Vulkan: Apply point size clamping workaround in NV.

include/platform/FeaturesVk.h

@@ -43,6 +43,11 @@ struct FeaturesVk
     // of various algorithms when a fallback format is used, such as using a packed format to
     // emulate a depth- or stencil-only format.
     bool forceFallbackFormat = false;
+
+    // On some NVIDIA drivers the point size range reported from the API is inconsistent with the
+    // actual behavior. Clamp the point size to the value from the API to fix this.
+    // Tracked in http://anglebug.com/2970.
+    bool clampPointSize = false;
 };
 
 }  // namespace angle

src/libANGLE/renderer/vulkan/RendererVk.cpp

@@ -780,6 +780,13 @@ void RendererVk::initFeatures()
 
     angle::PlatformMethods *platform = ANGLEPlatformCurrent();
     platform->overrideFeaturesVk(platform, &mFeatures);
+
+    // Work around incorrect NVIDIA point size range clamping.
+    // TODO(jmadill): Narrow driver range once fixed. http://anglebug.com/2970
+    if (IsNvidia(mPhysicalDeviceProperties.vendorID))
+    {
+        mFeatures.clampPointSize = true;
+    }
 }
 
 void RendererVk::initPipelineCacheVkKey()

src/libANGLE/renderer/vulkan/ShaderVk.cpp

@@ -10,6 +10,9 @@
 #include "libANGLE/renderer/vulkan/ShaderVk.h"
 
 #include "common/debug.h"
+#include "libANGLE/Context.h"
+#include "libANGLE/renderer/vulkan/ContextVk.h"
+#include "platform/FeaturesVk.h"
 
 namespace rx
 {
@@ -27,7 +30,17 @@ ShCompileOptions ShaderVk::prepareSourceAndReturnOptions(const gl::Context *cont
                                                          std::string *sourcePath)
 {
     *sourceStream << mData.getSource();
-    return SH_INITIALIZE_UNINITIALIZED_LOCALS;
+
+    ShCompileOptions compileOptions = SH_INITIALIZE_UNINITIALIZED_LOCALS;
+
+    ContextVk *contextVk = vk::GetImpl(context);
+
+    if (contextVk->getFeatures().clampPointSize)
+    {
+        compileOptions |= SH_CLAMP_POINT_SIZE;
+    }
+
+    return compileOptions;
 }
 
 bool ShaderVk::postTranslateCompile(gl::ShCompilerInstance *compiler, std::string *infoLog)