command_buffer: Implement path rendering functions for CHROMIUM_path_rendering

gpu/command_buffer/tests/gl_chromium_path_rendering_unittest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <GLES2/gl2.h>
 #include <GLES2/gl2ext.h>
 #include <GLES2/gl2extchromium.h>
 #include <cmath>
 
+#include "base/command_line.h"
+#include "gpu/command_buffer/service/gpu_switches.h"
 #include "gpu/command_buffer/tests/gl_manager.h"
 #include "gpu/command_buffer/tests/gl_test_utils.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
+#define SHADER(Src) #Src
+
 namespace gpu {
 
 class CHROMIUMPathRenderingTest : public testing::Test {
  public:
   static const GLsizei kResolution = 100;
 
  protected:
   void SetUp() override {
     GLManager::Options options;
     options.size = gfx::Size(kResolution, kResolution);
-    gl_.Initialize(options);
+    base::CommandLine command_line(*base::CommandLine::ForCurrentProcess());
+    command_line.AppendSwitch(switches::kEnableGLPathRendering);
+    gl_.InitializeWithCommandLine(options, &command_line);
   }
 
   void TearDown() override { gl_.Destroy(); }
 
   void ExpectEqualMatrix(const GLfloat* expected, const GLfloat* actual) {
     for (size_t i = 0; i < 16; ++i) {
       EXPECT_EQ(expected[i], actual[i]);
     }
   }
   void ExpectEqualMatrix(const GLfloat* expected, const GLint* actual) {
     for (size_t i = 0; i < 16; ++i) {
       EXPECT_EQ(static_cast<GLint>(round(expected[i])), actual[i]);
     }
   }
+
+  void SetupStateForTestPattern() {
+    glViewport(0, 0, kResolution, kResolution);
+    glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
+    glStencilMask(0xffffffff);
+    glClearStencil(0);
+    glClear(GL_COLOR_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
+
+    static const char* kVertexShaderSource =
+        SHADER(void main() { gl_Position = vec4(1); });
+    static const char* kFragmentShaderSource =
+        SHADER(precision mediump float; uniform vec4 color;
+               void main() { gl_FragColor = color; });
+
+    GLuint program =
+        GLTestHelper::LoadProgram(kVertexShaderSource, kFragmentShaderSource);
+    glUseProgram(program);
+    color_loc_ = glGetUniformLocation(program, "color");
+    glDeleteProgram(program);
+
+    // Set up orthogonal projection with near/far plane distance of 2.
+    static GLfloat matrix[16] = {2.0f / (kResolution - 1),
+                                 0.0f,
+                                 0.0f,
+                                 0.0f,
+                                 0.0f,
+                                 2.0f / (kResolution - 1),
+                                 0.0f,
+                                 0.0f,
+                                 0.0f,
+                                 0.0f,
+                                 -1.0f,
+                                 0.0f,
+                                 -1.0f,
+                                 -1.0f,
+                                 0.0f,
+                                 1.0f};
+    glMatrixLoadfCHROMIUM(GL_PATH_PROJECTION_CHROMIUM, matrix);
+    glMatrixLoadIdentityCHROMIUM(GL_PATH_MODELVIEW_CHROMIUM);
+
+    glEnable(GL_STENCIL_TEST);
+
+    GLTestHelper::CheckGLError("no errors at state setup", __LINE__);
+  }
+
+  void SetupPathStateForTestPattern(GLuint path) {
+    static const GLubyte kCommands[] = {GL_MOVE_TO_CHROMIUM,
+                                        GL_LINE_TO_CHROMIUM,
