bench/GLInstancedArraysBench.cpp - platform/external/skqp - Gitiles

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */

 #include "Benchmark.h"
 #include "SkCanvas.h"
 #include "SkImageEncoder.h"

 #if SK_SUPPORT_GPU
 #include "GLBench.h"
 #include "gl/GrGLContext.h"
 #include "gl/GrGLInterface.h"
 #include "gl/GrGLUtil.h"
 #include "glsl/GrGLSL.h"
 #include "glsl/GrGLSLCaps.h"
 #include "glsl/GrGLSLShaderVar.h"

 /*
  * This is a native GL benchmark for instanced arrays vs vertex buffer objects.  To benchmark this
  * functionality, we draw n * kDrawMultipier triangles per run.  If this number is less than
  * kNumTri then we do a single draw, either with instances, or drawArrays.  Otherwise we do
  * multiple draws.
  *
  * Additionally, there is a divisor, which if > 0 will act as a multiplier for the number of draws
  * issued.
  */

 class GLCpuPosInstancedArraysBench : public GLBench {
 public:
     /*
      * Clients can decide to use either:
      * kUseOne_VboSetup      - one vertex buffer with colors and positions interleaved
      * kUseTwo_VboSetup      - two vertex buffers, one for colors, one for positions
      * kUseInstance_VboSetup - two vertex buffers, one with per vertex indices, one with per
      *                         instance colors
      */
     enum VboSetup {
         kUseOne_VboSetup,
         kUseTwo_VboSetup,
         kUseInstance_VboSetup,
     };

     /*
      * drawDiv will act as a multiplier for the number of draws we issue if > 0. ie, 2 will issue
      * 2x as many draws, 4 will issue 4x as many draws etc.  There is a limit however, which is
      * kDrawMultipier.
      */
     GLCpuPosInstancedArraysBench(VboSetup vboSetup, int32_t drawDiv)
         : fVboSetup(vboSetup)
         , fDrawDiv(drawDiv)
         , fProgram(0)
         , fVAO(0) {
         fName = VboSetupToStr(vboSetup, fDrawDiv);
     }

 protected:
     const char* onGetName() override {
         return fName.c_str();
     }

     const GrGLContext* onGetGLContext(const GrGLContext*) override;
     void setup(const GrGLContext*) override;
     void glDraw(int loops, const GrGLContext*) override;
     void teardown(const GrGLInterface*) override;

 private:
     void setupInstanceVbo(const GrGLInterface*, const SkMatrix*);
     void setupDoubleVbo(const GrGLInterface*, const SkMatrix*);
     void setupSingleVbo(const GrGLInterface*, const SkMatrix*);
     GrGLuint setupShader(const GrGLContext*);

     static SkString VboSetupToStr(VboSetup vboSetup, uint32_t drawDiv) {
         SkString name("GLInstancedArraysBench");
         switch (vboSetup) {
             default:
             case kUseOne_VboSetup:
                 name.appendf("_one_%u", drawDiv);
                 break;
             case kUseTwo_VboSetup:
                 name.appendf("_two_%u", drawDiv);
                 break;
             case kUseInstance_VboSetup:
                 name.append("_instance");
                 break;
         }
         return name;
     }

     static const GrGLuint kScreenWidth = 800;
     static const GrGLuint kScreenHeight = 600;
     static const uint32_t kNumTri = 10000;
     static const uint32_t kVerticesPerTri = 3;
     static const uint32_t kDrawMultiplier = 512;

     SkString fName;
     VboSetup fVboSetup;
     uint32_t fDrawDiv;
     SkTArray<GrGLuint> fBuffers;
     GrGLuint fProgram;
     GrGLuint fVAO;
     GrGLuint fTexture;
 };

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

 GrGLuint GLCpuPosInstancedArraysBench::setupShader(const GrGLContext* ctx) {
     const GrGLSLCaps* glslCaps = ctx->caps()->glslCaps();
     const char* version = glslCaps->versionDeclString();

     // setup vertex shader
     GrGLSLShaderVar aPosition("a_position", kVec2f_GrSLType, GrShaderVar::kAttribute_TypeModifier);
     GrGLSLShaderVar aColor("a_color", kVec3f_GrSLType, GrShaderVar::kAttribute_TypeModifier);
     GrGLSLShaderVar oColor("o_color", kVec3f_GrSLType, GrShaderVar::kVaryingOut_TypeModifier);

     SkString vshaderTxt(version);
     aPosition.appendDecl(glslCaps, &vshaderTxt);
     vshaderTxt.append(";\n");
     aColor.appendDecl(glslCaps, &vshaderTxt);
     vshaderTxt.append(";\n");
     oColor.appendDecl(glslCaps, &vshaderTxt);
     vshaderTxt.append(";\n");

     vshaderTxt.append(
             "void main()\n"
             "{\n"
                 "gl_Position = vec4(a_position, 0.f, 1.f);\n"
                 "o_color = a_color;\n"
             "}\n");

     const GrGLInterface* gl = ctx->interface();

