| /* | |
| * Copyright 2024 Google LLC | |
| * | |
| * Use of this source code is governed by a BSD-style license that can be | |
| * found in the LICENSE file. | |
| */ | |
| #include "src/gpu/graphite/ShaderInfo.h" | |
| #include "src/gpu/BlendFormula.h" | |
| #include "src/gpu/graphite/ContextUtils.h" | |
| #include "src/gpu/graphite/PaintParamsKey.h" | |
| #include "src/gpu/graphite/Renderer.h" | |
| #include "src/gpu/graphite/ShaderCodeDictionary.h" | |
| #include "src/gpu/graphite/TextureFormat.h" | |
| #include "src/gpu/graphite/UniformManager.h" | |
| #include "src/sksl/SkSLString.h" | |
| #include "src/sksl/SkSLUtil.h" | |
| using namespace skia_private; | |
| namespace skgpu::graphite { | |
| namespace { | |
| struct LiftedExpression { | |
| // The node who's expression should be lifted. | |
| const ShaderNode* fNode; | |
| // The arguments to use as input to the lifted expression. | |
| ShaderSnippet::Args fArgs; | |
| // If true, capture the expression's resolved value in a varying. | |
| // This is false for expressions whose output is only used in other lifted expressions. | |
| bool fEmitVarying = true; | |
| }; | |
| std::string get_uniform_header(int set, int bufferID, const char* name) { | |
| std::string result; | |
| SkSL::String::appendf( | |
| &result, "layout (set=%d, binding=%d) uniform %sUniforms {\n", set, bufferID, name); | |
| return result; | |
| } | |
| std::string get_uniforms(UniformOffsetCalculator* offsetter, | |
| SkSpan<const Uniform> uniforms, | |
| int manglingSuffix, | |
| bool* wrotePaintColor) { | |
| std::string result; | |
| std::string uniformName; | |
| for (const Uniform& u : uniforms) { | |
| uniformName = u.name(); | |
| if (u.isPaintColor() && wrotePaintColor) { | |
| if (*wrotePaintColor) { | |
| SkSL::String::appendf(&result, " // deduplicated %s\n", u.name()); | |
| continue; | |
| } | |
| *wrotePaintColor = true; | |
| } else { | |
| if (manglingSuffix >= 0) { | |
| uniformName.append("_"); | |
| uniformName.append(std::to_string(manglingSuffix)); | |
| } | |
| } | |
| SkSL::String::appendf(&result, | |
| " layout(offset=%d) %s %s", | |
| offsetter->advanceOffset(u.type(), u.count()), | |
| SkSLTypeString(u.type()), | |
| uniformName.c_str()); | |
| if (u.count()) { | |
| result.append("["); | |
| result.append(std::to_string(u.count())); | |
| result.append("]"); | |
| } | |
| result.append(";\n"); | |
| } | |
| return result; | |
| } | |
| std::string get_node_uniforms(UniformOffsetCalculator* offsetter, | |
| const ShaderNode* node, | |
| int* numUniforms, | |
| int* numUnliftedUniforms, | |
| bool* wrotePaintColor) { | |
| std::string result; | |
| SkSpan<const Uniform> uniforms = node->entry()->fUniforms; | |
| if (!uniforms.empty()) { | |
| *numUniforms += uniforms.size(); | |
| if (!((node->requiredFlags() & SnippetRequirementFlags::kLiftExpression) || | |
| (node->requiredFlags() & SnippetRequirementFlags::kOmitExpression))) { | |
| *numUnliftedUniforms += uniforms.size(); | |
| } | |
| if (node->entry()->fUniformStructName) { | |
| auto substruct = UniformOffsetCalculator::ForStruct(offsetter->layout()); | |
| for (const Uniform& u : uniforms) { | |
| substruct.advanceOffset(u.type(), u.count()); | |
| } | |
| const int structOffset = offsetter->advanceStruct(substruct); | |
| SkSL::String::appendf(&result, | |
| "layout(offset=%d) %s node_%d;", | |
| structOffset, | |
| node->entry()->fUniformStructName, | |
| node->keyIndex()); | |
| } else { | |
| #if defined(SK_DEBUG) | |
| SkSL::String::appendf(&result, "// %d - %s uniforms\n", | |
| node->keyIndex(), node->entry()->fName); | |
| #endif | |
| result += get_uniforms(offsetter, uniforms, node->keyIndex(), wrotePaintColor); | |
| } | |
| } | |
| for (const ShaderNode* child : node->children()) { | |
| result += get_node_uniforms( | |
| offsetter, child, numUniforms, numUnliftedUniforms, wrotePaintColor); | |
| } | |
| return result; | |
| } | |
| std::string get_ssbo_fields(SkSpan<const Uniform> uniforms, | |
| int manglingSuffix, | |
| bool* wrotePaintColor) { | |
| std::string result; | |
| std::string uniformName; | |
| for (const Uniform& u : uniforms) { | |
| uniformName = u.name(); | |
| if (u.isPaintColor() && wrotePaintColor) { | |
| if (*wrotePaintColor) { | |
| #if defined(SK_DEBUG) | |
| SkSL::String::appendf(&result, " // deduplicated %s\n", u.name()); | |
| #endif | |
| continue; | |
| } | |
| *wrotePaintColor = true; | |
| } else { | |
| if (manglingSuffix >= 0) { | |
| uniformName.append("_"); | |
| uniformName.append(std::to_string(manglingSuffix)); | |
| } | |
| } | |
| SkSL::String::appendf(&result, " %s %s", SkSLTypeString(u.type()), uniformName.c_str()); | |
| if (u.count()) { | |
| SkSL::String::appendf(&result, "[%d]", u.count()); | |
| } | |
| result.append(";\n"); | |
| } | |
| return result; | |
| } | |
| std::string get_node_ssbo_fields(const ShaderNode* node, | |
| int* numUniforms, | |
| int* numUnliftedUniforms, | |
| bool* wrotePaintColor) { | |
| std::string result; | |
| SkSpan<const Uniform> uniforms = node->entry()->fUniforms; | |
| if (!uniforms.empty()) { | |
| *numUniforms += uniforms.size(); | |
| if (!((node->requiredFlags() & SnippetRequirementFlags::kLiftExpression) || | |
| (node->requiredFlags() & SnippetRequirementFlags::kOmitExpression))) { | |
| *numUnliftedUniforms += uniforms.size(); | |
| } | |
| if (node->entry()->fUniformStructName) { | |
| SkSL::String::appendf(&result, "%s node_%d;", | |
| node->entry()->fUniformStructName, node->keyIndex()); | |
| } else { | |
| #if defined(SK_DEBUG) | |
| SkSL::String::appendf(&result, "// %d - %s uniforms\n", | |
| node->keyIndex(), node->entry()->fName); | |
| #endif | |
| result += get_ssbo_fields(uniforms, node->keyIndex(), wrotePaintColor); | |
| } | |
| } | |
| for (const ShaderNode* child : node->children()) { | |
| result += get_node_ssbo_fields(child, numUniforms, numUnliftedUniforms, wrotePaintColor); | |
| } | |
| return result; | |
| } | |
| std::string emit_intrinsic_constants(const ResourceBindingRequirements& bindingReqs) { | |
| std::string result; | |
| auto offsetter = UniformOffsetCalculator::ForTopLevel(bindingReqs.fUniformBufferLayout); | |
| if (bindingReqs.fUsePushConstantsForIntrinsicConstants) { | |
| SkASSERT(bindingReqs.fBackendApi == BackendApi::kVulkan || | |
| bindingReqs.fBackendApi == BackendApi::kDawn); | |
| result = SkSL::String::printf( | |
| "layout (%s, push_constant) uniform IntrinsicUniforms {\n", | |
| bindingReqs.fBackendApi == BackendApi::kVulkan ? "vulkan" : "webgpu"); | |
| } else { | |
| result = get_uniform_header(bindingReqs.fUniformsSetIdx, | |
| bindingReqs.fIntrinsicBufferBinding, | |
| "Intrinsic"); | |
| } | |
| result += get_uniforms(&offsetter, kIntrinsicUniforms, -1, /* wrotePaintColor= */ nullptr); | |
| result.append("};\n\n"); | |
| SkASSERTF(bindingReqs.fUsePushConstantsForIntrinsicConstants || | |
| result.find('[') == std::string::npos, | |
| "Arrays are not supported in intrinsic uniforms"); | |
| return result; | |
| } | |
| std::string emit_paint_params_uniforms(int set, | |
| int bufferID, | |
| const Layout layout, | |
| SkSpan<const ShaderNode*> nodes, | |
| int* numUniforms, | |
| int* numUnliftedUniforms, | |
| bool* wrotePaintColor) { | |