+                                        GL_QUADRATIC_CURVE_TO_CHROMIUM,
+                                        GL_CUBIC_CURVE_TO_CHROMIUM,
+                                        GL_CLOSE_PATH_CHROMIUM};
+
+    static const GLfloat kCoords[] = {50.0f,
+                                      50.0f,
+                                      75.0f,
+                                      75.0f,
+                                      100.0f,
+                                      62.5f,
+                                      50.0f,
+                                      25.5f,
+                                      0.0f,
+                                      62.5f,
+                                      50.0f,
+                                      50.0f,
+                                      25.0f,
+                                      75.0f};
+
+    glPathCommandsCHROMIUM(path, arraysize(kCommands), kCommands,
+                           arraysize(kCoords), GL_FLOAT, kCoords);
+
+    glPathParameterfCHROMIUM(path, GL_PATH_STROKE_WIDTH_CHROMIUM, 5.0f);
+    glPathParameterfCHROMIUM(path, GL_PATH_MITER_LIMIT_CHROMIUM, 1.0f);
+    glPathParameterfCHROMIUM(path, GL_PATH_STROKE_BOUND_CHROMIUM, .02f);
+    glPathParameteriCHROMIUM(path, GL_PATH_JOIN_STYLE_CHROMIUM,
+                             GL_ROUND_CHROMIUM);
+    glPathParameteriCHROMIUM(path, GL_PATH_END_CAPS_CHROMIUM,
+                             GL_SQUARE_CHROMIUM);
+  }
+
+  void VerifyTestPatternFill(float x, float y) {
+    static const float kFillCoords[] = {
+        55.0f, 55.0f, 50.0f, 28.0f, 66.0f, 63.0f};
+    static const uint8 kBlue[] = {0, 0, 255, 255};
+
+    for (size_t i = 0; i < arraysize(kFillCoords); i += 2) {
+      float fx = kFillCoords[i];
+      float fy = kFillCoords[i + 1];
+
+      EXPECT_TRUE(GLTestHelper::CheckPixels(x + fx, y + fy, 1, 1, 0, kBlue));
+    }
+  }
+
+  void VerifyTestPatternBg(float x, float y) {
+    const float kBackgroundCoords[] = {80.0f, 80.0f, 20.0f, 20.0f, 90.0f, 1.0f};
+    const uint8 kExpectedColor[] = {0, 0, 0, 0};
+
+    for (size_t i = 0; i < arraysize(kBackgroundCoords); i += 2) {
+      float bx = kBackgroundCoords[i];
+      float by = kBackgroundCoords[i + 1];
+
+      EXPECT_TRUE(
+          GLTestHelper::CheckPixels(x + bx, y + by, 1, 1, 0, kExpectedColor));
+    }
+  }
+
+  void VerifyTestPatternStroke(float x, float y) {
+    // Inside the stroke we should have green.
+    const uint8 kGreen[] = {0, 255, 0, 255};
+    EXPECT_TRUE(GLTestHelper::CheckPixels(x + 50, y + 53, 1, 1, 0, kGreen));
+    EXPECT_TRUE(GLTestHelper::CheckPixels(x + 26, y + 76, 1, 1, 0, kGreen));
+
+    // Outside the path we should have black.
+    const uint8 black[] = {0, 0, 0, 0};
+    EXPECT_TRUE(GLTestHelper::CheckPixels(x + 10, y + 10, 1, 1, 0, black));
+    EXPECT_TRUE(GLTestHelper::CheckPixels(x + 80, y + 80, 1, 1, 0, black));
+  }
+
+  void TryAllDrawFunctions(GLuint path, GLenum expected_error) {
+    glStencilFillPathCHROMIUM(path, GL_COUNT_UP_CHROMIUM, 0x7F);
+    EXPECT_EQ(expected_error, glGetError());
+
+    glStencilFillPathCHROMIUM(path, GL_COUNT_UP_CHROMIUM, 0x7F);
+    EXPECT_EQ(expected_error, glGetError());
+
+    glStencilStrokePathCHROMIUM(path, 0x80, 0x80);
+    EXPECT_EQ(expected_error, glGetError());
+
+    glCoverFillPathCHROMIUM(path, GL_BOUNDING_BOX_CHROMIUM);
+    EXPECT_EQ(expected_error, glGetError());
+
+    glCoverStrokePathCHROMIUM(path, GL_BOUNDING_BOX_CHROMIUM);
+    EXPECT_EQ(expected_error, glGetError());
