Fix formsRenderingFeedbackLoopWith check

src/libANGLE/Framebuffer.cpp

@@ -1839,10 +1839,12 @@ void Framebuffer::setAttachmentImpl(const Context *context,
 
             if (!resource)
             {
+                mColorAttachmentBits.reset(colorIndex);
                 mFloat32ColorAttachmentBits.reset(colorIndex);
             }
             else
             {
+                mColorAttachmentBits.set(colorIndex);
                 updateFloat32ColorAttachmentBits(
                     colorIndex, resource->getAttachmentFormat(binding, textureIndex).info);
             }
@@ -1944,8 +1946,9 @@ FramebufferAttachment *Framebuffer::getAttachmentFromSubjectIndex(angle::Subject
     }
 }
 
-bool Framebuffer::formsRenderingFeedbackLoopWith(const State &state) const
+bool Framebuffer::formsRenderingFeedbackLoopWith(const Context *context) const
 {
+    const State &state     = context->getState();
     const Program *program = state.getProgram();
 
     // TODO(jmadill): Default framebuffer feedback loops.
@@ -1954,39 +1957,53 @@ bool Framebuffer::formsRenderingFeedbackLoopWith(const State &state) const
         return false;
     }
 
-    // The bitset will skip inactive draw buffers.
-    for (size_t drawIndex : mState.mEnabledDrawBuffers)
+    const FramebufferAttachment *depth   = getDepthbuffer();
+    const FramebufferAttachment *stencil = getStencilbuffer();
+
+    const bool checkDepth = depth && depth->type() == GL_TEXTURE;
+    // Skip the feedback loop check for stencil if depth/stencil point to the same resource.
+    const bool checkStencil =
+        (stencil && stencil->type() == GL_TEXTURE) && (!depth || *stencil != *depth);
+
+    const gl::ActiveTextureMask &activeTextures   = program->getActiveSamplersMask();
+    const gl::ActiveTexturePointerArray &textures = state.getActiveTexturesCache();
+
+    for (size_t textureUnit : activeTextures)
     {
-        const FramebufferAttachment &attachment = mState.mColorAttachments[drawIndex];
-        ASSERT(attachment.isAttached());
-        if (attachment.type() == GL_TEXTURE)
+        Texture *texture = textures[textureUnit];
+
+        if (texture == nullptr)
+        {
+            continue;
+        }
+
+        // Depth and stencil attachment form feedback loops
+        // Regardless of if enabled or masked.
+        if (checkDepth)
         {
-            // Validate the feedback loop.
-            if (program->samplesFromTexture(state, attachment.id()))
+            if (texture->id() == depth->id())
             {
                 return true;
             }
         }
-    }
 
-    // Validate depth-stencil feedback loop. This is independent of Depth/Stencil state.
-    const FramebufferAttachment *depth = getDepthbuffer();
-    if (depth && depth->type() == GL_TEXTURE)
-    {
-        if (program->samplesFromTexture(state, depth->id()))
+        if (checkStencil)
         {
-            return true;
+            if (texture->id() == stencil->id())
+            {
+                return true;
+            }
         }
-    }
 
-    const FramebufferAttachment *stencil = getStencilbuffer();
-    if (stencil && stencil->type() == GL_TEXTURE)
-    {
-        // Skip the feedback loop check if depth/stencil point to the same resource.
-        if (!depth || *stencil != *depth)
+        // Check if any color attachment forms a feedback loop.
+        for (size_t drawIndex : mColorAttachmentBits)
         {
-            if (program->samplesFromTexture(state, stencil->id()))
+            const FramebufferAttachment &attachment = mState.mColorAttachments[drawIndex];
+            ASSERT(attachment.isAttached());
+
+            if (attachment.isTextureWithId(texture->id()))
             {
+                // TODO(jmadill): Check for appropriate overlap.
                 return true;
             }
         }

src/libANGLE/Framebuffer.h

@@ -351,7 +351,7 @@ class Framebuffer final : public angle::ObserverInterface,
                               angle::SubjectIndex index,
                               angle::SubjectMessage message) override;
 
