First implementation of GrDawnUniformHandler.

Change-Id: I76824eca6e72505004b4dfb03fc35c2849176ecb
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/230459
Commit-Queue: Stephen White <senorblanco@chromium.org>
Reviewed-by: Greg Daniel <egdaniel@google.com>
diff --git a/src/gpu/dawn/GrDawnUniformHandler.cpp b/src/gpu/dawn/GrDawnUniformHandler.cpp
new file mode 100644
index 0000000..19ad35b
--- /dev/null
+++ b/src/gpu/dawn/GrDawnUniformHandler.cpp
@@ -0,0 +1,284 @@
+/*
+ * Copyright 2019 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "src/gpu/dawn/GrDawnUniformHandler.h"
+#include "src/gpu/glsl/GrGLSLProgramBuilder.h"
+
+GrDawnUniformHandler::GrDawnUniformHandler(GrGLSLProgramBuilder* program)
+    : INHERITED(program)
+    , fUniforms(kUniformsPerBlock)
+{
+}
+
+const GrShaderVar& GrDawnUniformHandler::getUniformVariable(UniformHandle u) const {
+    return fUniforms[u.toIndex()].fVar;
+}
+
+const char* GrDawnUniformHandler::getUniformCStr(UniformHandle u) const {
+    return fUniforms[u.toIndex()].fVar.getName().c_str();
+}
+
+// FIXME: this code was ripped from GrVkUniformHandler; should be refactored.
+namespace {
+
+uint32_t grsltype_to_alignment_mask(GrSLType type) {
+    switch(type) {
+        case kByte_GrSLType: // fall through
+        case kUByte_GrSLType:
+            return 0x0;
+        case kByte2_GrSLType: // fall through
+        case kUByte2_GrSLType:
+            return 0x1;
+        case kByte3_GrSLType: // fall through
+        case kByte4_GrSLType:
+        case kUByte3_GrSLType:
+        case kUByte4_GrSLType:
+            return 0x3;
+        case kShort_GrSLType: // fall through
+        case kUShort_GrSLType:
+            return 0x1;
+        case kShort2_GrSLType: // fall through
+        case kUShort2_GrSLType:
+            return 0x3;
+        case kShort3_GrSLType: // fall through
+        case kShort4_GrSLType:
+        case kUShort3_GrSLType:
+        case kUShort4_GrSLType:
+            return 0x7;
+        case kInt_GrSLType:
+        case kUint_GrSLType:
+            return 0x3;
+        case kHalf_GrSLType: // fall through
+        case kFloat_GrSLType:
+            return 0x3;
+        case kHalf2_GrSLType: // fall through
+        case kFloat2_GrSLType:
+            return 0x7;
+        case kHalf3_GrSLType: // fall through
+        case kFloat3_GrSLType:
+            return 0xF;
+        case kHalf4_GrSLType: // fall through
+        case kFloat4_GrSLType:
+            return 0xF;
+        case kUint2_GrSLType:
+            return 0x7;
+        case kInt2_GrSLType:
+            return 0x7;
+        case kInt3_GrSLType:
+            return 0xF;
+        case kInt4_GrSLType:
+            return 0xF;
+        case kHalf2x2_GrSLType: // fall through
+        case kFloat2x2_GrSLType:
+            return 0x7;
+        case kHalf3x3_GrSLType: // fall through
+        case kFloat3x3_GrSLType:
+            return 0xF;
+        case kHalf4x4_GrSLType: // fall through
+        case kFloat4x4_GrSLType:
+            return 0xF;
+
+        // This query is only valid for certain types.