+
+    glStencilThenCoverStrokePathCHROMIUM(path, 0x80, 0x80,
+                                         GL_BOUNDING_BOX_CHROMIUM);
+    EXPECT_EQ(expected_error, glGetError());
+
+    glStencilThenCoverFillPathCHROMIUM(path, GL_COUNT_UP_CHROMIUM, 0x7F,
+                                       GL_BOUNDING_BOX_CHROMIUM);
+    EXPECT_EQ(expected_error, glGetError());
+  }
+
   GLManager gl_;
+  GLint color_loc_;
 };
 
 TEST_F(CHROMIUMPathRenderingTest, TestMatrix) {
-  if (!GLTestHelper::HasExtension("GL_CHROMIUM_path_rendering")) {
+  if (!GLTestHelper::HasExtension("GL_CHROMIUM_path_rendering"))
     return;
-  }
+
   static const GLfloat kIdentityMatrix[16] = {
       1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f,
       0.0f, 0.0f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 1.0f};
   static const GLfloat kSeqMatrix[16] = {
       0.5f, -0.5f, -0.1f,  -0.8f,  4.4f,   5.5f,   6.6f,   7.7f,
       8.8f, 9.9f,  10.11f, 11.22f, 12.33f, 13.44f, 14.55f, 15.66f};
   static const GLenum kMatrixModes[] = {GL_PATH_MODELVIEW_CHROMIUM,
                                         GL_PATH_PROJECTION_CHROMIUM};
   static const GLenum kGetMatrixModes[] = {GL_PATH_MODELVIEW_MATRIX_CHROMIUM,
                                            GL_PATH_PROJECTION_MATRIX_CHROMIUM};
@@ skipping 22 matching lines @@
     glGetFloatv(kGetMatrixModes[i], mf);
     glGetIntegerv(kGetMatrixModes[i], mi);
     ExpectEqualMatrix(kIdentityMatrix, mf);
     ExpectEqualMatrix(kIdentityMatrix, mi);
 
     EXPECT_EQ(static_cast<GLenum>(GL_NO_ERROR), glGetError());
   }
 }
 
 TEST_F(CHROMIUMPathRenderingTest, TestMatrixErrors) {
-  if (!GLTestHelper::HasExtension("GL_CHROMIUM_path_rendering")) {
-    return;
-  }
+  if (!GLTestHelper::HasExtension("GL_CHROMIUM_path_rendering"))
+    return;
+
   GLfloat mf[16];
   memset(mf, 0, sizeof(mf));
 
-  // This should fail.
+  glMatrixLoadfCHROMIUM(GL_PATH_MODELVIEW_CHROMIUM, mf);
+  EXPECT_EQ(static_cast<GLenum>(GL_NO_ERROR), glGetError());
+
+  glMatrixLoadIdentityCHROMIUM(GL_PATH_PROJECTION_CHROMIUM);
+  EXPECT_EQ(static_cast<GLenum>(GL_NO_ERROR), glGetError());
+
+  // Test that invalid matrix targets fail.
   glMatrixLoadfCHROMIUM(GL_PATH_MODELVIEW_CHROMIUM - 1, mf);
   EXPECT_EQ(static_cast<GLenum>(GL_INVALID_ENUM), glGetError());
 
-  glMatrixLoadfCHROMIUM(GL_PATH_MODELVIEW_CHROMIUM, mf);
-  EXPECT_EQ(static_cast<GLenum>(GL_NO_ERROR), glGetError());
-
-  // This should fail.
+  // Test that invalid matrix targets fail.
   glMatrixLoadIdentityCHROMIUM(GL_PATH_PROJECTION_CHROMIUM + 1);
   EXPECT_EQ(static_cast<GLenum>(GL_INVALID_ENUM), glGetError());
-
-  glMatrixLoadIdentityCHROMIUM(GL_PATH_PROJECTION_CHROMIUM);
-  EXPECT_EQ(static_cast<GLenum>(GL_NO_ERROR), glGetError());
+}
+
+TEST_F(CHROMIUMPathRenderingTest, TestSimpleCalls) {
+  if (!GLTestHelper::HasExtension("GL_CHROMIUM_path_rendering"))
+    return;
+
+  // This is unspecified in NV_path_rendering.
+  EXPECT_EQ(0u, glGenPathsCHROMIUM(0));
+
+  GLuint path = glGenPathsCHROMIUM(1);
+  EXPECT_NE(path, 0u);
+  glDeletePathsCHROMIUM(path, 1);
+  EXPECT_EQ(static_cast<GLenum>(GL_NO_ERROR), glGetError());
+
+  GLuint first_path = glGenPathsCHROMIUM(5);
+  EXPECT_NE(first_path, 0u);
+  glDeletePathsCHROMIUM(first_path, 5);
+  EXPECT_EQ(static_cast<GLenum>(GL_NO_ERROR), glGetError());
+
+  // Test deleting paths that are not actually allocated:
+  // "unused names in /paths/ are silently ignored".