     // setup fragment shader
     GrGLSLShaderVar oFragColor("o_FragColor", kVec4f_GrSLType, GrShaderVar::kOut_TypeModifier);
     SkString fshaderTxt(version);
     GrGLSLAppendDefaultFloatPrecisionDeclaration(kDefault_GrSLPrecision, *glslCaps, &fshaderTxt);
     oColor.setTypeModifier(GrShaderVar::kVaryingIn_TypeModifier);
     oColor.appendDecl(glslCaps, &fshaderTxt);
     fshaderTxt.append(";\n");

     const char* fsOutName;
     if (glslCaps->mustDeclareFragmentShaderOutput()) {
         oFragColor.appendDecl(glslCaps, &fshaderTxt);
         fshaderTxt.append(";\n");
         fsOutName = oFragColor.c_str();
     } else {
         fsOutName = "gl_FragColor";
     }

     fshaderTxt.appendf(
             "void main()\n"
             "{\n"
                 "%s = vec4(o_color, 1.0f);\n"
             "}\n", fsOutName);

     return CreateProgram(gl, vshaderTxt.c_str(), fshaderTxt.c_str());
 }

 template<typename Func>
 static void setup_matrices(int numQuads, Func f) {
     // We draw a really small triangle so we are not fill rate limited
     for (int i = 0 ; i < numQuads; i++) {
         SkMatrix m = SkMatrix::I();
         m.setScale(0.0001f, 0.0001f);
         f(m);
     }
 }

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

 const GrGLContext* GLCpuPosInstancedArraysBench::onGetGLContext(const GrGLContext* ctx) {
     // We only care about gpus with drawArraysInstanced support
     if (!ctx->interface()->fFunctions.fDrawArraysInstanced) {
         return nullptr;
     }
     return ctx;
 }

 void GLCpuPosInstancedArraysBench::setupInstanceVbo(const GrGLInterface* gl,
                                                     const SkMatrix* viewMatrices) {
     // We draw all of the instances at a single place because we aren't allowed to have per vertex
     // per instance attributes
     SkPoint positions[kVerticesPerTri];
     positions[0].set(-1.0f, -1.0f);
     positions[1].set( 1.0f, -1.0f);
     positions[2].set( 1.0f,  1.0f);
     viewMatrices[0].mapPointsWithStride(positions, sizeof(SkPoint), kVerticesPerTri);

     // setup colors so we can detect we are actually drawing instances(the last triangle will be
     // a different color)
     GrGLfloat colors[kVerticesPerTri * kNumTri];
     for (uint32_t i = 0; i < kNumTri; i++) {
         // set colors
         uint32_t offset = i * kVerticesPerTri;
         float color = i == kNumTri - 1 ? 1.0f : 0.0f;
         colors[offset++] = color; colors[offset++] = 0.0f; colors[offset++] = 0.0f;
     }

     GrGLuint posVBO;
     // setup position VBO
     GR_GL_CALL(gl, GenBuffers(1, &posVBO));
     GR_GL_CALL(gl, BindBuffer(GR_GL_ARRAY_BUFFER, posVBO));
     GR_GL_CALL(gl, BufferData(GR_GL_ARRAY_BUFFER, sizeof(positions), positions, GR_GL_STATIC_DRAW));
     GR_GL_CALL(gl, EnableVertexAttribArray(0));
     GR_GL_CALL(gl, VertexAttribPointer(0, 2, GR_GL_FLOAT, GR_GL_FALSE, 2 * sizeof(GrGLfloat),
                                        (GrGLvoid*)0));

     // setup color VBO
     GrGLuint instanceVBO;
     GR_GL_CALL(gl, GenBuffers(1, &instanceVBO));
     GR_GL_CALL(gl, BindBuffer(GR_GL_ARRAY_BUFFER, instanceVBO));
     GR_GL_CALL(gl, BufferData(GR_GL_ARRAY_BUFFER, sizeof(colors), colors, GR_GL_STATIC_DRAW));
     GR_GL_CALL(gl, EnableVertexAttribArray(1));
     GR_GL_CALL(gl, VertexAttribPointer(1, 3, GR_GL_FLOAT, GR_GL_FALSE, 3 * sizeof(GrGLfloat),
                                        (GrGLvoid*)0));
     GR_GL_CALL(gl, VertexAttribDivisor(1, 1));
     fBuffers.push_back(posVBO);
     fBuffers.push_back(instanceVBO);
 }

 void GLCpuPosInstancedArraysBench::setupDoubleVbo(const GrGLInterface* gl,
                                                   const SkMatrix* viewMatrices) {
     // Constants for our various shader programs
     SkPoint positions[kVerticesPerTri * kNumTri];
     GrGLfloat colors[kVerticesPerTri * kNumTri * 3];
     for (uint32_t i = 0; i < kNumTri; i++) {
         SkPoint* position = &positions[i * kVerticesPerTri];
         position[0].set(-1.0f, -1.0f);
         position[1].set( 1.0f, -1.0f);
         position[2].set( 1.0f,  1.0f);
         viewMatrices[i].mapPointsWithStride(position, sizeof(SkPoint), kVerticesPerTri);

