tests/GrMeshTest.cpp - platform/external/skia - Gitiles

 /*
  * Copyright 2017 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */

 #include "SkTypes.h"
 #include "Test.h"

 #if SK_SUPPORT_GPU

 #include "GrContext.h"
 #include "GrGeometryProcessor.h"
 #include "GrGpuCommandBuffer.h"
 #include "GrOpFlushState.h"
 #include "GrRenderTargetContext.h"
 #include "GrRenderTargetContextPriv.h"
 #include "GrResourceProvider.h"
 #include "GrResourceKey.h"
 #include "SkMakeUnique.h"
 #include "glsl/GrGLSLVertexShaderBuilder.h"
 #include "glsl/GrGLSLFragmentShaderBuilder.h"
 #include "glsl/GrGLSLGeometryProcessor.h"
 #include "glsl/GrGLSLVarying.h"
 #include <array>
 #include <vector>


 GR_DECLARE_STATIC_UNIQUE_KEY(gIndexBufferKey);

 static constexpr int kBoxSize = 2;
 static constexpr int kBoxCountY = 8;
 static constexpr int kBoxCountX = 8;
 static constexpr int kBoxCount = kBoxCountY * kBoxCountX;

 static constexpr int kImageWidth = kBoxCountY * kBoxSize;
 static constexpr int kImageHeight = kBoxCountX * kBoxSize;

 static constexpr int kIndexPatternRepeatCount = 3;
 constexpr uint16_t kIndexPattern[6] = {0, 1, 2, 1, 2, 3};


 class DrawMeshHelper {
 public:
     DrawMeshHelper(GrOpFlushState* state) : fState(state) {}

     sk_sp<const GrBuffer> getIndexBuffer();

     template<typename T> sk_sp<const GrBuffer> makeVertexBuffer(const SkTArray<T>& data) {
         return this->makeVertexBuffer(data.begin(), data.count());
     }
     template<typename T> sk_sp<const GrBuffer> makeVertexBuffer(const std::vector<T>& data) {
         return this->makeVertexBuffer(data.data(), data.size());
     }
     template<typename T> sk_sp<const GrBuffer> makeVertexBuffer(const T* data, int count);

     void drawMesh(const GrMesh& mesh);

 private:
     GrOpFlushState* fState;
 };

 struct Box {
     float fX, fY;
     GrColor fColor;
 };

 ////////////////////////////////////////////////////////////////////////////////////////////////////

 /**
  * This is a GPU-backend specific test. It tries to test all possible usecases of GrMesh. The test
  * works by drawing checkerboards of colored boxes, reading back the pixels, and comparing with
  * expected results. The boxes are drawn on integer boundaries and the (opaque) colors are chosen
  * from the set (r,g,b) = (0,255)^3, so the GPU renderings ought to produce exact matches.
  */

 static void run_test(const char* testName, skiatest::Reporter*, const sk_sp<GrRenderTargetContext>&,
                      const SkBitmap& gold, std::function<void(DrawMeshHelper*)> testFn);

 DEF_GPUTEST_FOR_RENDERING_CONTEXTS(GrMeshTest, reporter, ctxInfo) {
     GrContext* const context = ctxInfo.grContext();

     sk_sp<GrRenderTargetContext> rtc(
         context->makeDeferredRenderTargetContext(SkBackingFit::kExact, kImageWidth, kImageHeight,
                                                  kRGBA_8888_GrPixelConfig, nullptr));
     if (!rtc) {
         ERRORF(reporter, "could not create render target context.");
         return;
     }

     SkTArray<Box> boxes;
     SkTArray<std::array<Box, 4>> vertexData;
     SkBitmap gold;

     // ---- setup ----------

     SkPaint paint;
     paint.setBlendMode(SkBlendMode::kSrc);
     gold.allocN32Pixels(kImageWidth, kImageHeight);

