Add file accidentally omitted from r6182.

git-svn-id: http://skia.googlecode.com/svn/branches/gpu_dev@6186 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 73 insertions, 0 deletions

diff --git a/include/gpu/GrTBackendEffectFactory.h b/include/gpu/GrTBackendEffectFactory.h
new file mode 100644
index 0000000000..52dbc64dd8
--- /dev/null
+++ b/include/gpu/GrTBackendEffectFactory.h
@@ -0,0 +1,73 @@
+/*
+ * Copyright 2012 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef GrTBackendEffectFactory_DEFINED
+#define GrTBackendEffectFactory_DEFINED
+
+#include "GrBackendEffectFactory.h"
+#include "GrEffectStage.h"
+
+/**
+ * Implements GrBackendEffectFactory for a GrEffect subclass as a singleton.
+ */
+template <typename EffectClass>
+class GrTBackendEffectFactory : public GrBackendEffectFactory {
+
+public:
+    typedef typename EffectClass::GLEffect GLEffect;
+
+    /** Returns a human-readable name that is accessible via GrEffect or
+        GrGLEffect and is consistent between the two of them.
+     */
+    virtual const char* name() const SK_OVERRIDE { return EffectClass::Name(); }
+
+    /** Returns a value that identifies the GLSL shader code generated by
+        a GrEffect. This enables caching of generated shaders. Part of the
+        id identifies the GrEffect subclass. The remainder is based
+        on the aspects of the GrEffect object's configuration that affect
+        GLSL code generation. */
+    virtual EffectKey glEffectKey(const GrEffectStage& stage,
+                                  const GrGLCaps& caps) const SK_OVERRIDE {
+        GrAssert(kIllegalEffectClassID != fEffectClassID);
+        EffectKey effectKey = GLEffect::GenKey(stage, caps);
+        EffectKey textureKey = GLEffect::GenTextureKey(*stage.getEffect(), caps);
+#if GR_DEBUG
+        static const EffectKey kIllegalIDMask = (uint16_t) (~((1U << kEffectKeyBits) - 1));
+        GrAssert(!(kIllegalIDMask & effectKey));
+
+        static const EffectKey kIllegalTextureKeyMask = (uint16_t) (~((1U << kTextureKeyBits) - 1));
+        GrAssert(!(kIllegalTextureKeyMask & textureKey));
+#endif
+        return fEffectClassID | (textureKey << kEffectKeyBits) | effectKey;
+    }
+
+    /** Returns a new instance of the appropriate *GL* implementation class
+        for the given GrEffect; caller is responsible for deleting
+        the object. */
+    virtual GLEffect* createGLInstance(const GrEffect& effect) const SK_OVERRIDE {
+        return SkNEW_ARGS(GLEffect, (*this, effect));
+    }
+
+    /** This class is a singleton. This function returns the single instance.
+     */
+    static const GrBackendEffectFactory& getInstance() {
+        static SkAlignedSTStorage<1, GrTBackendEffectFactory> gInstanceMem;
+        static const GrTBackendEffectFactory* gInstance;
+        if (!gInstance) {
+            gInstance = SkNEW_PLACEMENT(gInstanceMem.get(),
+                                        GrTBackendEffectFactory);
+        }
+        return *gInstance;
+    }
+
+protected:
+    GrTBackendEffectFactory() {
+        fEffectClassID = GenID() << (kEffectKeyBits + kTextureKeyBits) ;
+    }
+};
+
+#endif