-    bool formsRenderingFeedbackLoopWith(const State &state) const;
+    bool formsRenderingFeedbackLoopWith(const Context *context) const;
     bool formsCopyingFeedbackLoopWith(GLuint copyTextureID,
                                       GLint copyTextureLevel,
                                       GLint copyTextureLayer) const;
@@ -439,6 +439,7 @@ class Framebuffer final : public angle::ObserverInterface,
 
     DirtyBits mDirtyBits;
     DrawBufferMask mFloat32ColorAttachmentBits;
+    DrawBufferMask mColorAttachmentBits;
 
     // The dirty bits guard is checked when we get a dependent state change message. We verify that
     // we don't set a dirty bit that isn't already set, when inside the dirty bits syncState.

src/libANGLE/Program.cpp

@@ -4234,29 +4234,6 @@ void Program::getUniformInternal(const Context *context,
     }
 }
 
-bool Program::samplesFromTexture(const gl::State &state, GLuint textureID) const
-{
-    ASSERT(mLinkResolved);
-    // Must be called after samplers are validated.
-    ASSERT(mCachedValidateSamplersResult.valid() && mCachedValidateSamplersResult.value());
-
-    for (const auto &binding : mState.mSamplerBindings)
-    {
-        TextureType textureType = binding.textureType;
-        for (const auto &unit : binding.boundTextureUnits)
-        {
-            GLenum programTextureID = state.getSamplerTextureId(unit, textureType);
-            if (programTextureID == textureID)
-            {
-                // TODO(jmadill): Check for appropriate overlap.
-                return true;
-            }
-        }
-    }
-
-    return false;
-}
-
 angle::Result Program::syncState(const Context *context)
 {
     if (mDirtyBits.any())

src/libANGLE/Program.h

@@ -783,7 +783,6 @@ class Program final : angle::NonCopyable, public LabeledObject
     }
 
     bool isValidated() const;
-    bool samplesFromTexture(const State &state, GLuint textureID) const;
 
     const AttributesMask &getActiveAttribLocationsMask() const
     {

src/libANGLE/validationES.cpp

@@ -2746,7 +2746,7 @@ const char *ValidateDrawStates(Context *context)
             }
 
             // Detect rendering feedback loops for WebGL.
-            if (framebuffer->formsRenderingFeedbackLoopWith(state))
+            if (framebuffer->formsRenderingFeedbackLoopWith(context))
             {
                 return kFeedbackLoop;
             }

src/tests/gl_tests/WebGLCompatibilityTest.cpp

@@ -2441,7 +2441,9 @@ void main() {
                                GL_INVALID_OPERATION);
     drawBuffersEXTFeedbackLoop(program.get(), {{GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1}},
                                GL_INVALID_OPERATION);
-    drawBuffersEXTFeedbackLoop(program.get(), {{GL_COLOR_ATTACHMENT0, GL_NONE}}, GL_NO_ERROR);
+    // A feedback loop is formed regardless of drawBuffers settings.
+    drawBuffersEXTFeedbackLoop(program.get(), {{GL_COLOR_ATTACHMENT0, GL_NONE}},
+                               GL_INVALID_OPERATION);
 }
 
 // Test tests that texture copying feedback loops are properly rejected in WebGL.
@@ -3541,7 +3543,8 @@ void main() {
     drawBuffersFeedbackLoop(program.get(), {{GL_NONE, GL_COLOR_ATTACHMENT1}}, GL_INVALID_OPERATION);
     drawBuffersFeedbackLoop(program.get(), {{GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1}},
                             GL_INVALID_OPERATION);
-    drawBuffersFeedbackLoop(program.get(), {{GL_COLOR_ATTACHMENT0, GL_NONE}}, GL_NO_ERROR);
+    // A feedback loop is formed regardless of drawBuffers settings.
+    drawBuffersFeedbackLoop(program.get(), {{GL_COLOR_ATTACHMENT0, GL_NONE}}, GL_INVALID_OPERATION);
 }
 
 // This test covers detection of rendering feedback loops between the FBO and a depth Texture.