experimental/graphite/src/ContextUtils.cpp - skia - Git at Google

 /*
  * Copyright 2021 Google LLC
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */

 #include "experimental/graphite/src/ContextUtils.h"

 #include <string>
 #include "experimental/graphite/src/ContextPriv.h"
 #include "experimental/graphite/src/DrawTypes.h"
 #include "experimental/graphite/src/PaintParams.h"
 #include "experimental/graphite/src/Uniform.h"
 #include "experimental/graphite/src/UniformManager.h"
 #include "include/core/SkPaint.h"
 #include "include/private/SkShaderCodeDictionary.h"
 #include "include/private/SkUniquePaintParamsID.h"
 #include "src/core/SkKeyHelpers.h"

 namespace skgpu {

 namespace {

 // TODO: For the sprint we only support 4 stops in the gradients
 static constexpr int kMaxStops = 4;
 // TODO: For the sprint we unify all the gradient uniforms into a standard set of 6:
 //   kMaxStops colors
 //   kMaxStops offsets
 //   2 points
 //   2 radii
 static constexpr int kNumGradientUniforms = 6;
 static constexpr Uniform kGradientUniforms[kNumGradientUniforms] {
         {"colors",   SLType::kHalf4 , kMaxStops },
         {"offsets",  SLType::kFloat, kMaxStops },
         {"point0",   SLType::kFloat2 },
         {"point1",   SLType::kFloat2 },
         {"radius0",  SLType::kFloat },
         {"radius1",  SLType::kFloat },
 };

 static constexpr int kNumSolidUniforms = 1;
 static constexpr Uniform kSolidUniforms[kNumSolidUniforms] {
         {"color",  SLType::kFloat4 }
 };

 static const char* kGradientSkSL =
         // TODO: This should use local coords
         "float2 pos = sk_FragCoord.xy;\n"
         "float2 delta = point1 - point0;\n"
         "float2 pt = pos - point0;\n"
         "float t = dot(pt, delta) / dot(delta, delta);\n"
         "float4 result = colors[0];\n"
         "result = mix(result, colors[1],\n"
         "             clamp((t-offsets[0])/(offsets[1]-offsets[0]),\n"
         "                   0, 1));\n"
         "result = mix(result, colors[2],\n"
         "             clamp((t-offsets[1])/(offsets[2]-offsets[1]),\n"
         "                   0, 1));\n"
         "result = mix(result, colors[3],\n"
         "             clamp((t-offsets[2])/(offsets[3]-offsets[2]),\n"
         "             0, 1));\n"
         "outColor = half4(result);\n";

 static const char* kSolidColorSkSL = "    outColor = half4(color);\n";

 // TODO: kNone is for depth-only draws, so should actually have a fragment output type
 // that only defines a [[depth]] attribute but no color calculation.
 static const char* kNoneSkSL = "outColor = half4(0.0, 0.0, 1.0, 1.0);\n";

 sk_sp<UniformData> make_gradient_uniform_data_common(const void* srcs[kNumGradientUniforms]) {
     UniformManager mgr(Layout::kMetal);

     // TODO: Given that, for the sprint, we always know the uniforms we could cache 'dataSize'
     // for each layout and skip the first call.
     size_t dataSize = mgr.writeUniforms(SkSpan<const Uniform>(kGradientUniforms,
                                                               kNumGradientUniforms),
                                         nullptr, nullptr, nullptr);

     sk_sp<UniformData> result = UniformData::Make(kNumGradientUniforms,
                                                   kGradientUniforms,
                                                   dataSize);

     mgr.writeUniforms(SkSpan<const Uniform>(kGradientUniforms, kNumGradientUniforms),
                       srcs, result->offsets(), result->data());
     return result;
 }

 sk_sp<UniformData> make_linear_gradient_uniform_data(SkPoint startPoint,
                                                      SkPoint endPoint,
                                                      SkColor4f colors[kMaxStops],
                                                      float offsets[kMaxStops]) {
     float unusedRadii[2] = { 0.0f, 0.0f };
     const void* srcs[kNumGradientUniforms] = {
             colors,
             offsets,
             &startPoint,
             &endPoint,
             &unusedRadii[0],
             &unusedRadii[1],
     };

