Vulkan: Set the Vulkan scissor to the GLES viewport

include/platform/FeaturesVk.h

@@ -89,6 +89,11 @@ struct FeaturesVk
     // object within that set.  This flag results in empty descriptor sets being bound for any
     // unused descriptor set to work around this issue.  http://anglebug.com/2727
     bool bindEmptyForUnusedDescriptorSets = false;
+
+    // When the scissor is (0,0,0,0) on Windows Intel, the driver acts as if the scissor was
+    // disabled.  Work-around this by setting the scissor to just outside of the render area
+    // (e.g. (renderArea.x, renderArea.y, 1, 1)). http://anglebug.com/3153
+    bool forceNonZeroScissor = false;
 };
 
 inline FeaturesVk::FeaturesVk() = default;

src/libANGLE/renderer/vulkan/ContextVk.cpp

@@ -15,6 +15,8 @@
 #include "libANGLE/Context.h"
 #include "libANGLE/Program.h"
 #include "libANGLE/Surface.h"
+#include "libANGLE/angletypes.h"
+#include "libANGLE/renderer/renderer_utils.h"
 #include "libANGLE/renderer/vulkan/BufferVk.h"
 #include "libANGLE/renderer/vulkan/CommandGraph.h"
 #include "libANGLE/renderer/vulkan/CompilerVk.h"
@@ -704,10 +706,34 @@ void ContextVk::updateDepthRange(float nearPlane, float farPlane)
 
 void ContextVk::updateScissor(const gl::State &glState)
 {
-    FramebufferVk *framebufferVk      = vk::GetImpl(glState.getDrawFramebuffer());
-    gl::Rectangle scissoredRenderArea = framebufferVk->getScissoredRenderArea(this);
-    VkRect2D scissor                  = gl_vk::GetRect(scissoredRenderArea);
-    mGraphicsPipelineDesc->updateScissor(&mGraphicsPipelineTransition, scissor);
+    FramebufferVk *framebufferVk = vk::GetImpl(glState.getDrawFramebuffer());
+    gl::Rectangle renderArea     = framebufferVk->getCompleteRenderArea();
+
+    // Clip the render area to the viewport.
+    gl::Rectangle viewportClippedRenderArea;
+    gl::ClipRectangle(renderArea, glState.getViewport(), &viewportClippedRenderArea);
+
+    gl::Rectangle scissoredArea = ClipRectToScissor(getState(), viewportClippedRenderArea, false);
+    if (isViewportFlipEnabledForDrawFBO())
+    {
+        scissoredArea.y = renderArea.height - scissoredArea.y - scissoredArea.height;
+    }
+
+    if (getRenderer()->getFeatures().forceNonZeroScissor && scissoredArea.width == 0 &&
+        scissoredArea.height == 0)
+    {
+        // There is no overlap between the app-set viewport and clippedRect.  This code works
+        // around an Intel driver bug that causes the driver to treat a (0,0,0,0) scissor as if
+        // scissoring is disabled.  In this case, set the scissor to be just outside of the
+        // renderArea.  Remove this work-around when driver version 25.20.100.6519 has been
+        // deployed.  http://anglebug.com/3407
+        scissoredArea.x      = renderArea.x;
+        scissoredArea.y      = renderArea.y;
+        scissoredArea.width  = 1;
+        scissoredArea.height = 1;
+    }
+    mGraphicsPipelineDesc->updateScissor(&mGraphicsPipelineTransition,
+                                         gl_vk::GetRect(scissoredArea));
 
     framebufferVk->onScissorChange(this);
 }
@@ -736,6 +762,8 @@ angle::Result ContextVk::syncState(const gl::Context *context,
                 FramebufferVk *framebufferVk = vk::GetImpl(glState.getDrawFramebuffer());
                 updateViewport(framebufferVk, glState.getViewport(), glState.getNearPlane(),
                                glState.getFarPlane(), isViewportFlipEnabledForDrawFBO());
+                // Update the scissor, which will be constrained to the viewport
+                updateScissor(glState);
                 break;
             }
             case gl::State::DIRTY_BIT_DEPTH_RANGE:

src/libANGLE/renderer/vulkan/RendererVk.cpp

@@ -1314,6 +1314,11 @@ void RendererVk::initFeatures(const ExtensionNameList &deviceExtensionNames)
 
         mFeatures.bindEmptyForUnusedDescriptorSets = true;
     }
+
+    if (IsWindows() && IsIntel(mPhysicalDeviceProperties.vendorID))
+    {
+        mFeatures.forceNonZeroScissor = true;
+    }
 }
 
 void RendererVk::initPipelineCacheVkKey()

src/tests/deqp_support/deqp_gles2_test_expectations.txt

@@ -274,14 +274,6 @@
 3253 VULKAN : dEQP-GLES2.functional.clipping.point.wide_point_clip_viewport_center = FAIL
 3253 VULKAN : dEQP-GLES2.functional.clipping.point.wide_point_clip_viewport_corner = FAIL
 
-// Other clipping
-3254 VULKAN : dEQP-GLES2.functional.clipping.line.line_clip_viewport_center = FAIL
-3254 VULKAN : dEQP-GLES2.functional.clipping.line.line_clip_viewport_corner = FAIL
-
-// Only seems to be an issue on NVIDIA
-3254 VULKAN NVIDIA : dEQP-GLES2.functional.clipping.point.point_clip_viewport_center = FAIL
-3254 VULKAN NVIDIA : dEQP-GLES2.functional.clipping.point.point_clip_viewport_corner = FAIL
-
 // These seem to fail on both D3D11 and Vulkan
 3243 VULKAN : dEQP-GLES2.functional.texture.mipmap.cube.basic.linear_nearest = FAIL
 3243 VULKAN : dEQP-GLES2.functional.texture.mipmap.cube.basic.linear_linear = FAIL
@@ -334,9 +326,6 @@
 // Passes on Pixel XL. Fails on 5x and Pixel 2. Might be fixed in latest driver.
 2609 VULKAN ANDROID : dEQP-GLES2.functional.texture.mipmap.cube.generate.* = SKIP
 
-// Fails on Nexus 5x only. TODO(jmadill): Remove suppression when possible. http://anglebug.com/2791
-2791 VULKAN ANDROID : dEQP-GLES2.functional.clipping.* = SKIP
-
 // Failing on the Pixel 2.
 2727 VULKAN ANDROID : dEQP-GLES2.functional.shaders.builtin_variable.pointcoord = FAIL
 2808 VULKAN ANDROID : dEQP-GLES2.functional.shaders.builtin_variable.fragcoord_w = FAIL