Bug 1563076 - Forbid BeginTransformFeedback with a buffer bound to multiple indices. r=lsalzman

Differential Revision: https://phabricator.services.mozilla.com/D36688

--HG--
extra : moz-landing-system : lando

dom/canvas/WebGLContext.h

@@ -1096,6 +1096,9 @@ class WebGLContext : public nsICanvasRenderingContextInternal,
 
   // -
 
+  void GenErrorIllegalUse(GLenum useTarget, uint32_t useId, GLenum boundTarget,
+                          uint32_t boundId) const;
+
   bool ValidateBufferForNonTf(const WebGLBuffer&, GLenum nonTfTarget,
                               uint32_t nonTfId) const;
 

dom/canvas/WebGLContextDraw.cpp

@@ -202,10 +202,10 @@ bool WebGLContext::ValidateStencilParamsForDrawCall() const {
 
 // -
 
-static void GenErrorIllegalUse(const WebGLContext& webgl,
-                               const GLenum useTarget, const uint32_t useId,
-                               const GLenum boundTarget,
-                               const uint32_t boundId) {
+void WebGLContext::GenErrorIllegalUse(const GLenum useTarget,
+                                      const uint32_t useId,
+                                      const GLenum boundTarget,
+                                      const uint32_t boundId) const {
   const auto fnName = [&](const GLenum target, const uint32_t id) {
     auto name = nsCString(EnumString(target).c_str());
     if (id != static_cast<uint32_t>(-1)) {
@@ -215,10 +215,10 @@ static void GenErrorIllegalUse(const WebGLContext& webgl,
   };
   const auto& useName = fnName(useTarget, useId);
   const auto& boundName = fnName(boundTarget, boundId);
-  webgl.GenerateError(LOCAL_GL_INVALID_OPERATION,
-                      "Illegal use of buffer at %s"
-                      " while also bound to %s.",
-                      useName.BeginReading(), boundName.BeginReading());
+  GenerateError(LOCAL_GL_INVALID_OPERATION,
+                "Illegal use of buffer at %s"
+                " while also bound to %s.",
+                useName.BeginReading(), boundName.BeginReading());
 }
 
 bool WebGLContext::ValidateBufferForNonTf(const WebGLBuffer& nonTfBuffer,
@@ -236,7 +236,7 @@ bool WebGLContext::ValidateBufferForNonTf(const WebGLBuffer& nonTfBuffer,
     const auto& tfBuffer = tfAttribs[tfId].mBufferBinding;
     if (&nonTfBuffer == tfBuffer) {
       dupe = true;
-      GenErrorIllegalUse(*this, nonTfTarget, nonTfId,
+      GenErrorIllegalUse(nonTfTarget, nonTfId,
                          LOCAL_GL_TRANSFORM_FEEDBACK_BUFFER, tfId);
     }
   }
@@ -285,7 +285,7 @@ bool WebGLContext::ValidateBuffersForTf(
     for (const auto& tf : tfBuffers) {
       if (nonTf && tf.buffer == nonTf) {
         dupe = true;
-        GenErrorIllegalUse(*this, LOCAL_GL_TRANSFORM_FEEDBACK_BUFFER, tf.id,
+        GenErrorIllegalUse(LOCAL_GL_TRANSFORM_FEEDBACK_BUFFER, tf.id,
                            nonTfTarget, nonTfId);
       }
     }

dom/canvas/WebGLTransformFeedback.cpp

@@ -7,6 +7,7 @@
 
 #include "GLContext.h"
 #include "mozilla/dom/WebGL2RenderingContextBinding.h"
+#include "mozilla/IntegerRange.h"
 #include "WebGL2Context.h"
 #include "WebGLProgram.h"
 
@@ -73,6 +74,16 @@ void WebGLTransformFeedback::BeginTransformFeedback(GLenum primMode) {
       return;
     }
 
+    for (const auto iBound : IntegerRange(mIndexedBindings.size())) {
+      const auto& bound = mIndexedBindings[iBound].mBufferBinding.get();
+      if (iBound != i && buffer == bound) {
+        mContext->GenErrorIllegalUse(
+            LOCAL_GL_TRANSFORM_FEEDBACK_BUFFER, static_cast<uint32_t>(i),
+            LOCAL_GL_TRANSFORM_FEEDBACK_BUFFER, static_cast<uint32_t>(iBound));
+        return;
+      }
+    }
+
     const size_t vertCapacity = buffer->ByteLength() / 4 / componentsPerVert;
     minVertCapacity = std::min(minVertCapacity, vertCapacity);
   }

dom/canvas/test/webgl-conf/generated-mochitest.ini

@@ -7381,8 +7381,6 @@ subsuite = webgl2-core
 subsuite = webgl2-core
 [generated/test_2_conformance2__transform_feedback__same-buffer-two-binding-points.html]
 subsuite = webgl2-core
-fail-if = 1
-skip-if = (os == 'win')
 [generated/test_2_conformance2__transform_feedback__simultaneous_binding.html]
 subsuite = webgl2-core
 [generated/test_2_conformance2__transform_feedback__switching-objects.html]

dom/canvas/test/webgl-conf/mochitest-errata.ini

@@ -176,10 +176,6 @@ fail-if = 1
 
 [generated/test_2_conformance2__textures__misc__tex-unpack-params-with-flip-y-and-premultiply-alpha.html]
 fail-if = 1
-[generated/test_2_conformance2__transform_feedback__same-buffer-two-binding-points.html]
-fail-if = 1
-# ABORT_ON_ERROR from ANGLE
-skip-if = (os == 'win')
 
 ########################################################################
 # Complicated