         // set colors
         float color = i == kNumTri - 1 ? 1.0f : 0.0f;
         uint32_t offset = i * kVerticesPerTri * 3;
         for (uint32_t j = 0; j < kVerticesPerTri; j++) {
             colors[offset++] = color; colors[offset++] = 0.0f; colors[offset++] = 0.0f;
         }
     }

     GrGLuint posVBO, colorVBO;
     // setup position VBO
     GR_GL_CALL(gl, GenBuffers(1, &posVBO));
     GR_GL_CALL(gl, BindBuffer(GR_GL_ARRAY_BUFFER, posVBO));
     GR_GL_CALL(gl, EnableVertexAttribArray(0));
     GR_GL_CALL(gl, VertexAttribPointer(0, 2, GR_GL_FLOAT, GR_GL_FALSE, 2 * sizeof(GrGLfloat),
                                        (GrGLvoid*)0));
     GR_GL_CALL(gl, BufferData(GR_GL_ARRAY_BUFFER, sizeof(positions), positions, GR_GL_STATIC_DRAW));

     // setup color VBO
     GR_GL_CALL(gl, GenBuffers(1, &colorVBO));
     GR_GL_CALL(gl, BindBuffer(GR_GL_ARRAY_BUFFER, colorVBO));
     GR_GL_CALL(gl, EnableVertexAttribArray(1));
     GR_GL_CALL(gl, VertexAttribPointer(1, 3, GR_GL_FLOAT, GR_GL_FALSE, 3 * sizeof(GrGLfloat),
                                        (GrGLvoid*)0));
     GR_GL_CALL(gl, BufferData(GR_GL_ARRAY_BUFFER, sizeof(colors), colors, GR_GL_STATIC_DRAW));

     fBuffers.push_back(posVBO);
     fBuffers.push_back(colorVBO);
 }

 struct Vertex {
     SkPoint fPositions;
     GrGLfloat fColors[3];
 };

 void GLCpuPosInstancedArraysBench::setupSingleVbo(const GrGLInterface* gl,
                                                   const SkMatrix* viewMatrices) {
     // Constants for our various shader programs
     Vertex vertices[kVerticesPerTri * kNumTri];
     for (uint32_t i = 0; i < kNumTri; i++) {
         Vertex* v = &vertices[i * kVerticesPerTri];
         v[0].fPositions.set(-1.0f, -1.0f);
         v[1].fPositions.set( 1.0f, -1.0f);
         v[2].fPositions.set( 1.0f,  1.0f);

         SkPoint* position = reinterpret_cast<SkPoint*>(v);
         viewMatrices[i].mapPointsWithStride(position, sizeof(Vertex), kVerticesPerTri);

         // set colors
         float color = i == kNumTri - 1 ? 1.0f : 0.0f;
         for (uint32_t j = 0; j < kVerticesPerTri; j++) {
             uint32_t offset = 0;
             v->fColors[offset++] = color; v->fColors[offset++] = 0.0f; v->fColors[offset++] = 0.0f;
             v++;
         }
     }

     GrGLuint vbo;
     // setup VBO
     GR_GL_CALL(gl, GenBuffers(1, &vbo));
     GR_GL_CALL(gl, BindBuffer(GR_GL_ARRAY_BUFFER, vbo));
     GR_GL_CALL(gl, EnableVertexAttribArray(0));
     GR_GL_CALL(gl, EnableVertexAttribArray(1));
     GR_GL_CALL(gl, VertexAttribPointer(0, 2, GR_GL_FLOAT, GR_GL_FALSE, sizeof(Vertex),
                                        (GrGLvoid*)0));
     GR_GL_CALL(gl, VertexAttribPointer(1, 3, GR_GL_FLOAT, GR_GL_FALSE, sizeof(Vertex),
                                        (GrGLvoid*)(sizeof(SkPoint))));
     GR_GL_CALL(gl, BufferData(GR_GL_ARRAY_BUFFER, sizeof(vertices), vertices, GR_GL_STATIC_DRAW));
     fBuffers.push_back(vbo);
 }

 void GLCpuPosInstancedArraysBench::setup(const GrGLContext* ctx) {
     const GrGLInterface* gl = ctx->interface();
     fTexture = SetupFramebuffer(gl, kScreenWidth, kScreenHeight);

     fProgram = this->setupShader(ctx);

     // setup matrices
     int index = 0;
     SkMatrix viewMatrices[kNumTri];
     setup_matrices(kNumTri, [&index, &viewMatrices](const SkMatrix& m) {
         viewMatrices[index++] = m;
     });

