Implement client side PBOs for glReadPixel

gpu/command_buffer/client/gles2_implementation_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.
 
 // Tests for GLES2Implementation.
 
 #include "gpu/command_buffer/client/gles2_implementation.h"
 
 #include <GLES2/gl2ext.h>
 #include <GLES2/gl2extchromium.h>
@@ skipping 1402 matching lines @@
   expected.set_token.Init(GetNextToken());
   scoped_array<int8> buffer(new int8[kWidth * kHeight * kBytesPerPixel]);
 
   EXPECT_CALL(*command_buffer(), OnFlush())
       .Times(1)
       .RetiresOnSaturation();
 
   gl_->ReadPixels(0, 0, kWidth, kHeight, kFormat, kType, buffer.get());
 }
 
+TEST_F(GLES2ImplementationTest, ReadPixelsWithPBO) {
+  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;
     cmd::SetToken set_token;
   };
   const GLenum kTarget = GL_ELEMENT_ARRAY_BUFFER;
   const GLintptr kOffset = 15;
   const GLsizeiptr kSize = 16;
 
   ExpectedMemoryInfo mem1 = GetExpectedMemory(kSize);
@@ skipping 1369 matching lines @@
   ClearCommands();
   gl_->Enable(GL_BLEND);
   EXPECT_TRUE(NoCommandsWritten());
 }
 
 
 #include "gpu/command_buffer/client/gles2_implementation_unittest_autogen.h"
 
 }  // namespace gles2
 }  // namespace gpu
-