), 0,
+                                                               cbuf.resourceId, cbuf.byteOffset, cbuf.byteSize)
+
+        outcol: rd.ShaderVariable = variables[1]
+
+        self.check(outcol.name == "outcol")
+        if not rdtest.value_compare(outcol.value.fv[0:4], [0.0, 0.0, 0.0, 0.0]):
+            raise rdtest.TestFailureException("expected outcol to be 0s, but got {}".format(outcol.value.fv[0:4]))
+
+        if self.controller.GetAPIProperties().shaderDebugging:
+            # Debug the shader
+            trace: rd.ShaderDebugTrace = self.controller.DebugPixel(int(pipe.GetViewport(0).width/2),
+                                                                    int(pipe.GetViewport(0).height/2),
+                                                                    rd.ReplayController.NoPreference,
+                                                                    rd.ReplayController.NoPreference)
+
+            if trace.debugger is None:
+                self.controller.FreeTrace(trace)
+                raise rdtest.TestFailureException("Shader did not debug at all")
+            else:
+                cycles, variables = self.process_trace(trace)
+
+                cbuf_sourceVars = [s for s in trace.sourceVars if s.variables[0].type == rd.DebugVariableType.Constant and s.rows > 0]
+
+                # Vulkan style, one source var for the cbuffer
+                if len(cbuf_sourceVars) == 1:
+                    debugged_cb = trace.constantBlocks[0]
+
+                    self.check(debugged_cb.members[0].name == 'padding')
+                    self.check(debugged_cb.members[1].name == 'outcol')
+
+                    if not rdtest.value_compare(debugged_cb.members[1].value.fv[0:4], [0.0, 0.0, 0.0, 0.0]):
+                        raise rdtest.TestFailureException("expected outcol to be 0s, but got {}".format(debugged_cb.members[1].value.fv[0:4]))
+                # D3D style, one source var for each member mapping to a register
+                elif len(cbuf_sourceVars) == 17:
+                    debugged_cb = trace.constantBlocks[0].members[16]
+
+                    self.check(all(['consts.padding[' in c.name for c in cbuf_sourceVars[0:16]]))
+                    self.check(cbuf_sourceVars[16].name == 'consts.outcol')
+
+                    self.check(cbuf_sourceVars[16].variables[0].name == 'cb0[16]')
+
+                    if not rdtest.value_compare(debugged_cb.value.fv[0:4], [0.0, 0.0, 0.0, 0.0]):
+                        raise rdtest.TestFailureException("expected outcol to be 0s, but got {}".format(debugged_cb.members[1].value.fv[0:4]))
+                else:
+                    raise rdtest.TestFailureException("Unexpected number of constant buffer source vars {}".format(len(cbuf_sourceVars)))
+
+        rdtest.log.success("CBuffer value was truncated as expected")
diff --git a/util/test/rdtest/testcase.py b/util/test/rdtest/testcase.py
index ddb8754f8..240aecee4 100644
--- a/util/test/rdtest/testcase.py
+++ b/util/test/rdtest/testcase.py
@@ -259,13 +259,20 @@ class TestCase:
         else:
             num_indices = min(num_indices, draw.numIndices)
 
+        ioffs = draw.indexOffset * draw.indexByteWidth
+
         mesh = rd.MeshFormat()
         mesh.numIndices = num_indices
-        mesh.indexByteOffset = ib.byteOffset + draw.indexOffset * draw.indexByteWidth
+        mesh.indexByteOffset = ib.byteOffset + ioffs
         mesh.indexByteStride = draw.indexByteWidth
         mesh.indexResourceId = ib.resourceId
         mesh.baseVertex = draw.baseVertex
 
+        if ib.byteSize > ioffs:
+            mesh.indexByteSize = ib.byteSize - ioffs
+        else:
+            mesh.indexByteSize = 0
+
         if not (draw.flags & rd.DrawFlags.Indexed):
             mesh.indexByteOffset = 0
             mesh.indexByteStride = 0
@@ -295,13 +302,20 @@ class TestCase:
 
         ib: rd.BoundVBuffer = self.controller.GetPipelineState().GetIBuffer()
 
+        ioffs = draw.indexOffset * draw.indexByteWidth
+
         in_mesh = rd.MeshFormat()
         in_mesh.numIndices = num_indices
-        in_mesh.indexByteOffset = ib.byteOffset + draw.indexOffset * draw.indexByteWidth
+        in_mesh.indexByteOffset = ib.byteOffset + ioffs
         in_mesh.indexByteStride = draw.indexByteWidth
         in_mesh.indexResourceId = ib.resourceId
         in_mesh.baseVertex = draw.baseVertex
 
