From e59dea21420519418233cd9f1dde9a98384264ad Mon Sep 17 00:00:00 2001
From: baldurk <baldurk@baldurk.org>
Date: Mon, 8 Jan 2018 15:56:37 +0000
Subject: [PATCH] Add functions for adding declared constants

---
 renderdoc/driver/shaders/spirv/spirv_editor.cpp |  7 +++++++
 renderdoc/driver/shaders/spirv/spirv_editor.h   | 17 +++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/renderdoc/driver/shaders/spirv/spirv_editor.cpp b/renderdoc/driver/shaders/spirv/spirv_editor.cpp
index 0ee4d593b..d39ed4e8c 100644
--- a/renderdoc/driver/shaders/spirv/spirv_editor.cpp
+++ b/renderdoc/driver/shaders/spirv/spirv_editor.cpp
@@ -269,6 +269,13 @@ void SPIRVEditor::AddVariable(const SPIRVOperation &op)
   addWords(typeVarSection.endOffset, op.size());
 }
 
+void SPIRVEditor::AddConstant(const SPIRVOperation &op)
+{
+  idOffsets[op[2]] = typeVarSection.endOffset;
+  spirv.insert(spirv.begin() + typeVarSection.endOffset, op.begin(), op.end());
+  addWords(typeVarSection.endOffset, op.size());
+}
+
 void SPIRVEditor::AddFunction(const SPIRVOperation *ops, size_t count)
 {
   idOffsets[ops[0][2]] = spirv.size();
diff --git a/renderdoc/driver/shaders/spirv/spirv_editor.h b/renderdoc/driver/shaders/spirv/spirv_editor.h
index 5321c52e4..8c078fc31 100644
--- a/renderdoc/driver/shaders/spirv/spirv_editor.h
+++ b/renderdoc/driver/shaders/spirv/spirv_editor.h
@@ -319,6 +319,7 @@ public:
   void AddDecoration(const SPIRVOperation &op);
   void AddType(const SPIRVOperation &op);
   void AddVariable(const SPIRVOperation &op);
+  void AddConstant(const SPIRVOperation &op);
   void AddFunction(const SPIRVOperation *ops, size_t count);
 
   SPIRVIterator GetID(SPIRVId id);
@@ -340,6 +341,22 @@ public:
 
   SPIRVId DeclareStructType(std::vector<uint32_t> members);
 
+  // helper for AddConstant
+  template <typename T>
+  SPIRVId AddConstantImmediate(T t)
+  {
+    SPIRVId typeId = DeclareType(scalar<T>());
+    SPIRVId retId = MakeId();
+    std::vector<uint32_t> words = {typeId, retId};
+
+    words.insert(words.end(), sizeof(T) / 4, 0U);
+
+    memcpy(&words[2], &t, sizeof(T));
+
+    AddConstant(SPIRVOperation(spv::OpConstant, words));
+    return retId;
+  }
+
   // simple properties that are public.
   struct
   {