Benchmark to test native perf of GL Instanced Ararys

bench/GLInstancedArraysBench.cpp

+/*
+ * 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 "GrTest.h"
+#include "gl/GrGLGLSL.h"
+#include "gl/GrGLInterface.h"
+#include "gl/GrGLShaderVar.h"
+#include "gl/GrGLUtil.h"
+#include "glsl/GrGLSLCaps.h"
+#include <stdio.h>
+
+/*
+ * This is a native GL benchmark for instanced arrays
+ */
+class GLInstancedArraysBench : public Benchmark {
+protected:
+    void onPerCanvasPreDraw(SkCanvas* canvas) override;
+    virtual void setup(const GrGLContext*)=0;
+    void onPerCanvasPostDraw(SkCanvas* canvas) override;
+    virtual void teardown(const GrGLInterface*)=0;
+
+    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;
+
+private:
+    GrGLuint fTexture;
+    typedef Benchmark INHERITED;
+};
+
+#if 0
+class GLGpuPosInstancedArraysBench : public GLInstancedArraysBench {
+protected:
+    const char* onGetName() override {
+        return "GLInstancedArraysBench_gpupos";
+    }
+
+    void setup(const GrGLContext*) override;
+    void onDraw(const int loops, SkCanvas* canvas) override;
+};
+#endif
+
+class GLCpuPosInstancedArraysBench : public GLInstancedArraysBench {
+public:
+    enum VboSetup {
+        kUseOne_VboSetup,

[bsalomon, 2015/06/26 19:45:36]

comments? Don't think this is intuitive

+        kUseTwo_VboSetup,
+        kUseInstance_VboSetup,
+    };
+
+    GLCpuPosInstancedArraysBench(VboSetup vboSetup, int32_t drawDiv)

[bsalomon, 2015/06/26 19:45:37]

comments about what drawDiv means?

+        : fVboSetup(vboSetup)
+        , fDrawDiv(drawDiv) {
+        fName = VboSetupToStr(vboSetup, fDrawDiv);
+    }
+
+protected:
+    const char* onGetName() override {
+        return fName.c_str();
+    }
+
+    void setup(const GrGLContext*) override;
+    void onDraw(const int loops, SkCanvas* canvas) 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*);
+
+    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;
+    }
+
+    SkString fName;
+    VboSetup fVboSetup;
+    uint32_t fDrawDiv;
+    SkTArray<GrGLuint> fBuffers;
+    GrGLuint fProgram;
+    GrGLuint fVAO;
+};
+
+static const GrGLContext* get_gl_context(SkCanvas* canvas) {
+    // This bench exclusively tests GL calls directly
+    if (NULL == canvas->getGrContext()) {
+        return NULL;
+    }
+    GrContext* context = canvas->getGrContext();
+
+    GrTestTarget tt;
+    context->getTestTarget(&tt);
+    if (!tt.target()) {
+        SkDebugf("Couldn't get Gr test target.");
+        return NULL;
+    }
+
+    const GrGLContext* ctx = tt.glContext();
+    if (!ctx) {
+        SkDebugf("Couldn't get an interface\n");
+        return NULL;
+    }
+
+    // We only care about gpus with drawArraysInstanced support
+    if (!ctx->interface()->fFunctions.fDrawArraysInstanced) {
+        return NULL;
+    }
+    return ctx;
+}
+
+void GLInstancedArraysBench::onPerCanvasPreDraw(SkCanvas* canvas) {
+    // This bench exclusively tests GL calls directly
+    const GrGLContext* ctx = get_gl_context(canvas);
+    if (!ctx) {
+        return;
+    }
+    this->setup(ctx);
+}
+
+void GLInstancedArraysBench::onPerCanvasPostDraw(SkCanvas* canvas) {
+    // This bench exclusively tests GL calls directly