+  first_path = glGenPathsCHROMIUM(5);
+  EXPECT_NE(first_path, 0u);
+  glDeletePathsCHROMIUM(first_path, 6);
+  EXPECT_EQ(static_cast<GLenum>(GL_NO_ERROR), glGetError());
+
+  GLsizei big_range = 0xffff;
+  // Setting big_range = std::numeric_limits<GLsizei>::max() should go through
+  // too, as far as NV_path_rendering is concerned. Current chromium side id
+  // allocator will use too much memory.
+  first_path = glGenPathsCHROMIUM(big_range);
+  EXPECT_NE(first_path, 0u);
+  glDeletePathsCHROMIUM(first_path, big_range);
+  EXPECT_EQ(static_cast<GLenum>(GL_NO_ERROR), glGetError());
+
+  // Test glIsPathCHROMIUM().
+  path = glGenPathsCHROMIUM(1);
+  EXPECT_FALSE(glIsPathCHROMIUM(path));
+  GLubyte commands[] = {GL_MOVE_TO_CHROMIUM, GL_CLOSE_PATH_CHROMIUM};
+  GLfloat coords[] = {50.0f, 50.0f};
+  glPathCommandsCHROMIUM(path, arraysize(commands), commands, arraysize(coords),
+                         GL_FLOAT, coords);
+  EXPECT_TRUE(glIsPathCHROMIUM(path));
+  glDeletePathsCHROMIUM(path, 1);
+  EXPECT_FALSE(glIsPathCHROMIUM(path));
+}
+
+TEST_F(CHROMIUMPathRenderingTest, TestGenDeleteErrors) {
+  if (!GLTestHelper::HasExtension("GL_CHROMIUM_path_rendering"))
+    return;
+
+  // GenPaths / DeletePaths tests.
+  // std::numeric_limits<GLuint>::max() is wrong for GLsizei.
+  GLuint first_path = glGenPathsCHROMIUM(std::numeric_limits<GLuint>::max());
+  EXPECT_EQ(first_path, 0u);
+  EXPECT_EQ(static_cast<GLenum>(GL_INVALID_VALUE), glGetError());
+
+  first_path = glGenPathsCHROMIUM(-1);
+  EXPECT_EQ(first_path, 0u);
+  EXPECT_EQ(static_cast<GLenum>(GL_INVALID_VALUE), glGetError());
+
+  glDeletePathsCHROMIUM(1, -5);
+  EXPECT_EQ(static_cast<GLenum>(GL_INVALID_VALUE), glGetError());
+
+  first_path = glGenPathsCHROMIUM(-1);
+  EXPECT_EQ(first_path, 0u);
+  EXPECT_EQ(static_cast<GLenum>(GL_INVALID_VALUE), glGetError());
+
+  // Test that delete with first_id and range such that first_id + range
+  // overflows the GLuint. Example:
+  // Range is 0x7fffffff. First id is X. Last id will be X + 0x7ffffffe.
+  // X = 0x80000001 would succeed, where as X = 0x80000002 would fail.
+  // To get 0x80000002, we need to allocate first 0x7fffffff and then
+  // 3 (0x80000000, 0x80000001 and 0x80000002).
+  // While not guaranteed by the API, we expect the implementation
+  // hands us deterministic ids.
+  first_path = glGenPathsCHROMIUM(std::numeric_limits<GLsizei>::max());
+  EXPECT_EQ(first_path, 1u);
+  EXPECT_EQ(static_cast<GLenum>(GL_NO_ERROR), glGetError());
+
+  GLuint additional_paths = glGenPathsCHROMIUM(3);
+  EXPECT_EQ(additional_paths,
+            static_cast<GLuint>(std::numeric_limits<GLsizei>::max()) + 1u);
+  EXPECT_EQ(static_cast<GLenum>(GL_NO_ERROR), glGetError());
+
+  // Test that passing a range so big that it would overflow client_id
+  // + range - 1 check causes an error.
