commit 2eeb1b34ec59ecf701eb8fc31162b95d660cb90a
author Bryan Bernhart (Intel Americas Inc) <bryan.bernhart@intel.com> Wed Nov 29 16:06:43 2017 -0800
committer Commit Bot <commit-bot@chromium.org> Mon Dec 04 22:47:13 2017 +0000
tree 952a5ac2c9f92e58bb2a0da1c7bf4272001ca648
parent fdb400d7c3d2361fc305577563ee85b9117774ff

WebGLCompat: Fix depthstencil query results.

getFramebufferAttachmentParameter returns incorrect
result for framebuffers in an inconsistent state.

BUG=angleproject:2259

Change-Id: I76fa99f1b8847c30469d344bd93dedd9cf6657bf
Reviewed-on: https://chromium-review.googlesource.com/798318
Reviewed-by: Bryan Bernhart <bryan.bernhart@intel.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Commit-Queue: Geoff Lang <geofflang@chromium.org>

src/libANGLE/Framebuffer.cpp

diff --git a/src/libANGLE/Framebuffer.cpp b/src/libANGLE/Framebuffer.cpp
index 187733f..67db701 100644
--- a/src/libANGLE/Framebuffer.cpp
+++ b/src/libANGLE/Framebuffer.cpp
@@ -297,7 +297,8 @@
     return mLabel;
 }
 
-const FramebufferAttachment *FramebufferState::getAttachment(GLenum attachment) const
+const FramebufferAttachment *FramebufferState::getAttachment(const Context *context,
+                                                             GLenum attachment) const
 {
     if (attachment >= GL_COLOR_ATTACHMENT0 && attachment <= GL_COLOR_ATTACHMENT15)
     {
@@ -317,7 +318,17 @@
             return getStencilAttachment();
         case GL_DEPTH_STENCIL:
         case GL_DEPTH_STENCIL_ATTACHMENT:
-            return getDepthStencilAttachment();
+            // In WebG1, DEPTH_STENCIL_ATTACHMENT is an alternative attachment point and even when
+            // inconsistant (i.e. multiple conflicting attachment points), it is still permitted to
+            // query the attachment parameters.
+            if (context->isWebGL1())
+            {
+                return getWebGLDepthStencilAttachment();
+            }
+            else
+            {
+                return getDepthStencilAttachment();
+            }
         default:
             UNREACHABLE();
             return nullptr;
@@ -402,6 +413,11 @@
     return mDepthAttachment.isAttached() ? &mDepthAttachment : nullptr;
 }
 
+const FramebufferAttachment *FramebufferState::getWebGLDepthStencilAttachment() const
+{
+    return mWebGLDepthStencilAttachment.isAttached() ? &mWebGLDepthStencilAttachment : nullptr;
+}
+
 const FramebufferAttachment *FramebufferState::getStencilAttachment() const
 {
     return mStencilAttachment.isAttached() ? &mStencilAttachment : nullptr;
@@ -466,7 +482,15 @@
         // must be COLOR_ATTACHMENTi or NONE"
         ASSERT(mDrawBufferStates[drawBufferIdx] == GL_COLOR_ATTACHMENT0 + drawBufferIdx ||
                (drawBufferIdx == 0 && mDrawBufferStates[drawBufferIdx] == GL_BACK));
-        return getAttachment(mDrawBufferStates[drawBufferIdx]);
+
+        if (mDrawBufferStates[drawBufferIdx] == GL_BACK)
+        {
+            return getColorAttachment(0);
+        }
+        else
+        {
+            return getColorAttachment(mDrawBufferStates[drawBufferIdx] - GL_COLOR_ATTACHMENT0);
+        }
     }
     else
     {
@@ -797,9 +821,10 @@
     return mState.getFirstNonNullAttachment();
 }
 
-const FramebufferAttachment *Framebuffer::getAttachment(GLenum attachment) const
+const FramebufferAttachment *Framebuffer::getAttachment(const Context *context,
+                                                        GLenum attachment) const
 {
-    return mState.getAttachment(attachment);
+    return mState.getAttachment(context, attachment);
 }
 
 size_t Framebuffer::getDrawbufferStateCount() const