+        case kVoid_GrSLType:
+        case kBool_GrSLType:
+        case kTexture2DSampler_GrSLType:
+        case kTextureExternalSampler_GrSLType:
+        case kTexture2DRectSampler_GrSLType:
+        case kTexture2D_GrSLType:
+        case kSampler_GrSLType:
+            break;
+    }
+    SK_ABORT("Unexpected type");
+    return 0;
+}
+
+static inline uint32_t grsltype_to_size(GrSLType type) {
+    switch(type) {
+        case kByte_GrSLType:
+        case kUByte_GrSLType:
+            return 1;
+        case kByte2_GrSLType:
+        case kUByte2_GrSLType:
+            return 2;
+        case kByte3_GrSLType:
+        case kUByte3_GrSLType:
+            return 3;
+        case kByte4_GrSLType:
+        case kUByte4_GrSLType:
+            return 4;
+        case kShort_GrSLType:
+            return sizeof(int16_t);
+        case kShort2_GrSLType:
+            return 2 * sizeof(int16_t);
+        case kShort3_GrSLType:
+            return 3 * sizeof(int16_t);
+        case kShort4_GrSLType:
+            return 4 * sizeof(int16_t);
+        case kUShort_GrSLType:
+            return sizeof(uint16_t);
+        case kUShort2_GrSLType:
+            return 2 * sizeof(uint16_t);
+        case kUShort3_GrSLType:
+            return 3 * sizeof(uint16_t);
+        case kUShort4_GrSLType:
+            return 4 * sizeof(uint16_t);
+        case kInt_GrSLType:
+            return sizeof(int32_t);
+        case kUint_GrSLType:
+            return sizeof(int32_t);
+        case kHalf_GrSLType: // fall through
+        case kFloat_GrSLType:
+            return sizeof(float);
+        case kHalf2_GrSLType: // fall through
+        case kFloat2_GrSLType:
+            return 2 * sizeof(float);
+        case kHalf3_GrSLType: // fall through
+        case kFloat3_GrSLType:
+            return 3 * sizeof(float);
+        case kHalf4_GrSLType: // fall through
+        case kFloat4_GrSLType:
+            return 4 * sizeof(float);
+        case kUint2_GrSLType:
+            return 2 * sizeof(uint32_t);
+        case kInt2_GrSLType:
+            return 2 * sizeof(int32_t);
+        case kInt3_GrSLType:
+            return 3 * sizeof(int32_t);
+        case kInt4_GrSLType:
+            return 4 * sizeof(int32_t);
+        case kHalf2x2_GrSLType: // fall through
+        case kFloat2x2_GrSLType:
+            //TODO: this will be 4 * szof(float) on std430.
+            return 8 * sizeof(float);
+        case kHalf3x3_GrSLType: // fall through
+        case kFloat3x3_GrSLType:
+            return 12 * sizeof(float);
+        case kHalf4x4_GrSLType: // fall through
+        case kFloat4x4_GrSLType:
+            return 16 * sizeof(float);
+
+        // This query is only valid for certain types.
+        case kVoid_GrSLType:
+        case kBool_GrSLType:
+        case kTexture2DSampler_GrSLType:
+        case kTextureExternalSampler_GrSLType:
+        case kTexture2DRectSampler_GrSLType:
+        case kTexture2D_GrSLType:
+        case kSampler_GrSLType:
+            break;
+    }
+    SK_ABORT("Unexpected type");
+    return 0;
+}
+
+uint32_t get_ubo_offset(uint32_t* currentOffset,
+                        GrSLType type,
+                        int arrayCount) {
+    uint32_t alignmentMask = grsltype_to_alignment_mask(type);
+    // We want to use the std140 layout here, so we must make arrays align to 16 bytes.