+  glDeletePathsCHROMIUM(additional_paths + 2u,
+                        std::numeric_limits<GLsizei>::max());
+  EXPECT_EQ(static_cast<GLenum>(GL_INVALID_OPERATION), glGetError());
+
+  // Cleanup the above allocations. Also test that passing max value still
+  // works.
+  glDeletePathsCHROMIUM(1, std::numeric_limits<GLsizei>::max());
+  EXPECT_EQ(static_cast<GLenum>(GL_NO_ERROR), glGetError());
+  glDeletePathsCHROMIUM(std::numeric_limits<GLsizei>::max(),
+                        std::numeric_limits<GLsizei>::max());
+  EXPECT_EQ(static_cast<GLenum>(GL_NO_ERROR), glGetError());
+}
+
+TEST_F(CHROMIUMPathRenderingTest, TestPathParameterErrors) {
+  if (!GLTestHelper::HasExtension("GL_CHROMIUM_path_rendering"))
+    return;
+
+  GLuint path = glGenPathsCHROMIUM(1);
+  // PathParameter*: Wrong value for the pname should fail.
+  glPathParameteriCHROMIUM(path, GL_PATH_JOIN_STYLE_CHROMIUM, GL_FLAT_CHROMIUM);
+  EXPECT_EQ(static_cast<GLenum>(GL_INVALID_VALUE), glGetError());
+  glPathParameterfCHROMIUM(path, GL_PATH_END_CAPS_CHROMIUM,
+                           GL_MITER_REVERT_CHROMIUM);
+  EXPECT_EQ(static_cast<GLenum>(GL_INVALID_VALUE), glGetError());
+
+  // PathParameter*: Wrong floating-point value should fail.
+  glPathParameterfCHROMIUM(path, GL_PATH_STROKE_WIDTH_CHROMIUM, -0.1f);
+  EXPECT_EQ(static_cast<GLenum>(GL_INVALID_VALUE), glGetError());
+  glPathParameterfCHROMIUM(path, GL_PATH_MITER_LIMIT_CHROMIUM,
+                           std::numeric_limits<float>::quiet_NaN());
+  EXPECT_EQ(static_cast<GLenum>(GL_INVALID_VALUE), glGetError());
+  glPathParameterfCHROMIUM(path, GL_PATH_MITER_LIMIT_CHROMIUM,
+                           std::numeric_limits<float>::infinity());
+  EXPECT_EQ(static_cast<GLenum>(GL_INVALID_VALUE), glGetError());
+
+  // PathParameter*: Wrong pname should fail.
+  glPathParameteriCHROMIUM(path, GL_PATH_STROKE_WIDTH_CHROMIUM - 1, 5);
+  EXPECT_EQ(static_cast<GLenum>(GL_INVALID_ENUM), glGetError());
+  glDeletePathsCHROMIUM(path, 1);
+}
+
+TEST_F(CHROMIUMPathRenderingTest, TestPathObjectState) {
+  if (!GLTestHelper::HasExtension("GL_CHROMIUM_path_rendering"))
+    return;
+
+  glViewport(0, 0, kResolution, kResolution);
+  glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
+  glStencilMask(0xffffffff);
+  glClearStencil(0);
+  glClear(GL_COLOR_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
+  glPathStencilFuncCHROMIUM(GL_ALWAYS, 0, 0xFF);
+  glStencilOp(GL_KEEP, GL_KEEP, GL_ZERO);
+
+  // Test that trying to draw non-existing paths does not produce errors or
+  // results.
+  GLuint non_existing_paths[] = {0, 55, 74744};
+  for (auto& p : non_existing_paths) {
+    EXPECT_FALSE(glIsPathCHROMIUM(p));
+    EXPECT_EQ(static_cast<GLenum>(GL_NO_ERROR), glGetError());
+    TryAllDrawFunctions(p, GL_NO_ERROR);
+  }
+
+  // Path name marked as used but without path object state causes
+  // a GL error upon any draw command.
+  GLuint path = glGenPathsCHROMIUM(1);
+  EXPECT_FALSE(glIsPathCHROMIUM(path));
+  TryAllDrawFunctions(path, GL_INVALID_OPERATION);
+  glDeletePathsCHROMIUM(path, 1);
+
+  // Document a bit of an inconsistency: path name marked as used but without
+  // path object state causes a GL error upon any draw command (tested above).