+    const GrGLContext* ctx = get_gl_context(canvas);
+    if (!ctx) {
+        return;
+    }
+
+    const GrGLInterface* gl = ctx->interface();
+
+    // teardown
+    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));
+
+    this->teardown(gl);
+}
+
+///////////////////////////////////////////////////////////////////////////////////////////////////
+
+// TODO move all of the gpu positioning stuff to a new file
+#ifdef GPU_POS
+static const char* gpu_vertex_shader =
+        "layout (location = 0) in vec2 position;\n"
+        "layout (location = 1) in vec3 color;\n"
+        "layout (location = 2) in mat3 offset;\n"
+
+        "out vec3 fColor;\n"
+
+        "void main()\n"
+        "{\n"
+            "gl_Position = vec4(offset * vec3(position, 1.0f), 1.f);\n"
+            "fColor = color;\n"
+        "}\n";
+#endif
+
+static GrGLuint load_shader(const GrGLInterface* gl, const char* shaderSrc, GrGLenum type) {
+    GrGLuint shader;
+    // Create the shader object
+    GR_GL_CALL_RET(gl, shader, CreateShader(type));
+
+    // Load the shader source
+    GR_GL_CALL(gl, ShaderSource(shader, 1, &shaderSrc, NULL));
+
+    // Compile the shader
+    GR_GL_CALL(gl, CompileShader(shader));
+
+    // Check for compile time errors
+    GrGLint success;
+    GrGLchar infoLog[512];
+    GR_GL_CALL(gl, GetShaderiv(shader, GR_GL_COMPILE_STATUS, &success));
+    if (!success)
+    {
+     GR_GL_CALL(gl, GetShaderInfoLog(shader, 512, NULL, infoLog));
+     SkDebugf("ERROR::SHADER::COMPLIATION_FAILED: %s\n", infoLog);
+    }
+
+    return shader;
+}
+
+static GrGLuint compile_shader(const GrGLContext* ctx) {
+    const char* version = GrGLGetGLSLVersionDecl(*ctx);
+
+    // setup vertex shader
+    GrGLShaderVar aPosition("a_position", kVec2f_GrSLType, GrShaderVar::kAttribute_TypeModifier);
+    GrGLShaderVar aColor("a_color", kVec3f_GrSLType, GrShaderVar::kAttribute_TypeModifier);
+    GrGLShaderVar oColor("o_color", kVec3f_GrSLType, GrShaderVar::kVaryingOut_TypeModifier);
+
+    SkString vshaderTxt(version);
+    aPosition.appendDecl(*ctx, &vshaderTxt);
+    vshaderTxt.append(";\n");
+    aColor.appendDecl(*ctx, &vshaderTxt);
+    vshaderTxt.append(";\n");
+    oColor.appendDecl(*ctx, &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();
+    GrGLuint vertexShader = load_shader(gl, vshaderTxt.c_str(), GR_GL_VERTEX_SHADER);
+
+    // setup fragment shader
+    GrGLShaderVar oFragColor("o_FragColor", kVec4f_GrSLType, GrShaderVar::kOut_TypeModifier);
+    SkString fshaderTxt(version);
+    GrGLAppendGLSLDefaultFloatPrecisionDeclaration(kDefault_GrSLPrecision, gl->fStandard,
+                                                   &fshaderTxt);
+    oColor.setTypeModifier(GrShaderVar::kVaryingIn_TypeModifier);
+    oColor.appendDecl(*ctx, &fshaderTxt);
+    fshaderTxt.append(";\n");
+
+    const char* fsOutName;
+    if (ctx->caps()->glslCaps()->mustDeclareFragmentShaderOutput()) {
+        oFragColor.appendDecl(*ctx, &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);
+
+    GrGLuint fragmentShader = load_shader(gl, fshaderTxt.c_str(), GR_GL_FRAGMENT_SHADER);
+
+    GrGLint shaderProgram;
+    GR_GL_CALL_RET(gl, shaderProgram, CreateProgram());
