Initial OpenGL Image support.

This change along with recently landed changes is enough to make the new unit test work and not much else. imageLoad is support but not stores or any other image functions (atomics). Barriers in the shading language or the GL API are not yet hooked up.

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=4182

Change-Id: I5958b7c89e40ae5ee05f7bbaca3b3738162fe5ce
Reviewed-on: https://skia-review.googlesource.com/4182
Reviewed-by: Greg Daniel <egdaniel@google.com>
Reviewed-by: Chris Dalton <csmartdalton@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>

1 files changed, 72 insertions, 32 deletions

diff --git a/src/gpu/GrProgramDesc.cpp b/src/gpu/GrProgramDesc.cpp
index cdbbc23534..9f3278c927 100644
--- a/src/gpu/GrProgramDesc.cpp
+++ b/src/gpu/GrProgramDesc.cpp
@@ -15,48 +15,88 @@
 #include "glsl/GrGLSLFragmentShaderBuilder.h"
 #include "glsl/GrGLSLCaps.h"
 
+enum {
+    kSamplerOrImageTypeKeyBits = 4
+};
+
+static inline uint16_t image_storage_or_sampler_uniform_type_key(GrSLType type ) {
+    int value = UINT16_MAX;
+    switch (type) {
+        case kTexture2DSampler_GrSLType:
+            value = 0;
+            break;
+        case kITexture2DSampler_GrSLType:
+            value = 1;
+            break;
+        case kTextureExternalSampler_GrSLType:
+            value = 2;
+            break;
+        case kTexture2DRectSampler_GrSLType:
+            value = 3;
+            break;
+        case kBufferSampler_GrSLType:
+            value = 4;
+            break;
+        case kImageStorage2D_GrSLType:
+            value = 5;
+            break;
+        case kIImageStorage2D_GrSLType:
+            value = 6;
+            break;
+
+        default:
+            break;
+    }
+    SkASSERT((value & ((1 << kSamplerOrImageTypeKeyBits) - 1)) == value);
+    return value;
+}
+
 static uint16_t sampler_key(GrSLType samplerType, GrPixelConfig config, GrShaderFlags visibility,
                             const GrGLSLCaps& caps) {
-    enum {
-        kFirstSamplerType = kTexture2DSampler_GrSLType,
-        kLastSamplerType = kBufferSampler_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)));
+    int samplerTypeKey = image_storage_or_sampler_uniform_type_key(samplerType);
+
+    GR_STATIC_ASSERT(1 == sizeof(caps.configTextureSwizzle(config).asKey()));
+    return SkToU16(samplerTypeKey |
+                   caps.configTextureSwizzle(config).asKey() << kSamplerOrImageTypeKeyBits |
+                   (caps.samplerPrecision(config, visibility) << (8 + kSamplerOrImageTypeKeyBits)));
 }
 
-static void add_sampler_keys(GrProcessorKeyBuilder* b, const GrProcessor& proc,
-                             const GrGLSLCaps& caps) {
+static uint16_t storage_image_key(const GrProcessor::ImageStorageAccess& imageAccess) {
+    GrSLType type = imageAccess.texture()->texturePriv().imageStorageType();
+    return image_storage_or_sampler_uniform_type_key(type) |
+           (int)imageAccess.format() << kSamplerOrImageTypeKeyBits;
+}
+
+static void add_sampler_and_image_keys(GrProcessorKeyBuilder* b, const GrProcessor& proc,
+                                       const GrGLSLCaps& caps) {
     int numTextureSamplers = proc.numTextureSamplers();
-    int numSamplers = numTextureSamplers + proc.numBuffers();
-    // Need two bytes per key (swizzle, sampler type, and precision).
-    int word32Count = (numSamplers + 1) / 2;
+    int numBuffers = proc.numBuffers();
+    int numImageStorages = proc.numImageStorages();
+    int numUniforms = numTextureSamplers + numBuffers + numImageStorages;
+    // Need two bytes per key.
+    int word32Count = (numUniforms + 1) / 2;
     if (0 == word32Count) {
         return;
     }
     uint16_t* k16 = SkTCast<uint16_t*>(b->add32n(word32Count));
-    int i = 0;
-    for (; i < numTextureSamplers; ++i) {
-        const GrProcessor::TextureSampler& textureSampler = proc.textureSampler(i);
-        const GrTexture* tex = textureSampler.texture();
-        k16[i] = sampler_key(tex->texturePriv().samplerType(), tex->config(),
-                             textureSampler.visibility(), caps);
+    int j = 0;
+    for (int i = 0; i < numTextureSamplers; ++i, ++j) {
+        const GrProcessor::TextureSampler& sampler = proc.textureSampler(i);
+        const GrTexture* tex = sampler.texture();
+        k16[j] = sampler_key(tex->texturePriv().samplerType(), tex->config(), sampler.visibility(),
+                             caps);
+    }
+    for (int i = 0; i < numBuffers; ++i, ++j) {
+        const GrProcessor::BufferAccess& access = proc.bufferAccess(i);
+        k16[j] = sampler_key(kBufferSampler_GrSLType, access.texelConfig(), access.visibility(),
+                             caps);
     }
-    for (; i < numSamplers; ++i) {
-        const GrProcessor::BufferAccess& access = proc.bufferAccess(i - numTextureSamplers);
-        k16[i] = sampler_key(kBufferSampler_GrSLType, access.texelConfig(),
-                             access.visibility(), caps);
+    for (int i = 0; i < numImageStorages; ++i, ++j) {
+        k16[j] = storage_image_key(proc.imageStorageAccess(i));
     }
-    // zero the last 16 bits if the number of samplers is odd.
-    if (numSamplers & 0x1) {
-        k16[numSamplers] = 0;
+    // zero the last 16 bits if the number of uniforms for samplers and image storages is odd.
+    if (numUniforms & 0x1) {
+        k16[numUniforms] = 0;
     }
 }
 
@@ -82,7 +122,7 @@ static bool gen_meta_key(const GrProcessor& proc,
         return false;
     }
 
-    add_sampler_keys(b, proc, glslCaps);
+    add_sampler_and_image_keys(b, proc, glslCaps);
 
     uint32_t* key = b->add32n(2);
     key[0] = (classID << 16) | SkToU32(processorKeySize);