+  // Path name that had path object state, but then was "cleared", still has a
+  // path object state, even though the state is empty.
+  path = glGenPathsCHROMIUM(1);
+  EXPECT_FALSE(glIsPathCHROMIUM(path));
+  GLubyte commands[] = {GL_MOVE_TO_CHROMIUM, GL_CLOSE_PATH_CHROMIUM};
+  GLfloat coords[] = {50.0f, 50.0f};
+  glPathCommandsCHROMIUM(path, arraysize(commands), commands, arraysize(coords),
+                         GL_FLOAT, coords);
+  EXPECT_TRUE(glIsPathCHROMIUM(path));
+  glPathCommandsCHROMIUM(path, 0, NULL, 0, GL_FLOAT, NULL);
+  EXPECT_TRUE(glIsPathCHROMIUM(path));  // The surprise.
+  TryAllDrawFunctions(path, GL_NO_ERROR);
+  glDeletePathsCHROMIUM(path, 1);
+
+  // Document a bit of an inconsistency: "clearing" a used path name causes
+  // path to acquire state.
+  path = glGenPathsCHROMIUM(1);
+  EXPECT_FALSE(glIsPathCHROMIUM(path));
+  glPathCommandsCHROMIUM(path, 0, NULL, 0, GL_FLOAT, NULL);
+  EXPECT_TRUE(glIsPathCHROMIUM(path));  // The surprise.
+  glDeletePathsCHROMIUM(path, 1);
+
+  // Make sure nothing got drawn by the drawing commands that should not produce
+  // anything.
+  const uint8 black[] = {0, 0, 0, 0};
+  EXPECT_TRUE(
+      GLTestHelper::CheckPixels(0, 0, kResolution, kResolution, 0, black));
+}
+
+TEST_F(CHROMIUMPathRenderingTest, TestUnnamedPathsErrors) {
+  if (!GLTestHelper::HasExtension("GL_CHROMIUM_path_rendering"))
+    return;
+
+  // Unnamed paths: Trying to create a path object with non-existing path name
+  // produces error.  (Not a error in real NV_path_rendering).
+  EXPECT_EQ(static_cast<GLenum>(GL_NO_ERROR), glGetError());
+  GLubyte commands[] = {GL_MOVE_TO_CHROMIUM, GL_CLOSE_PATH_CHROMIUM};
+  GLfloat coords[] = {50.0f, 50.0f};
+  glPathCommandsCHROMIUM(555, arraysize(commands), commands, arraysize(coords),
+                         GL_FLOAT, coords);
+  EXPECT_EQ(static_cast<GLenum>(GL_INVALID_OPERATION), glGetError());
+
+  // PathParameter*: Using non-existing path object produces error.
+  EXPECT_EQ(static_cast<GLenum>(GL_NO_ERROR), glGetError());
+  glPathParameterfCHROMIUM(555, GL_PATH_STROKE_WIDTH_CHROMIUM, 5.0f);
+  EXPECT_EQ(static_cast<GLenum>(GL_INVALID_OPERATION), glGetError());
+
+  EXPECT_EQ(static_cast<GLenum>(GL_NO_ERROR), glGetError());
+  glPathParameteriCHROMIUM(555, GL_PATH_JOIN_STYLE_CHROMIUM, GL_ROUND_CHROMIUM);
+  EXPECT_EQ(static_cast<GLenum>(GL_INVALID_OPERATION), glGetError());
+}
+
+TEST_F(CHROMIUMPathRenderingTest, TestPathCommandsErrors) {
+  if (!GLTestHelper::HasExtension("GL_CHROMIUM_path_rendering"))
+    return;
+
+  static const GLenum kInvalidCoordType = GL_NONE;
+
+  GLuint path = glGenPathsCHROMIUM(1);
+  GLubyte commands[] = {GL_MOVE_TO_CHROMIUM, GL_CLOSE_PATH_CHROMIUM};
+  GLfloat coords[] = {50.0f, 50.0f};
+
+  glPathCommandsCHROMIUM(path, arraysize(commands), commands, -4, GL_FLOAT,
+                         coords);
+  EXPECT_EQ(static_cast<GLenum>(GL_INVALID_VALUE), glGetError());
+
+  glPathCommandsCHROMIUM(path, -1, commands, arraysize(coords), GL_FLOAT,
+                         coords);
+  EXPECT_EQ(static_cast<GLenum>(GL_INVALID_VALUE), glGetError());
+
+  glPathCommandsCHROMIUM(path, arraysize(commands), commands, arraysize(coords),
+                         kInvalidCoordType, coords);
+  EXPECT_EQ(static_cast<GLenum>(GL_INVALID_ENUM), glGetError());
+
+  // These can not distinquish between the check that should fail them.