+    GR_GL_CALL(gl, AttachShader(shaderProgram, vertexShader));
+    GR_GL_CALL(gl, AttachShader(shaderProgram, fragmentShader));
+    GR_GL_CALL(gl, LinkProgram(shaderProgram));
+
+    // Check for linking errors
+    GrGLint success;
+    GrGLchar infoLog[512];
+    GR_GL_CALL(gl, GetProgramiv(shaderProgram, GR_GL_LINK_STATUS, &success));
+    if (!success) {
+        GR_GL_CALL(gl, GetProgramInfoLog(shaderProgram, 512, NULL, infoLog));
+        SkDebugf("Linker Error: %s\n", infoLog);
+    }
+    GR_GL_CALL(gl, DeleteShader(vertexShader));
+    GR_GL_CALL(gl, DeleteShader(fragmentShader));
+
+    return shaderProgram;
+}
+
+//#define DUMP_IMAGES
+#ifdef DUMP_IMAGES
+static void dump_image(const GrGLInterface* gl, uint32_t screenWidth, uint32_t screenHeight,
+                       const char* filename) {
+    // read back pixels
+    uint32_t readback[screenWidth * screenHeight];
+    GR_GL_CALL(gl, ReadPixels(0, // x
+                              0, // y
+                              screenWidth, // width
+                              screenHeight, // height
+                              GR_GL_RGBA, //format
+                              GR_GL_UNSIGNED_BYTE, //type
+                              readback));
+
+    // dump png
+    SkBitmap bm;
+    if (!bm.tryAllocPixels(SkImageInfo::MakeN32Premul(screenWidth, screenHeight))) {
+        SkDebugf("couldn't allocate bitmap\n");
+        return;
+    }
+
+    bm.setPixels(readback);
+
+    if (!SkImageEncoder::EncodeFile(filename, bm, SkImageEncoder::kPNG_Type, 100)) {
+        SkDebugf("------ failed to encode %s\n", filename);
+        remove(filename);   // remove any partial file
+        return;
+    }
+}
+#endif
+
+static void setup_framebuffer(const GrGLInterface* gl, int screenWidth, int screenHeight) {
+    //Setup framebuffer
+    GrGLuint texture;
+    GR_GL_CALL(gl, PixelStorei(GR_GL_UNPACK_ROW_LENGTH, 0));
+    GR_GL_CALL(gl, PixelStorei(GR_GL_PACK_ROW_LENGTH, 0));
+    GR_GL_CALL(gl, GenTextures(1, &texture));
+    GR_GL_CALL(gl, ActiveTexture(GR_GL_TEXTURE15));
+    GR_GL_CALL(gl, BindTexture(GR_GL_TEXTURE_2D, texture));
+    GR_GL_CALL(gl, TexParameteri(GR_GL_TEXTURE_2D, GR_GL_TEXTURE_MAG_FILTER, GR_GL_NEAREST));
+    GR_GL_CALL(gl, TexParameteri(GR_GL_TEXTURE_2D, GR_GL_TEXTURE_MIN_FILTER, GR_GL_NEAREST));
+    GR_GL_CALL(gl, TexParameteri(GR_GL_TEXTURE_2D, GR_GL_TEXTURE_WRAP_S, GR_GL_CLAMP_TO_EDGE));
+    GR_GL_CALL(gl, TexParameteri(GR_GL_TEXTURE_2D, GR_GL_TEXTURE_WRAP_T, GR_GL_CLAMP_TO_EDGE));
+    GR_GL_CALL(gl, TexImage2D(GR_GL_TEXTURE_2D,
+                              0, //level
+                              GR_GL_RGBA8, //internal format
+                              screenWidth, // width
+                              screenHeight, // height
+                              0, //border
+                              GR_GL_RGBA, //format
+                              GR_GL_UNSIGNED_BYTE, // type
+                              NULL));
+
+    // bind framebuffer
+    GrGLuint framebuffer;
+    GR_GL_CALL(gl, BindTexture(GR_GL_TEXTURE_2D, 0));
+    GR_GL_CALL(gl, GenFramebuffers(1, &framebuffer));
+    GR_GL_CALL(gl, BindFramebuffer(GR_GL_FRAMEBUFFER, framebuffer));
