Implement texel buffers

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 "GrProcessor.h"
 #include "GrPipeline.h"
 #include "GrRenderTargetPriv.h"
 #include "SkChecksum.h"
 #include "gl/GrGLDefines.h"
 #include "gl/GrGLTexture.h"
 #include "gl/GrGLTypes.h"
 #include "glsl/GrGLSLFragmentProcessor.h"
 #include "glsl/GrGLSLFragmentShaderBuilder.h"
 #include "glsl/GrGLSLCaps.h"
 
-static uint16_t texture_key(GrSLType samplerType, GrPixelConfig config, GrShaderFlags visibility,
+static uint16_t sampler_key(GrSLType samplerType, GrPixelConfig config, GrShaderFlags visibility,
                             const GrGLSLCaps& caps) {
     static constexpr int kFirstSamplerType = kSampler2D_GrSLType;
-    static constexpr int kLastSamplerType = kSampler2DRect_GrSLType;
+    static constexpr int kLastSamplerType = kSamplerBuffer_GrSLType;
     static constexpr int kSamplerTypeKeyBits = 4;
     GR_STATIC_ASSERT(kLastSamplerType - kFirstSamplerType < (1 << kSamplerTypeKeyBits));
 
     SkASSERT(samplerType >= kFirstSamplerType && samplerType <= kLastSamplerType);
     int samplerTypeKey = samplerType - kFirstSamplerType;
 
     return SkToU16(caps.configTextureSwizzle(config).asKey() |
                    (samplerTypeKey << 8) |
                    (caps.samplerPrecision(config, visibility) << (8 + kSamplerTypeKeyBits)));
 }
 
-static void add_texture_key(GrProcessorKeyBuilder* b, const GrProcessor& proc,
-                            const GrGLSLCaps& caps) {
+static void add_sampler_keys(GrProcessorKeyBuilder* b, const GrProcessor& proc,
+                             const GrGLSLCaps& caps) {
     int numTextures = proc.numTextures();
+    int numSamplers = numTextures + proc.numBuffers();
     // Need two bytes per key (swizzle, sampler type, and precision).
-    int word32Count = (proc.numTextures() + 1) / 2;
+    int word32Count = (numSamplers + 1) / 2;
     if (0 == word32Count) {
         return;
     }
     uint16_t* k16 = SkTCast<uint16_t*>(b->add32n(word32Count));
-    for (int i = 0; i < numTextures; ++i) {
+    int i = 0;
+    for (; i < numTextures; ++i) {
         const GrTextureAccess& access = proc.textureAccess(i);
         const GrTexture* tex = access.getTexture();
-        k16[i] = texture_key(tex->samplerType(), tex->config(), access.getVisibility(), caps);
+        k16[i] = sampler_key(tex->samplerType(), tex->config(), access.getVisibility(), caps);
     }
-    // zero the last 16 bits if the number of textures is odd.
-    if (numTextures & 0x1) {
-        k16[numTextures] = 0;
+    for (; i < numSamplers; ++i) {
+        const GrBufferAccess& access = proc.bufferAccess(i - numTextures);
+        k16[i] = sampler_key(kSamplerBuffer_GrSLType, access.texelConfig(), access.visibility(),
+                             caps);
+    }
+    // zero the last 16 bits if the number of samplers is odd.
+    if (numSamplers & 0x1) {
+        k16[numSamplers] = 0;
     }
 }
 
 /**
  * A function which emits a meta key into the key builder.  This is required because shader code may
  * be dependent on properties of the effect that the effect itself doesn't use
  * in its key (e.g. the pixel format of textures used). So we create a meta-key for
  * every effect using this function. It is also responsible for inserting the effect's class ID
  * which must be different for every GrProcessor subclass. It can fail if an effect uses too many
  * transforms, etc, for the space allotted in the meta-key.  NOTE, both FPs and GPs share this
  * function because it is hairy, though FPs do not have attribs, and GPs do not have transforms
  */
 static bool gen_meta_key(const GrProcessor& proc,
                          const GrGLSLCaps& glslCaps,
                          uint32_t transformKey,
                          GrProcessorKeyBuilder* b) {
     size_t processorKeySize = b->size();
     uint32_t classID = proc.classID();
 
     // Currently we allow 16 bits for the class id and the overall processor key size.
     static const uint32_t kMetaKeyInvalidMask = ~((uint32_t) SK_MaxU16);
     if ((processorKeySize | classID) & kMetaKeyInvalidMask) {
         return false;
     }
 
-    add_texture_key(b, proc, glslCaps);
+    add_sampler_keys(b, proc, glslCaps);
 
     uint32_t* key = b->add32n(2);
     key[0] = (classID << 16) | SkToU32(processorKeySize);
     key[1] = transformKey;
     return true;
 }
 
 static bool gen_frag_proc_and_meta_keys(const GrPrimitiveProcessor& primProc,
                                         const GrFragmentProcessor& fp,
                                         const GrGLSLCaps& glslCaps,
@@ skipping 84 matching lines @@
     } else {
         header->fIgnoresCoverage = 0;
     }
 
     header->fSnapVerticesToPixelCenters = pipeline.snapVerticesToPixelCenters();
     header->fColorEffectCnt = pipeline.numColorFragmentProcessors();
     header->fCoverageEffectCnt = pipeline.numCoverageFragmentProcessors();
     glDesc->finalize();
     return true;
 }