[Command buffer] workaround the framebuffer completeness bug for Intel 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 6f0d2e8db079242a81d3e81a1c5dcb2d04f1e9c2..8ea561fe86e2061e93f6e19274d8383bb12f219b 100644
--- a/gpu/command_buffer/service/gles2_cmd_decoder.cc
+++ b/gpu/command_buffer/service/gles2_cmd_decoder.cc
@@ -1431,6 +1431,14 @@ class GLES2DecoderImpl : public GLES2Decoder, public ErrorStateClient {
   void DoBufferSubData(
     GLenum target, GLintptr offset, GLsizeiptr size, const GLvoid * data);
 
+  // A workaround to adjust read buffer and draw buffers to GL_NONE
+  // if the specified read buffer or draw buffers have no image attached.

[Zhenyao Mo, 2016/11/14 19:42:24]

have missing images.

[yunchao, 2016/11/15 16:21:59]

Done.

+  // Return false if read buffer has no image or all of the draw buffers
+  // have no image. Then we can generate INVALID_OPERATION or return directly
+  // in the callers accordingly.
+  bool AdjustColorBufferAttachmentsIfNecessary(
+    bool read, bool draw);
+
   // Wrapper for glCheckFramebufferStatus
   GLenum DoCheckFramebufferStatus(GLenum target);
 
@@ -7213,6 +7221,13 @@ error::Error GLES2DecoderImpl::HandleDeleteProgram(
 error::Error GLES2DecoderImpl::DoClear(GLbitfield mask) {
   const char* func_name = "glClear";
   DCHECK(!ShouldDeferDraws());
+  if (mask & GL_COLOR_BUFFER_BIT &&

[Zhenyao Mo, 2016/11/14 19:42:24]

(mask & GL_COLOR_BUFFER_BIT) != 0

[yunchao, 2016/11/15 16:21:59]

Done.

+      workarounds().adjust_framebuffer_complete_status &&
+      SupportsDrawBuffers() &&
+      framebuffer_state_.clear_state_dirty) {
+    if (!AdjustColorBufferAttachmentsIfNecessary(false, true))
+      return error::kNoError;
+  }
   if (CheckBoundDrawFramebufferValid(func_name)) {
     ApplyDirtyState();
     if (workarounds().gl_clear_broken) {
@@ -7532,6 +7547,39 @@ void GLES2DecoderImpl::RestoreClearState() {
             state_.scissor_height);
 }
 
+bool GLES2DecoderImpl::AdjustColorBufferAttachmentsIfNecessary(
+    bool read, bool draw) {
+  DCHECK(workarounds().adjust_framebuffer_complete_status &&
+      SupportsDrawBuffers() &&
+      framebuffer_state_.clear_state_dirty);
+  if (read) {
+    const Framebuffer* framebuffer =
+        GetFramebufferInfoForTarget(GL_READ_FRAMEBUFFER);
+    if (framebuffer &&
+        framebuffer->ReadBufferHasNoImage() &&
+        framebuffer->ColorBuffersHaveImage()) {
+      glReadBuffer(GL_NONE);
+      return false;
+    }
+  } else {
+    GLsizei num = 0;
+    GLenum buf[8];
+    for (int i = 0; i < 8; ++i)
+      buf[i] = GL_NONE;
+    const Framebuffer* framebuffer =
+        GetFramebufferInfoForTarget(GL_DRAW_FRAMEBUFFER);
+    if (framebuffer &&
+        framebuffer->DrawBuffersHaveNoImage(num, buf) &&
+        framebuffer->ColorBuffersHaveImage()) {
+      glDrawBuffersARB(8, buf);
+    }
+    if (num == 0) {
+      return false;
+    }
+  }
+  return true;
+}
+
 GLenum GLES2DecoderImpl::DoCheckFramebufferStatus(GLenum target) {
   Framebuffer* framebuffer =
       GetFramebufferInfoForTarget(target);
@@ -7542,6 +7590,21 @@ GLenum GLES2DecoderImpl::DoCheckFramebufferStatus(GLenum target) {
   if (completeness != GL_FRAMEBUFFER_COMPLETE) {
     return completeness;
   }
+
+  bool has_image = true;
+  if (workarounds().adjust_framebuffer_complete_status &&
+      SupportsDrawBuffers() &&
+      framebuffer_state_.clear_state_dirty) {
+    if (target == GL_READ_FRAMEBUFFER) {
+      has_image = AdjustColorBufferAttachmentsIfNecessary(true, false);
+    } else {
+      has_image = AdjustColorBufferAttachmentsIfNecessary(false, true);
+    }
+    if (!has_image) {
+      return GL_FRAMEBUFFER_COMPLETE;
+    }
+  }
+
   return framebuffer->GetStatus(texture_manager(), target);
 }
 
@@ -7832,6 +7895,19 @@ void GLES2DecoderImpl::DoBlitFramebufferCHROMIUM(
   const char* func_name = "glBlitFramebufferCHROMIUM";
   DCHECK(!ShouldDeferReads() && !ShouldDeferDraws());
 
