Support async readbacks on OpenGL ES 3.0 drivers

R=apatrick@chromium.org, hubbe@chromium.org

Review URL: https://codereview.chromium.org/22891024

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@219669 0039d316-1c4b-4281-b951-d872f2087c98

8 files changed, 65 insertions, 17 deletions

diff --git a/gpu/command_buffer/service/feature_info.cc b/gpu/command_buffer/service/feature_info.cc
index 41c6a1b..453b43d 100644
--- a/gpu/command_buffer/service/feature_info.cc
+++ b/gpu/command_buffer/service/feature_info.cc
@@ -120,7 +120,8 @@ FeatureInfo::FeatureFlags::FeatureFlags()
       enable_samplers(false),
       ext_draw_buffers(false),
       ext_frag_depth(false),
-      use_async_readpixels(false) {
+      use_async_readpixels(false),
+      map_buffer_range(false) {
 }
 
 FeatureInfo::Workarounds::Workarounds() :
@@ -644,16 +645,6 @@ void FeatureInfo::AddFeatures(const CommandLine& command_line) {
     feature_flags_.ext_frag_depth = true;
   }
 
-  bool ui_gl_fence_works =
-      extensions.Contains("GL_NV_fence") ||
-      extensions.Contains("GL_ARB_sync");
-
-  if (ui_gl_fence_works &&
-      extensions.Contains("GL_ARB_pixel_buffer_object") &&
-      !workarounds_.disable_async_readpixels) {
-    feature_flags_.use_async_readpixels = true;
-  }
-
   if (!disallowed_features_.swap_buffer_complete_callback)
     AddExtensionString("GL_CHROMIUM_swapbuffers_complete_callback");
 
@@ -664,6 +655,24 @@ void FeatureInfo::AddFeatures(const CommandLine& command_line) {
     is_es3 = (lstr.substr(0, 12) == "opengl es 3.");
   }
 
+  bool ui_gl_fence_works = extensions.Contains("GL_NV_fence") ||
+                           extensions.Contains("GL_ARB_sync") ||
+                           extensions.Contains("EGL_KHR_fence_sync");
+
+  feature_flags_.map_buffer_range =
+      is_es3 || extensions.Contains("GL_ARB_map_buffer_range");
+
+  // Really it's part of core OpenGL 2.1 and up, but let's assume the
+  // extension is still advertised.
+  bool has_pixel_buffers =
+      is_es3 || extensions.Contains("GL_ARB_pixel_buffer_object");
+
+  // We will use either glMapBuffer() or glMapBufferRange() for async readbacks.
+  if (has_pixel_buffers && ui_gl_fence_works &&
+      !workarounds_.disable_async_readpixels) {
+    feature_flags_.use_async_readpixels = true;
+  }
+
   if (is_es3 || extensions.Contains("GL_ARB_sampler_objects")) {
     feature_flags_.enable_samplers = true;
     // TODO(dsinclair): Add AddExtensionString("GL_CHROMIUM_sampler_objects")
diff --git a/gpu/command_buffer/service/feature_info.h b/gpu/command_buffer/service/feature_info.h
index a9ccf64..8b33bb1 100644
--- a/gpu/command_buffer/service/feature_info.h
+++ b/gpu/command_buffer/service/feature_info.h
@@ -49,6 +49,7 @@ class GPU_EXPORT FeatureInfo : public base::RefCounted<FeatureInfo> {
     bool ext_draw_buffers;
     bool ext_frag_depth;
     bool use_async_readpixels;
+    bool map_buffer_range;
   };
 
   struct Workarounds {
diff --git a/gpu/command_buffer/service/feature_info_unittest.cc b/gpu/command_buffer/service/feature_info_unittest.cc
index 0dc1685..1d1cba4 100644
--- a/gpu/command_buffer/service/feature_info_unittest.cc
+++ b/gpu/command_buffer/service/feature_info_unittest.cc
@@ -96,6 +96,8 @@ TEST_F(FeatureInfoTest, Basic) {
   EXPECT_FALSE(info_->feature_flags(
       ).use_arb_occlusion_query_for_occlusion_query_boolean);
   EXPECT_FALSE(info_->feature_flags().native_vertex_array_object);
+  EXPECT_FALSE(info_->feature_flags().map_buffer_range);
+  EXPECT_FALSE(info_->feature_flags().use_async_readpixels);
 
 #define GPU_OP(type, name) EXPECT_FALSE(info_->workarounds().name);
   GPU_DRIVER_BUG_WORKAROUNDS(GPU_OP)
@@ -864,10 +866,12 @@ TEST_F(FeatureInfoTest, InitializeSamplersWithARBSamplerObjects) {
   EXPECT_TRUE(info_->feature_flags().enable_samplers);
 }
 
-TEST_F(FeatureInfoTest, InitializeSamplersWithES3) {
+TEST_F(FeatureInfoTest, InitializeWithES3) {
   SetupInitExpectationsWithGLVersion("", "OpenGL ES 3.0");
   info_->Initialize(NULL);
   EXPECT_TRUE(info_->feature_flags().enable_samplers);
+  EXPECT_TRUE(info_->feature_flags().map_buffer_range);
+  EXPECT_FALSE(info_->feature_flags().use_async_readpixels);
 }
 
 TEST_F(FeatureInfoTest, InitializeWithoutSamplers) {
@@ -876,6 +880,12 @@ TEST_F(FeatureInfoTest, InitializeWithoutSamplers) {
   EXPECT_FALSE(info_->feature_flags().enable_samplers);
 }
 