     // setup VAO
     GR_GL_CALL(gl, GenVertexArrays(1, &fVAO));
     GR_GL_CALL(gl, BindVertexArray(fVAO));

     switch (fVboSetup) {
         case kUseOne_VboSetup:
             this->setupSingleVbo(gl, viewMatrices);
             break;
         case kUseTwo_VboSetup:
             this->setupDoubleVbo(gl, viewMatrices);
             break;
         case kUseInstance_VboSetup:
             this->setupInstanceVbo(gl, viewMatrices);
             break;
     }

     // clear screen
     GR_GL_CALL(gl, ClearColor(0.03f, 0.03f, 0.03f, 1.0f));
     GR_GL_CALL(gl, Clear(GR_GL_COLOR_BUFFER_BIT));

     // set us up to draw
     GR_GL_CALL(gl, UseProgram(fProgram));
     GR_GL_CALL(gl, BindVertexArray(fVAO));
 }

 void GLCpuPosInstancedArraysBench::glDraw(int loops, const GrGLContext* ctx) {
     const GrGLInterface* gl = ctx->interface();

     uint32_t maxTrianglesPerFlush = fDrawDiv == 0 ?  kNumTri :
                                                      kDrawMultiplier / fDrawDiv;
     uint32_t trianglesToDraw = loops * kDrawMultiplier;

     if (kUseInstance_VboSetup == fVboSetup) {
         while (trianglesToDraw > 0) {
             uint32_t triangles = SkTMin(trianglesToDraw, maxTrianglesPerFlush);
             GR_GL_CALL(gl, DrawArraysInstanced(GR_GL_TRIANGLES, 0, kVerticesPerTri, triangles));
             trianglesToDraw -= triangles;
         }
     } else {
         while (trianglesToDraw > 0) {
             uint32_t triangles = SkTMin(trianglesToDraw, maxTrianglesPerFlush);
             GR_GL_CALL(gl, DrawArrays(GR_GL_TRIANGLES, 0, kVerticesPerTri * triangles));
             trianglesToDraw -= triangles;
         }
     }

 #if 0
     //const char* filename = "/data/local/tmp/out.png";
     SkString filename("out");
     filename.appendf("_%s.png", this->getName());
     DumpImage(gl, kScreenWidth, kScreenHeight, filename.c_str());
 #endif
 }

 void GLCpuPosInstancedArraysBench::teardown(const GrGLInterface* gl) {
     GR_GL_CALL(gl, BindBuffer(GR_GL_ARRAY_BUFFER, 0));
     GR_GL_CALL(gl, BindVertexArray(0));
     GR_GL_CALL(gl, BindTexture(GR_GL_TEXTURE_2D, 0));
     GR_GL_CALL(gl, BindFramebuffer(GR_GL_FRAMEBUFFER, 0));
     GR_GL_CALL(gl, DeleteTextures(1, &fTexture));
     GR_GL_CALL(gl, DeleteProgram(fProgram));
     GR_GL_CALL(gl, DeleteBuffers(fBuffers.count(), fBuffers.begin()));
     GR_GL_CALL(gl, DeleteVertexArrays(1, &fVAO));
     fBuffers.reset();
 }

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

 DEF_BENCH( return new GLCpuPosInstancedArraysBench(GLCpuPosInstancedArraysBench::kUseInstance_VboSetup, 0) )
 DEF_BENCH( return new GLCpuPosInstancedArraysBench(GLCpuPosInstancedArraysBench::kUseOne_VboSetup, 0) )
 DEF_BENCH( return new GLCpuPosInstancedArraysBench(GLCpuPosInstancedArraysBench::kUseTwo_VboSetup, 0) )
 DEF_BENCH( return new GLCpuPosInstancedArraysBench(GLCpuPosInstancedArraysBench::kUseOne_VboSetup, 1) )
 DEF_BENCH( return new GLCpuPosInstancedArraysBench(GLCpuPosInstancedArraysBench::kUseTwo_VboSetup, 1) )
 DEF_BENCH( return new GLCpuPosInstancedArraysBench(GLCpuPosInstancedArraysBench::kUseOne_VboSetup, 2) )
 DEF_BENCH( return new GLCpuPosInstancedArraysBench(GLCpuPosInstancedArraysBench::kUseTwo_VboSetup, 2) )
 DEF_BENCH( return new GLCpuPosInstancedArraysBench(GLCpuPosInstancedArraysBench::kUseOne_VboSetup, 4) )
 DEF_BENCH( return new GLCpuPosInstancedArraysBench(GLCpuPosInstancedArraysBench::kUseTwo_VboSetup, 4) )
 DEF_BENCH( return new GLCpuPosInstancedArraysBench(GLCpuPosInstancedArraysBench::kUseOne_VboSetup, 8) )
 DEF_BENCH( return new GLCpuPosInstancedArraysBench(GLCpuPosInstancedArraysBench::kUseTwo_VboSetup, 8) )

