Expose and generalize Clear11's CompareStates function, and add methods for…

src/common/angleutils.h

@@ -56,6 +56,28 @@ void SafeDeleteArray(T*& resource)
     resource = NULL;
 }
 
+// Provide a less-than function for comparing structs
+// Note: struct memory must be initialized to zero, because of packing gaps
+template <typename T>
+inline bool StructLessThan(const T &a, const T &b)
+{
+    return (memcmp(&a, &b, sizeof(T)) < 0);
+}
+
+// Provide a less-than function for comparing structs
+// Note: struct memory must be initialized to zero, because of packing gaps
+template <typename T>
+inline bool StructEquals(const T &a, const T &b)
+{
+    return (memcmp(&a, &b, sizeof(T)) == 0);
+}
+
+template <typename T>
+inline void StructZero(T *obj)
+{
+    memset(obj, 0, sizeof(T));
+}
+
 #if defined(_MSC_VER)
 #define snprintf _snprintf
 #endif

src/libGLESv2/renderer/Clear11.cpp

@@ -28,13 +28,6 @@
 namespace rx
 {
 
-// Provide a less-than function for comparing states in the caches
-template <typename T>
-static bool CompareStates(const T &a, const T &b)
-{
-    return memcmp(&a, &b, sizeof(T)) < 0;
-}
-
 template <typename T>
 static void ApplyVertices(const gl::Extents &framebufferSize, const gl::Rectangle *scissor, const gl::Color<T> &color, float depth, void *buffer)
 {
@@ -87,7 +80,7 @@ Clear11::ClearShader Clear11::CreateClearShader(ID3D11Device *device, DXGI_FORMA
 }
 
 Clear11::Clear11(Renderer11 *renderer)
-    : mRenderer(renderer), mClearBlendStates(CompareStates<ClearBlendInfo>), mClearDepthStencilStates(CompareStates<ClearDepthStencilInfo>),
+    : mRenderer(renderer), mClearBlendStates(StructLessThan<ClearBlendInfo>), mClearDepthStencilStates(StructLessThan<ClearDepthStencilInfo>),
       mVertexBuffer(NULL), mRasterizerState(NULL)
 {
     HRESULT result;