+  // This should fail due to coord count * float size overflow.
+  glPathCommandsCHROMIUM(path, arraysize(commands), commands,
+                         std::numeric_limits<GLsizei>::max(), GL_FLOAT, coords);
+  // This should fail due to cmd count + coord count * short size.
+  glPathCommandsCHROMIUM(path, arraysize(commands), commands,
+                         std::numeric_limits<GLsizei>::max(), GL_SHORT, coords);
+  EXPECT_EQ(static_cast<GLenum>(GL_INVALID_OPERATION), glGetError());
+
+  glDeletePathsCHROMIUM(path, 1);
+}
+
+TEST_F(CHROMIUMPathRenderingTest, TestPathRenderingInvalidArgs) {
+  if (!GLTestHelper::HasExtension("GL_CHROMIUM_path_rendering"))
+    return;
+
+  GLuint path = glGenPathsCHROMIUM(1);
+  glPathCommandsCHROMIUM(path, 0, NULL, 0, GL_FLOAT, NULL);
+
+  // Verify that normal calls work.
+  glStencilFillPathCHROMIUM(path, GL_COUNT_UP_CHROMIUM, 0x7F);
+  EXPECT_EQ(static_cast<GLenum>(GL_NO_ERROR), glGetError());
+  glStencilThenCoverFillPathCHROMIUM(path, GL_COUNT_UP_CHROMIUM, 0x7F,
+                                     GL_BOUNDING_BOX_CHROMIUM);
+  EXPECT_EQ(static_cast<GLenum>(GL_NO_ERROR), glGetError());
+
+  // Using invalid fill mode causes INVALID_ENUM.
+  glStencilFillPathCHROMIUM(path, GL_COUNT_UP_CHROMIUM - 1, 0x7F);
+  EXPECT_EQ(static_cast<GLenum>(GL_INVALID_ENUM), glGetError());
+  glStencilThenCoverFillPathCHROMIUM(path, GL_COUNT_UP_CHROMIUM - 1, 0x7F,
+                                     GL_BOUNDING_BOX_CHROMIUM);
+  EXPECT_EQ(static_cast<GLenum>(GL_INVALID_ENUM), glGetError());
+
+  // Using invalid cover mode causes INVALID_ENUM.
+  glCoverFillPathCHROMIUM(path, GL_CONVEX_HULL_CHROMIUM - 1);
+  EXPECT_EQ(static_cast<GLenum>(GL_INVALID_ENUM), glGetError());
+  glStencilThenCoverFillPathCHROMIUM(path, GL_COUNT_UP_CHROMIUM, 0x7F,
+                                     GL_BOUNDING_BOX_CHROMIUM + 1);
+  EXPECT_EQ(static_cast<GLenum>(GL_INVALID_ENUM), glGetError());
+
+  // Using mask+1 not being power of two causes INVALID_VALUE with up/down fill
+  // mode.
+  glStencilFillPathCHROMIUM(path, GL_COUNT_UP_CHROMIUM, 0x40);
+  EXPECT_EQ(static_cast<GLenum>(GL_INVALID_VALUE), glGetError());
+  glStencilThenCoverFillPathCHROMIUM(path, GL_COUNT_DOWN_CHROMIUM, 12,
+                                     GL_BOUNDING_BOX_CHROMIUM);
+  EXPECT_EQ(static_cast<GLenum>(GL_INVALID_VALUE), glGetError());
+
+  glDeletePathsCHROMIUM(path, 1);
+}
+
+// Tests that drawing with CHROMIUM_path_rendering functions work.
