Vulkan: Add support for FBO with unequal sized attachments

src/libANGLE/Framebuffer.cpp

@@ -517,6 +517,34 @@ const FramebufferAttachment *FramebufferState::getDepthStencilAttachment() const
     return nullptr;
 }
 
+const Extents FramebufferState::getAttachmentExtentsIntersection() const
+{
+    int32_t width  = std::numeric_limits<int32_t>::max();
+    int32_t height = std::numeric_limits<int32_t>::max();
+    for (const FramebufferAttachment &attachment : mColorAttachments)
+    {
+        if (attachment.isAttached())
+        {
+            width  = std::min(width, attachment.getSize().width);
+            height = std::min(height, attachment.getSize().height);
+        }
+    }
+
+    if (mDepthAttachment.isAttached())
+    {
+        width  = std::min(width, mDepthAttachment.getSize().width);
+        height = std::min(height, mDepthAttachment.getSize().height);
+    }
+
+    if (mStencilAttachment.isAttached())
+    {
+        width  = std::min(width, mStencilAttachment.getSize().width);
+        height = std::min(height, mStencilAttachment.getSize().height);
+    }
+
+    return Extents(width, height, 0);
+}
+
 bool FramebufferState::attachmentsHaveSameDimensions() const
 {
     Optional<Extents> attachmentSize;
@@ -673,11 +701,12 @@ Box FramebufferState::getDimensions() const
 
 Extents FramebufferState::getExtents() const
 {
-    ASSERT(attachmentsHaveSameDimensions());
+    // OpenGLES3.0 (https://www.khronos.org/registry/OpenGL/specs/es/3.0/es_spec_3.0.pdf
+    // section 4.4.4.2) allows attachments have unequal size.
     const FramebufferAttachment *first = getFirstNonNullAttachment();
     if (first)
     {
-        return first->getSize();
+        return getAttachmentExtentsIntersection();
     }
     return Extents(getDefaultWidth(), getDefaultHeight(), 0);
 }

src/libANGLE/Framebuffer.h

@@ -81,6 +81,7 @@ class FramebufferState final : angle::NonCopyable
     }
     const DrawBufferMask getColorAttachmentsMask() const { return mColorAttachmentsMask; }
 
+    const Extents getAttachmentExtentsIntersection() const;
     bool attachmentsHaveSameDimensions() const;
     bool hasSeparateDepthAndStencilAttachments() const;
     bool colorAttachmentsAreUniqueImages() const;

src/libANGLE/renderer/vulkan/FramebufferVk.cpp

@@ -2020,7 +2020,8 @@ angle::Result FramebufferVk::getFramebuffer(ContextVk *contextVk,
 
     // Gather VkImageViews over all FBO attachments, also size of attached region.
     std::vector<VkImageView> attachments;
-    gl::Extents attachmentsSize;
+    gl::Extents attachmentsSize = mState.getExtents();
+    ASSERT(attachmentsSize.width != 0 && attachmentsSize.height != 0);
 
     // Color attachments.
     const auto &colorRenderTargets = mRenderTargetCache.getColors();
@@ -2034,9 +2035,6 @@ angle::Result FramebufferVk::getFramebuffer(ContextVk *contextVk,
             contextVk, mCurrentFramebufferDesc.getWriteControlMode(), &imageView));
 
         attachments.push_back(imageView->getHandle());
-
-        ASSERT(attachmentsSize.empty() || attachmentsSize == colorRenderTarget->getExtents());
-        attachmentsSize = colorRenderTarget->getExtents();
     }
 
     // Depth/stencil attachment.
@@ -2047,10 +2045,6 @@ angle::Result FramebufferVk::getFramebuffer(ContextVk *contextVk,
         ANGLE_TRY(depthStencilRenderTarget->getImageView(contextVk, &imageView));
 
         attachments.push_back(imageView->getHandle());
-
-        ASSERT(attachmentsSize.empty() ||
-               attachmentsSize == depthStencilRenderTarget->getExtents());
-        attachmentsSize = depthStencilRenderTarget->getExtents();
     }
 
     // Color resolve attachments.
@@ -2076,8 +2070,6 @@ angle::Result FramebufferVk::getFramebuffer(ContextVk *contextVk,
                 ANGLE_TRY(colorRenderTarget->getResolveImageView(contextVk, &resolveImageView));
 
                 attachments.push_back(resolveImageView->getHandle());
-
-                ASSERT(!attachmentsSize.empty());
             }
         }
     }
@@ -2089,17 +2081,8 @@ angle::Result FramebufferVk::getFramebuffer(ContextVk *contextVk,
         ANGLE_TRY(depthStencilRenderTarget->getResolveImageView(contextVk, &imageView));
 
         attachments.push_back(imageView->getHandle());
-
-        ASSERT(!attachmentsSize.empty());
     }
 
-    if (attachmentsSize.empty())
-    {
-        // No attachments, so use the default values.
-        attachmentsSize.height = mState.getDefaultHeight();
-        attachmentsSize.width  = mState.getDefaultWidth();
-        attachmentsSize.depth  = 0;
-    }
     VkFramebufferCreateInfo framebufferInfo = {};
 
     framebufferInfo.sType           = VK_STRUCTURE_TYPE_FRAMEBUFFER_CREATE_INFO;
@@ -2708,10 +2691,6 @@ angle::Result FramebufferVk::readPixelsImpl(ContextVk *contextVk,
 gl::Extents FramebufferVk::getReadImageExtents() const
 {
     RenderTargetVk *readRenderTarget = mRenderTargetCache.getColorRead(mState);
-
-    ASSERT(readRenderTarget->getExtents().width == mState.getDimensions().width);
-    ASSERT(readRenderTarget->getExtents().height == mState.getDimensions().height);
-
     return readRenderTarget->getExtents();
 }
 

src/tests/gl_tests/FramebufferTest.cpp

@@ -3054,8 +3054,6 @@ TEST_P(FramebufferTest_ES3, ChangeAttachmentThenInvalidateAndDraw)
 // outside common intersection area are undefined.
 TEST_P(FramebufferTest_ES3, AttachmentsWithUnequalDimensions)
 {
-    // TODO: https://issuetracker.google.com/181800403
-    ANGLE_SKIP_TEST_IF(IsVulkan());
     // TODO: https://anglebug.com/5866
     ANGLE_SKIP_TEST_IF(IsD3D() || IsMetal());