     SkCanvas goldCanvas(gold);

     for (int y = 0; y < kBoxCountY; ++y) {
         for (int x = 0; x < kBoxCountX; ++x) {
             int c = y + x;
             int rgb[3] = {-(c & 1) & 0xff, -((c >> 1) & 1) & 0xff, -((c >> 2) & 1) & 0xff};

             const Box box = boxes.push_back() = {
                 float(x * kBoxSize),
                 float(y * kBoxSize),
                 GrColorPackRGBA(rgb[0], rgb[1], rgb[2], 255)
             };

             std::array<Box, 4>& boxVertices = vertexData.push_back();
             for (int i = 0; i < 4; ++i) {
                 boxVertices[i] = {
                     box.fX + (i/2) * kBoxSize,
                     box.fY + (i%2) * kBoxSize,
                     box.fColor
                 };
             }

             paint.setARGB(255, rgb[0], rgb[1], rgb[2]);
             goldCanvas.drawRect(SkRect::MakeXYWH(box.fX, box.fY, kBoxSize, kBoxSize), paint);
         }
     }

     goldCanvas.flush();

     // ---- tests ----------

 #define VALIDATE(buff) \
     if (!buff) { \
         ERRORF(reporter, #buff " is null."); \
         return; \
     }

     run_test("setNonIndexedNonInstanced", reporter, rtc, gold, [&](DrawMeshHelper* helper) {
         SkTArray<Box> expandedVertexData;
         for (int i = 0; i < kBoxCount; ++i) {
             for (int j = 0; j < 6; ++j) {
                 expandedVertexData.push_back(vertexData[i][kIndexPattern[j]]);
             }
         }

         // Draw boxes one line at a time to exercise base vertex.
         auto vbuff = helper->makeVertexBuffer(expandedVertexData);
         VALIDATE(vbuff);
         for (int y = 0; y < kBoxCountY; ++y) {
             GrMesh mesh(GrPrimitiveType::kTriangles);
             mesh.setNonIndexedNonInstanced(kBoxCountX * 6);
             mesh.setVertexData(vbuff.get(), y * kBoxCountX * 6);
             helper->drawMesh(mesh);
         }
     });

     run_test("setIndexed", reporter, rtc, gold, [&](DrawMeshHelper* helper) {
         auto ibuff = helper->getIndexBuffer();
         VALIDATE(ibuff);
         auto vbuff = helper->makeVertexBuffer(vertexData);
         VALIDATE(vbuff);
         int baseRepetition = 0;
         int i = 0;

         // Start at various repetitions within the patterned index buffer to exercise base index.
         while (i < kBoxCount) {
             GR_STATIC_ASSERT(kIndexPatternRepeatCount >= 3);
             int repetitionCount = SkTMin(3 - baseRepetition, kBoxCount - i);

             GrMesh mesh(GrPrimitiveType::kTriangles);
             mesh.setIndexed(ibuff.get(), repetitionCount * 6, baseRepetition * 6,
                             baseRepetition * 4, (baseRepetition + repetitionCount) * 4 - 1);
             mesh.setVertexData(vbuff.get(), (i - baseRepetition) * 4);
             helper->drawMesh(mesh);

             baseRepetition = (baseRepetition + 1) % 3;
             i += repetitionCount;
         }
     });

     run_test("setIndexedPatterned", reporter, rtc, gold, [&](DrawMeshHelper* helper) {
         auto ibuff = helper->getIndexBuffer();
         VALIDATE(ibuff);
         auto vbuff = helper->makeVertexBuffer(vertexData);
         VALIDATE(vbuff);

         // Draw boxes one line at a time to exercise base vertex. setIndexedPatterned does not
         // support a base index.
         for (int y = 0; y < kBoxCountY; ++y) {
             GrMesh mesh(GrPrimitiveType::kTriangles);
             mesh.setIndexedPatterned(ibuff.get(), 6, 4, kBoxCountX, kIndexPatternRepeatCount);
             mesh.setVertexData(vbuff.get(), y * kBoxCountX * 4);
             helper->drawMesh(mesh);
         }
     });

     for (bool indexed : {false, true}) {
         if (!context->caps()->instanceAttribSupport()) {
             break;
         }

         run_test(indexed ? "setIndexedInstanced" : "setInstanced",
                  reporter, rtc, gold, [&](DrawMeshHelper* helper) {
             auto idxbuff = indexed ? helper->getIndexBuffer() : nullptr;
             auto instbuff = helper->makeVertexBuffer(boxes);
             VALIDATE(instbuff);
             auto vbuff = helper->makeVertexBuffer(std::vector<float>{0,0, 0,1, 1,0, 1,1});
             VALIDATE(vbuff);
             auto vbuff2 = helper->makeVertexBuffer( // for testing base vertex.
                               std::vector<float>{-1,-1, -1,-1, 0,0, 0,1, 1,0, 1,1});
             VALIDATE(vbuff2);