+TEST_F(FeatureInfoTest, InitializeWithES3AndFences) {
+  SetupInitExpectationsWithGLVersion("EGL_KHR_fence_sync", "OpenGL ES 3.0");
+  info_->Initialize(NULL);
+  EXPECT_TRUE(info_->feature_flags().use_async_readpixels);
+}
+
 TEST_F(FeatureInfoTest, ParseDriverBugWorkaroundsSingle) {
   SetupInitExpectations("");
   CommandLine command_line(0, NULL);
diff --git a/gpu/command_buffer/service/gles2_cmd_decoder.cc b/gpu/command_buffer/service/gles2_cmd_decoder.cc
index 77a6b8a..1cca696 100644
--- a/gpu/command_buffer/service/gles2_cmd_decoder.cc
+++ b/gpu/command_buffer/service/gles2_cmd_decoder.cc
@@ -6716,7 +6716,13 @@ void GLES2DecoderImpl::FinishReadPixels(
 
   if (buffer != 0) {
     glBindBuffer(GL_PIXEL_PACK_BUFFER_ARB, buffer);
-    void* data = glMapBuffer(GL_PIXEL_PACK_BUFFER_ARB, GL_READ_ONLY);
+    void* data;
+    if (features().map_buffer_range) {
+      data = glMapBufferRange(
+          GL_PIXEL_PACK_BUFFER_ARB, 0, pixels_size, GL_MAP_READ_BIT);
+    } else {
+      data = glMapBuffer(GL_PIXEL_PACK_BUFFER_ARB, GL_READ_ONLY);
+    }
     memcpy(pixels, data, pixels_size);
     // GL_PIXEL_PACK_BUFFER_ARB is currently unused, so we don't
     // have to restore the state.
diff --git a/gpu/command_buffer/tests/gl_tests_main.cc b/gpu/command_buffer/tests/gl_tests_main.cc
index e6044e7..4a689a2 100644
--- a/gpu/command_buffer/tests/gl_tests_main.cc
+++ b/gpu/command_buffer/tests/gl_tests_main.cc
@@ -38,8 +38,7 @@ int main(int argc, char** argv) {
   gfx::GLSurface::InitializeOneOff();
   ::gles2::Initialize();
   gpu::ApplyGpuDriverBugWorkarounds(CommandLine::ForCurrentProcess());
-  base::MessageLoop::Type message_loop_type = base::MessageLoop::TYPE_UI;
-  base::MessageLoop main_message_loop(message_loop_type);
+  base::MessageLoop main_message_loop;
   return GLTestHelper::RunTests(argc, argv);
 }
 
diff --git a/gpu/config/gpu_driver_bug_list_json.cc b/gpu/config/gpu_driver_bug_list_json.cc
index 7b2d8df..2383998 100644
--- a/gpu/config/gpu_driver_bug_list_json.cc
+++ b/gpu/config/gpu_driver_bug_list_json.cc
@@ -85,7 +85,7 @@ const char kGpuDriverBugListJson[] = LONG_STRING_CONST(
 {
   "name": "gpu driver bug list",
   // Please update the version number whenever you change this file.
-  "version": "2.6",
+  "version": "2.7",
   "entries": [
     {
       "id": 1,
@@ -436,6 +436,21 @@ const char kGpuDriverBugListJson[] = LONG_STRING_CONST(
       "features": [
         "disable_angle_instanced_arrays"
       ]
+    },
+    {
+      "id": 29,
+      "cr_bugs": [278606],
+      "description": "Testing fences is broken on QualComm.",
+      "os": {
+        "type": "android"
+      },
+      "gl_vendor": {
+        "op": "beginwith",
+        "value": "Qualcomm"
+      },
+      "features": [
+        "disable_async_readpixels"
+      ]
     }
   ]
 }
diff --git a/ui/gl/generate_bindings.py b/ui/gl/generate_bindings.py
index 3b37a17..3e51dcb 100755
--- a/ui/gl/generate_bindings.py
+++ b/ui/gl/generate_bindings.py
@@ -432,6 +432,13 @@ GL_FUNCTIONS = [
 { 'return_type': 'void*',
   'names': ['glMapBuffer', 'glMapBufferOES'],
   'arguments': 'GLenum target, GLenum access', },
+{ 'return_type': 'void*',
+  'names': ['glMapBufferRange'],
+  'arguments':
+      'GLenum target, GLintptr offset, GLsizeiptr length, GLenum access', },
+{ 'return_type': 'void',
+  'names': ['glFlushMappedBufferRange'],
+  'arguments': 'GLenum target, GLintptr offset, GLsizeiptr length', },
 { 'return_type': 'void',
   'names': ['glPixelStorei'],
   'arguments': 'GLenum pname, GLint param', },
diff --git a/ui/gl/gl_fence.cc b/ui/gl/gl_fence.cc
index b9d9513..9b85300 100644
--- a/ui/gl/gl_fence.cc
+++ b/ui/gl/gl_fence.cc
@@ -80,6 +80,7 @@ class EGLFenceSync : public gfx::GLFence {
   EGLFenceSync() {
     display_ = eglGetCurrentDisplay();
     sync_ = eglCreateSyncKHR(display_, EGL_SYNC_FENCE_KHR, NULL);
+    glFlush();
   }
 
   virtual bool HasCompleted() OVERRIDE {
@@ -90,7 +91,7 @@ class EGLFenceSync : public gfx::GLFence {
   }
 
   virtual void ClientWait() OVERRIDE {
-    EGLint flags = EGL_SYNC_FLUSH_COMMANDS_BIT_KHR;
+    EGLint flags = 0;
     EGLTimeKHR time = EGL_FOREVER_KHR;
     eglClientWaitSyncKHR(display_, sync_, flags, time);
   }