| auto offsetter = UniformOffsetCalculator::ForTopLevel(layout); | |
| std::string result = get_uniform_header(set, bufferID, "FS"); | |
| for (const ShaderNode* n : nodes) { | |
| result += | |
| get_node_uniforms(&offsetter, n, numUniforms, numUnliftedUniforms, wrotePaintColor); | |
| } | |
| result.append("};\n\n"); | |
| if (*numUniforms == 0) { | |
| // No uniforms were added | |
| return {}; | |
| } | |
| return result; | |
| } | |
| std::string emit_render_step_uniforms(int set, | |
| int bufferID, | |
| const Layout layout, | |
| SkSpan<const Uniform> uniforms) { | |
| auto offsetter = UniformOffsetCalculator::ForTopLevel(layout); | |
| std::string result = get_uniform_header(set, bufferID, "Step"); | |
| result += get_uniforms(&offsetter, uniforms, -1, /* wrotePaintColor= */ nullptr); | |
| result.append("};\n\n"); | |
| return result; | |
| } | |
| std::string emit_paint_params_storage_buffer(int set, | |
| int bufferID, | |
| SkSpan<const ShaderNode*> nodes, | |
| int* numUniforms, | |
| int* numUnliftedUniforms, | |
| bool* wrotePaintColor) { | |
| std::string fields; | |
| for (const ShaderNode* n : nodes) { | |
| fields += get_node_ssbo_fields(n, numUniforms, numUnliftedUniforms, wrotePaintColor); | |
| } | |
| if (*numUniforms == 0) { | |
| // No uniforms were added | |
| return {}; | |
| } | |
| return SkSL::String::printf( | |
| "struct FSUniformData {\n" | |
| "%s\n" | |
| "};\n\n" | |
| "layout (set=%d, binding=%d) readonly buffer FSUniforms {\n" | |
| "FSUniformData fsUniformData[];\n" | |
| "};\n", | |
| fields.c_str(), | |
| set, | |
| bufferID); | |
| } | |
| std::string emit_render_step_storage_buffer(int set, int bufferID, SkSpan<const Uniform> uniforms) { | |
| SkASSERT(!uniforms.empty()); | |
| std::string fields = get_ssbo_fields(uniforms, -1, /*wrotePaintColor=*/nullptr); | |
| return SkSL::String::printf( | |
| "struct StepUniformData {\n" | |
| "%s\n" | |
| "};\n\n" | |
| "layout (set=%d, binding=%d) readonly buffer StepUniforms {\n" | |
| " StepUniformData stepUniformData[];\n" | |
| "};\n", | |
| fields.c_str(), | |
| set, | |
| bufferID); | |
| } | |
| std::string emit_uniforms_from_storage_buffer(const char* bufferNamePrefix, | |
| const char* shadingSsboIndex, | |
| SkSpan<const Uniform> uniforms) { | |
| std::string result; | |
| for (const Uniform& u : uniforms) { | |
| SkSL::String::appendf(&result, "%s %s", SkSLTypeString(u.type()), u.name()); | |
| if (u.count()) { | |
| SkSL::String::appendf(&result, "[%d]", u.count()); | |
| } | |
| SkSL::String::appendf(&result, | |
| " = %sUniformData[%s].%s;\n", | |
| bufferNamePrefix, | |
| shadingSsboIndex, | |
| u.name()); | |
| } | |
| return result; | |
| } | |
| void append_sampler_descs(const SkSpan<const uint32_t> samplerData, | |
| skia_private::TArray<SamplerDesc>& outDescs) { | |
| // Sampler data consists of variable-length SamplerDesc representations which can differ based | |
| // upon a sampler's immutability and format. For this reason, handle incrementing i in the loop. | |
| for (size_t i = 0; i < samplerData.size();) { | |
| // Create a default-initialized SamplerDesc (which only takes up one uint32). If we are | |
| // using a dynamic sampler, this will be directly inserted into outDescs. Otherwise, it will | |
| // be populated with actual immutable sampler data and then inserted. | |
| SamplerDesc desc{}; | |
| size_t samplerDescLength = 1; | |
| SkASSERT(desc.asSpan().size() == samplerDescLength); | |
| // Isolate the ImmutableSamplerInfo portion of the SamplerDesc represented by samplerData. | |
| // If immutableSamplerInfo is non-zero, that means we are using an immutable sampler. | |
| uint32_t immutableSamplerInfo = samplerData[i] >> SamplerDesc::kImmutableSamplerInfoShift; | |
| if (immutableSamplerInfo != 0) { | |
| // Consult the first bit of immutableSamplerInfo which tells us whether the sampler uses | |
| // a known or external format. With this, update sampler description length. | |
| bool usesExternalFormat = immutableSamplerInfo & 0b1; | |
| samplerDescLength = usesExternalFormat ? SamplerDesc::kInt32sNeededExternalFormat | |
| : SamplerDesc::kInt32sNeededKnownFormat; | |
| // Populate a SamplerDesc with samplerDescLength quantity of immutable sampler data | |
| memcpy(&desc, samplerData.begin() + i, samplerDescLength * sizeof(uint32_t)); | |
| } | |
| outDescs.push_back(desc); | |
| i += samplerDescLength; | |
| } | |
| } | |
| std::string get_node_texture_samplers(const ResourceBindingRequirements& bindingReqs, | |
| const ShaderNode* node, | |
| int* binding, | |
| skia_private::TArray<SamplerDesc>* outDescs) { | |
| std::string result; | |
| SkSpan<const TextureAndSampler> samplers = node->entry()->fTexturesAndSamplers; | |
| if (!samplers.empty()) { | |
| #if defined(SK_DEBUG) | |
| SkSL::String::appendf(&result, "// %d - %s samplers\n", | |
| node->keyIndex(), node->entry()->fName); | |
| #endif | |
| // Determine whether we need to analyze & interpret a ShaderNode's data as immutable | |
| // SamplerDescs based upon whether: | |
| // 1) A backend passes in a non-nullptr outImmutableSamplers param (may be nullptr in | |
| // backends or circumstances where we know immutable sampler data is never stored) | |
| // 2) Any data is stored on the ShaderNode | |
| // 3) Whether the ShaderNode snippet's ID matches that of any snippet ID that could store | |
| // immutable sampler data. | |
| int32_t snippetId = node->codeSnippetId(); | |
| if (outDescs) { | |
| // TODO(b/369846881): Refactor checking snippet ID to instead having a named | |
| // snippet requirement flag that we can check here to decrease fragility. | |
| if (!node->data().empty() && | |
| (snippetId == static_cast<int32_t>(BuiltInCodeSnippetID::kImageShader) || | |
| snippetId == static_cast<int32_t>(BuiltInCodeSnippetID::kImageShaderClamp) || | |
| snippetId == static_cast<int32_t>(BuiltInCodeSnippetID::kCubicImageShader) || | |
| snippetId == static_cast<int32_t>(BuiltInCodeSnippetID::kHWImageShader))) { | |
| append_sampler_descs(node->data(), *outDescs); | |
| } else { | |
| // Add default SamplerDescs for any dynamic samplers to outDescs. | |
| outDescs->push_back_n(samplers.size()); | |
| } | |
| } | |
| for (const TextureAndSampler& t : samplers) { | |
| result += EmitSamplerLayout(bindingReqs, binding); | |
| SkSL::String::appendf(&result, " sampler2D %s_%d;\n", t.name(), node->keyIndex()); | |
| } | |
| } | |
| for (const ShaderNode* child : node->children()) { | |
| result += get_node_texture_samplers(bindingReqs, child, binding, outDescs); | |
| } | |
| return result; | |
| } | |
| std::string emit_textures_and_samplers(const ResourceBindingRequirements& bindingReqs, | |
| SkSpan<const ShaderNode*> nodes, | |
| int* binding, | |
| skia_private::TArray<SamplerDesc>* outDescs) { | |
| std::string result; | |
| for (const ShaderNode* n : nodes) { | |
| result += get_node_texture_samplers(bindingReqs, n, binding, outDescs); | |
| } | |
| return result; | |
| } | |
| SkSLType sksl_type_for_lifted_expression( | |
| ShaderSnippet::LiftableExpressionType liftedExpressionType) { | |
| switch (liftedExpressionType) { | |
| case ShaderSnippet::LiftableExpressionType::kNone: | |
| return SkSLType::kVoid; | |
| case ShaderSnippet::LiftableExpressionType::kLocalCoords: | |