+  if (workarounds().adjust_framebuffer_complete_status &&
+      (mask & GL_COLOR_BUFFER_BIT) != 0 &&
+      SupportsDrawBuffers() &&
+      framebuffer_state_.clear_state_dirty) {
+    if (!AdjustColorBufferAttachmentsIfNecessary(false, true)) {
+      return;
+    }
+    if (!AdjustColorBufferAttachmentsIfNecessary(true, false)) {
+      LOCAL_SET_GL_ERROR(GL_INVALID_OPERATION, func_name,
+          "no valid color image");
+      return;
+    }
+  }
   if (!CheckBoundFramebufferValid(func_name)) {
     return;
   }
@@ -9806,6 +9882,13 @@ error::Error GLES2DecoderImpl::DoDrawArrays(
     LOCAL_SET_GL_ERROR(GL_INVALID_VALUE, function_name, "primcount < 0");
     return error::kNoError;
   }
+  if (workarounds().adjust_framebuffer_complete_status &&
+      SupportsDrawBuffers() &&
+      framebuffer_state_.clear_state_dirty) {
+    if (!AdjustColorBufferAttachmentsIfNecessary(false, true)) {
+      return error::kNoError;
+    }
+  }
   if (!CheckBoundDrawFramebufferValid(function_name)) {

[Zhenyao Mo, 2016/11/14 19:42:24]

All this same code is right above CheckBoundDrawFramebufferValid or
CheckBoundFramebufferValid.  It looks to me that the workaround should just be
part of that function, so we don't have to repeat ourselves all over the places.

[yunchao, 2016/11/15 16:21:59]

Done. 

It is a little different in Clear and ClearBuffer*, so, still handle it like
this in the callers for these functions. 

     return error::kNoError;
   }
@@ -9970,6 +10053,13 @@ error::Error GLES2DecoderImpl::DoDrawElements(const char* function_name,
     return error::kNoError;
   }
 
+  if (workarounds().adjust_framebuffer_complete_status &&
+      SupportsDrawBuffers() &&
+      framebuffer_state_.clear_state_dirty) {
+    if (!AdjustColorBufferAttachmentsIfNecessary(false, true)) {
+      return error::kNoError;
+    }
+  }
   if (!CheckBoundDrawFramebufferValid(function_name)) {
     return error::kNoError;
   }
@@ -11195,6 +11285,16 @@ error::Error GLES2DecoderImpl::HandleReadPixels(uint32_t immediate_data_size,
     return error::kNoError;
   }
 
+  if (workarounds().adjust_framebuffer_complete_status &&
+      SupportsDrawBuffers() &&
+      framebuffer_state_.clear_state_dirty) {
+    if (!AdjustColorBufferAttachmentsIfNecessary(true, false)) {
+      LOCAL_SET_GL_ERROR(GL_INVALID_OPERATION, func_name,
+          "no valid color image");
+      return error::kNoError;
+    }
+  }
+
   if (!CheckBoundReadFramebufferValid(
           func_name, GL_INVALID_FRAMEBUFFER_OPERATION)) {
     return error::kNoError;
@@ -13828,6 +13928,16 @@ void GLES2DecoderImpl::DoCopyTexImage2D(
     return;
   }
 
+  if (workarounds().adjust_framebuffer_complete_status &&
+      SupportsDrawBuffers() &&
+      framebuffer_state_.clear_state_dirty) {
+    if (!AdjustColorBufferAttachmentsIfNecessary(true, false)) {
+      LOCAL_SET_GL_ERROR(GL_INVALID_OPERATION, func_name,
+          "no valid color image");
+      return;
+    }
+  }
+
   if (!CheckBoundReadFramebufferValid(func_name,
                                       GL_INVALID_FRAMEBUFFER_OPERATION)) {
     return;
@@ -14075,6 +14185,15 @@ void GLES2DecoderImpl::DoCopyTexSubImage2D(
     return;
   }
 
+  if (workarounds().adjust_framebuffer_complete_status &&
+      SupportsDrawBuffers() &&
+      framebuffer_state_.clear_state_dirty) {
+    if (!AdjustColorBufferAttachmentsIfNecessary(true, false)) {
+      LOCAL_SET_GL_ERROR(GL_INVALID_OPERATION, func_name,
+          "no valid color image");
+      return;
+    }
+  }
   if (!CheckBoundReadFramebufferValid(func_name,
                                       GL_INVALID_FRAMEBUFFER_OPERATION)) {
     return;
@@ -14191,6 +14310,15 @@ void GLES2DecoderImpl::DoCopyTexSubImage3D(
     return;
   }
 
+  if (workarounds().adjust_framebuffer_complete_status &&
+      SupportsDrawBuffers() &&
+      framebuffer_state_.clear_state_dirty) {
+    if (!AdjustColorBufferAttachmentsIfNecessary(true, false)) {
+      LOCAL_SET_GL_ERROR(GL_INVALID_OPERATION, func_name,
+          "no valid color image");
+      return;
+    }
+  }
   if (!CheckBoundReadFramebufferValid(func_name,
                                       GL_INVALID_FRAMEBUFFER_OPERATION)) {
     return;