 #endif
	/*
	* Copyright 2015 Google Inc.
	*
	* Use of this source code is governed by a BSD-style license that can be
	* found in the LICENSE file.
	*/

	#include "Benchmark.h"
	#include "SkCanvas.h"
	#include "SkImageEncoder.h"

	#if SK_SUPPORT_GPU
	#include "GLBench.h"
	#include "gl/GrGLContext.h"
	#include "gl/GrGLInterface.h"
	#include "gl/GrGLUtil.h"
	#include "glsl/GrGLSL.h"
	#include "glsl/GrGLSLCaps.h"
	#include "glsl/GrGLSLShaderVar.h"

	/*
	* This is a native GL benchmark for instanced arrays vs vertex buffer objects. To benchmark this
	* functionality, we draw n * kDrawMultipier triangles per run. If this number is less than
	* kNumTri then we do a single draw, either with instances, or drawArrays. Otherwise we do
	* multiple draws.
	*
	* Additionally, there is a divisor, which if > 0 will act as a multiplier for the number of draws
	* issued.
	*/

	class GLCpuPosInstancedArraysBench : public GLBench {
	public:
	/*
	* Clients can decide to use either:
	* kUseOne_VboSetup - one vertex buffer with colors and positions interleaved
	* kUseTwo_VboSetup - two vertex buffers, one for colors, one for positions
	* kUseInstance_VboSetup - two vertex buffers, one with per vertex indices, one with per
	* instance colors
	*/
	enum VboSetup {
	kUseOne_VboSetup,
	kUseTwo_VboSetup,
	kUseInstance_VboSetup,
	};

	/*
	* drawDiv will act as a multiplier for the number of draws we issue if > 0. ie, 2 will issue
	* 2x as many draws, 4 will issue 4x as many draws etc. There is a limit however, which is
	* kDrawMultipier.
	*/
	GLCpuPosInstancedArraysBench(VboSetup vboSetup, int32_t drawDiv)
	: fVboSetup(vboSetup)
	, fDrawDiv(drawDiv)
	, fProgram(0)
	, fVAO(0) {
	fName = VboSetupToStr(vboSetup, fDrawDiv);
	}

	protected:
	const char* onGetName() override {
	return fName.c_str();
	}

	const GrGLContext* onGetGLContext(const GrGLContext*) override;
	void setup(const GrGLContext*) override;
	void glDraw(int loops, const GrGLContext*) override;
	void teardown(const GrGLInterface*) override;

	private:
	void setupInstanceVbo(const GrGLInterface, const SkMatrix);
	void setupDoubleVbo(const GrGLInterface, const SkMatrix);
	void setupSingleVbo(const GrGLInterface, const SkMatrix);
	GrGLuint setupShader(const GrGLContext*);

	static SkString VboSetupToStr(VboSetup vboSetup, uint32_t drawDiv) {
	SkString name("GLInstancedArraysBench");
	switch (vboSetup) {
	default:
	case kUseOne_VboSetup:
	name.appendf("_one_%u", drawDiv);
	break;
	case kUseTwo_VboSetup:
	name.appendf("_two_%u", drawDiv);
	break;
	case kUseInstance_VboSetup:
	name.append("_instance");
	break;
	}
	return name;
	}

	static const GrGLuint kScreenWidth = 800;
	static const GrGLuint kScreenHeight = 600;
	static const uint32_t kNumTri = 10000;
	static const uint32_t kVerticesPerTri = 3;
	static const uint32_t kDrawMultiplier = 512;

	SkString fName;
	VboSetup fVboSetup;
	uint32_t fDrawDiv;
	SkTArray<GrGLuint> fBuffers;
	GrGLuint fProgram;
	GrGLuint fVAO;
	GrGLuint fTexture;
	};

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

	GrGLuint GLCpuPosInstancedArraysBench::setupShader(const GrGLContext* ctx) {
	const GrGLSLCaps* glslCaps = ctx->caps()->glslCaps();
	const char* version = glslCaps->versionDeclString();

	// setup vertex shader
	GrGLSLShaderVar aPosition("a_position", kVec2f_GrSLType, GrShaderVar::kAttribute_TypeModifier);
	GrGLSLShaderVar aColor("a_color", kVec3f_GrSLType, GrShaderVar::kAttribute_TypeModifier);
	GrGLSLShaderVar oColor("o_color", kVec3f_GrSLType, GrShaderVar::kVaryingOut_TypeModifier);

	SkString vshaderTxt(version);
	aPosition.appendDecl(glslCaps, &vshaderTxt);
	vshaderTxt.append(";\n");
	aColor.appendDecl(glslCaps, &vshaderTxt);
	vshaderTxt.append(";\n");
	oColor.appendDecl(glslCaps, &vshaderTxt);
	vshaderTxt.append(";\n");

	vshaderTxt.append(
	"void main()\n"
	"{\n"
	"gl_Position = vec4(a_position, 0.f, 1.f);\n"
	"o_color = a_color;\n"
	"}\n");

	const GrGLInterface* gl = ctx->interface();

