WebGL 2: Fix bugs in negativetextureapi.html for Mac

gpu/command_buffer/service/gles2_cmd_decoder.cc

Index: gpu/command_buffer/service/gles2_cmd_decoder.cc
diff --git a/gpu/command_buffer/service/gles2_cmd_decoder.cc b/gpu/command_buffer/service/gles2_cmd_decoder.cc
index 953c4741b012a8758e8fcd25144d3c28e5920f47..eaa02c8514c9eed3f9089b8c000c886527ed09a5 100644
--- a/gpu/command_buffer/service/gles2_cmd_decoder.cc
+++ b/gpu/command_buffer/service/gles2_cmd_decoder.cc
@@ -1007,6 +1007,18 @@ class GLES2DecoderImpl : public GLES2Decoder, public ErrorStateClient {
       GLsizei width,
       GLsizei height);
 
+  // Wrapper for CopyTexSubImage3D.
+  void DoCopyTexSubImage3D(
+      GLenum target,
+      GLint level,
+      GLint xoffset,
+      GLint yoffset,
+      GLint zoffset,
+      GLint x,
+      GLint y,
+      GLsizei width,
+      GLsizei height);
+
   void DoCopyTextureCHROMIUM(GLuint source_id,
                              GLuint dest_id,
                              GLenum internal_format,
@@ -13019,7 +13031,7 @@ void GLES2DecoderImpl::DoCopyTexImage2D(
       CopyTexImageResourceManager::CopyTexImageRequiresBlit(feature_info_.get(),
                                                             format);
   if (requires_luma_blit &&
-      !InitializeCopyTexImageBlitter("glCopyTexSubImage2D")) {
+      !InitializeCopyTexImageBlitter(func_name)) {
     return;
   }
 
@@ -13240,6 +13252,59 @@ void GLES2DecoderImpl::DoCopyTexSubImage2D(
   ExitCommandProcessingEarly();
 }
 
+void GLES2DecoderImpl::DoCopyTexSubImage3D(
+    GLenum target,
+    GLint level,
+    GLint xoffset,
+    GLint yoffset,
+    GLint zoffset,
+    GLint x,
+    GLint y,
+    GLsizei width,
+    GLsizei height) {
+  const char* func_name = "glCopyTexSubImage3D";
+  DCHECK(!ShouldDeferReads());
+  TextureRef* texture_ref = texture_manager()->GetTextureInfoForTarget(
+      &state_, target);
+  if (!texture_ref) {
+    LOCAL_SET_GL_ERROR(
+        GL_INVALID_OPERATION, func_name, "unknown texture for target");
+    return;
+  }
+  Texture* texture = texture_ref->texture();
+  GLenum type = 0;
+  GLenum internal_format = 0;
+  if (!texture->GetLevelType(target, level, &type, &internal_format) ||
+      !texture->ValidForTexture(
+          target, level, xoffset, yoffset, zoffset, width, height, 1)) {
+    LOCAL_SET_GL_ERROR(GL_INVALID_VALUE, func_name, "bad dimensions.");
+    return;
+  }
+
+  if (!CheckBoundReadFramebufferValid(func_name,
+                                      GL_INVALID_FRAMEBUFFER_OPERATION)) {
+    return;
+  }
+
+  GLenum read_format = GetBoundReadFrameBufferInternalFormat();
+  GLenum read_type = GetBoundReadFrameBufferTextureType();
+  if (!ValidateCopyTexFormat(func_name, internal_format,
+                             read_format, read_type)) {
+    return;
+  }
+
+  // TODO(yunchao): Follow-up CLs are necessary. For instance, feedback loop
+  // detection, emulation of unsized formats in core profile, clear the 3d
+  // textures if it is uncleared, out-of-bounds reading, etc.

[Zhenyao Mo, 2016/07/28 00:10:54]

Please do follow up.  Can you also add a conformance test? Say you create a 3D
texture without data, and then do CopyTexSubImage3D to one of the level/slice. 
At this point, in Chrome the texture is still marked as uninitialized. Now you
try to render using the that slice. You will find it's been initialized to 0
instead of the data CopyTexSubImage3D wrote into.

Once the test is added, we can get a CL to fix it.

[yunchao, 2016/07/28 00:41:04]

Yes. In fact, I have already had a CL to handle the feedback loop issue. I will
improve it and submit it to review today.
OK. I will add this test case in gpu_unittests by follow-up CL, as well as the
code to fix it in the same CL.

[Zhenyao Mo, 2016/07/28 05:13:26]

I suggest adding a webgl2 conformance test instead of a unit test.

+
+  glCopyTexSubImage3D(target, level, xoffset, yoffset, zoffset, x, y, width,
+                      height);
+
+  // This may be a slow command.  Exit command processing to allow for
+  // context preemption and GPU watchdog checks.
+  ExitCommandProcessingEarly();
+}
+
 error::Error GLES2DecoderImpl::HandleTexSubImage2D(uint32_t immediate_data_size,
                                                    const void* cmd_data) {
   const gles2::cmds::TexSubImage2D& c =