| return SkSLType::kFloat2; | |
| case ShaderSnippet::LiftableExpressionType::kPriorStageOutput: | |
| return SkSLType::kHalf4; | |
| } | |
| return SkSLType::kVoid; | |
| } | |
| std::string emit_varyings(const RenderStep* step, | |
| const char* direction, | |
| SkSpan<const LiftedExpression> liftedExpressions, | |
| bool emitSsboIndicesVarying, | |
| bool emitLocalCoordsVarying) { | |
| std::string result; | |
| int location = 0; | |
| auto appendVarying = [&](const Varying& v) { | |
| const char* interpolation; | |
| switch (v.interpolation()) { | |
| case Interpolation::kPerspective: interpolation = ""; break; | |
| case Interpolation::kLinear: interpolation = "noperspective "; break; | |
| case Interpolation::kFlat: interpolation = "flat "; break; | |
| } | |
| SkSL::String::appendf(&result, "layout(location=%d) %s %s%s %s;\n", | |
| location++, | |
| direction, | |
| interpolation, | |
| SkSLTypeString(v.gpuType()), | |
| v.name()); | |
| }; | |
| if (emitSsboIndicesVarying) { | |
| appendVarying({RenderStep::ssboIndicesVarying(), SkSLType::kUInt2}); | |
| } | |
| if (emitLocalCoordsVarying) { | |
| appendVarying({"localCoordsVar", SkSLType::kFloat2}); | |
| } | |
| for (const LiftedExpression& expr : liftedExpressions) { | |
| if (expr.fEmitVarying) { | |
| const ShaderNode* node = expr.fNode; | |
| const std::string name = node->getExpressionVaryingName(); | |
| appendVarying({name.c_str(), | |
| sksl_type_for_lifted_expression(node->entry()->fLiftableExpressionType), | |
| node->entry()->fLiftableExpressionInterpolation}); | |
| } | |
| } | |
| for (auto v : step->varyings()) { | |
| appendVarying(v); | |
| } | |
| return result; | |
| } | |
| // Walk the node tree and generate all preambles, accumulating into 'preamble'. | |
| void emit_preambles(const ShaderInfo& shaderInfo, | |
| SkSpan<const ShaderNode*> nodes, | |
| std::string treeLabel, | |
| std::string* preamble) { | |
| for (int i = 0; i < SkTo<int>(nodes.size()); ++i) { | |
| const ShaderNode* node = nodes[i]; | |
| std::string nodeLabel = std::to_string(i); | |
| std::string nextLabel = treeLabel.empty() ? nodeLabel : (treeLabel + "<-" + nodeLabel); | |
| if (node->numChildren() > 0) { | |
| emit_preambles(shaderInfo, node->children(), nextLabel, preamble); | |
| } | |
| std::string nodePreamble = node->entry()->fPreambleGenerator | |
| ? node->entry()->fPreambleGenerator(shaderInfo, node) | |
| : node->generateDefaultPreamble(shaderInfo); | |
| if (!nodePreamble.empty()) { | |
| SkSL::String::appendf(preamble, | |
| "// [%d] %s: %s\n" | |
| "%s\n", | |
| node->keyIndex(), | |
| nextLabel.c_str(), | |
| node->entry()->fName, | |
| nodePreamble.c_str()); | |
| } | |
| } | |
| } | |
| std::string emit_color_output(BlendFormula::OutputType outputType, | |
| const char* outColor, | |
| const char* inColor) { | |
| switch (outputType) { | |
| case BlendFormula::kNone_OutputType: | |
| return SkSL::String::printf("%s = half4(0.0);", outColor); | |
| case BlendFormula::kCoverage_OutputType: | |
| return SkSL::String::printf("%s = outputCoverage;", outColor); | |
| case BlendFormula::kModulate_OutputType: | |
| return SkSL::String::printf("%s = %s * outputCoverage;", outColor, inColor); | |
| case BlendFormula::kSAModulate_OutputType: | |
| return SkSL::String::printf("%s = %s.a * outputCoverage;", outColor, inColor); | |
| case BlendFormula::kISAModulate_OutputType: | |
| return SkSL::String::printf("%s = (1.0 - %s.a) * outputCoverage;", outColor, inColor); | |
| case BlendFormula::kISCModulate_OutputType: | |
| return SkSL::String::printf( | |
| "%s = (half4(1.0) - %s) * outputCoverage;", outColor, inColor); | |
| default: | |
| SkUNREACHABLE; | |
| } | |
| } | |
| std::string emit_advanced_blend_color_output(const char* outColor, const char* inColor) { | |
| /* | |
| When using hardware for advanced blend modes, we apply coverage for advanced blend modes by | |
| multiplying it into the src color before blending. This will "just work" given the following: | |
| The general SVG blend equation is defined in the spec as follows: | |
| Dca' = B(Sc, Dc) * Sa * Da + Y * Sca * (1-Da) + Z * Dca * (1-Sa) | |
| Da' = X * Sa * Da + Y * Sa * (1-Da) + Z * Da * (1-Sa) | |
| (Note that Sca, Dca indicate RGB vectors that are premultiplied by alpha, | |
| and that B(Sc, Dc) is a mode-specific function that accepts non-multiplied | |
| RGB colors.) | |
| For every blend mode supported by this class, i.e. the "advanced" blend | |
| modes, X=Y=Z=1 and this equation reduces to the PDF blend equation. | |
| It can be shown that when X=Y=Z=1, these equations can modulate alpha for | |
| coverage. | |
| == Color == | |
| We substitute Y=Z=1 and define a blend() function that calculates Dca' in | |
| terms of premultiplied alpha only: | |
| blend(Sca, Dca, Sa, Da) = { | |
| Dca : if Sa == 0, | |
| Sca : if Da == 0, | |
| B(Sca/Sa, Dca/Da) * Sa * Da + Sca * (1-Da) + Dca * (1-Sa) : if Sa,Da != 0} | |
| And for coverage modulation, we use a post blend src-over model: | |
| Dca'' = f * blend(Sca, Dca, Sa, Da) + (1-f) * Dca | |
| (Where f is the fractional coverage.) | |
| Next we show that we can multiply coverage into the src color by proving the | |
| following relationship: | |
| blend(f*Sca, Dca, f*Sa, Da) == f * blend(Sca, Dca, Sa, Da) + (1-f) * Dca | |
| General case (f,Sa,Da != 0): | |
| f * blend(Sca, Dca, Sa, Da) + (1-f) * Dca | |
| = f * (B(Sca/Sa, Dca/Da) * Sa * Da + Sca * (1-Da) + Dca * (1-Sa)) + (1-f) * Dca | |
| [Sa,Da != 0, definition of blend()] | |
| = B(Sca/Sa, Dca/Da) * f*Sa * Da + f*Sca * (1-Da) + f*Dca * (1-Sa) + Dca - f*Dca | |
| = B(Sca/Sa, Dca/Da) * f*Sa * Da + f*Sca - f*Sca * Da + f*Dca - f*Dca * Sa + Dca - f*Dca | |
| = B(Sca/Sa, Dca/Da) * f*Sa * Da + f*Sca - f*Sca * Da - f*Dca * Sa + Dca | |
| = B(Sca/Sa, Dca/Da) * f*Sa * Da + f*Sca * (1-Da) - f*Dca * Sa + Dca | |
| = B(Sca/Sa, Dca/Da) * f*Sa * Da + f*Sca * (1-Da) + Dca * (1 - f*Sa) | |
| = B(f*Sca/f*Sa, Dca/Da) * f*Sa * Da + f*Sca * (1-Da) + Dca * (1 - f*Sa) [f!=0] | |
| = blend(f*Sca, Dca, f*Sa, Da) [definition of blend()] | |
| Corner cases (Sa=0, Da=0, and f=0): | |
| Sa=0: f * blend(Sca, Dca, Sa, Da) + (1-f) * Dca | |
| = f * Dca + (1-f) * Dca [Sa=0, definition of blend()] | |
| = Dca | |
| = blend(0, Dca, 0, Da) [definition of blend()] | |
| = blend(f*Sca, Dca, f*Sa, Da) [Sa=0] | |
| Da=0: f * blend(Sca, Dca, Sa, Da) + (1-f) * Dca | |
| = f * Sca + (1-f) * Dca [Da=0, definition of blend()] | |
| = f * Sca [Da=0] | |
| = blend(f*Sca, 0, f*Sa, 0) [definition of blend()] | |
| = blend(f*Sca, Dca, f*Sa, Da) [Da=0] | |
| f=0: f * blend(Sca, Dca, Sa, Da) + (1-f) * Dca | |
| = Dca [f=0] | |
| = blend(0, Dca, 0, Da) [definition of blend()] | |
| = blend(f*Sca, Dca, f*Sa, Da) [f=0] | |
| == Alpha == | |
| We substitute X=Y=Z=1 and define a blend() function that calculates Da': | |
| blend(Sa, Da) = Sa * Da + Sa * (1-Da) + Da * (1-Sa) | |
| = Sa * Da + Sa - Sa * Da + Da - Da * Sa | |
| = Sa + Da - Sa * Da | |
| We use the same model for coverage modulation as we did with color: | |
| Da'' = f * blend(Sa, Da) + (1-f) * Da | |
| And show that show that we can multiply coverage into src alpha by proving the following | |
| relationship: | |
| blend(f*Sa, Da) == f * blend(Sa, Da) + (1-f) * Da | |
| f * blend(Sa, Da) + (1-f) * Da | |