     return make_gradient_uniform_data_common(srcs);
 };

 sk_sp<UniformData> make_radial_gradient_uniform_data(SkPoint point,
                                                      float radius,
                                                      SkColor4f colors[kMaxStops],
                                                      float offsets[kMaxStops]) {
     SkPoint unusedPoint = {0.0f, 0.0f};
     float unusedRadius = 0.0f;

     const void* srcs[kNumGradientUniforms] = {
             colors,
             offsets,
             &point,
             &unusedPoint,
             &radius,
             &unusedRadius,
     };

     return make_gradient_uniform_data_common(srcs);
 };

 sk_sp<UniformData> make_sweep_gradient_uniform_data(SkPoint point,
                                                     SkColor4f colors[kMaxStops],
                                                     float offsets[kMaxStops]) {
     SkPoint unusedPoint = {0.0f, 0.0f};
     float unusedRadii[2] = {0.0f, 0.0f};

     const void* srcs[kNumGradientUniforms] = {
             colors,
             offsets,
             &point,
             &unusedPoint,
             &unusedRadii[0],
             &unusedRadii[1],
     };

     return make_gradient_uniform_data_common(srcs);
 };

 sk_sp<UniformData> make_conical_gradient_uniform_data(SkPoint point0,
                                                       SkPoint point1,
                                                       float radius0,
                                                       float radius1,
                                                       SkColor4f colors[kMaxStops],
                                                       float offsets[kMaxStops]) {

     const void* srcs[kNumGradientUniforms] = {
             colors,
             offsets,
             &point0,
             &point1,
             &radius0,
             &radius1,
     };

     return make_gradient_uniform_data_common(srcs);
 };

 void to_color4fs(int numColors, SkColor colors[kMaxStops], SkColor4f color4fs[kMaxStops]) {
     SkASSERT(numColors >= 2 && numColors <= kMaxStops);

     int i;
     for (i = 0; i < numColors; ++i) {
         color4fs[i] = SkColor4f::FromColor(colors[i]);
     }
     for ( ; i < kMaxStops; ++i) {
         color4fs[i] = color4fs[numColors-1];
     }
 }

 void expand_stops(int numStops, float offsets[kMaxStops]) {
     SkASSERT(numStops >= 2 && numStops <= kMaxStops);

     for (int i = numStops ; i < kMaxStops; ++i) {
         offsets[i] = offsets[numStops-1];
     }
 }

 sk_sp<UniformData> make_solid_uniform_data(SkColor4f color) {
     UniformManager mgr(Layout::kMetal);

     size_t dataSize = mgr.writeUniforms(SkSpan<const Uniform>(kSolidUniforms, kNumSolidUniforms),
                                         nullptr, nullptr, nullptr);

     sk_sp<UniformData> result = UniformData::Make(kNumSolidUniforms, kSolidUniforms, dataSize);

     const void* srcs[kNumSolidUniforms] = { &color };

     mgr.writeUniforms(SkSpan<const Uniform>(kSolidUniforms, kNumSolidUniforms),
                       srcs, result->offsets(), result->data());
     return result;
 }

 } // anonymous namespace

 sk_sp<UniformData> UniformData::Make(int count,
                                      const Uniform* uniforms,
                                      size_t dataSize) {
     // TODO: the offsets and data should just be allocated right after UniformData in an arena
     uint32_t* offsets = new uint32_t[count];
     char* data = new char[dataSize];

     return sk_sp<UniformData>(new UniformData(count, uniforms, offsets, data, dataSize));
 }

 std::tuple<SkUniquePaintParamsID, sk_sp<UniformData>> ExtractPaintData(Context* context,
                                                                        const PaintParams& p) {
     SkPaintParamsKey key;
     sk_sp<UniformData> uniforms;

     if (auto s = p.shader()) {
         SkColor colors[kMaxStops];
         SkColor4f color4fs[kMaxStops];
         float offsets[kMaxStops];
         SkShader::GradientInfo gradInfo;

         gradInfo.fColorCount = kMaxStops;
         gradInfo.fColors = colors;
         gradInfo.fColorOffsets = offsets;

