Implement NVPR on GLES

src/gpu/gl/GrGLProgramDesc.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrGLProgramDesc.h"
 #include "GrBackendEffectFactory.h"
 #include "GrDrawEffect.h"
 #include "GrEffect.h"
 #include "GrGLShaderBuilder.h"
 #include "GrGpuGL.h"
 
 #include "SkChecksum.h"
 
 bool GrGLProgramDesc::GetEffectKeyAndUpdateStats(const GrEffectStage& stage,
                                                  const GrGLCaps& caps,
                                                  bool useExplicitLocalCoords,
                                                  GrEffectKeyBuilder* b,
                                                  uint16_t* effectKeySize,
                                                  bool* setTrueIfReadsDst,
                                                  bool* setTrueIfReadsPos,
-                                                 bool* setTrueIfHasVertexCode) {
+                                                 bool* setTrueIfRequiresVertexShader) {
     const GrBackendEffectFactory& factory = stage.getEffect()->getFactory();
     GrDrawEffect drawEffect(stage, useExplicitLocalCoords);
     if (stage.getEffect()->willReadDstColor()) {
         *setTrueIfReadsDst = true;
     }
     if (stage.getEffect()->willReadFragmentPosition()) {
         *setTrueIfReadsPos = true;
     }
-    if (stage.getEffect()->hasVertexCode()) {
-        *setTrueIfHasVertexCode = true;
+    if (stage.getEffect()->requiresVertexShader()) {
+        *setTrueIfRequiresVertexShader = true;
     }
     factory.getGLEffectKey(drawEffect, caps, b);
     size_t size = b->size();
     if (size > SK_MaxU16) {
         *effectKeySize = 0; // suppresses a warning.
         return false;
     }
     *effectKeySize = SkToU16(size);
     if (!GrGLProgramEffects::GenEffectMetaKey(drawEffect, caps, b)) {
         return false;
@@ skipping 50 matching lines @@
     // to a canonical value to avoid duplicate programs with different keys.
 
     bool requiresColorAttrib = !skipColor && drawState.hasColorVertexAttribute();
     bool requiresCoverageAttrib = !skipCoverage && drawState.hasCoverageVertexAttribute();
     // we only need the local coords if we're actually going to generate effect code
     bool requiresLocalCoordAttrib = !(skipCoverage  && skipColor) &&
                                     drawState.hasLocalCoordAttribute();
 
     bool readsDst = false;
     bool readFragPosition = false;
-    // We use vertexshader-less shader programs only when drawing paths.
-    bool hasVertexCode = !(GrGpu::kDrawPath_DrawType == drawType ||
-                           GrGpu::kDrawPaths_DrawType == drawType);
+
+    // Provide option for shader programs without vertex shader only when drawing paths.
+    bool requiresVertexShader = !GrGpu::IsPathRenderingDrawType(drawType);
+
     int numStages = 0;
     if (!skipColor) {
         numStages += drawState.numColorStages() - firstEffectiveColorStage;
     }
     if (!skipCoverage) {
         numStages += drawState.numCoverageStages() - firstEffectiveCoverageStage;
     }
     GR_STATIC_ASSERT(0 == kEffectKeyOffsetsAndLengthOffset % sizeof(uint32_t));
     // Make room for everything up to and including the array of offsets to effect keys.
     desc->fKey.reset();
     desc->fKey.push_back_n(kEffectKeyOffsetsAndLengthOffset + 2 * sizeof(uint16_t) * numStages);
 
     int offsetAndSizeIndex = 0;
-
     bool effectKeySuccess = true;
     if (!skipColor) {
         for (int s = firstEffectiveColorStage; s < drawState.numColorStages(); ++s) {
             uint16_t* offsetAndSize =
                 reinterpret_cast<uint16_t*>(desc->fKey.begin() + kEffectKeyOffsetsAndLengthOffset +
                                             offsetAndSizeIndex * 2 * sizeof(uint16_t));
 