	// setup fragment shader
	GrGLSLShaderVar oFragColor("o_FragColor", kVec4f_GrSLType, GrShaderVar::kOut_TypeModifier);
	SkString fshaderTxt(version);
	GrGLSLAppendDefaultFloatPrecisionDeclaration(kDefault_GrSLPrecision, *glslCaps, &fshaderTxt);
	oColor.setTypeModifier(GrShaderVar::kVaryingIn_TypeModifier);
	oColor.appendDecl(glslCaps, &fshaderTxt);
	fshaderTxt.append(";\n");

	const char* fsOutName;
	if (glslCaps->mustDeclareFragmentShaderOutput()) {
	oFragColor.appendDecl(glslCaps, &fshaderTxt);
	fshaderTxt.append(";\n");
	fsOutName = oFragColor.c_str();
	} else {
	fsOutName = "gl_FragColor";
	}

	fshaderTxt.appendf(
	"void main()\n"
	"{\n"
	"%s = vec4(o_color, 1.0f);\n"
	"}\n", fsOutName);

	return CreateProgram(gl, vshaderTxt.c_str(), fshaderTxt.c_str());
	}

	template<typename Func>
	static void setup_matrices(int numQuads, Func f) {
	// We draw a really small triangle so we are not fill rate limited
	for (int i = 0 ; i < numQuads; i++) {
	SkMatrix m = SkMatrix::I();
	m.setScale(0.0001f, 0.0001f);
	f(m);
	}
	}

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

	const GrGLContext* GLCpuPosInstancedArraysBench::onGetGLContext(const GrGLContext* ctx) {
	// We only care about gpus with drawArraysInstanced support
	if (!ctx->interface()->fFunctions.fDrawArraysInstanced) {
	return nullptr;
	}
	return ctx;
	}

	void GLCpuPosInstancedArraysBench::setupInstanceVbo(const GrGLInterface* gl,
	const SkMatrix* viewMatrices) {
	// We draw all of the instances at a single place because we aren't allowed to have per vertex
	// per instance attributes
	SkPoint positions[kVerticesPerTri];
	positions[0].set(-1.0f, -1.0f);
	positions[1].set( 1.0f, -1.0f);
	positions[2].set( 1.0f, 1.0f);
	viewMatrices[0].mapPointsWithStride(positions, sizeof(SkPoint), kVerticesPerTri);

	// setup colors so we can detect we are actually drawing instances(the last triangle will be
	// a different color)
	GrGLfloat colors[kVerticesPerTri * kNumTri];
	for (uint32_t i = 0; i < kNumTri; i++) {
	// set colors
	uint32_t offset = i * kVerticesPerTri;
	float color = i == kNumTri - 1 ? 1.0f : 0.0f;
	colors[offset++] = color; colors[offset++] = 0.0f; colors[offset++] = 0.0f;
	}

	GrGLuint posVBO;
	// setup position VBO
	GR_GL_CALL(gl, GenBuffers(1, &posVBO));
	GR_GL_CALL(gl, BindBuffer(GR_GL_ARRAY_BUFFER, posVBO));
	GR_GL_CALL(gl, BufferData(GR_GL_ARRAY_BUFFER, sizeof(positions), positions, GR_GL_STATIC_DRAW));
	GR_GL_CALL(gl, EnableVertexAttribArray(0));
	GR_GL_CALL(gl, VertexAttribPointer(0, 2, GR_GL_FLOAT, GR_GL_FALSE, 2 * sizeof(GrGLfloat),
	(GrGLvoid*)0));

	// setup color VBO
	GrGLuint instanceVBO;
	GR_GL_CALL(gl, GenBuffers(1, &instanceVBO));
	GR_GL_CALL(gl, BindBuffer(GR_GL_ARRAY_BUFFER, instanceVBO));
	GR_GL_CALL(gl, BufferData(GR_GL_ARRAY_BUFFER, sizeof(colors), colors, GR_GL_STATIC_DRAW));
	GR_GL_CALL(gl, EnableVertexAttribArray(1));
	GR_GL_CALL(gl, VertexAttribPointer(1, 3, GR_GL_FLOAT, GR_GL_FALSE, 3 * sizeof(GrGLfloat),
	(GrGLvoid*)0));
	GR_GL_CALL(gl, VertexAttribDivisor(1, 1));
	fBuffers.push_back(posVBO);
	fBuffers.push_back(instanceVBO);
	}

	void GLCpuPosInstancedArraysBench::setupDoubleVbo(const GrGLInterface* gl,
	const SkMatrix* viewMatrices) {
	// Constants for our various shader programs
	SkPoint positions[kVerticesPerTri * kNumTri];
	GrGLfloat colors[kVerticesPerTri * kNumTri * 3];
	for (uint32_t i = 0; i < kNumTri; i++) {
	SkPoint* position = &positions[i * kVerticesPerTri];
	position[0].set(-1.0f, -1.0f);
	position[1].set( 1.0f, -1.0f);
	position[2].set( 1.0f, 1.0f);
	viewMatrices[i].mapPointsWithStride(position, sizeof(SkPoint), kVerticesPerTri);

