Initial refactor of shaderbuilder

src/gpu/gl/builders/GrGLShaderBuilder.cpp

+/*
+ * Copyright 2014 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "GrGLShaderBuilder.h"
+#include "GrGLProgramBuilder.h"
+#include "../GrGpuGL.h"
+#include "../GrGLShaderVar.h"
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+// local ///////////////////////////////////////////////////////////////////////////////////////////
+namespace {
+inline const char* sample_function_name(GrSLType type, GrGLSLGeneration glslGen) {
+    if (kVec2f_GrSLType == type) {
+        return glslGen >= k130_GrGLSLGeneration ? "texture" : "texture2D";
+    } else {
+        SkASSERT(kVec3f_GrSLType == type);
+        return glslGen >= k130_GrGLSLGeneration ? "textureProj" : "texture2DProj";
+    }
+}
+void append_texture_lookup(SkString* out,
+                           GrGpuGL* gpu,
+                           const char* samplerName,
+                           const char* coordName,
+                           uint32_t configComponentMask,
+                           const char* swizzle,
+                           GrSLType varyingType = kVec2f_GrSLType) {
+    SkASSERT(NULL != coordName);
+
+    out->appendf("%s(%s, %s)",
+                 sample_function_name(varyingType, gpu->glslGeneration()),
+                 samplerName,
+                 coordName);
+
+    char mangledSwizzle[5];
+
+    // The swizzling occurs using texture params instead of shader-mangling if ARB_texture_swizzle
+    // is available.
+    if (!gpu->glCaps().textureSwizzleSupport() &&
+        (kA_GrColorComponentFlag == configComponentMask)) {
+        char alphaChar = gpu->glCaps().textureRedSupport() ? 'r' : 'a';
+        int i;
+        for (i = 0; '\0' != swizzle[i]; ++i) {
+            mangledSwizzle[i] = alphaChar;
+        }
+        mangledSwizzle[i] ='\0';
+        swizzle = mangledSwizzle;
+    }
+    // For shader prettiness we omit the swizzle rather than appending ".rgba".
+    if (memcmp(swizzle, "rgba", 4)) {
+        out->appendf(".%s", swizzle);
+    }
+}
+static const int kVarsPerBlock = 8;
+}
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+// GrGLShaderBuilder public ////////////////////////////////////////////////////////////////////////
+GrGLShaderBuilder::GrGLShaderBuilder(GrGLProgramBuilder* program)
+    : fProgram(program)
+    , fInputs(kVarsPerBlock)
+    , fOutputs(kVarsPerBlock)
+    , fFeaturesAddedMask(0) {
+}
+
+void GrGLShaderBuilder::emitFunction(GrSLType returnType,
+                                     const char* name,
+                                     int argCnt,
+                                     const GrGLShaderVar* args,
+                                     const char* body,
+                                     SkString* outName) {
+    fFunctions.append(GrGLSLTypeString(returnType));
+    fProgram->nameVariable(outName, '\0', name);
+    fFunctions.appendf(" %s", outName->c_str());
+    fFunctions.append("(");
+    const GrGLContextInfo& ctxInfo = fProgram->gpu()->ctxInfo();
+    for (int i = 0; i < argCnt; ++i) {
+        args[i].appendDecl(ctxInfo, &fFunctions);
+        if (i < argCnt - 1) {
+            fFunctions.append(", ");
+        }
+    }
+    fFunctions.append(") {\n");
+    fFunctions.append(body);
+    fFunctions.append("}\n\n");
+}
+
+void GrGLShaderBuilder::appendTextureLookup(SkString* out,
+                                            const TextureSampler& sampler,
+                                            const char* coordName,
+                                            GrSLType varyingType) const {
+    append_texture_lookup(out,
+                          fProgram->gpu(),
+                          fProgram->getUniformCStr(sampler.samplerUniform()),
+                          coordName,
+                          sampler.configComponentMask(),
+                          sampler.swizzle(),
+                          varyingType);
+}
+
+void GrGLShaderBuilder::appendTextureLookup(const TextureSampler& sampler,
+                                            const char* coordName,
+                                            GrSLType varyingType) {
+    this->appendTextureLookup(&fCode, sampler, coordName, varyingType);
+}
+
+void GrGLShaderBuilder::appendTextureLookupAndModulate(const char* modulation,
+                                                       const TextureSampler& sampler,
+                                                       const char* coordName,
+                                                       GrSLType varyingType) {
+    SkString lookup;
+    this->appendTextureLookup(&lookup, sampler, coordName, varyingType);
+    this->codeAppend((GrGLSLExpr4(modulation) * GrGLSLExpr4(lookup)).c_str());
+}
+
+
+const GrGLenum* GrGLShaderBuilder::GetTexParamSwizzle(GrPixelConfig config, const GrGLCaps& caps) {
+    if (caps.textureSwizzleSupport() && GrPixelConfigIsAlphaOnly(config)) {
+        if (caps.textureRedSupport()) {
+            static const GrGLenum gRedSmear[] = { GR_GL_RED, GR_GL_RED, GR_GL_RED, GR_GL_RED };
+            return gRedSmear;
+        } else {
+            static const GrGLenum gAlphaSmear[] = { GR_GL_ALPHA, GR_GL_ALPHA,
+                                                    GR_GL_ALPHA, GR_GL_ALPHA };
+            return gAlphaSmear;
+        }
+    } else {
+        static const GrGLenum gStraight[] = { GR_GL_RED, GR_GL_GREEN, GR_GL_BLUE, GR_GL_ALPHA };
+        return gStraight;
+    }
+}
+
+// GrGLShaderBuilder private //////////////////////////////////////////////////////////////////////
+void GrGLShaderBuilder::addFeature(uint32_t featureBit, const char* extensionName) {
+    if (!(featureBit & fFeaturesAddedMask)) {
+        fExtensions.appendf("#extension %s: require\n", extensionName);
+            fFeaturesAddedMask |= featureBit;
+    }
+}
+
+void GrGLShaderBuilder::appendTextureLookup(const char* samplerName,
+                                            const char* coordName,
+                                            uint32_t configComponentMask,
+                                            const char* swizzle) {
+    append_texture_lookup(&fCode,
+                          fProgram->gpu(),
+                          samplerName,
+                          coordName,
+                          configComponentMask,
+                          swizzle,
+                          kVec2f_GrSLType);
+}
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+// GrGLFullShaderBuilder public ////////////////////////////////////////////////////////////////////
+GrGLFullShaderBuilder::GrGLFullShaderBuilder(GrGLFullProgramBuilder* program)
+    : INHERITED(program)
+    , fFullProgram(program) {}