Implement color filter as GrGLEffect

src/gpu/gl/GrGLSL_impl.h

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrGLSL_impl_DEFINED
 #define GrGLSL_impl_DEFINED
 
-template<>
-inline const char* GrGLSLExpr<4>::ZerosStr() {
+template<typename Self>
+template<typename T>
+inline Self GrGLSLExpr<Self>::VectorCastImpl(const T& expr) {
+    if (expr.isZeros()) {
+        return Self(0);
+    }
+    if (expr.isOnes()) {
+        return Self(1);
+    }
+    return Self(Self::CastStr(), expr.c_str());
+}
+
+template<typename Self>
+template<typename T0, typename T1>
+inline Self GrGLSLExpr<Self>::Mul(T0 in0, T1 in1) {
+    if (in0.isZeros() || in1.isZeros()) {
+        return Self(0);
+    }
+    if (in0.isOnes()) {
+        return Self::VectorCast(in1);
+    }
+    if (in1.isOnes()) {
+        return Self::VectorCast(in0);
+    }
+    return Self("(%s * %s)", in0.c_str(), in1.c_str());
+}
+
+template<typename Self>
+template<typename T0, typename T1>
+inline Self GrGLSLExpr<Self>::Add(T0 in0, T1 in1) {
+    if (in1.isZeros()) {
+        return Self::VectorCast(in0);
+    }
+    if (in0.isZeros()) {
+        return Self::VectorCast(in1);
+    }
+    if (in0.isOnes() && in1.isOnes()) {
+        return Self(2);
+    }
+    return Self("(%s + %s)", in0.c_str(), in1.c_str());
+}
+
+template<typename Self>
+template<typename T0, typename T1>
+inline Self GrGLSLExpr<Self>::Sub(T0 in0, T1 in1) {
+    if (in1.isZeros()) {
+        return Self::VectorCast(in0);
+    }
+    if (in1.isOnes()) {
+        if (in0.isOnes()) {
+            return Self(0);
+        }
+    }
+
+    return Self("(%s - %s)", in0.c_str(), in1.c_str());
+}
+
+template <typename Self>
+template <typename T>
+T GrGLSLExpr<Self>::extractComponents(const char format[]) const {
+    if (this->isZeros()) {
+        return T(0);
+    }
+    if (this->isOnes()) {
+        return T(1);
+    }
+    return T(format, this->c_str());
+}
+
+inline GrGLSLExpr1 GrGLSLExpr1::VectorCast(const GrGLSLExpr1& expr) {
+    return expr;
+}
+
+inline const char* GrGLSLExpr1::ZerosStr() {
+    return "0";
+}
+
+inline const char* GrGLSLExpr1::OnesStr() {
+    return "1.0";
+}
+
+// GrGLSLExpr1::CastStr() is unimplemented because using them is likely an
+// error. This is now caught compile-time.
+
+inline const char* GrGLSLExpr1::CastIntStr() {
+    return "%d";
+}
+
+inline GrGLSLExpr1 operator*(const GrGLSLExpr1& in0, const GrGLSLExpr1& in1) {
+    return GrGLSLExpr1::Mul(in0, in1);
+}
+
+inline GrGLSLExpr1 operator+(const GrGLSLExpr1& in0, const GrGLSLExpr1& in1) {
+    return GrGLSLExpr1::Add(in0, in1);
+}
+
+inline GrGLSLExpr1 operator-(const GrGLSLExpr1& in0, const GrGLSLExpr1& in1) {
+    return GrGLSLExpr1::Sub(in0, in1);
+}
+
+inline const char* GrGLSLExpr4::ZerosStr() {
     return "vec4(0)";
 }
 
-template<>
-inline const char* GrGLSLExpr<4>::OnesStr() {
+inline const char* GrGLSLExpr4::OnesStr() {
     return "vec4(1)";
 }
 
-template<>
-inline const char* GrGLSLExpr<4>::ExtractAlphaStr() {
-    return "%s.a";
+inline const char* GrGLSLExpr4::CastStr() {
+    return "vec4(%s)";
 }
 
-template<>
-inline const char* GrGLSLExpr<4>::CastStr() {
-    return "vec4(%s)";
-}
-template<>
-inline const char* GrGLSLExpr<4>::CastIntStr() {
+inline const char* GrGLSLExpr4::CastIntStr() {
     return "vec4(%d)";
 }
 
-template<>
-inline const char* GrGLSLExpr<1>::ZerosStr() {
-    return "0";
+inline GrGLSLExpr4 GrGLSLExpr4::VectorCast(const GrGLSLExpr1& expr) {
+    return INHERITED::VectorCastImpl(expr);
 }
 
-template<>
-inline const char* GrGLSLExpr<1>::OnesStr() {
-    return "1";
-}
-
-// GrGLSLExpr<1>::ExtractAlphaStr() and GrGLSLExpr<1>::CastStr() are
-// unimplemented because using them is likely an error. This is now caught
-// compile-time.
-
-template<>
-inline const char* GrGLSLExpr<1>::CastIntStr() {
-    return "%d";
-}
-
-template<>
-template<>
-inline GrGLSLExpr<4> GrGLSLExpr<4>::VectorCast(const GrGLSLExpr<4>& expr) {
+inline GrGLSLExpr4 GrGLSLExpr4::VectorCast(const GrGLSLExpr4& expr) {
     return expr;
 }
 