             // Draw boxes one line at a time to exercise base instance, base vertex, and null vertex
             // buffer. setIndexedInstanced intentionally does not support a base index.
             for (int y = 0; y < kBoxCountY; ++y) {
                 GrMesh mesh(indexed ? GrPrimitiveType::kTriangles
                                     : GrPrimitiveType::kTriangleStrip);
                 if (indexed) {
                     VALIDATE(idxbuff);
                     mesh.setIndexedInstanced(idxbuff.get(), 6,
                                              instbuff.get(), kBoxCountX, y * kBoxCountX);
                 } else {
                     mesh.setInstanced(instbuff.get(), kBoxCountX, y * kBoxCountX, 4);
                 }
                 switch (y % 3) {
                     case 0:
                         if (context->caps()->shaderCaps()->vertexIDSupport()) {
                             if (y % 2) {
                                 // We don't need this call because it's the initial state of GrMesh.
                                 mesh.setVertexData(nullptr);
                             }
                             break;
                         }
                         // Fallthru.
                     case 1:
                         mesh.setVertexData(vbuff.get());
                         break;
                     case 2:
                         mesh.setVertexData(vbuff2.get(), 2);
                         break;
                 }
                 helper->drawMesh(mesh);
             }
         });
     }
 }

 ////////////////////////////////////////////////////////////////////////////////////////////////////

 class GrMeshTestOp : public GrDrawOp {
 public:
     DEFINE_OP_CLASS_ID

     GrMeshTestOp(std::function<void(DrawMeshHelper*)> testFn)
         : INHERITED(ClassID())
         , fTestFn(testFn) {
         this->setBounds(SkRect::MakeIWH(kImageWidth, kImageHeight),
                         HasAABloat::kNo, IsZeroArea::kNo);
     }

 private:
     const char* name() const override { return "GrMeshTestOp"; }
     FixedFunctionFlags fixedFunctionFlags() const override { return FixedFunctionFlags::kNone; }
     RequiresDstTexture finalize(const GrCaps&, const GrAppliedClip*,
                                 GrPixelConfigIsClamped) override {
         return RequiresDstTexture::kNo;
     }
     bool onCombineIfPossible(GrOp* other, const GrCaps& caps) override { return false; }
     void onPrepare(GrOpFlushState*) override {}
     void onExecute(GrOpFlushState* state) override {
         DrawMeshHelper helper(state);
         fTestFn(&helper);
     }

     std::function<void(DrawMeshHelper*)> fTestFn;

     typedef GrDrawOp INHERITED;
 };

 class GrMeshTestProcessor : public GrGeometryProcessor {
 public:
     GrMeshTestProcessor(bool instanced, bool hasVertexBuffer)
         : fInstanceLocation(nullptr)
         , fVertex(nullptr)
         , fColor(nullptr) {
         if (instanced) {
             fInstanceLocation = &this->addInstanceAttrib("location", kHalf2_GrVertexAttribType);
             if (hasVertexBuffer) {
                 fVertex = &this->addVertexAttrib("vertex", kHalf2_GrVertexAttribType);
             }
             fColor = &this->addInstanceAttrib("color", kUByte4_norm_GrVertexAttribType);
         } else {
             fVertex = &this->addVertexAttrib("vertex", kHalf2_GrVertexAttribType);
             fColor = &this->addVertexAttrib("color", kUByte4_norm_GrVertexAttribType);
         }
         this->initClassID<GrMeshTestProcessor>();
     }

     const char* name() const override { return "GrMeshTest Processor"; }

     void getGLSLProcessorKey(const GrShaderCaps&, GrProcessorKeyBuilder* b) const final {
         b->add32(SkToBool(fInstanceLocation));
         b->add32(SkToBool(fVertex));
     }

     GrGLSLPrimitiveProcessor* createGLSLInstance(const GrShaderCaps&) const final;

 protected:
     const Attribute* fInstanceLocation;
     const Attribute* fVertex;
     const Attribute* fColor;

     friend class GLSLMeshTestProcessor;
     typedef GrGeometryProcessor INHERITED;
 };

 class GLSLMeshTestProcessor : public GrGLSLGeometryProcessor {
     void setData(const GrGLSLProgramDataManager& pdman, const GrPrimitiveProcessor&,
                  FPCoordTransformIter&& transformIter) final {}

     void onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) final {
         const GrMeshTestProcessor& mp = args.fGP.cast<GrMeshTestProcessor>();

         GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler;
         varyingHandler->emitAttributes(mp);
         varyingHandler->addPassThroughAttribute(mp.fColor, args.fOutputColor);

         GrGLSLVertexBuilder* v = args.fVertBuilder;
         if (!mp.fInstanceLocation) {
             v->codeAppendf("float2 vertex = %s;", mp.fVertex->fName);
         } else {
             if (mp.fVertex) {
                 v->codeAppendf("float2 offset = %s;", mp.fVertex->fName);
             } else {
                 v->codeAppend ("float2 offset = float2(sk_VertexID / 2, sk_VertexID % 2);");
             }
             v->codeAppendf("float2 vertex = %s + offset * %i;",
                            mp.fInstanceLocation->fName, kBoxSize);
         }
         gpArgs->fPositionVar.set(kFloat2_GrSLType, "vertex");

         GrGLSLPPFragmentBuilder* f = args.fFragBuilder;
         f->codeAppendf("%s = half4(1);", args.fOutputCoverage);
     }
 };

 GrGLSLPrimitiveProcessor* GrMeshTestProcessor::createGLSLInstance(const GrShaderCaps&) const {
     return new GLSLMeshTestProcessor;
 }

 ////////////////////////////////////////////////////////////////////////////////////////////////////

 template<typename T>
 sk_sp<const GrBuffer> DrawMeshHelper::makeVertexBuffer(const T* data, int count) {
     return sk_sp<const GrBuffer>(
         fState->resourceProvider()->createBuffer(
             count * sizeof(T), kVertex_GrBufferType, kDynamic_GrAccessPattern,
             GrResourceProvider::kNoPendingIO_Flag |
             GrResourceProvider::kRequireGpuMemory_Flag, data));
 }

 sk_sp<const GrBuffer> DrawMeshHelper::getIndexBuffer() {
     GR_DEFINE_STATIC_UNIQUE_KEY(gIndexBufferKey);
     return sk_sp<const GrBuffer>(
         fState->resourceProvider()->findOrCreatePatternedIndexBuffer(
             kIndexPattern, 6, kIndexPatternRepeatCount, 4, gIndexBufferKey));
 }

 void DrawMeshHelper::drawMesh(const GrMesh& mesh) {
     GrRenderTargetProxy* proxy = fState->drawOpArgs().fProxy;
     GrPipeline pipeline(proxy, GrPipeline::ScissorState::kDisabled, SkBlendMode::kSrc);
     GrMeshTestProcessor mtp(mesh.isInstanced(), mesh.hasVertexData());
     fState->rtCommandBuffer()->draw(pipeline, mtp, &mesh, nullptr, 1,
                                     SkRect::MakeIWH(kImageWidth, kImageHeight));
 }

 static void run_test(const char* testName, skiatest::Reporter* reporter,
                      const sk_sp<GrRenderTargetContext>& rtc, const SkBitmap& gold,
                      std::function<void(DrawMeshHelper*)> testFn) {
     const int w = gold.width(), h = gold.height(), rowBytes = gold.rowBytes();
     const uint32_t* goldPx = reinterpret_cast<const uint32_t*>(gold.getPixels());
     if (h != rtc->height() || w != rtc->width()) {
         ERRORF(reporter, "[%s] expectation and rtc not compatible (?).", testName);
         return;
     }
     if (sizeof(uint32_t) * kImageWidth != gold.rowBytes()) {
         ERRORF(reporter, "unexpected row bytes in gold image.", testName);
         return;
     }

     SkAutoSTMalloc<kImageHeight * kImageWidth, uint32_t> resultPx(h * rowBytes);
     rtc->clear(nullptr, 0xbaaaaaad, true);
     rtc->priv().testingOnly_addDrawOp(skstd::make_unique<GrMeshTestOp>(testFn));
     rtc->readPixels(gold.info(), resultPx, rowBytes, 0, 0, 0);
     for (int y = 0; y < h; ++y) {
         for (int x = 0; x < w; ++x) {
             uint32_t expected = goldPx[y * kImageWidth + x];
             uint32_t actual = resultPx[y * kImageWidth + x];
             if (expected != actual) {
                 ERRORF(reporter, "[%s] pixel (%i,%i): got 0x%x expected 0x%x",
                        testName, x, y, actual, expected);
                 return;
             }
         }
     }
 }

