Handle SPIR-V GL shaders with no location on texture binds. Closes #3405

* Since GL doesn't have sets, use the fixedBindSetOrSpace to namespace bindings
  with locations (that need to be queried) from bindings without locations
  (which have a fixed bind). Prior to the descriptor refactor this was indiated
  with negative binds.

renderdoc/driver/gl/gl_shader_refl.cpp

@@ -2485,11 +2485,25 @@ void GetCurrentBinding(GLuint curProg, ShaderReflection *refl, const ShaderResou
 
   if(refl->encoding == ShaderEncoding::OpenGLSPIRV)
   {
-    if(resource.isTexture && resource.fixedBindNumber != ~0U)
+    slot = 0;
+    if(resource.isTexture)
     {
-      GL.glGetUniformiv(curProg, resource.fixedBindNumber, dummyReadback);
-      slot = dummyReadback[0];
-      used = true;
+      if(resource.fixedBindNumber == ~0U)
+      {
+        slot = 0;
+      }
+      // the fixedBindSetOrSpace is set to 1 if a location is provided (whether or not there's a fixed binding)
+      else if(resource.fixedBindSetOrSpace == 0)
+      {
+        slot = resource.fixedBindNumber;
+        used = true;
+      }
+      else
+      {
+        GL.glGetUniformiv(curProg, resource.fixedBindNumber, dummyReadback);
+        slot = dummyReadback[0];
+        used = true;
+      }
     }
   }
   else if(resource.isReadOnly)
@@ -2669,6 +2683,8 @@ void GetCurrentBinding(GLuint curProg, ShaderReflection *refl, const ConstantBlo
   {
     // It's fuzzy on whether UBOs can be remapped with glUniformBlockBinding so for now we hope that
     // anyone using UBOs and SPIR-V will at least specify immutable bindings in the SPIR-V.
+    slot = cblock.fixedBindNumber;
+    used = true;
     return;
   }
 

renderdoc/driver/shaders/spirv/spirv_reflect.cpp

@@ -1386,9 +1386,12 @@ void Reflector::MakeReflection(const GraphicsAPI sourceAPI, const ShaderStage st
         Decorations::Flags flags = Decorations::Flags(
             decorations[global.id].flags & (Decorations::HasLocation | Decorations::HasBinding));
 
+        bindset = 0;
+
         if(flags == Decorations::HasLocation)
         {
           bind = decorations[global.id].location;
+          bindset = 1;
         }
         else if(flags == Decorations::NoFlags)
         {
@@ -1422,7 +1425,7 @@ void Reflector::MakeReflection(const GraphicsAPI sourceAPI, const ShaderStage st
         res.variableType.baseType = VarType::UInt;
         res.variableType.name = varType->name;
 
-        res.fixedBindSetOrSpace = 0;
+        res.fixedBindSetOrSpace = bindset;
         res.fixedBindNumber = GetBinding(decorations[global.id].binding);
         res.bindArraySize = arraySize;