+    GR_GL_CALL(gl, FramebufferTexture2D(GR_GL_FRAMEBUFFER,
+                                        GR_GL_COLOR_ATTACHMENT0,
+                                        GR_GL_TEXTURE_2D,
+                                        texture, 0));
+    GR_GL_CALL(gl, CheckFramebufferStatus(GR_GL_FRAMEBUFFER));
+    GR_GL_CALL(gl, Viewport(0, 0, screenWidth, screenHeight));
+}
+
+template<typename Func>
+static void setup_matrices(int numQuads, Func f) {
+#if 0
+    float max = sqrt(numQuads);
+    float pos = 1.f / (2 * max);
+    GrGLfloat offset = pos * 2;
+    for(GrGLint row = 0; row < max; row++) {
+        for(GrGLint col = 0; col < max; col++) {
+            SkScalar xOffset = col / max * 2.f - 1.f + offset;
+            SkScalar yOffset = row / max * 2.f - 1.f + offset;
+            SkMatrix translation;
+            SkRandom random;
+            translation.setScale(pos, pos);
+            translation.postTranslate(xOffset, yOffset);
+            f(translation);
+        }
+    }
+#endif
+    // 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);
+    }
+}
+
+#ifdef GPU_POS
+void GLGpuPosInstancedArraysBench::setup(const GrGLInterface* gl) {
+    setup_framebuffer(gl, kScreenWidth, kScreenHeight);
+
+    // compile and use shaders
+    GrGLint shaderProgram = compile_shader(gl, gpu_vertex_shader, fragment_shader);
+
+    // translations
+    int index = 0;
+    GrGLfloat viewMatrices[fNumQuads * fSkMatrixNumCells];
+    setup_matrices(fNumQuads, [&index, &viewMatrices](const SkMatrix& m) {
+        GrGLGetMatrix<3>(&viewMatrices[index], m);
+        index += fSkMatrixNumCells;
+    });
+
+    // Constants for our various shader programs
+    GrGLfloat quad_vertices[] = {
+            // Positions // Colors
+            -1.0f,  1.0f,  1.0f, 0.0f, 0.0f,
+             1.0f, -1.0f,  0.0f, 1.0f, 0.0f,
+            -1.0f, -1.0f,  0.0f, 0.0f, 1.0f,
+
+            -1.0f,  1.0f,  1.0f, 0.0f, 0.0f,
+             1.0f, -1.0f,  0.0f, 1.0f, 0.0f,
+             1.0f,  1.0f,  0.0f, 1.0f, 1.0f
+    };
+
+    // update vertex data
+    GrGLuint quadVAO, quadVBO;
+    GR_GL_CALL(gl, GenVertexArrays(1, &quadVAO));
+    GR_GL_CALL(gl, GenBuffers(1, &quadVBO));
+    GR_GL_CALL(gl, BindVertexArray(quadVAO));
+    GR_GL_CALL(gl, BindBuffer(GR_GL_ARRAY_BUFFER, quadVBO));
+    GR_GL_CALL(gl, EnableVertexAttribArray(0));
+    GR_GL_CALL(gl, VertexAttribPointer(0, 2, GR_GL_FLOAT, GR_GL_FALSE, 5 * sizeof(GrGLfloat), (GrGLvoid*)0));
+    GR_GL_CALL(gl, EnableVertexAttribArray(1));
+    GR_GL_CALL(gl, VertexAttribPointer(1, 3, GR_GL_FLOAT, GR_GL_FALSE, 5 * sizeof(GrGLfloat), (GrGLvoid*)(2 * sizeof(GrGLfloat))));
+    GR_GL_CALL(gl, BufferData(GR_GL_ARRAY_BUFFER, sizeof(quad_vertices), quad_vertices, GR_GL_STATIC_DRAW));
+
+    // Also set instance data
+    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(GrGLfloat) * fSkMatrixNumCells * fNumQuads,
+                              &viewMatrices[0], GR_GL_STATIC_DRAW));
+    GR_GL_CALL(gl, EnableVertexAttribArray(2));
+    GR_GL_CALL(gl, EnableVertexAttribArray(3));
+    GR_GL_CALL(gl, EnableVertexAttribArray(4));
+    GR_GL_CALL(gl, VertexAttribPointer(2, 3, GR_GL_FLOAT, GR_GL_FALSE, 9 * sizeof(GrGLfloat), (GrGLvoid*)0));