         SkShader::GradientType type = s->asAGradient(&gradInfo);
         if (gradInfo.fColorCount > kMaxStops) {
             type = SkShader::GradientType::kNone_GradientType;
         }

         switch (type) {
             case SkShader::kLinear_GradientType: {
                 to_color4fs(gradInfo.fColorCount, colors, color4fs);
                 expand_stops(gradInfo.fColorCount, offsets);

                 GradientShaderBlocks::AddToKey(&key, type, gradInfo.fTileMode);

                 uniforms = make_linear_gradient_uniform_data(gradInfo.fPoint[0],
                                                              gradInfo.fPoint[1],
                                                              color4fs,
                                                              offsets);
             } break;
             case SkShader::kRadial_GradientType: {
                 to_color4fs(gradInfo.fColorCount, colors, color4fs);
                 expand_stops(gradInfo.fColorCount, offsets);

                 GradientShaderBlocks::AddToKey(&key, type, gradInfo.fTileMode);

                 uniforms =  make_radial_gradient_uniform_data(gradInfo.fPoint[0],
                                                               gradInfo.fRadius[0],
                                                               color4fs,
                                                               offsets);
             } break;
             case SkShader::kSweep_GradientType:
                 to_color4fs(gradInfo.fColorCount, colors, color4fs);
                 expand_stops(gradInfo.fColorCount, offsets);

                 GradientShaderBlocks::AddToKey(&key, type, gradInfo.fTileMode);

                 uniforms = make_sweep_gradient_uniform_data(gradInfo.fPoint[0],
                                                             color4fs,
                                                             offsets);
                 break;
             case SkShader::GradientType::kConical_GradientType:
                 to_color4fs(gradInfo.fColorCount, colors, color4fs);
                 expand_stops(gradInfo.fColorCount, offsets);

                 GradientShaderBlocks::AddToKey(&key, type, gradInfo.fTileMode);

                 uniforms = make_conical_gradient_uniform_data(gradInfo.fPoint[0],
                                                               gradInfo.fPoint[1],
                                                               gradInfo.fRadius[0],
                                                               gradInfo.fRadius[1],
                                                               color4fs,
                                                               offsets);
                 break;
             case SkShader::GradientType::kColor_GradientType:
                 // TODO: The solid color gradient type should use its color, not
                 // the paint color
             case SkShader::GradientType::kNone_GradientType:
             default:
                 SolidColorShaderBlock::AddToKey(&key);

                 uniforms = make_solid_uniform_data(p.color());
                 break;
         }
     } else {
         // Solid colored paint
         SolidColorShaderBlock::AddToKey(&key);

         uniforms = make_solid_uniform_data(p.color());
     }

     BlendModeBlock::AddToKey(&key, p.blendMode());

     auto entry = context->priv().shaderCodeDictionary()->findOrCreate(key);

     return { entry->uniqueID(), std::move(uniforms) };
 }

 SkSpan<const Uniform> GetUniforms(CodeSnippetID snippetID) {
     switch (snippetID) {
         case CodeSnippetID::kDepthStencilOnlyDraw:
             return {nullptr, 0};
         case CodeSnippetID::kLinearGradientShader:
             return SkMakeSpan(kGradientUniforms, kNumGradientUniforms);
         case CodeSnippetID::kSolidColorShader:
         case CodeSnippetID::kRadialGradientShader:
         case CodeSnippetID::kSweepGradientShader:
         case CodeSnippetID::kConicalGradientShader:
         default:
             return SkMakeSpan(kSolidUniforms, kNumSolidUniforms);
     }
 }

 const char* GetShaderSkSL(CodeSnippetID snippetID) {
     switch (snippetID) {
         case CodeSnippetID::kDepthStencilOnlyDraw:
             return kNoneSkSL;
         case CodeSnippetID::kLinearGradientShader:
             return kGradientSkSL;
         case CodeSnippetID::kSolidColorShader:
         case CodeSnippetID::kRadialGradientShader:
         case CodeSnippetID::kSweepGradientShader:
         case CodeSnippetID::kConicalGradientShader:
         default:
             return kSolidColorSkSL;
     }
 }