| = f * (Sa + Da - Sa * Da) + (1-f) * Da | |
| = f*Sa + f*Da - f*Sa * Da + Da - f*Da | |
| = f*Sa - f*Sa * Da + Da | |
| = f*Sa + Da - f*Sa * Da | |
| = blend(f*Sa, Da) | |
| */ | |
| return emit_color_output(BlendFormula::OutputType::kModulate_OutputType, outColor, inColor); | |
| } | |
| void collect_lifted_expressions(SkSpan<const ShaderNode*> nodes, | |
| const ShaderSnippet::Args& args, | |
| std::vector<LiftedExpression>& lifted) { | |
| for (const ShaderNode* node : nodes) { | |
| const bool emitVaryingInFS = | |
| static_cast<bool>(node->requiredFlags() & SnippetRequirementFlags::kLiftExpression); | |
| const bool emitExpressionInVS = | |
| emitVaryingInFS || | |
| (node->requiredFlags() & SnippetRequirementFlags::kOmitExpression); | |
| SkASSERT(!emitExpressionInVS || node->entry()->fLiftableExpressionGenerator); | |
| ShaderSnippet::Args childArgs = args; | |
| if (emitExpressionInVS && node->entry()->fLiftableExpressionGenerator) { | |
| lifted.push_back({node, args, emitVaryingInFS}); | |
| switch (node->entry()->fLiftableExpressionType) { | |
| case ShaderSnippet::LiftableExpressionType::kLocalCoords: | |
| childArgs.fFragCoord = node->getExpressionVaryingName(); | |
| break; | |
| case ShaderSnippet::LiftableExpressionType::kPriorStageOutput: | |
| childArgs.fPriorStageOutput = node->getExpressionVaryingName(); | |
| break; | |
| default: | |
| SkUNREACHABLE; | |
| } | |
| } | |
| collect_lifted_expressions(node->children(), childArgs, lifted); | |
| } | |
| }; | |
| std::vector<LiftedExpression> collect_lifted_expressions(SkSpan<const ShaderNode*> nodes) { | |
| std::vector<LiftedExpression> lifted; | |
| ShaderSnippet::Args args = ShaderSnippet::kDefaultArgs; | |
| args.fFragCoord = "stepLocalCoords"; // Render Steps' stepLocalCoords | |
| collect_lifted_expressions(nodes, args, lifted); | |
| return lifted; | |
| } | |
| constexpr skgpu::BlendInfo make_simple_blendInfo(skgpu::BlendCoeff srcCoeff, | |
| skgpu::BlendCoeff dstCoeff) { | |
| return { skgpu::BlendEquation::kAdd, | |
| srcCoeff, | |
| dstCoeff, | |
| SK_PMColor4fTRANSPARENT, | |
| skgpu::BlendModifiesDst(skgpu::BlendEquation::kAdd, srcCoeff, dstCoeff) }; | |
| } | |
| constexpr skgpu::BlendEquation get_advanced_blend_equation(SkBlendMode mode) { | |
| SkASSERT(mode > SkBlendMode::kLastCoeffMode); | |
| constexpr int kEqOffset = ((int)skgpu::BlendEquation::kOverlay - (int)SkBlendMode::kOverlay); | |
| static_assert((int)skgpu::BlendEquation::kOverlay == | |
| (int)SkBlendMode::kOverlay + kEqOffset); | |
| static_assert((int)skgpu::BlendEquation::kDarken == | |
| (int)SkBlendMode::kDarken + kEqOffset); | |
| static_assert((int)skgpu::BlendEquation::kLighten == | |
| (int)SkBlendMode::kLighten + kEqOffset); | |
| static_assert((int)skgpu::BlendEquation::kColorDodge == | |
| (int)SkBlendMode::kColorDodge + kEqOffset); | |
| static_assert((int)skgpu::BlendEquation::kColorBurn == | |
| (int)SkBlendMode::kColorBurn + kEqOffset); | |
| static_assert((int)skgpu::BlendEquation::kHardLight == | |
| (int)SkBlendMode::kHardLight + kEqOffset); | |
| static_assert((int)skgpu::BlendEquation::kSoftLight == | |
| (int)SkBlendMode::kSoftLight + kEqOffset); | |
| static_assert((int)skgpu::BlendEquation::kDifference == | |
| (int)SkBlendMode::kDifference + kEqOffset); | |
| static_assert((int)skgpu::BlendEquation::kExclusion == | |
| (int)SkBlendMode::kExclusion + kEqOffset); | |
| static_assert((int)skgpu::BlendEquation::kMultiply == | |
| (int)SkBlendMode::kMultiply + kEqOffset); | |
| static_assert((int)skgpu::BlendEquation::kHSLHue == | |
| (int)SkBlendMode::kHue + kEqOffset); | |
| static_assert((int)skgpu::BlendEquation::kHSLSaturation == | |
| (int)SkBlendMode::kSaturation + kEqOffset); | |
| static_assert((int)skgpu::BlendEquation::kHSLColor == | |
| (int)SkBlendMode::kColor + kEqOffset); | |
| static_assert((int)skgpu::BlendEquation::kHSLLuminosity == | |
| (int)SkBlendMode::kLuminosity + kEqOffset); | |
| // There's an illegal BlendEquation that corresponds to no SkBlendMode, hence the extra +1. | |
| static_assert(skgpu::kBlendEquationCnt == (int)SkBlendMode::kLastMode + 1 + 1 + kEqOffset); | |
| return static_cast<skgpu::BlendEquation>((int)mode + kEqOffset); | |
| } | |
| constexpr skgpu::BlendInfo make_hardware_advanced_blendInfo(SkBlendMode advancedBlendMode) { | |
| BlendInfo blendInfo; | |
| blendInfo.fEquation = get_advanced_blend_equation(advancedBlendMode); | |
| return blendInfo; | |
| } | |
| static constexpr skgpu::BlendInfo gBlendTable[kSkBlendModeCount] = { | |
| /* Porter-Duff blend modes */ | |
| /* clear */ make_simple_blendInfo(skgpu::BlendCoeff::kZero, skgpu::BlendCoeff::kZero), | |
| /* src */ make_simple_blendInfo(skgpu::BlendCoeff::kOne, skgpu::BlendCoeff::kZero), | |
| /* dst */ make_simple_blendInfo(skgpu::BlendCoeff::kZero, skgpu::BlendCoeff::kOne), | |
| /* src-over */ make_simple_blendInfo(skgpu::BlendCoeff::kOne, skgpu::BlendCoeff::kISA), | |
| /* dst-over */ make_simple_blendInfo(skgpu::BlendCoeff::kIDA, skgpu::BlendCoeff::kOne), | |
| /* src-in */ make_simple_blendInfo(skgpu::BlendCoeff::kDA, skgpu::BlendCoeff::kZero), | |
| /* dst-in */ make_simple_blendInfo(skgpu::BlendCoeff::kZero, skgpu::BlendCoeff::kSA), | |
| /* src-out */ make_simple_blendInfo(skgpu::BlendCoeff::kIDA, skgpu::BlendCoeff::kZero), | |
| /* dst-out */ make_simple_blendInfo(skgpu::BlendCoeff::kZero, skgpu::BlendCoeff::kISA), | |
| /* src-atop */ make_simple_blendInfo(skgpu::BlendCoeff::kDA, skgpu::BlendCoeff::kISA), | |
| /* dst-atop */ make_simple_blendInfo(skgpu::BlendCoeff::kIDA, skgpu::BlendCoeff::kSA), | |
| /* xor */ make_simple_blendInfo(skgpu::BlendCoeff::kIDA, skgpu::BlendCoeff::kISA), | |
| /* plus */ make_simple_blendInfo(skgpu::BlendCoeff::kOne, skgpu::BlendCoeff::kOne), | |
| /* modulate */ make_simple_blendInfo(skgpu::BlendCoeff::kZero, skgpu::BlendCoeff::kSC), | |
| /* screen */ make_simple_blendInfo(skgpu::BlendCoeff::kOne, skgpu::BlendCoeff::kISC), | |
| /* BlendInfo for advanced blend modes */ | |
| make_hardware_advanced_blendInfo(SkBlendMode::kOverlay), | |
| make_hardware_advanced_blendInfo(SkBlendMode::kDarken), | |
| make_hardware_advanced_blendInfo(SkBlendMode::kLighten), | |
| make_hardware_advanced_blendInfo(SkBlendMode::kColorDodge), | |
| make_hardware_advanced_blendInfo(SkBlendMode::kColorBurn), | |
| make_hardware_advanced_blendInfo(SkBlendMode::kHardLight), | |
| make_hardware_advanced_blendInfo(SkBlendMode::kSoftLight), | |
| make_hardware_advanced_blendInfo(SkBlendMode::kDifference), | |
| make_hardware_advanced_blendInfo(SkBlendMode::kExclusion), | |
| make_hardware_advanced_blendInfo(SkBlendMode::kMultiply), | |
| make_hardware_advanced_blendInfo(SkBlendMode::kHue), | |
| make_hardware_advanced_blendInfo(SkBlendMode::kSaturation), | |
| make_hardware_advanced_blendInfo(SkBlendMode::kColor), | |
| make_hardware_advanced_blendInfo(SkBlendMode::kLuminosity) | |
| }; | |
| } // anonymous namespace | |
| std::unique_ptr<ShaderInfo> ShaderInfo::Make(const Caps* caps, | |
| const ShaderCodeDictionary* dict, | |
| const RuntimeEffectDictionary* rteDict, | |
| const RenderStep* step, | |
| UniquePaintParamsID paintID, | |
| bool useStorageBuffers, | |
| TextureFormat targetFormat, | |
| skgpu::Swizzle writeSwizzle, | |
| DstReadStrategy dstReadStrategy, | |