 #endif
	/*
	* Copyright 2017 Google Inc.
	*
	* Use of this source code is governed by a BSD-style license that can be
	* found in the LICENSE file.
	*/

	#include "SkTypes.h"
	#include "Test.h"

	#if SK_SUPPORT_GPU

	#include "GrContext.h"
	#include "GrGeometryProcessor.h"
	#include "GrGpuCommandBuffer.h"
	#include "GrOpFlushState.h"
	#include "GrRenderTargetContext.h"
	#include "GrRenderTargetContextPriv.h"
	#include "GrResourceProvider.h"
	#include "GrResourceKey.h"
	#include "SkMakeUnique.h"
	#include "glsl/GrGLSLVertexShaderBuilder.h"
	#include "glsl/GrGLSLFragmentShaderBuilder.h"
	#include "glsl/GrGLSLGeometryProcessor.h"
	#include "glsl/GrGLSLVarying.h"
	#include <array>
	#include <vector>


	GR_DECLARE_STATIC_UNIQUE_KEY(gIndexBufferKey);

	static constexpr int kBoxSize = 2;
	static constexpr int kBoxCountY = 8;
	static constexpr int kBoxCountX = 8;
	static constexpr int kBoxCount = kBoxCountY * kBoxCountX;

	static constexpr int kImageWidth = kBoxCountY * kBoxSize;
	static constexpr int kImageHeight = kBoxCountX * kBoxSize;

	static constexpr int kIndexPatternRepeatCount = 3;
	constexpr uint16_t kIndexPattern[6] = {0, 1, 2, 1, 2, 3};


	class DrawMeshHelper {
	public:
	DrawMeshHelper(GrOpFlushState* state) : fState(state) {}

	sk_sp<const GrBuffer> getIndexBuffer();

	template<typename T> sk_sp<const GrBuffer> makeVertexBuffer(const SkTArray<T>& data) {
	return this->makeVertexBuffer(data.begin(), data.count());
	}
	template<typename T> sk_sp<const GrBuffer> makeVertexBuffer(const std::vector<T>& data) {
	return this->makeVertexBuffer(data.data(), data.size());
	}
	template<typename T> sk_sp<const GrBuffer> makeVertexBuffer(const T* data, int count);

	void drawMesh(const GrMesh& mesh);

	private:
	GrOpFlushState* fState;
	};

	struct Box {
	float fX, fY;
	GrColor fColor;
	};

	////////////////////////////////////////////////////////////////////////////////////////////////////

	/**
	* This is a GPU-backend specific test. It tries to test all possible usecases of GrMesh. The test
	* works by drawing checkerboards of colored boxes, reading back the pixels, and comparing with
	* expected results. The boxes are drawn on integer boundaries and the (opaque) colors are chosen
	* from the set (r,g,b) = (0,255)^3, so the GPU renderings ought to produce exact matches.
	*/

	static void run_test(const char* testName, skiatest::Reporter*, const sk_sp<GrRenderTargetContext>&,
	const SkBitmap& gold, std::function<void(DrawMeshHelper*)> testFn);

	DEF_GPUTEST_FOR_RENDERING_CONTEXTS(GrMeshTest, reporter, ctxInfo) {
	GrContext* const context = ctxInfo.grContext();

	sk_sp<GrRenderTargetContext> rtc(
	context->makeDeferredRenderTargetContext(SkBackingFit::kExact, kImageWidth, kImageHeight,
	kRGBA_8888_GrPixelConfig, nullptr));
	if (!rtc) {
	ERRORF(reporter, "could not create render target context.");
	return;
	}

	SkTArray<Box> boxes;
	SkTArray<std::array<Box, 4>> vertexData;
	SkBitmap gold;

	// ---- setup ----------

	SkPaint paint;
	paint.setBlendMode(SkBlendMode::kSrc);
	gold.allocN32Pixels(kImageWidth, kImageHeight);