+        if ib.byteSize > ioffs:
+            in_mesh.indexByteSize = ib.byteSize - ioffs
+        else:
+            in_mesh.indexByteSize = 0
+
         if not (draw.flags & rd.DrawFlags.Indexed):
             in_mesh.indexByteOffset = 0
             in_mesh.indexByteStride = 0
diff --git a/util/test/tests/D3D11/D3D11_Buffer_Truncation.py b/util/test/tests/D3D11/D3D11_Buffer_Truncation.py
new file mode 100644
index 000000000..cb0d42a75
--- /dev/null
+++ b/util/test/tests/D3D11/D3D11_Buffer_Truncation.py
@@ -0,0 +1,7 @@
+import rdtest
+import renderdoc as rd
+
+
+class D3D11_Buffer_Truncation(rdtest.Buffer_Truncation):
+    demos_test_name = 'D3D11_Buffer_Truncation'
+    internal = False
\ No newline at end of file
diff --git a/util/test/tests/D3D12/D3D12_Buffer_Truncation.py b/util/test/tests/D3D12/D3D12_Buffer_Truncation.py
new file mode 100644
index 000000000..e3adf8f86
--- /dev/null
+++ b/util/test/tests/D3D12/D3D12_Buffer_Truncation.py
@@ -0,0 +1,7 @@
+import rdtest
+import renderdoc as rd
+
+
+class D3D12_Buffer_Truncation(rdtest.Buffer_Truncation):
+    demos_test_name = 'D3D12_Buffer_Truncation'
+    internal = False
\ No newline at end of file
diff --git a/util/test/tests/GL/GL_Buffer_Truncation.py b/util/test/tests/GL/GL_Buffer_Truncation.py
new file mode 100644
index 000000000..a1cd9c36c
--- /dev/null
+++ b/util/test/tests/GL/GL_Buffer_Truncation.py
@@ -0,0 +1,7 @@
+import rdtest
+import renderdoc as rd
+
+
+class GL_Buffer_Truncation(rdtest.Buffer_Truncation):
+    demos_test_name = 'GL_Buffer_Truncation'
+    internal = False
\ No newline at end of file
diff --git a/util/test/tests/Vulkan/VK_Buffer_Truncation.py b/util/test/tests/Vulkan/VK_Buffer_Truncation.py
new file mode 100644
index 000000000..a1613e61e
--- /dev/null
+++ b/util/test/tests/Vulkan/VK_Buffer_Truncation.py
@@ -0,0 +1,7 @@
+import rdtest
+import renderdoc as rd
+
+
+class VK_Buffer_Truncation(rdtest.Buffer_Truncation):
+    demos_test_name = 'VK_Buffer_Truncation'
+    internal = False
\ No newline at end of file
diff --git a/util/test/tests/Vulkan/VK_Truncated_CBuffer.py b/util/test/tests/Vulkan/VK_Truncated_CBuffer.py
deleted file mode 100644
index 44461b721..000000000
--- a/util/test/tests/Vulkan/VK_Truncated_CBuffer.py
+++ /dev/null
@@ -1,32 +0,0 @@
-import rdtest
-import renderdoc as rd
-
-
-class VK_Truncated_CBuffer(rdtest.TestCase):
-    demos_test_name = 'VK_Truncated_CBuffer'
-
-    def check_capture(self):
-        draw = self.find_draw("Draw")
-
-        self.check(draw is not None)
-
-        self.controller.SetFrameEvent(draw.eventId, False)
-
-        pipe: rd.PipeState = self.controller.GetPipelineState()
-
-        stage = rd.ShaderStage.Pixel
-
-        cbuf: rd.BoundCBuffer = pipe.GetConstantBuffer(stage, 0, 0)
-
-        variables = self.controller.GetCBufferVariableContents(pipe.GetGraphicsPipelineObject(),
-                                                               pipe.GetShader(stage),
-                                                               pipe.GetShaderEntryPoint(stage), 0,
-                                                               cbuf.resourceId, cbuf.byteOffset, cbuf.byteSize)
-
-        outcol: rd.ShaderVariable = variables[1]
-
-        self.check(outcol.name == "outcol")
-        if not rdtest.value_compare(outcol.value.fv[0:4], [0.0, 0.0, 0.0, 0.0]):
-            raise rdtest.TestFailureException("expected outcol to be 0s, but got {}".format(outcol.value.fv[0:4]))
-
-        rdtest.log.success("CBuffer value was truncated as expected")