| /* |
| * 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); |
| } |
| |
| 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 |