 } // namespace skgpu
	/*
	* Copyright 2021 Google LLC
	*
	* Use of this source code is governed by a BSD-style license that can be
	* found in the LICENSE file.
	*/

	#include "experimental/graphite/src/ContextUtils.h"

	#include <string>
	#include "experimental/graphite/src/ContextPriv.h"
	#include "experimental/graphite/src/DrawTypes.h"
	#include "experimental/graphite/src/PaintParams.h"
	#include "experimental/graphite/src/Uniform.h"
	#include "experimental/graphite/src/UniformManager.h"
	#include "include/core/SkPaint.h"
	#include "include/private/SkShaderCodeDictionary.h"
	#include "include/private/SkUniquePaintParamsID.h"
	#include "src/core/SkKeyHelpers.h"

	namespace skgpu {

	namespace {

	// TODO: For the sprint we only support 4 stops in the gradients
	static constexpr int kMaxStops = 4;
	// TODO: For the sprint we unify all the gradient uniforms into a standard set of 6:
	// kMaxStops colors
	// kMaxStops offsets
	// 2 points
	// 2 radii
	static constexpr int kNumGradientUniforms = 6;
	static constexpr Uniform kGradientUniforms[kNumGradientUniforms] {
	{"colors", SLType::kHalf4 , kMaxStops },
	{"offsets", SLType::kFloat, kMaxStops },
	{"point0", SLType::kFloat2 },
	{"point1", SLType::kFloat2 },
	{"radius0", SLType::kFloat },
	{"radius1", SLType::kFloat },
	};

	static constexpr int kNumSolidUniforms = 1;
	static constexpr Uniform kSolidUniforms[kNumSolidUniforms] {
	{"color", SLType::kFloat4 }
	};

	static const char* kGradientSkSL =
	// TODO: This should use local coords
	"float2 pos = sk_FragCoord.xy;\n"
	"float2 delta = point1 - point0;\n"
	"float2 pt = pos - point0;\n"
	"float t = dot(pt, delta) / dot(delta, delta);\n"
	"float4 result = colors[0];\n"
	"result = mix(result, colors[1],\n"
	" clamp((t-offsets[0])/(offsets[1]-offsets[0]),\n"
	" 0, 1));\n"
	"result = mix(result, colors[2],\n"
	" clamp((t-offsets[1])/(offsets[2]-offsets[1]),\n"
	" 0, 1));\n"
	"result = mix(result, colors[3],\n"
	" clamp((t-offsets[2])/(offsets[3]-offsets[2]),\n"
	" 0, 1));\n"
	"outColor = half4(result);\n";

	static const char* kSolidColorSkSL = " outColor = half4(color);\n";

	// TODO: kNone is for depth-only draws, so should actually have a fragment output type
	// that only defines a [[depth]] attribute but no color calculation.
	static const char* kNoneSkSL = "outColor = half4(0.0, 0.0, 1.0, 1.0);\n";

	sk_sp<UniformData> make_gradient_uniform_data_common(const void* srcs[kNumGradientUniforms]) {
	UniformManager mgr(Layout::kMetal);

	// TODO: Given that, for the sprint, we always know the uniforms we could cache 'dataSize'
	// for each layout and skip the first call.
	size_t dataSize = mgr.writeUniforms(SkSpan<const Uniform>(kGradientUniforms,
	kNumGradientUniforms),
	nullptr, nullptr, nullptr);

	sk_sp<UniformData> result = UniformData::Make(kNumGradientUniforms,
	kGradientUniforms,
	dataSize);

	mgr.writeUniforms(SkSpan<const Uniform>(kGradientUniforms, kNumGradientUniforms),
	srcs, result->offsets(), result->data());
	return result;
	}

	sk_sp<UniformData> make_linear_gradient_uniform_data(SkPoint startPoint,
	SkPoint endPoint,
	SkColor4f colors[kMaxStops],
	float offsets[kMaxStops]) {
	float unusedRadii[2] = { 0.0f, 0.0f };
	const void* srcs[kNumGradientUniforms] = {
	colors,
	offsets,
	&startPoint,
	&endPoint,
	&unusedRadii[0],
	&unusedRadii[1],
	};