| skia_private::TArray<SamplerDesc>* outDescs) { | |
| const char* shadingSsboIndex = | |
| useStorageBuffers && step->performsShading() ? "shadingSsboIndex" : nullptr; | |
| // If paintID is not valid this is a depth-only draw and there's no fragment shader to compile. | |
| const bool hasFragShader = paintID.isValid(); | |
| // Each ShaderInfo is responsible for determining whether or not a dst read is required. This | |
| // generally occurs while generating the frag shader, but if we do not use one, then we know we | |
| // do not need to read the dst texture and can assign the DstReadStrategy to kNoneRequired. | |
| auto result = std::unique_ptr<ShaderInfo>( | |
| new ShaderInfo(dict, rteDict, | |
| shadingSsboIndex, | |
| hasFragShader ? dstReadStrategy : DstReadStrategy::kNoneRequired)); | |
| // De-compressed shader tree from a PaintParamsKey. There can be 1 or 2 root nodes, the first | |
| // being the paint effects (rooted with a BlendCompose for the final paint blend) and the | |
| // optional second being any analytic clip effect (geometric or shader treated as coverage). | |
| SkSpan<const ShaderNode*> rootNodes; | |
| // All shader nodes and arrays of children pointers are held in this arena | |
| SkArenaAlloc shaderNodeAlloc{256}; | |
| // The fragment shader must be generated before the vertex shader, because we determine | |
| // properties of the entire program while generating the fragment shader. | |
| if (hasFragShader) { | |
| result->generateFragmentSkSL(caps, | |
| dict, | |
| step, | |
| paintID, | |
| useStorageBuffers, | |
| targetFormat, | |
| writeSwizzle, | |
| outDescs, | |
| shaderNodeAlloc, | |
| &rootNodes); | |
| } else { | |
| // Disable color write if there is no fragment shader | |
| result->fBlendInfo.fWritesColor = false; | |
| } | |
| result->generateVertexSkSL(caps, step, useStorageBuffers, rootNodes); | |
| return result; | |
| } | |
| ShaderInfo::ShaderInfo(const ShaderCodeDictionary* shaderCodeDictionary, | |
| const RuntimeEffectDictionary* rteDict, | |
| const char* shadingSsboIndex, | |
| DstReadStrategy dstReadStrategy) | |
| : fShaderCodeDictionary(shaderCodeDictionary) | |
| , fRuntimeEffectDictionary(rteDict) | |
| , fShadingSsboIndex(shadingSsboIndex) | |
| , fDstReadStrategy(dstReadStrategy) {} | |
| namespace { | |
| std::string dst_read_strategy_to_str(DstReadStrategy strategy) { | |
| switch (strategy) { | |
| case DstReadStrategy::kNoneRequired: | |
| return "NoneRequired"; | |
| case DstReadStrategy::kTextureCopy: | |
| return "TextureCopy"; | |
| case DstReadStrategy::kTextureSample: | |
| return "TextureSample"; | |
| case DstReadStrategy::kReadFromInput: | |
| return "ReadFromInput"; | |
| case DstReadStrategy::kFramebufferFetch: | |
| return "FramebufferFetch"; | |
| default: | |
| SkUNREACHABLE; | |
| } | |
| return ""; | |
| } | |
| } // anonymous | |
| // The current, incomplete, model for shader construction is: | |
| // - Static code snippets (which can have an arbitrary signature) live in the Graphite | |
| // pre-compiled module, which is located at `src/sksl/sksl_graphite_frag.sksl`. | |
| // - Glue code is generated in a `main` method which calls these static code snippets. | |
| // The glue code is responsible for: | |
| // 1) gathering the correct (mangled) uniforms | |
| // 2) passing the uniforms and any other parameters to the helper method | |
| // - The result of the final code snippet is then copied into "sk_FragColor". | |
| // Note: each entry's 'fStaticFunctionName' field is expected to match the name of a function | |
| // in the Graphite pre-compiled module, or be null if the preamble and expression generators are | |
| // overridden to not use a static function. | |
| void ShaderInfo::generateFragmentSkSL(const Caps* caps, | |
| const ShaderCodeDictionary* dict, | |
| const RenderStep* step, | |
| UniquePaintParamsID paintID, | |
| bool useStorageBuffers, | |
| TextureFormat targetFormat, | |
| Swizzle writeSwizzle, | |
| skia_private::TArray<SamplerDesc>* outDescs, | |
| SkArenaAlloc& shaderNodeAlloc, | |
| SkSpan<const ShaderNode*>* rootNodes) { | |
| PaintParamsKey key = dict->lookup(paintID); | |
| SkASSERT(key.isValid()); // invalid keys should have been caught by invalid paint ID earlier | |
| std::string label = key.toString(dict).c_str(); | |
| // Two varyings are reserved for 1) the SSBO indices and 2) local coordinates. | |
| constexpr int kFixedVaryings = 2; | |
| const int availableVaryings = caps->maxVaryings() - kFixedVaryings - step->varyings().size(); | |
| *rootNodes = key.getRootNodes(caps, dict, &shaderNodeAlloc, availableVaryings); | |
| fNeedsLocalCoords = !rootNodes->empty() && SkToBool((*rootNodes)[0]->requiredFlags() & | |
| SnippetRequirementFlags::kLocalCoords); | |
| // TODO(b/366220690): aggregateSnippetData() goes away entirely once the VulkanGraphicsPipeline | |
| // is updated to use the extracted SamplerDescs directly. | |
| for (const ShaderNode* root : *rootNodes) { | |
| this->aggregateSnippetData(root); | |
| } | |
| #if defined(SK_DEBUG) | |
| // Validate the root node structure of the key. | |
| SkASSERT(rootNodes->size() == 2 || rootNodes->size() == 3); | |
| // First node produces the source color (all snippets return a half4), so we just require that | |
| // its signature takes no extra args or just local coords. | |
| const ShaderSnippet* srcSnippet = dict->getEntry((*rootNodes)[0]->codeSnippetId()); | |
| // TODO(b/349997190): Once SkEmptyShader doesn't use the passthrough snippet, we can assert | |
| // that srcSnippet->needsPriorStageOutput() is false. | |
| SkASSERT(!srcSnippet->needsBlenderDstColor()); | |
| // Second node is the final blender, so it must take both the src color and dst color, and not | |
| // any local coordinate. | |
| const ShaderSnippet* blendSnippet = dict->getEntry((*rootNodes)[1]->codeSnippetId()); | |
| SkASSERT(blendSnippet->needsPriorStageOutput() && blendSnippet->needsBlenderDstColor()); | |
| SkASSERT(!blendSnippet->needsLocalCoords()); | |
| const ShaderSnippet* clipSnippet = | |
| rootNodes->size() > 2 ? dict->getEntry((*rootNodes)[2]->codeSnippetId()) : nullptr; | |
| SkASSERT(!clipSnippet || | |
| (!clipSnippet->needsPriorStageOutput() && !clipSnippet->needsBlenderDstColor())); | |
| #endif | |
| // The RenderStep should be performing shading since otherwise there's no need to generate a | |
| // fragment shader program at all. | |
| SkASSERT(step->performsShading()); | |
| // Check for unexpected corruption / illegal instructions occurring in the wild. | |
| SkASSERTF_RELEASE(rootNodes->size() == 2 || rootNodes->size() == 3, | |
| "root node size = %zu, label = %s", | |
| rootNodes->size(), | |
| label.c_str()); | |
| // Extract the root nodes for clarity | |
| const ShaderNode* const srcColorRoot = (*rootNodes)[0]; | |
| const ShaderNode* const finalBlendRoot = (*rootNodes)[1]; | |
| const int32_t finalBlendRootSnippetId = finalBlendRoot->codeSnippetId(); | |
| const ShaderNode* const clipRoot = rootNodes->size() > 2 ? (*rootNodes)[2] : nullptr; | |
| // Determine the algorithm for final blending: direct HW blending, coverage-modified HW | |
| // blending (w/ or w/o dual-source blending) or via dst-read requirement. | |
| Coverage finalCoverage = step->coverage(); | |