+    if (arrayCount || type == kFloat2x2_GrSLType) {
+        alignmentMask = 0xF;
+    }
+    uint32_t offsetDiff = *currentOffset & alignmentMask;
+    if (offsetDiff != 0) {
+        offsetDiff = alignmentMask - offsetDiff + 1;
+    }
+    uint32_t uniformOffset = *currentOffset + offsetDiff;
+    SkASSERT(sizeof(float) == 4);
+    if (arrayCount) {
+        uint32_t elementSize = SkTMax<uint32_t>(16, grsltype_to_size(type));
+        SkASSERT(0 == (elementSize & 0xF));
+        *currentOffset = uniformOffset + elementSize * arrayCount;
+    } else {
+        *currentOffset = uniformOffset + grsltype_to_size(type);
+    }
+    return uniformOffset;
+}
+
+}
+
+GrGLSLUniformHandler::UniformHandle GrDawnUniformHandler::internalAddUniformArray(
+        uint32_t visibility,
+        GrSLType type,
+        const char* name,
+        bool mangleName,
+        int arrayCount,
+        const char** outName) {
+    UniformInfo& info = fUniforms.push_back();
+    info.fVisibility = visibility;
+    if (visibility == kFragment_GrShaderFlag) {
+        info.fUBOOffset = get_ubo_offset(&fCurrentFragmentUBOOffset, type, arrayCount);
+    } else {
+        info.fUBOOffset = get_ubo_offset(&fCurrentGeometryUBOOffset, type, arrayCount);
+    }
+    GrShaderVar& var = info.fVar;
+    char prefix = 'u';
+    if ('u' == name[0] || !strncmp(name, GR_NO_MANGLE_PREFIX, strlen(GR_NO_MANGLE_PREFIX))) {
+        prefix = '\0';
+    }
+    fProgramBuilder->nameVariable(var.accessName(), prefix, name, mangleName);
+    var.setType(type);
+    var.setTypeModifier(GrShaderVar::kNone_TypeModifier);
+    var.setArrayCount(arrayCount);
+    SkString layoutQualifier;
+    layoutQualifier.appendf("offset = %d", info.fUBOOffset);
+    var.addLayoutQualifier(layoutQualifier.c_str());
+    if (outName) {
+        *outName = var.c_str();
+    }
+    return GrGLSLUniformHandler::UniformHandle(fUniforms.count() - 1);
+}
+
+GrGLSLUniformHandler::SamplerHandle GrDawnUniformHandler::addSampler(const GrTexture* texture,
+                                                                     const GrSamplerState&,
+                                                                     const GrSwizzle& swizzle,
+                                                                     const char* name,
+                                                                     const GrShaderCaps* caps) {
+    SkASSERT(!"unimplemented");
+    SkASSERT(name && strlen(name));
+
+    return GrGLSLUniformHandler::SamplerHandle(0);
+}
+
+const char* GrDawnUniformHandler::samplerVariable(
+        GrGLSLUniformHandler::SamplerHandle handle) const {
+    SkASSERT(!"unimplemented");
+    return "";
+}
+
+GrSwizzle GrDawnUniformHandler::samplerSwizzle(GrGLSLUniformHandler::SamplerHandle handle) const {
+    SkASSERT(!"unimplemented");
+    return GrSwizzle();
+}
+
+void GrDawnUniformHandler::appendUniformDecls(GrShaderFlags visibility, SkString* out) const {
+    SkString uniformsString;
+    for (int i = 0; i < fUniforms.count(); ++i) {
+        if (fUniforms[i].fVisibility & visibility) {
+            fUniforms[i].fVar.appendDecl(fProgramBuilder->shaderCaps(), &uniformsString);
+            uniformsString.append(";\n");
+        }
+    }
+    if (!uniformsString.isEmpty()) {
+        uint32_t uniformBinding;
+        const char* stage;
+        if (kVertex_GrShaderFlag == visibility) {
+            uniformBinding = kGeometryBinding;
+            stage = "vertex";
+        } else if (kGeometry_GrShaderFlag == visibility) {
+            uniformBinding = kGeometryBinding;
+            stage = "geometry";
+        } else {
+            SkASSERT(kFragment_GrShaderFlag == visibility);
+            uniformBinding = kFragBinding;
+            stage = "fragment";
+        }
+        out->appendf("layout (set = %d, binding = %d) uniform %sUniformBuffer\n{\n",
+                     kUniformBufferBindGroup, uniformBinding, stage);
+        out->appendf("%s\n};\n", uniformsString.c_str());
+    }
+}