-template<>
-template<>
-inline GrGLSLExpr<1>  GrGLSLExpr<1>::VectorCast(const GrGLSLExpr<1>& expr)  {
-    return expr;
+inline GrGLSLExpr4::AExpr GrGLSLExpr4::a() const {
+    return this->extractComponents<GrGLSLExpr4::AExpr>("%s.a");
 }
 
-template<int N>
-template<int M>
-inline GrGLSLExpr<N> GrGLSLExpr<N>::VectorCast(const GrGLSLExpr<M>& expr) {
-    if (expr.isZeros()) {
-        return GrGLSLExpr<N>(0);
-    }
-    if (expr.isOnes()) {
-        return GrGLSLExpr<N>(1);
-    }
-    return GrGLSLExpr<N>(GrGLSLExpr<N>::CastStr(), expr.c_str());
+inline GrGLSLExpr4 operator*(const GrGLSLExpr1& in0, const GrGLSLExpr4& in1) {
+    return GrGLSLExpr4::Mul(in0, in1);
 }
 
-template<int N>
-template<int M>
-inline GrGLSLExpr<N> GrGLSLExpr<N>::Mul(const GrGLSLExpr<N>& in0, const GrGLSLExpr<M>& in1) {
-    SK_COMPILE_ASSERT(N == M || M == 1, binary_op_dimensions_incompatible);
-    if (in0.isZeros() || in1.isZeros()) {
-        return GrGLSLExpr<N>(0);
-    }
-    if (in0.isOnes()) {
-        return VectorCast<M>(in1);
-    }
-    if (in1.isOnes()) {
-        return in0;
-    }
-    return GrGLSLExpr<N>("(%s * %s)", in0.c_str(), in1.c_str());
+inline GrGLSLExpr4 operator+(const GrGLSLExpr1& in0, const GrGLSLExpr4& in1) {
+    return GrGLSLExpr4::Add(in0, in1);
 }
 
-template<int N>
-template<int M>
-inline GrGLSLExpr<N> GrGLSLExpr<N>::Add(const GrGLSLExpr<N>& in0, const GrGLSLExpr<M>& in1) {
-    SK_COMPILE_ASSERT(N == M || M == 1, binary_op_dimensions_incompatible);
-    if (in1.isZeros()) {
-        return in0;
-    }
-    if (in0.isZeros()) {
-        return VectorCast<M>(in1);
-    }
-    if (in0.isOnes() && in1.isOnes()) {
-        return GrGLSLExpr<N>(2);
-    }
-    return GrGLSLExpr<N>("(%s + %s)", in0.c_str(), in1.c_str());
+inline GrGLSLExpr4 operator-(const GrGLSLExpr1& in0, const GrGLSLExpr4& in1) {
+    return GrGLSLExpr4::Sub(in0, in1);
 }
 
-template<int N>
-template<int M>
-inline GrGLSLExpr<N> GrGLSLExpr<N>::Sub(const GrGLSLExpr<N>& in0, const GrGLSLExpr<M>& in1) {
-    SK_COMPILE_ASSERT(N == M || M == 1, binary_op_dimensions_incompatible);
-    if (in1.isZeros()) {
-        return in0;
-    }
-    if (in1.isOnes()) {
-        if (in0.isOnes()) {
-            return GrGLSLExpr<N>(0);
-        }
-    }
-
-    return GrGLSLExpr<N>("(%s - %s)", in0.c_str(), in1.c_str());
+inline GrGLSLExpr4 operator*(const GrGLSLExpr4& in0, const GrGLSLExpr1& in1) {
+    return GrGLSLExpr4::Mul(in0, in1);
 }
 
-inline GrGLSLExpr<4> GrGLSLExprCast4(const GrGLSLExpr<1>& expr) {
-    return GrGLSLExpr<4>::VectorCast(expr);
+inline GrGLSLExpr4 operator+(const GrGLSLExpr4& in0, const GrGLSLExpr1& in1) {
+    return GrGLSLExpr4::Add(in0, in1);
 }
 
-inline GrGLSLExpr<1> GrGLSLExprExtractAlpha(const GrGLSLExpr<4>& expr) {
-    if (expr.isZeros()) {
-        return GrGLSLExpr<1>(0);
-    }
-    if (expr.isOnes()) {
-        return GrGLSLExpr<1>(1);
-    }
-    return GrGLSLExpr<1>(GrGLSLExpr<4>::ExtractAlphaStr(), expr.c_str());
+inline GrGLSLExpr4 operator-(const GrGLSLExpr4& in0, const GrGLSLExpr1& in1) {
+    return GrGLSLExpr4::Sub(in0, in1);
+}
+
+inline GrGLSLExpr4 operator*(const GrGLSLExpr4& in0, const GrGLSLExpr4& in1) {
+    return GrGLSLExpr4::Mul(in0, in1);
+}
+
+inline GrGLSLExpr4 operator+(const GrGLSLExpr4& in0, const GrGLSLExpr4& in1) {
+    return GrGLSLExpr4::Add(in0, in1);
+}
+
+inline GrGLSLExpr4 operator-(const GrGLSLExpr4& in0, const GrGLSLExpr4& in1) {
+    return GrGLSLExpr4::Sub(in0, in1);
 }
 
 #endif