Merge GrGLSLProgramDesc into GrProgramDesc

BUG=skia:

Review-Url: https://codereview.chromium.org/2318523006
diff --git a/src/gpu/GrProgramDesc.cpp b/src/gpu/GrProgramDesc.cpp
new file mode 100644
index 0000000..a22063c
--- /dev/null
+++ b/src/gpu/GrProgramDesc.cpp
@@ -0,0 +1,184 @@
+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+#include "GrProgramDesc.h"
+
+#include "GrProcessor.h"
+#include "GrPipeline.h"
+#include "GrRenderTargetPriv.h"
+#include "SkChecksum.h"
+#include "glsl/GrGLSLFragmentProcessor.h"
+#include "glsl/GrGLSLFragmentShaderBuilder.h"
+#include "glsl/GrGLSLCaps.h"
+
+static uint16_t sampler_key(GrSLType samplerType, GrPixelConfig config, GrShaderFlags visibility,
+                            const GrGLSLCaps& caps) {
+    enum {
+        kFirstSamplerType = kTexture2DSampler_GrSLType,
+        kLastSamplerType = kTextureBufferSampler_GrSLType,
+        kSamplerTypeKeyBits = 4
+    };
+    GR_STATIC_ASSERT(kLastSamplerType - kFirstSamplerType < (1 << kSamplerTypeKeyBits));
+
+    SkASSERT((int)samplerType >= kFirstSamplerType && (int)samplerType <= kLastSamplerType);
+    int samplerTypeKey = samplerType - kFirstSamplerType;
+
+    return SkToU16(caps.configTextureSwizzle(config).asKey() |
+                   (samplerTypeKey << 8) |
+                   (caps.samplerPrecision(config, visibility) << (8 + kSamplerTypeKeyBits)));
+}
+
+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 = (numSamplers + 1) / 2;
+    if (0 == word32Count) {
+        return;
+    }
+    uint16_t* k16 = SkTCast<uint16_t*>(b->add32n(word32Count));
+    int i = 0;
+    for (; i < numTextures; ++i) {
+        const GrTextureAccess& access = proc.textureAccess(i);
+        const GrTexture* tex = access.getTexture();
+        k16[i] = sampler_key(tex->samplerType(), tex->config(), access.getVisibility(), caps);
+    }
+    for (; i < numSamplers; ++i) {
+        const GrBufferAccess& access = proc.bufferAccess(i - numTextures);
+        k16[i] = sampler_key(kTextureBufferSampler_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_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,
+                                        GrProcessorKeyBuilder* b) {
+    for (int i = 0; i < fp.numChildProcessors(); ++i) {
+        if (!gen_frag_proc_and_meta_keys(primProc, fp.childProcessor(i), glslCaps, b)) {
+            return false;
+        }
+    }
+
+    fp.getGLSLProcessorKey(glslCaps, b);
+
+    return gen_meta_key(fp, glslCaps, primProc.getTransformKey(fp.coordTransforms(),
+                                                               fp.numTransformsExclChildren()), b);
+}
+
+bool GrProgramDesc::Build(GrProgramDesc* desc,
+                          const GrPrimitiveProcessor& primProc,
+                          const GrPipeline& pipeline,
+                          const GrGLSLCaps& glslCaps) {
+    // The descriptor is used as a cache key. Thus when a field of the
+    // descriptor will not affect program generation (because of the attribute
+    // bindings in use or other descriptor field settings) it should be set
+    // to a canonical value to avoid duplicate programs with different keys.
+
+    GR_STATIC_ASSERT(0 == kProcessorKeysOffset % sizeof(uint32_t));
+    // Make room for everything up to the effect keys.
+    desc->key().reset();
+    desc->key().push_back_n(kProcessorKeysOffset);
+
+    GrProcessorKeyBuilder b(&desc->key());
+
+    primProc.getGLSLProcessorKey(glslCaps, &b);
+    if (!gen_meta_key(primProc, glslCaps, 0, &b)) {
+        desc->key().reset();
+        return false;
+    }
+    GrProcessor::RequiredFeatures requiredFeatures = primProc.requiredFeatures();
+
+    for (int i = 0; i < pipeline.numFragmentProcessors(); ++i) {
+        const GrFragmentProcessor& fp = pipeline.getFragmentProcessor(i);
+        if (!gen_frag_proc_and_meta_keys(primProc, fp, glslCaps, &b)) {
+            desc->key().reset();
+            return false;
+        }
+        requiredFeatures |= fp.requiredFeatures();
+    }
+
+    const GrXferProcessor& xp = pipeline.getXferProcessor();
+    xp.getGLSLProcessorKey(glslCaps, &b);
+    if (!gen_meta_key(xp, glslCaps, 0, &b)) {
+        desc->key().reset();
+        return false;
+    }
+    requiredFeatures |= xp.requiredFeatures();
+
+    // --------DO NOT MOVE HEADER ABOVE THIS LINE--------------------------------------------------
+    // Because header is a pointer into the dynamic array, we can't push any new data into the key
+    // below here.
+    KeyHeader* header = desc->atOffset<KeyHeader, kHeaderOffset>();
+
+    // make sure any padding in the header is zeroed.
+    memset(header, 0, kHeaderSize);
+
+    GrRenderTarget* rt = pipeline.getRenderTarget();
+
+    if (requiredFeatures & (GrProcessor::kFragmentPosition_RequiredFeature |
+                            GrProcessor::kSampleLocations_RequiredFeature)) {
+        header->fSurfaceOriginKey = GrGLSLFragmentShaderBuilder::KeyForSurfaceOrigin(rt->origin());
+    } else {
+        header->fSurfaceOriginKey = 0;
+    }
+
+    if (requiredFeatures & GrProcessor::kSampleLocations_RequiredFeature) {
+        SkASSERT(pipeline.isHWAntialiasState());
+        header->fSamplePatternKey =
+            rt->renderTargetPriv().getMultisampleSpecs(pipeline.getStencil()).fUniqueID;
+    } else {
+        header->fSamplePatternKey = 0;
+    }
+
+    header->fOutputSwizzle = glslCaps.configOutputSwizzle(rt->config()).asKey();
+
+    if (pipeline.ignoresCoverage()) {
+        header->fIgnoresCoverage = 1;
+    } else {
+        header->fIgnoresCoverage = 0;
+    }
+
+    header->fSnapVerticesToPixelCenters = pipeline.snapVerticesToPixelCenters();
+    header->fColorEffectCnt = pipeline.numColorFragmentProcessors();
+    header->fCoverageEffectCnt = pipeline.numCoverageFragmentProcessors();
+    return true;
+}