	// set colors
	float color = i == kNumTri - 1 ? 1.0f : 0.0f;
	uint32_t offset = i * kVerticesPerTri * 3;
	for (uint32_t j = 0; j < kVerticesPerTri; j++) {
	colors[offset++] = color; colors[offset++] = 0.0f; colors[offset++] = 0.0f;
	}
	}

	GrGLuint posVBO, colorVBO;
	// setup position VBO
	GR_GL_CALL(gl, GenBuffers(1, &posVBO));
	GR_GL_CALL(gl, BindBuffer(GR_GL_ARRAY_BUFFER, posVBO));
	GR_GL_CALL(gl, EnableVertexAttribArray(0));
	GR_GL_CALL(gl, VertexAttribPointer(0, 2, GR_GL_FLOAT, GR_GL_FALSE, 2 * sizeof(GrGLfloat),
	(GrGLvoid*)0));
	GR_GL_CALL(gl, BufferData(GR_GL_ARRAY_BUFFER, sizeof(positions), positions, GR_GL_STATIC_DRAW));

	// setup color VBO
	GR_GL_CALL(gl, GenBuffers(1, &colorVBO));
	GR_GL_CALL(gl, BindBuffer(GR_GL_ARRAY_BUFFER, colorVBO));
	GR_GL_CALL(gl, EnableVertexAttribArray(1));
	GR_GL_CALL(gl, VertexAttribPointer(1, 3, GR_GL_FLOAT, GR_GL_FALSE, 3 * sizeof(GrGLfloat),
	(GrGLvoid*)0));
	GR_GL_CALL(gl, BufferData(GR_GL_ARRAY_BUFFER, sizeof(colors), colors, GR_GL_STATIC_DRAW));

	fBuffers.push_back(posVBO);
	fBuffers.push_back(colorVBO);
	}

	struct Vertex {
	SkPoint fPositions;
	GrGLfloat fColors[3];
	};

	void GLCpuPosInstancedArraysBench::setupSingleVbo(const GrGLInterface* gl,
	const SkMatrix* viewMatrices) {
	// Constants for our various shader programs
	Vertex vertices[kVerticesPerTri * kNumTri];
	for (uint32_t i = 0; i < kNumTri; i++) {
	Vertex* v = &vertices[i * kVerticesPerTri];
	v[0].fPositions.set(-1.0f, -1.0f);
	v[1].fPositions.set( 1.0f, -1.0f);
	v[2].fPositions.set( 1.0f, 1.0f);

	SkPoint* position = reinterpret_cast<SkPoint*>(v);
	viewMatrices[i].mapPointsWithStride(position, sizeof(Vertex), kVerticesPerTri);

	// set colors
	float color = i == kNumTri - 1 ? 1.0f : 0.0f;
	for (uint32_t j = 0; j < kVerticesPerTri; j++) {
	uint32_t offset = 0;
	v->fColors[offset++] = color; v->fColors[offset++] = 0.0f; v->fColors[offset++] = 0.0f;
	v++;
	}
	}

	GrGLuint vbo;
	// setup VBO
	GR_GL_CALL(gl, GenBuffers(1, &vbo));
	GR_GL_CALL(gl, BindBuffer(GR_GL_ARRAY_BUFFER, vbo));
	GR_GL_CALL(gl, EnableVertexAttribArray(0));
	GR_GL_CALL(gl, EnableVertexAttribArray(1));
	GR_GL_CALL(gl, VertexAttribPointer(0, 2, GR_GL_FLOAT, GR_GL_FALSE, sizeof(Vertex),
	(GrGLvoid*)0));
	GR_GL_CALL(gl, VertexAttribPointer(1, 3, GR_GL_FLOAT, GR_GL_FALSE, sizeof(Vertex),
	(GrGLvoid*)(sizeof(SkPoint))));
	GR_GL_CALL(gl, BufferData(GR_GL_ARRAY_BUFFER, sizeof(vertices), vertices, GR_GL_STATIC_DRAW));
	fBuffers.push_back(vbo);
	}

	void GLCpuPosInstancedArraysBench::setup(const GrGLContext* ctx) {
	const GrGLInterface* gl = ctx->interface();
	fTexture = SetupFramebuffer(gl, kScreenWidth, kScreenHeight);

	fProgram = this->setupShader(ctx);

	// setup matrices
	int index = 0;
	SkMatrix viewMatrices[kNumTri];
	setup_matrices(kNumTri, [&index, &viewMatrices](const SkMatrix& m) {
	viewMatrices[index++] = m;
	});