| if (finalCoverage == Coverage::kNone && SkToBool(clipRoot)) { | |
| finalCoverage = Coverage::kSingleChannel; | |
| } | |
| // Initialize the final blend mode to the final snippet's blend mode. It may be changed based | |
| // upon whether or not we can use hardware blending. | |
| std::optional<SkBlendMode> finalBlendMode; | |
| if (finalBlendRootSnippetId < kBuiltInCodeSnippetIDCount && | |
| finalBlendRootSnippetId >= kFixedBlendIDOffset) { | |
| finalBlendMode = static_cast<SkBlendMode>(finalBlendRootSnippetId - kFixedBlendIDOffset); | |
| } | |
| const bool useHardwareBlending = | |
| CanUseHardwareBlending(caps, targetFormat, finalBlendMode, finalCoverage); | |
| if (useHardwareBlending) { | |
| // If we can use hardware blending, update the dstReadStrategy to be kNoneRequired to ensure | |
| // that ShaderInfo properly informs PipelineInfo of the pipeline's dst read requirement. | |
| fDstReadStrategy = DstReadStrategy::kNoneRequired; | |
| } else { | |
| // If we cannot use hardware blending, then we must perform a dst read within the shader. | |
| // Therefore we should assert that a valid strategy to do so was passed in. Later operations | |
| // also expect the blend mode to be kSrc, so update that here. | |
| SkASSERT(fDstReadStrategy != DstReadStrategy::kNoneRequired); | |
| finalBlendMode = SkBlendMode::kSrc; | |
| } | |
| const bool hasStepUniforms = step->numUniforms() > 0 && step->usesUniformsInFragmentSkSL(); | |
| const bool useStepStorageBuffer = useStorageBuffers && hasStepUniforms; | |
| const bool useShadingStorageBuffer = useStorageBuffers && step->performsShading(); | |
| auto allReqFlags = srcColorRoot->requiredFlags() | finalBlendRoot->requiredFlags(); | |
| if (clipRoot) { | |
| allReqFlags |= clipRoot->requiredFlags(); | |
| } | |
| const bool useGradientStorageBuffer = caps->gradientBufferSupport() && | |
| (allReqFlags & SnippetRequirementFlags::kGradientBuffer); | |
| const bool useDstSampler = fDstReadStrategy == DstReadStrategy::kTextureCopy || | |
| fDstReadStrategy == DstReadStrategy::kTextureSample; | |
| const std::vector<LiftedExpression> liftedExpr = collect_lifted_expressions(*rootNodes); | |
| // The uniforms are mangled by having their index in 'fEntries' as a suffix (i.e., "_%d") | |
| const ResourceBindingRequirements& bindingReqs = caps->resourceBindingRequirements(); | |
| std::string preamble; | |
| int numPaintUniforms = 0; | |
| int numUnliftedPaintUniforms = 0; | |
| bool wrotePaintColor = false; | |
| if (useShadingStorageBuffer) { | |
| preamble = emit_paint_params_storage_buffer(bindingReqs.fUniformsSetIdx, | |
| bindingReqs.fPaintParamsBufferBinding, | |
| *rootNodes, | |
| &numPaintUniforms, | |
| &numUnliftedPaintUniforms, | |
| &wrotePaintColor); | |
| SkSL::String::appendf(&preamble, "uint %s;\n", this->shadingSsboIndex()); | |
| } else { | |
| preamble = emit_paint_params_uniforms(bindingReqs.fUniformsSetIdx, | |
| bindingReqs.fPaintParamsBufferBinding, | |
| bindingReqs.fUniformBufferLayout, | |
| *rootNodes, | |
| &numPaintUniforms, | |
| &numUnliftedPaintUniforms, | |
| &wrotePaintColor); | |
| } | |
| fHasPaintUniforms = numPaintUniforms > 0; | |
| fHasLiftedPaintUniforms = numPaintUniforms - numUnliftedPaintUniforms > 0; | |
| const bool hasUnliftedPaintUniforms = numUnliftedPaintUniforms > 0; | |
| fHasSsboIndicesVarying = useShadingStorageBuffer && | |
| (hasUnliftedPaintUniforms || hasStepUniforms); | |
| const bool defineLocalCoordsVarying = this->needsLocalCoords(); | |
| preamble += emit_varyings(step, | |
| /*direction=*/"in", | |
| liftedExpr, | |
| fHasSsboIndicesVarying, | |
| defineLocalCoordsVarying); | |
| preamble += emit_intrinsic_constants(bindingReqs); | |
| if (fDstReadStrategy == DstReadStrategy::kReadFromInput) { | |
| // If this shader reads the dst texture as an input attachment, assert that a valid set | |
| // index has been assigned within ResourceBindingRequirements. | |
| SkASSERT(bindingReqs.fInputAttachmentSetIdx != ResourceBindingRequirements::kUnassigned); | |
| // TODO: The following SkSL depends upon the fact that Vulkan is currently the only backend | |
| // that utilizes DstReadStrategy::kReadFromInput. Update accordingly if other backends add | |
| // support for this DstReadStrategy. | |
| SkSL::String::appendf( | |
| &preamble, | |
| "layout (vulkan, input_attachment_index=%d, set=%d, binding=%d) " | |
| "subpassInput DstTextureInput;\n", | |
| /*input attachment idx within set=*/0, | |
| /*input attachment set idx=*/bindingReqs.fInputAttachmentSetIdx, | |
| /*binding=*/0); | |
| } | |
| if (hasStepUniforms) { | |
| if (useStepStorageBuffer) { | |
| preamble += emit_render_step_storage_buffer(bindingReqs.fUniformsSetIdx, | |
| bindingReqs.fRenderStepBufferBinding, | |
| step->uniforms()); | |
| } else { | |
| preamble += emit_render_step_uniforms(bindingReqs.fUniformsSetIdx, | |
| bindingReqs.fRenderStepBufferBinding, | |
| bindingReqs.fUniformBufferLayout, | |
| step->uniforms()); | |
| } | |
| } | |
| if (useGradientStorageBuffer) { | |
| SkSL::String::appendf(&preamble, | |
| "layout (set=%d, binding=%d) readonly buffer FSGradientBuffer {\n" | |
| " float %s[];\n" | |
| "};\n", | |
| bindingReqs.fUniformsSetIdx, | |
| bindingReqs.fGradientBufferBinding, | |
| ShaderInfo::kGradientBufferName); | |
| fHasGradientBuffer = true; | |
| } | |
| { | |
| int binding = 0; | |
| preamble += emit_textures_and_samplers(bindingReqs, *rootNodes, &binding, outDescs); | |
| int paintTextureCount = binding; | |
| if (step->hasTextures()) { | |
| preamble += step->texturesAndSamplersSkSL(bindingReqs, &binding); | |
| if (outDescs) { | |
| // Determine how many render step samplers were used by comparing the binding value | |
| // against paintTextureCount, taking into account the binding requirements. We | |
| // assume and do not anticipate the render steps to use immutable samplers. | |
| int renderStepSamplerCount = bindingReqs.fSeparateTextureAndSamplerBinding | |
| ? (binding - paintTextureCount) / 2 | |
| : binding - paintTextureCount; | |
| // Add default SamplerDescs for all the dynamic samplers used by the render step so | |
| // the size of outDescs will be equivalent to the total number of samplers. | |
| outDescs->push_back_n(renderStepSamplerCount); | |
| } | |
| } | |
| if (useDstSampler) { | |
| preamble += EmitSamplerLayout(bindingReqs, &binding); | |
| preamble += " sampler2D dstSampler;"; | |
| // Add default SamplerDesc for the intrinsic dstSampler to stay consistent with | |
| // `fNumFragmentTexturesAndSamplers`. | |
| if (outDescs) { | |
| outDescs->push_back({}); | |
| } | |
| } | |
| // Record how many textures and samplers are used. | |
| fNumFragmentTexturesAndSamplers = binding; | |
| } | |
| // Emit preamble declarations and helper functions required for snippets. In the default case | |
| // this adds functions that bind a node's specific mangled uniforms to the snippet's | |
| // implementation in the SkSL modules. | |
| emit_preambles(*this, *rootNodes, /*treeLabel=*/"", &preamble); | |
| std::string mainBody = "void main() {"; | |
| if (fHasSsboIndicesVarying) { | |
| SkSL::String::appendf(&mainBody, | |
| "%s = %s.y;\n", | |
| this->shadingSsboIndex(), | |
| RenderStep::ssboIndicesVarying()); | |
| } | |