	return make_gradient_uniform_data_common(srcs);
	};

	sk_sp<UniformData> make_radial_gradient_uniform_data(SkPoint point,
	float radius,
	SkColor4f colors[kMaxStops],
	float offsets[kMaxStops]) {
	SkPoint unusedPoint = {0.0f, 0.0f};
	float unusedRadius = 0.0f;

	const void* srcs[kNumGradientUniforms] = {
	colors,
	offsets,
	&point,
	&unusedPoint,
	&radius,
	&unusedRadius,
	};

	return make_gradient_uniform_data_common(srcs);
	};

	sk_sp<UniformData> make_sweep_gradient_uniform_data(SkPoint point,
	SkColor4f colors[kMaxStops],
	float offsets[kMaxStops]) {
	SkPoint unusedPoint = {0.0f, 0.0f};
	float unusedRadii[2] = {0.0f, 0.0f};

	const void* srcs[kNumGradientUniforms] = {
	colors,
	offsets,
	&point,
	&unusedPoint,
	&unusedRadii[0],
	&unusedRadii[1],
	};

	return make_gradient_uniform_data_common(srcs);
	};

	sk_sp<UniformData> make_conical_gradient_uniform_data(SkPoint point0,
	SkPoint point1,
	float radius0,
	float radius1,
	SkColor4f colors[kMaxStops],
	float offsets[kMaxStops]) {

	const void* srcs[kNumGradientUniforms] = {
	colors,
	offsets,
	&point0,
	&point1,
	&radius0,
	&radius1,
	};

	return make_gradient_uniform_data_common(srcs);
	};

	void to_color4fs(int numColors, SkColor colors[kMaxStops], SkColor4f color4fs[kMaxStops]) {
	SkASSERT(numColors >= 2 && numColors <= kMaxStops);

	int i;
	for (i = 0; i < numColors; ++i) {
	color4fs[i] = SkColor4f::FromColor(colors[i]);
	}
	for ( ; i < kMaxStops; ++i) {
	color4fs[i] = color4fs[numColors-1];
	}
	}

	void expand_stops(int numStops, float offsets[kMaxStops]) {
	SkASSERT(numStops >= 2 && numStops <= kMaxStops);

	for (int i = numStops ; i < kMaxStops; ++i) {
	offsets[i] = offsets[numStops-1];
	}
	}

	sk_sp<UniformData> make_solid_uniform_data(SkColor4f color) {
	UniformManager mgr(Layout::kMetal);

	size_t dataSize = mgr.writeUniforms(SkSpan<const Uniform>(kSolidUniforms, kNumSolidUniforms),
	nullptr, nullptr, nullptr);

	sk_sp<UniformData> result = UniformData::Make(kNumSolidUniforms, kSolidUniforms, dataSize);

	const void* srcs[kNumSolidUniforms] = { &color };

	mgr.writeUniforms(SkSpan<const Uniform>(kSolidUniforms, kNumSolidUniforms),
	srcs, result->offsets(), result->data());
	return result;
	}

	} // anonymous namespace

	sk_sp<UniformData> UniformData::Make(int count,
	const Uniform* uniforms,
	size_t dataSize) {
	// TODO: the offsets and data should just be allocated right after UniformData in an arena
	uint32_t* offsets = new uint32_t[count];
	char* data = new char[dataSize];

	return sk_sp<UniformData>(new UniformData(count, uniforms, offsets, data, dataSize));
	}

	std::tuple<SkUniquePaintParamsID, sk_sp<UniformData>> ExtractPaintData(Context* context,
	const PaintParams& p) {
	SkPaintParamsKey key;
	sk_sp<UniformData> uniforms;

	if (auto s = p.shader()) {
	SkColor colors[kMaxStops];
	SkColor4f color4fs[kMaxStops];
	float offsets[kMaxStops];
	SkShader::GradientInfo gradInfo;

	gradInfo.fColorCount = kMaxStops;
	gradInfo.fColors = colors;
	gradInfo.fColorOffsets = offsets;