	// setup VAO
	GR_GL_CALL(gl, GenVertexArrays(1, &fVAO));
	GR_GL_CALL(gl, BindVertexArray(fVAO));

	switch (fVboSetup) {
	case kUseOne_VboSetup:
	this->setupSingleVbo(gl, viewMatrices);
	break;
	case kUseTwo_VboSetup:
	this->setupDoubleVbo(gl, viewMatrices);
	break;
	case kUseInstance_VboSetup:
	this->setupInstanceVbo(gl, viewMatrices);
	break;
	}

	// clear screen
	GR_GL_CALL(gl, ClearColor(0.03f, 0.03f, 0.03f, 1.0f));
	GR_GL_CALL(gl, Clear(GR_GL_COLOR_BUFFER_BIT));

	// set us up to draw
	GR_GL_CALL(gl, UseProgram(fProgram));
	GR_GL_CALL(gl, BindVertexArray(fVAO));
	}

	void GLCpuPosInstancedArraysBench::glDraw(int loops, const GrGLContext* ctx) {
	const GrGLInterface* gl = ctx->interface();

	uint32_t maxTrianglesPerFlush = fDrawDiv == 0 ? kNumTri :
	kDrawMultiplier / fDrawDiv;
	uint32_t trianglesToDraw = loops * kDrawMultiplier;

	if (kUseInstance_VboSetup == fVboSetup) {
	while (trianglesToDraw > 0) {
	uint32_t triangles = SkTMin(trianglesToDraw, maxTrianglesPerFlush);
	GR_GL_CALL(gl, DrawArraysInstanced(GR_GL_TRIANGLES, 0, kVerticesPerTri, triangles));
	trianglesToDraw -= triangles;
	}
	} else {
	while (trianglesToDraw > 0) {
	uint32_t triangles = SkTMin(trianglesToDraw, maxTrianglesPerFlush);
	GR_GL_CALL(gl, DrawArrays(GR_GL_TRIANGLES, 0, kVerticesPerTri * triangles));
	trianglesToDraw -= triangles;
	}
	}

	#if 0
	//const char* filename = "/data/local/tmp/out.png";
	SkString filename("out");
	filename.appendf("_%s.png", this->getName());
	DumpImage(gl, kScreenWidth, kScreenHeight, filename.c_str());
	#endif
	}

	void GLCpuPosInstancedArraysBench::teardown(const GrGLInterface* gl) {
	GR_GL_CALL(gl, BindBuffer(GR_GL_ARRAY_BUFFER, 0));
	GR_GL_CALL(gl, BindVertexArray(0));
	GR_GL_CALL(gl, BindTexture(GR_GL_TEXTURE_2D, 0));
	GR_GL_CALL(gl, BindFramebuffer(GR_GL_FRAMEBUFFER, 0));
	GR_GL_CALL(gl, DeleteTextures(1, &fTexture));
	GR_GL_CALL(gl, DeleteProgram(fProgram));
	GR_GL_CALL(gl, DeleteBuffers(fBuffers.count(), fBuffers.begin()));
	GR_GL_CALL(gl, DeleteVertexArrays(1, &fVAO));
	fBuffers.reset();
	}

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

	DEF_BENCH( return new GLCpuPosInstancedArraysBench(GLCpuPosInstancedArraysBench::kUseInstance_VboSetup, 0) )
	DEF_BENCH( return new GLCpuPosInstancedArraysBench(GLCpuPosInstancedArraysBench::kUseOne_VboSetup, 0) )
	DEF_BENCH( return new GLCpuPosInstancedArraysBench(GLCpuPosInstancedArraysBench::kUseTwo_VboSetup, 0) )
	DEF_BENCH( return new GLCpuPosInstancedArraysBench(GLCpuPosInstancedArraysBench::kUseOne_VboSetup, 1) )
	DEF_BENCH( return new GLCpuPosInstancedArraysBench(GLCpuPosInstancedArraysBench::kUseTwo_VboSetup, 1) )
	DEF_BENCH( return new GLCpuPosInstancedArraysBench(GLCpuPosInstancedArraysBench::kUseOne_VboSetup, 2) )
	DEF_BENCH( return new GLCpuPosInstancedArraysBench(GLCpuPosInstancedArraysBench::kUseTwo_VboSetup, 2) )
	DEF_BENCH( return new GLCpuPosInstancedArraysBench(GLCpuPosInstancedArraysBench::kUseOne_VboSetup, 4) )
	DEF_BENCH( return new GLCpuPosInstancedArraysBench(GLCpuPosInstancedArraysBench::kUseTwo_VboSetup, 4) )
	DEF_BENCH( return new GLCpuPosInstancedArraysBench(GLCpuPosInstancedArraysBench::kUseOne_VboSetup, 8) )
	DEF_BENCH( return new GLCpuPosInstancedArraysBench(GLCpuPosInstancedArraysBench::kUseTwo_VboSetup, 8) )

	#endif