+    GR_GL_CALL(gl, VertexAttribPointer(3, 3, GR_GL_FLOAT, GR_GL_FALSE, 9 * sizeof(GrGLfloat), (GrGLvoid*)(3 * sizeof(GrGLfloat))));
+    GR_GL_CALL(gl, VertexAttribPointer(4, 3, GR_GL_FLOAT, GR_GL_FALSE, 9 * sizeof(GrGLfloat), (GrGLvoid*)(6 * sizeof(GrGLfloat))));
+    GR_GL_CALL(gl, VertexAttribDivisor(2, 1));
+    GR_GL_CALL(gl, VertexAttribDivisor(3, 1));
+    GR_GL_CALL(gl, VertexAttribDivisor(4, 1));
+
+    // draw
+    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(shaderProgram));
+    GR_GL_CALL(gl, BindVertexArray(quadVAO));
+}
+
+void GLGpuPosInstancedArraysBench::onDraw(const int loops, SkCanvas* canvas) {
+    const GrGLInterface* gl = get_interface(canvas);
+    if (!gl) {
+        return;
+    }
+
+    GR_GL_CALL(gl, DrawArraysInstanced(GR_GL_TRIANGLES, 0, 6, fNumQuads));
+
+#ifdef DUMP_IMAGES
+    const char* filename = "out.png";
+    dump_image(gl, kScreenWidth, kScreenHeight, filename);
+#endif
+    SkFAIL("done\n");
+}
+
+static uint32_t setup_quad_index_buffer(const GrGLInterface* gl) {
+    static const int kMaxQuads = 1;//1 << 12; // max possible: (1 << 14) - 1;
+    GR_STATIC_ASSERT(4 * kMaxQuads <= 65535);
+    static const uint16_t kPattern[] = { 0, 1, 2, 0, 2, 3 };
+    static const int kPatternSize = 6;
+    static const int kVertCount = 4;
+    static const int kIndicesCount = kPatternSize * kMaxQuads;
+    int size = kPatternSize * kMaxQuads * sizeof(uint16_t);
+
+    uint16_t* data = SkNEW_ARRAY(uint16_t, kMaxQuads * kPatternSize);
+
+    for (int i = 0; i < kMaxQuads; ++i) {
+        int baseIdx = i * kPatternSize;
+        uint16_t baseVert = (uint16_t)(i * kVertCount);
+        for (int j = 0; j < kPatternSize; ++j) {
+            data[baseIdx+j] = baseVert + kPattern[j];
+        }
+    }
+
+    GrGLuint quadIBO;
+    GR_GL_CALL(gl, GenBuffers(1, &quadIBO));
+    GR_GL_CALL(gl, BindBuffer(GR_GL_ELEMENT_ARRAY_BUFFER, quadIBO));
+    GR_GL_CALL(gl, BufferData(GR_GL_ELEMENT_ARRAY_BUFFER, size, data, GR_GL_STATIC_DRAW));
+
+    SkDELETE_ARRAY(data);
+    return kIndicesCount;
+}
+#endif
+
+///////////////////////////////////////////////////////////////////////////////////////////////////
+
+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();
+    setup_framebuffer(gl, kScreenWidth, kScreenHeight);
+
+    fProgram = compile_shader(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::onDraw(const int loops, SkCanvas* canvas) {
+    const GrGLContext* ctx = get_gl_context(canvas);
+    if (!ctx) {
+        return;
+    }
+
+    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;
+        }
+    }
+
+#ifdef DUMP_IMAGES
+    //const char* filename = "/data/local/tmp/out.png";
+    SkString filename("out");
+    filename.appendf("_%s.png", this->getName());
+    dump_image(gl, kScreenWidth, kScreenHeight, filename.c_str());
+#endif
+}
+
+void GLCpuPosInstancedArraysBench::teardown(const GrGLInterface* gl) {
+    GR_GL_CALL(gl, DeleteProgram(fProgram));
+    GR_GL_CALL(gl, DeleteBuffers(fBuffers.count(), fBuffers.begin()));
+    GR_GL_CALL(gl, DeleteVertexArrays(1, &fVAO));
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+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