             GrEffectKeyBuilder b(&desc->fKey);
             uint16_t effectKeySize;
             uint32_t effectOffset = desc->fKey.count();
             effectKeySuccess |= GetEffectKeyAndUpdateStats(
                                     drawState.getColorStage(s), gpu->glCaps(),
                                     requiresLocalCoordAttrib, &b,
                                     &effectKeySize, &readsDst,
-                                    &readFragPosition, &hasVertexCode);
+                                    &readFragPosition, &requiresVertexShader);
             effectKeySuccess |= (effectOffset <= SK_MaxU16);
 
             offsetAndSize[0] = SkToU16(effectOffset);
             offsetAndSize[1] = effectKeySize;
             ++offsetAndSizeIndex;
         }
     }
     if (!skipCoverage) {
         for (int s = firstEffectiveCoverageStage; s < drawState.numCoverageStages(); ++s) {
             uint16_t* offsetAndSize =
                 reinterpret_cast<uint16_t*>(desc->fKey.begin() + kEffectKeyOffsetsAndLengthOffset +
                                             offsetAndSizeIndex * 2 * sizeof(uint16_t));
 
             GrEffectKeyBuilder b(&desc->fKey);
             uint16_t effectKeySize;
             uint32_t effectOffset = desc->fKey.count();
             effectKeySuccess |= GetEffectKeyAndUpdateStats(
                                     drawState.getCoverageStage(s), gpu->glCaps(),
                                     requiresLocalCoordAttrib, &b,
                                     &effectKeySize, &readsDst,
-                                    &readFragPosition, &hasVertexCode);
+                                    &readFragPosition, &requiresVertexShader);
             effectKeySuccess |= (effectOffset <= SK_MaxU16);
 
             offsetAndSize[0] = SkToU16(effectOffset);
             offsetAndSize[1] = effectKeySize;
             ++offsetAndSizeIndex;
         }
     }
     if (!effectKeySuccess) {
         desc->fKey.reset();
         return false;
     }
 
     KeyHeader* header = desc->header();
     // make sure any padding in the header is zeroed.
     memset(desc->header(), 0, kHeaderSize);
 
     // Because header is a pointer into the dynamic array, we can't push any new data into the key
     // below here.
 
-    header->fHasVertexCode = hasVertexCode || requiresLocalCoordAttrib;
+    header->fRequiresVertexShader = requiresVertexShader || requiresLocalCoordAttrib;
     header->fEmitsPointSize = GrGpu::kDrawPoints_DrawType == drawType;
 
     // Currently the experimental GS will only work with triangle prims (and it doesn't do anything
     // other than pass through values from the VS to the FS anyway).
 #if GR_GL_EXPERIMENTAL_GS
 #if 0
     header->fExperimentalGS = gpu->caps().geometryShaderSupport();
 #else
     header->fExperimentalGS = false;
 #endif
 #endif
     bool defaultToUniformInputs = GR_GL_NO_CONSTANT_ATTRIBUTES || gpu->caps()->pathRenderingSupport();
 
     if (defaultToUniformInputs && !requiresColorAttrib && inputColorIsUsed) {
         header->fColorInput = kUniform_ColorInput;
     } else {
         header->fColorInput = kAttribute_ColorInput;
-        header->fHasVertexCode = true;
+        header->fRequiresVertexShader = true;
     }
 
     bool covIsSolidWhite = !requiresCoverageAttrib && 0xffffffff == drawState.getCoverageColor();
 
     if ((covIsSolidWhite || !inputCoverageIsUsed) && !skipCoverage) {
         header->fCoverageInput = kSolidWhite_ColorInput;
     } else if (defaultToUniformInputs && !requiresCoverageAttrib && inputCoverageIsUsed) {
         header->fCoverageInput = kUniform_ColorInput;
     } else {
         header->fCoverageInput = kAttribute_ColorInput;
-        header->fHasVertexCode = true;
+        header->fRequiresVertexShader = true;
     }
 
     if (readsDst) {
         SkASSERT(NULL != dstCopy || gpu->caps()->dstReadInShaderSupport());
         const GrTexture* dstCopyTexture = NULL;
         if (NULL != dstCopy) {
             dstCopyTexture = dstCopy->texture();
         }
         header->fDstReadKey = GrGLShaderBuilder::KeyForDstRead(dstCopyTexture, gpu->glCaps());
         SkASSERT(0 != header->fDstReadKey);
@@ skipping 98 matching lines @@
     *checksum = 0;
     *checksum = SkChecksum::Compute(reinterpret_cast<uint32_t*>(fKey.begin()), keyLength);
 }
 
 GrGLProgramDesc& GrGLProgramDesc::operator= (const GrGLProgramDesc& other) {
     size_t keyLength = other.keyLength();
     fKey.reset(keyLength);
     memcpy(fKey.begin(), other.fKey.begin(), keyLength);
     return *this;
 }