	SkCanvas goldCanvas(gold);

	for (int y = 0; y < kBoxCountY; ++y) {
	for (int x = 0; x < kBoxCountX; ++x) {
	int c = y + x;
	int rgb[3] = {-(c & 1) & 0xff, -((c >> 1) & 1) & 0xff, -((c >> 2) & 1) & 0xff};

	const Box box = boxes.push_back() = {
	float(x * kBoxSize),
	float(y * kBoxSize),
	GrColorPackRGBA(rgb[0], rgb[1], rgb[2], 255)
	};

	std::array<Box, 4>& boxVertices = vertexData.push_back();
	for (int i = 0; i < 4; ++i) {
	boxVertices[i] = {
	box.fX + (i/2) * kBoxSize,
	box.fY + (i%2) * kBoxSize,
	box.fColor
	};
	}

	paint.setARGB(255, rgb[0], rgb[1], rgb[2]);
	goldCanvas.drawRect(SkRect::MakeXYWH(box.fX, box.fY, kBoxSize, kBoxSize), paint);
	}
	}

	goldCanvas.flush();

	// ---- tests ----------

	#define VALIDATE(buff) \
	if (!buff) { \
	ERRORF(reporter, #buff " is null."); \
	return; \
	}

	run_test("setNonIndexedNonInstanced", reporter, rtc, gold, [&](DrawMeshHelper* helper) {
	SkTArray<Box> expandedVertexData;
	for (int i = 0; i < kBoxCount; ++i) {
	for (int j = 0; j < 6; ++j) {
	expandedVertexData.push_back(vertexData[i][kIndexPattern[j]]);
	}
	}

	// Draw boxes one line at a time to exercise base vertex.
	auto vbuff = helper->makeVertexBuffer(expandedVertexData);
	VALIDATE(vbuff);
	for (int y = 0; y < kBoxCountY; ++y) {
	GrMesh mesh(GrPrimitiveType::kTriangles);
	mesh.setNonIndexedNonInstanced(kBoxCountX * 6);
	mesh.setVertexData(vbuff.get(), y * kBoxCountX * 6);
	helper->drawMesh(mesh);
	}
	});

	run_test("setIndexed", reporter, rtc, gold, [&](DrawMeshHelper* helper) {
	auto ibuff = helper->getIndexBuffer();
	VALIDATE(ibuff);
	auto vbuff = helper->makeVertexBuffer(vertexData);
	VALIDATE(vbuff);
	int baseRepetition = 0;
	int i = 0;

	// Start at various repetitions within the patterned index buffer to exercise base index.
	while (i < kBoxCount) {
	GR_STATIC_ASSERT(kIndexPatternRepeatCount >= 3);
	int repetitionCount = SkTMin(3 - baseRepetition, kBoxCount - i);

	GrMesh mesh(GrPrimitiveType::kTriangles);
	mesh.setIndexed(ibuff.get(), repetitionCount * 6, baseRepetition * 6,
	baseRepetition * 4, (baseRepetition + repetitionCount) * 4 - 1);
	mesh.setVertexData(vbuff.get(), (i - baseRepetition) * 4);
	helper->drawMesh(mesh);

	baseRepetition = (baseRepetition + 1) % 3;
	i += repetitionCount;
	}
	});

	run_test("setIndexedPatterned", reporter, rtc, gold, [&](DrawMeshHelper* helper) {
	auto ibuff = helper->getIndexBuffer();
	VALIDATE(ibuff);
	auto vbuff = helper->makeVertexBuffer(vertexData);
	VALIDATE(vbuff);

	// Draw boxes one line at a time to exercise base vertex. setIndexedPatterned does not
	// support a base index.
	for (int y = 0; y < kBoxCountY; ++y) {
	GrMesh mesh(GrPrimitiveType::kTriangles);
	mesh.setIndexedPatterned(ibuff.get(), 6, 4, kBoxCountX, kIndexPatternRepeatCount);
	mesh.setVertexData(vbuff.get(), y * kBoxCountX * 4);
	helper->drawMesh(mesh);
	}
	});

	for (bool indexed : {false, true}) {
	if (!context->caps()->instanceAttribSupport()) {
	break;
	}

	run_test(indexed ? "setIndexedInstanced" : "setInstanced",
	reporter, rtc, gold, [&](DrawMeshHelper* helper) {
	auto idxbuff = indexed ? helper->getIndexBuffer() : nullptr;
	auto instbuff = helper->makeVertexBuffer(boxes);
	VALIDATE(instbuff);
	auto vbuff = helper->makeVertexBuffer(std::vector<float>{0,0, 0,1, 1,0, 1,1});
	VALIDATE(vbuff);
	auto vbuff2 = helper->makeVertexBuffer( // for testing base vertex.
	std::vector<float>{-1,-1, -1,-1, 0,0, 0,1, 1,0, 1,1});
	VALIDATE(vbuff2);

