Move stencil mask validation to before the draw.

src/libGLESv2/Context.cpp

@@ -575,6 +575,21 @@ void Context::setStencilBackOperations(GLenum stencilBackFail, GLenum stencilBac
     mState.depthStencil.stencilBackPassDepthPass = stencilBackPassDepthPass;
 }
 
+const gl::DepthStencilState &Context::getDepthStencilState() const
+{
+    return mState.depthStencil;
+}
+
+GLint Context::getStencilRef() const
+{
+    return mState.stencilRef;
+}
+
+GLint Context::getStencilBackRef() const
+{
+    return mState.stencilBackRef;
+}
+
 void Context::setPolygonOffsetFill(bool enabled)
 {
      mState.rasterizer.polygonOffsetFill = enabled;

src/libGLESv2/Context.h

@@ -182,6 +182,9 @@ class Context
     void setStencilBackWritemask(GLuint stencilBackWritemask);
     void setStencilOperations(GLenum stencilFail, GLenum stencilPassDepthFail, GLenum stencilPassDepthPass);
     void setStencilBackOperations(GLenum stencilBackFail, GLenum stencilBackPassDepthFail, GLenum stencilBackPassDepthPass);
+    const gl::DepthStencilState &getDepthStencilState() const;
+    GLint getStencilRef() const;
+    GLint getStencilBackRef() const;
 
     void setPolygonOffsetFill(bool enabled);
     bool isPolygonOffsetFillEnabled() const;

src/libGLESv2/renderer/d3d11/Renderer11.cpp

@@ -654,14 +654,9 @@ void Renderer11::setDepthStencilState(const gl::DepthStencilState &depthStencilS
         memcmp(&depthStencilState, &mCurDepthStencilState, sizeof(gl::DepthStencilState)) != 0 ||
         stencilRef != mCurStencilRef || stencilBackRef != mCurStencilBackRef)
     {
-        if (depthStencilState.stencilWritemask != depthStencilState.stencilBackWritemask ||
-            stencilRef != stencilBackRef ||
-            depthStencilState.stencilMask != depthStencilState.stencilBackMask)
-        {
-            ERR("Separate front/back stencil writemasks, reference values, or stencil mask values are "
-                "invalid under WebGL.");
-            return gl::error(GL_INVALID_OPERATION);
-        }
+        ASSERT(depthStencilState.stencilWritemask == depthStencilState.stencilBackWritemask);
+        ASSERT(stencilRef == stencilBackRef);
+        ASSERT(depthStencilState.stencilMask == depthStencilState.stencilBackMask);
 
         ID3D11DepthStencilState *dxDepthStencilState = mStateCache.getDepthStencilState(depthStencilState);
         if (!dxDepthStencilState)

src/libGLESv2/renderer/d3d9/Renderer9.cpp

@@ -893,13 +893,10 @@ void Renderer9::setDepthStencilState(const gl::DepthStencilState &depthStencilSt
             const D3DRENDERSTATETYPE D3DRS_CCW_STENCILREF = D3DRS_STENCILREF;
             const D3DRENDERSTATETYPE D3DRS_CCW_STENCILMASK = D3DRS_STENCILMASK;
             const D3DRENDERSTATETYPE D3DRS_CCW_STENCILWRITEMASK = D3DRS_STENCILWRITEMASK;
-            if (depthStencilState.stencilWritemask != depthStencilState.stencilBackWritemask ||
-                stencilRef != stencilBackRef ||
-                depthStencilState.stencilMask != depthStencilState.stencilBackMask)
-            {
-                ERR("Separate front/back stencil writemasks, reference values, or stencil mask values are invalid under WebGL.");
-                return gl::error(GL_INVALID_OPERATION);
-            }
+
+            ASSERT(depthStencilState.stencilWritemask == depthStencilState.stencilBackWritemask);
+            ASSERT(stencilRef == stencilBackRef);
+            ASSERT(depthStencilState.stencilMask == depthStencilState.stencilBackMask);
 
             // get the maximum size of the stencil ref
             unsigned int maxStencil = (1 << mCurStencilSize) - 1;

src/libGLESv2/validationES.cpp

@@ -1302,6 +1302,18 @@ static bool ValidateDrawBase(const gl::Context *context, GLsizei count)
         return gl::error(GL_INVALID_OPERATION, false);
     }
 
+    const gl::DepthStencilState &depthStencilState = context->getDepthStencilState();
+    if (depthStencilState.stencilWritemask != depthStencilState.stencilBackWritemask ||
+        context->getStencilRef() != context->getStencilBackRef() ||
+        depthStencilState.stencilMask != depthStencilState.stencilBackMask)
+    {
+        // Note: these separate values are not supported in WebGL, due to D3D's limitations.
+        // See Section 6.10 of the WebGL 1.0 spec
+        ERR("This ANGLE implementation does not support separate front/back stencil "
+            "writemasks, reference values, or stencil mask values.");
+        return gl::error(GL_INVALID_OPERATION, false);
+    }
+
     // No-op if zero count
     return (count > 0);
 }