Vulkan: Add Features class.

src/libANGLE/renderer/vulkan/ContextVk.cpp

@@ -795,4 +795,8 @@ VkColorComponentFlags ContextVk::getClearColorMask() const
 {
     return mClearColorMask;
 }
+const FeaturesVk &ContextVk::getFeatures() const
+{
+    return mRenderer->getFeatures();
+}
 }  // namespace rx

src/libANGLE/renderer/vulkan/ContextVk.h

@@ -17,6 +17,7 @@
 
 namespace rx
 {
+struct FeaturesVk;
 class RendererVk;
 
 class ContextVk : public ContextImpl
@@ -150,7 +151,8 @@ class ContextVk : public ContextImpl
     gl::Error memoryBarrierByRegion(const gl::Context *context, GLbitfield barriers) override;
 
     VkDevice getDevice() const;
-    RendererVk *getRenderer() { return mRenderer; }
+    RendererVk *getRenderer() const { return mRenderer; }
+    const FeaturesVk &getFeatures() const;
 
     void invalidateCurrentPipeline();
 

src/libANGLE/renderer/vulkan/FeaturesVk.h

+//
+// Copyright 2018 The ANGLE Project Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+// vk_helpers:
+//   Optional features for the Vulkan renderer.
+
+#ifndef LIBANGLE_RENDERER_VULKAN_FEATURESVK_H_
+#define LIBANGLE_RENDERER_VULKAN_FEATURESVK_H_
+
+namespace rx
+{
+struct FeaturesVk
+{
+    // Line segment rasterization must follow OpenGL rules. This means using an algorithm similar
+    // to Bresenham's. Vulkan uses a different algorithm. This feature enables the use of pixel
+    // shader patching to implement OpenGL basic line rasterization rules. This feature will
+    // normally always be enabled. Exposing it as an option enables performance testing.
+    bool basicGLLineRasterization = false;
+};
+}  // namespace rx
+
+#endif  // LIBANGLE_RENDERER_VULKAN_FEATURESVK_H_
\ No newline at end of file

src/libANGLE/renderer/vulkan/RendererVk.cpp

@@ -603,7 +603,7 @@ void RendererVk::ensureCapsInitialized() const
     if (!mCapsInitialized)
     {
         vk::GenerateCaps(mPhysicalDeviceProperties, mNativeTextureCaps, &mNativeCaps,
-                         &mNativeExtensions, &mNativeLimitations);
+                         &mNativeExtensions, &mNativeLimitations, &mFeatures);
         mCapsInitialized = true;
     }
 }

src/libANGLE/renderer/vulkan/RendererVk.h

@@ -16,6 +16,7 @@
 #include "common/angleutils.h"
 #include "libANGLE/Caps.h"
 #include "libANGLE/renderer/vulkan/CommandGraph.h"
+#include "libANGLE/renderer/vulkan/FeaturesVk.h"
 #include "libANGLE/renderer/vulkan/vk_format_utils.h"
 #include "libANGLE/renderer/vulkan/vk_internal_shaders.h"
 
@@ -138,6 +139,7 @@ class RendererVk : angle::NonCopyable
     Serial issueShaderSerial();
 
     vk::ShaderLibrary *getShaderLibrary();
+    const FeaturesVk &getFeatures() const { return mFeatures; }
 
   private:
     vk::Error initializeDevice(uint32_t queueFamilyIndex);
@@ -152,6 +154,7 @@ class RendererVk : angle::NonCopyable
     mutable gl::TextureCapsMap mNativeTextureCaps;
     mutable gl::Extensions mNativeExtensions;
     mutable gl::Limitations mNativeLimitations;
+    mutable FeaturesVk mFeatures;
 
     VkInstance mInstance;
     bool mEnableValidationLayers;

src/libANGLE/renderer/vulkan/vk_caps_utils.cpp

@@ -13,7 +13,7 @@
 #include "libANGLE/Caps.h"
 #include "libANGLE/formatutils.h"
 #include "libANGLE/renderer/vulkan/DisplayVk.h"
-
+#include "libANGLE/renderer/vulkan/FeaturesVk.h"
 #include "vk_format_utils.h"
 
 namespace
@@ -30,7 +30,8 @@ void GenerateCaps(const VkPhysicalDeviceProperties &physicalDeviceProperties,
                   const gl::TextureCapsMap &textureCaps,
                   gl::Caps *outCaps,
                   gl::Extensions *outExtensions,
-                  gl::Limitations * /* outLimitations */)
+                  gl::Limitations * /* outLimitations */,
+                  FeaturesVk *features)
 {
     outExtensions->setTextureExtensionSupport(textureCaps);
 
@@ -141,6 +142,9 @@ void GenerateCaps(const VkPhysicalDeviceProperties &physicalDeviceProperties,
     outCaps->maxVaryingVectors =
         (physicalDeviceProperties.limits.maxVertexOutputComponents / 4) - kReservedVaryingCount;
     outCaps->maxVertexOutputComponents = outCaps->maxVaryingVectors * 4;
+
+    // Use OpenGL line rasterization rules by default.
+    features->basicGLLineRasterization = true;
 }
 }  // namespace vk
 

src/libANGLE/renderer/vulkan/vk_caps_utils.h

@@ -26,6 +26,7 @@ struct InternalFormat;
 
 namespace rx
 {
+struct FeaturesVk;
 
 class DisplayVk;
 
@@ -35,7 +36,8 @@ void GenerateCaps(const VkPhysicalDeviceProperties &physicalDeviceProperties,
                   const gl::TextureCapsMap &textureCaps,
                   gl::Caps *outCaps,
                   gl::Extensions *outExtensions,
-                  gl::Limitations * /* outLimitations */);
+                  gl::Limitations * /* outLimitations */,
+                  FeaturesVk *features);
 }  // namespace vk
 
 namespace egl_vk

src/libGLESv2.gypi

@@ -771,6 +771,7 @@
             'libANGLE/renderer/vulkan/DeviceVk.h',
             'libANGLE/renderer/vulkan/DisplayVk.cpp',
             'libANGLE/renderer/vulkan/DisplayVk.h',
+            'libANGLE/renderer/vulkan/FeaturesVk.h',
             'libANGLE/renderer/vulkan/FenceNVVk.cpp',
             'libANGLE/renderer/vulkan/FenceNVVk.h',
             'libANGLE/renderer/vulkan/FramebufferVk.cpp',