	// Draw boxes one line at a time to exercise base instance, base vertex, and null vertex
	// buffer. setIndexedInstanced intentionally does not support a base index.
	for (int y = 0; y < kBoxCountY; ++y) {
	GrMesh mesh(indexed ? GrPrimitiveType::kTriangles
	: GrPrimitiveType::kTriangleStrip);
	if (indexed) {
	VALIDATE(idxbuff);
	mesh.setIndexedInstanced(idxbuff.get(), 6,
	instbuff.get(), kBoxCountX, y * kBoxCountX);
	} else {
	mesh.setInstanced(instbuff.get(), kBoxCountX, y * kBoxCountX, 4);
	}
	switch (y % 3) {
	case 0:
	if (context->caps()->shaderCaps()->vertexIDSupport()) {
	if (y % 2) {
	// We don't need this call because it's the initial state of GrMesh.
	mesh.setVertexData(nullptr);
	}
	break;
	}
	// Fallthru.
	case 1:
	mesh.setVertexData(vbuff.get());
	break;
	case 2:
	mesh.setVertexData(vbuff2.get(), 2);
	break;
	}
	helper->drawMesh(mesh);
	}
	});
	}
	}

	////////////////////////////////////////////////////////////////////////////////////////////////////

	class GrMeshTestOp : public GrDrawOp {
	public:
	DEFINE_OP_CLASS_ID

	GrMeshTestOp(std::function<void(DrawMeshHelper*)> testFn)
	: INHERITED(ClassID())
	, fTestFn(testFn) {
	this->setBounds(SkRect::MakeIWH(kImageWidth, kImageHeight),
	HasAABloat::kNo, IsZeroArea::kNo);
	}

	private:
	const char* name() const override { return "GrMeshTestOp"; }
	FixedFunctionFlags fixedFunctionFlags() const override { return FixedFunctionFlags::kNone; }
	RequiresDstTexture finalize(const GrCaps&, const GrAppliedClip*,
	GrPixelConfigIsClamped) override {
	return RequiresDstTexture::kNo;
	}
	bool onCombineIfPossible(GrOp* other, const GrCaps& caps) override { return false; }
	void onPrepare(GrOpFlushState*) override {}
	void onExecute(GrOpFlushState* state) override {
	DrawMeshHelper helper(state);
	fTestFn(&helper);
	}

	std::function<void(DrawMeshHelper*)> fTestFn;

	typedef GrDrawOp INHERITED;
	};

	class GrMeshTestProcessor : public GrGeometryProcessor {
	public:
	GrMeshTestProcessor(bool instanced, bool hasVertexBuffer)
	: fInstanceLocation(nullptr)
	, fVertex(nullptr)
	, fColor(nullptr) {
	if (instanced) {
	fInstanceLocation = &this->addInstanceAttrib("location", kHalf2_GrVertexAttribType);
	if (hasVertexBuffer) {
	fVertex = &this->addVertexAttrib("vertex", kHalf2_GrVertexAttribType);
	}
	fColor = &this->addInstanceAttrib("color", kUByte4_norm_GrVertexAttribType);
	} else {
	fVertex = &this->addVertexAttrib("vertex", kHalf2_GrVertexAttribType);
	fColor = &this->addVertexAttrib("color", kUByte4_norm_GrVertexAttribType);
	}
	this->initClassID<GrMeshTestProcessor>();
	}

	const char* name() const override { return "GrMeshTest Processor"; }

	void getGLSLProcessorKey(const GrShaderCaps&, GrProcessorKeyBuilder* b) const final {
	b->add32(SkToBool(fInstanceLocation));
	b->add32(SkToBool(fVertex));
	}

	GrGLSLPrimitiveProcessor* createGLSLInstance(const GrShaderCaps&) const final;

	protected:
	const Attribute* fInstanceLocation;
	const Attribute* fVertex;
	const Attribute* fColor;

	friend class GLSLMeshTestProcessor;
	typedef GrGeometryProcessor INHERITED;
	};

	class GLSLMeshTestProcessor : public GrGLSLGeometryProcessor {
	void setData(const GrGLSLProgramDataManager& pdman, const GrPrimitiveProcessor&,
	FPCoordTransformIter&& transformIter) final {}

	void onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) final {
	const GrMeshTestProcessor& mp = args.fGP.cast<GrMeshTestProcessor>();

	GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler;
	varyingHandler->emitAttributes(mp);
	varyingHandler->addPassThroughAttribute(mp.fColor, args.fOutputColor);

	GrGLSLVertexBuilder* v = args.fVertBuilder;
	if (!mp.fInstanceLocation) {
	v->codeAppendf("float2 vertex = %s;", mp.fVertex->fName);
	} else {
	if (mp.fVertex) {
	v->codeAppendf("float2 offset = %s;", mp.fVertex->fName);
	} else {
	v->codeAppend ("float2 offset = float2(sk_VertexID / 2, sk_VertexID % 2);");
	}
	v->codeAppendf("float2 vertex = %s + offset * %i;",
	mp.fInstanceLocation->fName, kBoxSize);
	}
	gpArgs->fPositionVar.set(kFloat2_GrSLType, "vertex");

	GrGLSLPPFragmentBuilder* f = args.fFragBuilder;
	f->codeAppendf("%s = half4(1);", args.fOutputCoverage);
	}
	};

	GrGLSLPrimitiveProcessor* GrMeshTestProcessor::createGLSLInstance(const GrShaderCaps&) const {
	return new GLSLMeshTestProcessor;
	}

	////////////////////////////////////////////////////////////////////////////////////////////////////

	template<typename T>
	sk_sp<const GrBuffer> DrawMeshHelper::makeVertexBuffer(const T* data, int count) {
	return sk_sp<const GrBuffer>(
	fState->resourceProvider()->createBuffer(
	count * sizeof(T), kVertex_GrBufferType, kDynamic_GrAccessPattern,
	GrResourceProvider::kNoPendingIO_Flag \|
	GrResourceProvider::kRequireGpuMemory_Flag, data));
	}

	sk_sp<const GrBuffer> DrawMeshHelper::getIndexBuffer() {
	GR_DEFINE_STATIC_UNIQUE_KEY(gIndexBufferKey);
	return sk_sp<const GrBuffer>(
	fState->resourceProvider()->findOrCreatePatternedIndexBuffer(
	kIndexPattern, 6, kIndexPatternRepeatCount, 4, gIndexBufferKey));
	}

	void DrawMeshHelper::drawMesh(const GrMesh& mesh) {
	GrRenderTargetProxy* proxy = fState->drawOpArgs().fProxy;
	GrPipeline pipeline(proxy, GrPipeline::ScissorState::kDisabled, SkBlendMode::kSrc);
	GrMeshTestProcessor mtp(mesh.isInstanced(), mesh.hasVertexData());
	fState->rtCommandBuffer()->draw(pipeline, mtp, &mesh, nullptr, 1,
	SkRect::MakeIWH(kImageWidth, kImageHeight));
	}

	static void run_test(const char* testName, skiatest::Reporter* reporter,
	const sk_sp<GrRenderTargetContext>& rtc, const SkBitmap& gold,
	std::function<void(DrawMeshHelper*)> testFn) {
	const int w = gold.width(), h = gold.height(), rowBytes = gold.rowBytes();
	const uint32_t* goldPx = reinterpret_cast<const uint32_t*>(gold.getPixels());
	if (h != rtc->height() \|\| w != rtc->width()) {
	ERRORF(reporter, "[%s] expectation and rtc not compatible (?).", testName);
	return;
	}
	if (sizeof(uint32_t) * kImageWidth != gold.rowBytes()) {
	ERRORF(reporter, "unexpected row bytes in gold image.", testName);
	return;
	}

	SkAutoSTMalloc<kImageHeight * kImageWidth, uint32_t> resultPx(h * rowBytes);
	rtc->clear(nullptr, 0xbaaaaaad, true);
	rtc->priv().testingOnly_addDrawOp(skstd::make_unique<GrMeshTestOp>(testFn));
	rtc->readPixels(gold.info(), resultPx, rowBytes, 0, 0, 0);
	for (int y = 0; y < h; ++y) {
	for (int x = 0; x < w; ++x) {
	uint32_t expected = goldPx[y * kImageWidth + x];
	uint32_t actual = resultPx[y * kImageWidth + x];
	if (expected != actual) {
	ERRORF(reporter, "[%s] pixel (%i,%i): got 0x%x expected 0x%x",
	testName, x, y, actual, expected);
	return;
	}
	}
	}
	}

	#endif