| if (step->emitsPrimitiveColor()) { | |
| mainBody += "half4 primitiveColor;"; | |
| mainBody += step->fragmentColorSkSL(); | |
| } else { | |
| SkASSERT(!((*rootNodes)[0]->requiredFlags() & SnippetRequirementFlags::kPrimitiveColor)); | |
| } | |
| // Using kDefaultArgs as the initial value means it will refer to undefined variables, but the | |
| // root nodes should--at most--be depending on the coordinate when "needsLocalCoords" is true. | |
| // If the PaintParamsKey violates that structure, this will produce SkSL compile errors. | |
| ShaderSnippet::Args args = ShaderSnippet::kDefaultArgs; | |
| args.fFragCoord = "localCoordsVar"; // the varying added in emit_varyings() | |
| // TODO(b/349997190): The paint root node should not depend on any prior stage's output, but | |
| // it can happen with how SkEmptyShader is currently mapped to `sk_passthrough`. In this case | |
| // it requires that prior stage color to be transparent black. When SkEmptyShader can instead | |
| // cause the draw to be skipped, this can go away. | |
| args.fPriorStageOutput = "half4(0)"; | |
| // Calculate the src color and stash its output variable in `args` | |
| args.fPriorStageOutput = srcColorRoot->invokeAndAssign(*this, args, &mainBody); | |
| // If not using hardware blending, we perform a dst read in the shader and must add SkSL | |
| // accordingly. | |
| const bool readDstInShader = !useHardwareBlending; | |
| if (readDstInShader) { | |
| // Get the current dst color into a local variable, it may be used later on for coverage | |
| // blending as well as the final blend. | |
| mainBody += "half4 dstColor;"; | |
| if (useDstSampler) { | |
| // dstReadBounds is in frag coords and already includes the replay translation. The | |
| // reciprocol of the dstCopy dimensions are in ZW. | |
| mainBody += "dstColor = sample(dstSampler," | |
| "dstReadBounds.zw*(sk_FragCoord.xy - dstReadBounds.xy));"; | |
| } else if (fDstReadStrategy == DstReadStrategy::kReadFromInput) { | |
| // The dst texture should have been written to with the appropriate write swizzle, so we | |
| // do not need to worry about the read swizzle when accessing that value for blending. | |
| mainBody += "// Read color from input attachment\n"; | |
| mainBody += "dstColor = subpassLoad(DstTextureInput);\n"; | |
| } else { | |
| SkASSERT(fDstReadStrategy == DstReadStrategy::kFramebufferFetch); | |
| mainBody += "dstColor = sk_LastFragColor;"; | |
| } | |
| args.fBlenderDstColor = "dstColor"; | |
| args.fPriorStageOutput = finalBlendRoot->invokeAndAssign(*this, args, &mainBody); | |
| } | |
| if (writeSwizzle != Swizzle::RGBA()) { | |
| SkSL::String::appendf(&mainBody, "%s = %s.%s;", args.fPriorStageOutput.c_str(), | |
| args.fPriorStageOutput.c_str(), | |
| writeSwizzle.asString().c_str()); | |
| } | |
| if (finalCoverage == Coverage::kNone) { | |
| // Either direct HW blending or a dst-read w/o any extra coverage. In both cases we just | |
| // need to assign directly to sk_FragCoord and update the HW blend info to finalBlendMode. | |
| SkASSERT(finalBlendMode.has_value()); | |
| fBlendInfo = gBlendTable[static_cast<int>(*finalBlendMode)]; | |
| SkSL::String::appendf(&mainBody, "sk_FragColor = %s;", args.fPriorStageOutput.c_str()); | |
| } else { | |
| // Accumulate the output coverage. This will either modify the src color and secondary | |
| // outputs for dual-source blending, or be combined directly with the in-shader blended | |
| // final color if a dst-readback was required. | |
| if (useStepStorageBuffer) { | |
| SkSL::String::appendf(&mainBody, | |
| "uint stepSsboIndex = %s.x;\n", | |
| RenderStep::ssboIndicesVarying()); | |
| mainBody += | |
| emit_uniforms_from_storage_buffer("step", "stepSsboIndex", step->uniforms()); | |
| } | |
| mainBody += "half4 outputCoverage = half4(1);"; | |
| if (step->coverage() != Coverage::kNone) { | |
| mainBody += step->fragmentCoverageSkSL(); | |
| } | |
| if (clipRoot) { | |
| // The clip block node is invoked with device coords, not local coords like the main | |
| // shading root node. However sk_FragCoord includes any replay translation and we | |
| // need to recover the original device coordinate. | |
| mainBody += "float2 devCoord = sk_FragCoord.xy - viewport.xy;"; | |
| args.fFragCoord = "devCoord"; | |
| std::string clipBlockOutput = clipRoot->invokeAndAssign(*this, args, &mainBody); | |
| SkSL::String::appendf(&mainBody, "outputCoverage *= %s.a;", clipBlockOutput.c_str()); | |
| } | |
| const char* outColor = args.fPriorStageOutput.c_str(); | |
| if (readDstInShader) { | |
| // If this draw uses a non-coherent dst read, we want to keep the existing dst color (or | |
| // whatever has been previously drawn) when there's no coverage. This helps for batching | |
| // text draws that need to read from a dst copy for blends. However, this only helps the | |
| // case where the outer bounding boxes of each letter overlap and not two actual parts | |
| // of the text. | |
| if (useDstSampler) { | |
| // We don't think any shaders actually output negative coverage, but just as a | |
| // safety check for floating point precision errors, we compare with <= here. We | |
| // just check the RGB values of the coverage, since the alpha may not have been set | |
| // when using LCD. If we are using single-channel coverage, alpha will be equal to | |
| // RGB anyway. | |
| mainBody += | |
| "if (all(lessThanEqual(outputCoverage.rgb, half3(0)))) {" | |
| "discard;" | |
| "}"; | |
| } | |
| // Use kSrc HW BlendInfo and do the coverage blend with dst in the shader. | |
| SkASSERT(finalBlendMode.has_value() && finalBlendMode.value() == SkBlendMode::kSrc); | |
| fBlendInfo = gBlendTable[static_cast<int>(*finalBlendMode)]; | |
| SkSL::String::appendf( | |
| &mainBody, | |
| "sk_FragColor = %s * outputCoverage + dstColor * (1.0 - outputCoverage);", | |
| outColor); | |
| if (finalCoverage == Coverage::kLCD) { | |
| SkSL::String::appendf( | |
| &mainBody, | |
| "half3 lerpRGB = mix(dstColor.aaa, %s.aaa, outputCoverage.rgb);" | |
| "sk_FragColor.a = max(max(lerpRGB.r, lerpRGB.g), lerpRGB.b);", | |
| outColor); | |
| } | |
| } else { | |
| // Adjust the shader output(s) to incorporate the coverage so that HW blending produces | |
| // the correct output. | |
| if (finalBlendMode > SkBlendMode::kLastCoeffMode) { | |
| SkASSERT(finalCoverage == Coverage::kSingleChannel); | |
| fBlendInfo = gBlendTable[static_cast<int>(*finalBlendMode)]; | |
| mainBody += emit_advanced_blend_color_output("sk_FragColor", outColor); | |
| } else { | |
| // Porter-Duff blend modes can utilize BlendFormula. | |
| // TODO: Determine whether draw is opaque and pass that to GetBlendFormula. | |
| BlendFormula coverageBlendFormula = | |
| finalCoverage == Coverage::kLCD | |
| ? skgpu::GetLCDBlendFormula(*finalBlendMode) | |
| : skgpu::GetBlendFormula( | |
| /*isOpaque=*/false, /*hasCoverage=*/true, *finalBlendMode); | |
| fBlendInfo = {coverageBlendFormula.equation(), | |
| coverageBlendFormula.srcCoeff(), | |
| coverageBlendFormula.dstCoeff(), | |
| SK_PMColor4fTRANSPARENT, | |
| coverageBlendFormula.modifiesDst()}; | |
| if (finalCoverage == Coverage::kLCD) { | |
| mainBody += "outputCoverage.a = max(max(outputCoverage.r, " | |
| "outputCoverage.g), " | |
| "outputCoverage.b);"; | |
| } | |
