Add a command-line option to override uniform locations

glslang/MachineIndependent/ShaderLang.cpp

@@ -1759,6 +1759,10 @@ void TShader::setAutoMapBindings(bool map)              { intermediate->setAutoM
 void TShader::setInvertY(bool invert)                   { intermediate->setInvertY(invert); }
 // Fragile: currently within one stage: simple auto-assignment of location
 void TShader::setAutoMapLocations(bool map)             { intermediate->setAutoMapLocations(map); }
+void TShader::addUniformLocationOverride(const char* name, int loc)
+{
+    intermediate->addUniformLocationOverride(name, loc);
+}
 // See comment above TDefaultHlslIoMapper in iomapper.cpp:
 void TShader::setHlslIoMapping(bool hlslIoMap)          { intermediate->setHlslIoMapping(hlslIoMap); }
 void TShader::setFlattenUniformArrays(bool flatten)     { intermediate->setFlattenUniformArrays(flatten); }

glslang/MachineIndependent/iomapper.cpp

@@ -434,7 +434,7 @@ struct TDefaultIoResolverBase : public glslang::TIoMapResolver
 
         return 0;
     }
-    int resolveUniformLocation(EShLanguage /*stage*/, const char* /*name*/, const glslang::TType& type, bool /*is_live*/) override
+    int resolveUniformLocation(EShLanguage /*stage*/, const char* name, const glslang::TType& type, bool /*is_live*/) override
     {
         // kick out of not doing this
         if (!doAutoLocationMapping())
@@ -455,7 +455,11 @@ struct TDefaultIoResolverBase : public glslang::TIoMapResolver
                 return -1;
         }
 
-        int location = nextUniformLocation;
+        int location = intermediate.getUniformLocationOverride(name);
+        if (location != -1)
+                return location;
+
+        location = nextUniformLocation;
 
         nextUniformLocation += TIntermediate::computeTypeUniformLocationSize(type);
 

glslang/MachineIndependent/localintermediate.h

@@ -671,6 +671,20 @@ public:
     void addProcessArgument(const std::string& arg) { processes.addArgument(arg); }
     const std::vector<std::string>& getProcesses() const { return processes.getProcesses(); }
 
+    void addUniformLocationOverride(const TString& name, int location)
+    {
+            uniformLocationOverrides[name] = location;
+    }
+
+    int getUniformLocationOverride(const TString& name) const
+    {
+            auto pos = uniformLocationOverrides.find(name);
+            if (pos == uniformLocationOverrides.end())
+                    return -1;
+            else
+                    return pos->second;
+    }
+
     void setNeedsLegalization() { needToLegalize = true; }
     bool needsLegalization() const { return needToLegalize; }
 
@@ -796,6 +810,8 @@ protected:
     bool needToLegalize;
     bool binaryDoubleOutput;
 
+    std::unordered_map<TString, int> uniformLocationOverrides;
+
 private:
     void operator=(TIntermediate&); // prevent assignments
 };

glslang/Public/ShaderLang.h

@@ -413,6 +413,7 @@ public:
     void setResourceSetBinding(const std::vector<std::string>& base);
     void setAutoMapBindings(bool map);
     void setAutoMapLocations(bool map);
+    void addUniformLocationOverride(const char* name, int loc);
     void setInvertY(bool invert);
     void setHlslIoMapping(bool hlslIoMap);
     void setFlattenUniformArrays(bool flatten);