+TEST_F(CHROMIUMPathRenderingTest, TestPathRendering) {
+  if (!GLTestHelper::HasExtension("GL_CHROMIUM_path_rendering"))
+    return;
+
+  static const float kBlue[] = {0.0f, 0.0f, 1.0f, 1.0f};
+  static const float kGreen[] = {0.0f, 1.0f, 0.0f, 1.0f};
+
+  SetupStateForTestPattern();
+
+  GLuint path = glGenPathsCHROMIUM(1);
+  SetupPathStateForTestPattern(path);
+
+  // Do the stencil fill, cover fill, stencil stroke, cover stroke
+  // in unconventional order:
+  // 1) stencil the stroke in stencil high bit
+  // 2) stencil the fill in low bits
+  // 3) cover the fill
+  // 4) cover the stroke
+  // This is done to check that glPathStencilFunc works, eg the mask
+  // goes through. Stencil func is not tested ATM, for simplicity.
+
+  glPathStencilFuncCHROMIUM(GL_ALWAYS, 0, 0xFF);
+  glStencilStrokePathCHROMIUM(path, 0x80, 0x80);
+
+  glPathStencilFuncCHROMIUM(GL_ALWAYS, 0, 0x7F);
+  glStencilFillPathCHROMIUM(path, GL_COUNT_UP_CHROMIUM, 0x7F);
+
+  glStencilFunc(GL_LESS, 0, 0x7F);
+  glStencilOp(GL_KEEP, GL_KEEP, GL_ZERO);
+  glUniform4fv(color_loc_, 1, kBlue);
+  glCoverFillPathCHROMIUM(path, GL_BOUNDING_BOX_CHROMIUM);
+
+  glStencilFunc(GL_EQUAL, 0x80, 0x80);
+  glStencilOp(GL_KEEP, GL_KEEP, GL_ZERO);
+  glUniform4fv(color_loc_, 1, kGreen);
+  glCoverStrokePathCHROMIUM(path, GL_CONVEX_HULL_CHROMIUM);
+
+  glDeletePathsCHROMIUM(path, 1);
+
+  // Verify the image.
+  VerifyTestPatternFill(0.0f, 0.0f);
+  VerifyTestPatternBg(0.0f, 0.0f);
+  VerifyTestPatternStroke(0.0f, 0.0f);
+}
+
+// Tests that drawing with CHROMIUM_path_rendering
+// StencilThenCover{Stroke,Fill}Path functions work.
+TEST_F(CHROMIUMPathRenderingTest, TestPathRenderingThenFunctions) {
+  if (!GLTestHelper::HasExtension("GL_CHROMIUM_path_rendering"))
+    return;
+
+  static float kBlue[] = {0.0f, 0.0f, 1.0f, 1.0f};
+  static float kGreen[] = {0.0f, 1.0f, 0.0f, 1.0f};
+
+  SetupStateForTestPattern();
+
+  GLuint path = glGenPathsCHROMIUM(1);
+  SetupPathStateForTestPattern(path);
+
+  glPathStencilFuncCHROMIUM(GL_ALWAYS, 0, 0xFF);
+  glStencilFunc(GL_EQUAL, 0x80, 0x80);
+  glStencilOp(GL_KEEP, GL_KEEP, GL_ZERO);
+  glUniform4fv(color_loc_, 1, kGreen);
+  glStencilThenCoverStrokePathCHROMIUM(path, 0x80, 0x80,
+                                       GL_BOUNDING_BOX_CHROMIUM);
+
+  glPathStencilFuncCHROMIUM(GL_ALWAYS, 0, 0x7F);
+  glStencilFunc(GL_LESS, 0, 0x7F);
+  glStencilOp(GL_KEEP, GL_KEEP, GL_ZERO);
+  glUniform4fv(color_loc_, 1, kBlue);
+  glStencilThenCoverFillPathCHROMIUM(path, GL_COUNT_UP_CHROMIUM, 0x7F,
+                                     GL_CONVEX_HULL_CHROMIUM);
+
+  glDeletePathsCHROMIUM(path, 1);
+
+  // Verify the image.
+  VerifyTestPatternFill(0.0f, 0.0f);
+  VerifyTestPatternBg(0.0f, 0.0f);
+  VerifyTestPatternStroke(0.0f, 0.0f);
 }
 
 }  // namespace gpu