| mainBody += emit_color_output(coverageBlendFormula.primaryOutput(), | |
| "sk_FragColor", | |
| outColor); | |
| if (coverageBlendFormula.hasSecondaryOutput()) { | |
| SkASSERT(caps->shaderCaps()->fDualSourceBlendingSupport); | |
| mainBody += emit_color_output(coverageBlendFormula.secondaryOutput(), | |
| "sk_SecondaryFragColor", | |
| outColor); | |
| } | |
| } | |
| } | |
| } | |
| mainBody += "}\n"; | |
| fFragmentSkSL = preamble + "\n" + mainBody; | |
| fFSLabel = writeSwizzle.asString().c_str(); | |
| fFSLabel += " + "; | |
| fFSLabel = step->name(); | |
| fFSLabel += " + "; | |
| fFSLabel += label; | |
| if (fDstReadStrategy != DstReadStrategy::kNoneRequired) { | |
| fFSLabel += " + Dst Read ("; | |
| fFSLabel += dst_read_strategy_to_str(fDstReadStrategy); | |
| fFSLabel += ")"; | |
| } | |
| } | |
| void ShaderInfo::generateVertexSkSL(const Caps* caps, | |
| const RenderStep* step, | |
| bool useStorageBuffers, | |
| SkSpan<const ShaderNode*> rootNodes) { | |
| const bool hasStepUniforms = step->numUniforms() > 0; | |
| const bool useStepStorageBuffer = useStorageBuffers && hasStepUniforms; | |
| const bool useShadingStorageBuffer = useStorageBuffers && step->performsShading(); | |
| const bool defineLocalCoordsVarying = this->needsLocalCoords(); | |
| // Fixed program header (intrinsics are always declared as an uniform interface block) | |
| const ResourceBindingRequirements& bindingReqs = caps->resourceBindingRequirements(); | |
| std::string sksl = emit_intrinsic_constants(bindingReqs); | |
| if (step->numStaticAttributes() > 0 || step->numAppendAttributes() > 0) { | |
| int attr = 0; | |
| auto add_attrs = [&sksl, &attr](SkSpan<const Attribute> attrs) { | |
| for (auto a : attrs) { | |
| SkSL::String::appendf(&sksl, " layout(location=%d) in ", attr++); | |
| sksl.append(SkSLTypeString(a.gpuType())); | |
| SkSL::String::appendf(&sksl, " %s;\n", a.name()); | |
| } | |
| }; | |
| if (step->numStaticAttributes() > 0) { | |
| #if defined(SK_DEBUG) | |
| sksl.append("// static attrs\n"); | |
| #endif | |
| add_attrs(step->staticAttributes()); | |
| } | |
| if (step->numAppendAttributes() > 0) { | |
| #if defined(SK_DEBUG) | |
| sksl.append("// append attrs\n"); | |
| #endif | |
| add_attrs(step->appendAttributes()); | |
| } | |
| } | |
| // Uniforms needed by RenderStep | |
| // The uniforms are mangled by having their index in 'fEntries' as a suffix (i.e., "_%d") | |
| if (hasStepUniforms) { | |
| if (useStepStorageBuffer) { | |
| sksl += emit_render_step_storage_buffer(bindingReqs.fUniformsSetIdx, | |
| bindingReqs.fRenderStepBufferBinding, | |
| step->uniforms()); | |
| } else { | |
| sksl += emit_render_step_uniforms(bindingReqs.fUniformsSetIdx, | |
| bindingReqs.fRenderStepBufferBinding, | |
| bindingReqs.fUniformBufferLayout, | |
| step->uniforms()); | |
| } | |
| } | |
| const std::vector<LiftedExpression> liftedExpr = collect_lifted_expressions(rootNodes); | |
| if (fHasLiftedPaintUniforms) { | |
| int unusedNumPaintUniforms = 0; | |
| int unusedNumUnliftedPaintUniforms = 0; | |
| bool unusedWrotePaintColor = false; | |
| if (useShadingStorageBuffer) { | |
| sksl += emit_paint_params_storage_buffer(bindingReqs.fUniformsSetIdx, | |
| bindingReqs.fPaintParamsBufferBinding, | |
| rootNodes, | |
| &unusedNumPaintUniforms, | |
| &unusedNumUnliftedPaintUniforms, | |
| &unusedWrotePaintColor); | |
| } else { | |
| sksl += emit_paint_params_uniforms(bindingReqs.fUniformsSetIdx, | |
| bindingReqs.fPaintParamsBufferBinding, | |
| bindingReqs.fUniformBufferLayout, | |
| rootNodes, | |
| &unusedNumPaintUniforms, | |
| &unusedNumUnliftedPaintUniforms, | |
| &unusedWrotePaintColor); | |
| } | |
| } | |
| // Varyings needed by RenderStep | |
| sksl += emit_varyings( | |
| step, "out", liftedExpr, fHasSsboIndicesVarying, defineLocalCoordsVarying); | |
| // Vertex shader function declaration | |
| sksl += "void main() {"; | |
| // Create stepLocalCoords which render steps can write to. | |
| sksl += "float2 stepLocalCoords = float2(0);"; | |
| // Vertex shader body | |
| if (useStepStorageBuffer) { | |
| // Extract out render step uniforms from SSBO, declaring local variables with the expected | |
| // uniform names so that RenderStep SkSL is independent of storage choice. | |
| SkSL::String::appendf( | |
| &sksl, "uint stepSsboIndex = %s.x;\n", RenderStep::ssboIndicesAttribute()); | |
| sksl += emit_uniforms_from_storage_buffer("step", "stepSsboIndex", step->uniforms()); | |
| } | |
| sksl += step->vertexSkSL(); | |
| // We want to map the rectangle of logical device pixels from (0,0) to (viewWidth, viewHeight) | |
| // to normalized device coordinates: (-1,-1) to (1,1) (actually -w to w since it's before | |
| // homogenous division). | |
| // | |
| // For efficiency, this assumes viewport.zw holds the reciprocol of twice the viewport width and | |
| // height. On some backends the NDC Y axis is flipped relative to the device and | |
| // viewport coords (i.e. it points up instead of down). In those cases, it's also assumed that | |
| // viewport.w holds a negative value. In that case the sign(viewport.zw) changes from | |
| // subtracting w to adding w. | |
| sksl += "sk_Position = float4(viewport.zw*devPosition.xy - sign(viewport.zw)*devPosition.ww," | |
| "devPosition.zw);"; | |
| if (fHasSsboIndicesVarying) { | |
| // Assign SSBO index values to the SSBO index varying. | |
| SkSL::String::appendf(&sksl, | |
| "%s = %s;", | |
| RenderStep::ssboIndicesVarying(), | |
| RenderStep::ssboIndicesAttribute()); | |
| } | |
| if (defineLocalCoordsVarying) { | |
| // Assign Render Step's stepLocalCoords to the localCoordsVar varying. | |
| sksl += "localCoordsVar = stepLocalCoords;"; | |
| } | |
| if (!liftedExpr.empty()) { | |
| // If we're reading uniforms from a storage buffer, emit the SSBO index first. | |
| if (this->shadingSsboIndex() && fHasLiftedPaintUniforms) { | |
| SkSL::String::appendf(&sksl, | |
| "uint %s = %s.y;\n", | |
| this->shadingSsboIndex(), | |
| RenderStep::ssboIndicesAttribute()); | |
| } | |
| for (const LiftedExpression& expr : liftedExpr) { | |
| const ShaderNode* node = expr.fNode; | |
| const char* type = expr.fEmitVarying ? "" | |
| : SkSLTypeString(sksl_type_for_lifted_expression( | |
| node->entry()->fLiftableExpressionType)); | |
| const std::string varName = node->getExpressionVaryingName(); | |
| const std::string expression = | |
| node->entry()->fLiftableExpressionGenerator(*this, node, expr.fArgs); | |
| SkSL::String::appendf(&sksl, "%s %s = %s;", type, varName.c_str(), expression.c_str()); | |
| } | |
| } | |
| sksl += "}"; | |
| fVertexSkSL = std::move(sksl); | |
| fVSLabel = step->name(); | |
| if (defineLocalCoordsVarying) { | |
| fVSLabel += " (w/ local coords)"; | |
| } | |
| fHasStepUniforms = hasStepUniforms; | |
| } | |
| void ShaderInfo::aggregateSnippetData(const ShaderNode* node) { | |
| if (!node) { | |
| return; | |
| } | |
| // Accumulate data of children first. | |
| for (const ShaderNode* child : node->children()) { | |
| this->aggregateSnippetData(child); | |
| } | |
| if (node->requiredFlags() & SnippetRequirementFlags::kStoresSamplerDescData && | |
| !node->data().empty()) { | |
| fData.push_back_n(node->data().size(), node->data().data()); | |
| } | |
| } | |
| } // namespace skgpu::graphite |