Implement client side PBOs for glReadPixel

gpu/command_buffer/client/gles2_implementation_unittest.cc

Index: gpu/command_buffer/client/gles2_implementation_unittest.cc
diff --git a/gpu/command_buffer/client/gles2_implementation_unittest.cc b/gpu/command_buffer/client/gles2_implementation_unittest.cc
index edc7c6a08b920d1aabd338fef8b678c58bcdd6b9..860116eb286e836c3613569b86709b596444d0da 100644
--- a/gpu/command_buffer/client/gles2_implementation_unittest.cc
+++ b/gpu/command_buffer/client/gles2_implementation_unittest.cc
@@ -1420,6 +1420,45 @@ TEST_F(GLES2ImplementationTest, ReadPixelsBadFormatType) {
   gl_->ReadPixels(0, 0, kWidth, kHeight, kFormat, kType, buffer.get());
 }
 
+TEST_F(GLES2ImplementationTest, ReadPixelsWithPBO) {

[greggman, 2013/03/19 20:54:11]

Tests for failure would be good?

*) Test that a buffer that can't fit the result fails?
*) Test that a buffer than can fit the result but the result
   won't fit at the given offset fails?
*) Test that mapping a buffer that's in use waits for a
   token?

[hubbe, 2013/03/19 22:42:42]

Is there a good test that I can use as a template for these kinds of tests?

+  struct Cmds {
+    cmds::ReadPixels read;
+    cmd::SetToken set_token;
+  };
+  const GLint kBytesPerPixel = 4;
+  const GLint kWidth = 2;
+  const GLint kHeight = 2;
+  const GLenum kFormat = 0;
+  const GLenum kType = 0;
+
+  ExpectedMemoryInfo mem1 =
+      GetExpectedMemory(kWidth * kHeight * kBytesPerPixel);
+  ExpectedMemoryInfo result1 =
+      GetExpectedResultMemory(sizeof(cmds::ReadPixels::Result));
+
+  Cmds expected;
+  expected.read.Init(
+      0, 0, kWidth, kHeight, kFormat, kType,
+      mem1.id, mem1.offset, result1.id, result1.offset);
+  expected.set_token.Init(GetNextToken());
+  scoped_array<int8> buffer(new int8[kWidth * kHeight * kBytesPerPixel]);
+
+  GLuint b;
+  gl_->GenBuffers(1, &b);
+  gl_->BindBuffer(GL_PIXEL_UNPACK_TRANSFER_BUFFER_CHROMIUM, b);
+  gl_->BufferData(GL_PIXEL_UNPACK_TRANSFER_BUFFER_CHROMIUM,
+                  kWidth * kHeight * kBytesPerPixel,
+                  NULL,
+                  0 /* GL_STREAM_READ */ );
+  gl_->ReadPixels(0, 0, kWidth, kHeight, kFormat, kType, 0);
+  EXPECT_TRUE(gl_->MapBufferCHROMIUM(
+      GL_PIXEL_UNPACK_TRANSFER_BUFFER_CHROMIUM,
+      GL_READ_ONLY));
+  gl_->UnmapBufferCHROMIUM(GL_PIXEL_UNPACK_TRANSFER_BUFFER_CHROMIUM);
+  gl_->BindBuffer(GL_PIXEL_UNPACK_TRANSFER_BUFFER_CHROMIUM, 0);
+  gl_->DeleteBuffers(1, &b);
+}
+
 TEST_F(GLES2ImplementationTest, FreeUnusedSharedMemory) {
   struct Cmds {
     cmds::BufferSubData buf;
@@ -2809,4 +2848,3 @@ TEST_F(GLES2ImplementationTest, Enable) {
 
 }  // namespace gles2
 }  // namespace gpu
-