	SkShader::GradientType type = s->asAGradient(&gradInfo);
	if (gradInfo.fColorCount > kMaxStops) {
	type = SkShader::GradientType::kNone_GradientType;
	}

	switch (type) {
	case SkShader::kLinear_GradientType: {
	to_color4fs(gradInfo.fColorCount, colors, color4fs);
	expand_stops(gradInfo.fColorCount, offsets);

	GradientShaderBlocks::AddToKey(&key, type, gradInfo.fTileMode);

	uniforms = make_linear_gradient_uniform_data(gradInfo.fPoint[0],
	gradInfo.fPoint[1],
	color4fs,
	offsets);
	} break;
	case SkShader::kRadial_GradientType: {
	to_color4fs(gradInfo.fColorCount, colors, color4fs);
	expand_stops(gradInfo.fColorCount, offsets);

	GradientShaderBlocks::AddToKey(&key, type, gradInfo.fTileMode);

	uniforms = make_radial_gradient_uniform_data(gradInfo.fPoint[0],
	gradInfo.fRadius[0],
	color4fs,
	offsets);
	} break;
	case SkShader::kSweep_GradientType:
	to_color4fs(gradInfo.fColorCount, colors, color4fs);
	expand_stops(gradInfo.fColorCount, offsets);

	GradientShaderBlocks::AddToKey(&key, type, gradInfo.fTileMode);

	uniforms = make_sweep_gradient_uniform_data(gradInfo.fPoint[0],
	color4fs,
	offsets);
	break;
	case SkShader::GradientType::kConical_GradientType:
	to_color4fs(gradInfo.fColorCount, colors, color4fs);
	expand_stops(gradInfo.fColorCount, offsets);

	GradientShaderBlocks::AddToKey(&key, type, gradInfo.fTileMode);

	uniforms = make_conical_gradient_uniform_data(gradInfo.fPoint[0],
	gradInfo.fPoint[1],
	gradInfo.fRadius[0],
	gradInfo.fRadius[1],
	color4fs,
	offsets);
	break;
	case SkShader::GradientType::kColor_GradientType:
	// TODO: The solid color gradient type should use its color, not
	// the paint color
	case SkShader::GradientType::kNone_GradientType:
	default:
	SolidColorShaderBlock::AddToKey(&key);

	uniforms = make_solid_uniform_data(p.color());
	break;
	}
	} else {
	// Solid colored paint
	SolidColorShaderBlock::AddToKey(&key);

	uniforms = make_solid_uniform_data(p.color());
	}

	BlendModeBlock::AddToKey(&key, p.blendMode());

	auto entry = context->priv().shaderCodeDictionary()->findOrCreate(key);

	return { entry->uniqueID(), std::move(uniforms) };
	}

	SkSpan<const Uniform> GetUniforms(CodeSnippetID snippetID) {
	switch (snippetID) {
	case CodeSnippetID::kDepthStencilOnlyDraw:
	return {nullptr, 0};
	case CodeSnippetID::kLinearGradientShader:
	return SkMakeSpan(kGradientUniforms, kNumGradientUniforms);
	case CodeSnippetID::kSolidColorShader:
	case CodeSnippetID::kRadialGradientShader:
	case CodeSnippetID::kSweepGradientShader:
	case CodeSnippetID::kConicalGradientShader:
	default:
	return SkMakeSpan(kSolidUniforms, kNumSolidUniforms);
	}
	}

	const char* GetShaderSkSL(CodeSnippetID snippetID) {
	switch (snippetID) {
	case CodeSnippetID::kDepthStencilOnlyDraw:
	return kNoneSkSL;
	case CodeSnippetID::kLinearGradientShader:
	return kGradientSkSL;
	case CodeSnippetID::kSolidColorShader:
	case CodeSnippetID::kRadialGradientShader:
	case CodeSnippetID::kSweepGradientShader:
	case CodeSnippetID::kConicalGradientShader:
	default:
	return kSolidColorSkSL;
	}
	}

	} // namespace skgpu