Vulkan: Use PackedScissor struct to reduce GraphicsPipelineDesc size

src/libANGLE/renderer/vulkan/vk_cache_utils.cpp

@@ -31,12 +31,9 @@ namespace vk
 
 namespace
 {
-
-constexpr int32_t kDynamicScissorSentinel = std::numeric_limits<int32_t>::min();
-
-bool IsScissorStateDynamic(const VkRect2D &scissor)
+bool IsScissorStateDynamic(const PackedScissor &scissor)
 {
-    return scissor.offset.x == kDynamicScissorSentinel;
+    return scissor.x == kDynamicScissorSentinel;
 }
 
 uint8_t PackGLBlendOp(GLenum blendOp)
@@ -1596,10 +1593,10 @@ void GraphicsPipelineDesc::initDefaults()
     mViewport.minDepth = 0.0f;
     mViewport.maxDepth = 1.0f;
 
-    mScissor.offset.x      = 0;
-    mScissor.offset.y      = 0;
-    mScissor.extent.width  = 0;
-    mScissor.extent.height = 0;
+    mScissor.x      = 0;
+    mScissor.y      = 0;
+    mScissor.width  = 0;
+    mScissor.height = 0;
 }
 
 angle::Result GraphicsPipelineDesc::initializePipeline(
@@ -1771,8 +1768,21 @@ angle::Result GraphicsPipelineDesc::initializePipeline(
     viewportState.flags         = 0;
     viewportState.viewportCount = 1;
     viewportState.pViewports    = &viewport;
-    viewportState.scissorCount  = 1;
-    viewportState.pScissors     = IsScissorStateDynamic(mScissor) ? nullptr : &mScissor;
+
+    viewportState.scissorCount = 1;
+    VkRect2D scissor;
+    if (IsScissorStateDynamic(mScissor))
+    {
+        viewportState.pScissors = nullptr;
+    }
+    else
+    {
+        viewportState.pScissors = &scissor;
+        scissor.offset.x        = mScissor.x;
+        scissor.offset.y        = mScissor.y;
+        scissor.extent.width    = mScissor.width;
+        scissor.extent.height   = mScissor.height;
+    }
 
     const PackedRasterizationAndMultisampleStateInfo &rasterAndMS =
         mRasterizationAndMultisampleStateInfo;
@@ -2433,25 +2443,32 @@ void GraphicsPipelineDesc::updateDepthRange(GraphicsPipelineTransitionBits *tran
 
 void GraphicsPipelineDesc::setDynamicScissor()
 {
-    mScissor.offset.x      = kDynamicScissorSentinel;
-    mScissor.offset.y      = 0;
-    mScissor.extent.width  = 0;
-    mScissor.extent.height = 0;
+    mScissor.x      = kDynamicScissorSentinel;
+    mScissor.y      = 0;
+    mScissor.width  = 0;
+    mScissor.height = 0;
 }
 
 void GraphicsPipelineDesc::setScissor(const VkRect2D &scissor)
 {
-    mScissor = scissor;
+    ASSERT(scissor.offset.x < kDynamicScissorSentinel &&
+           scissor.offset.y < kDynamicScissorSentinel &&
+           scissor.extent.width < kDynamicScissorSentinel &&
+           scissor.extent.height < kDynamicScissorSentinel);
+    SetBitField(mScissor.x, scissor.offset.x);
+    SetBitField(mScissor.y, scissor.offset.y);
+    SetBitField(mScissor.width, scissor.extent.width);
+    SetBitField(mScissor.height, scissor.extent.height);
 }
 
 void GraphicsPipelineDesc::updateScissor(GraphicsPipelineTransitionBits *transition,
                                          const VkRect2D &scissor)
 {
-    mScissor = scissor;
-    transition->set(ANGLE_GET_TRANSITION_BIT(mScissor, offset.x));
-    transition->set(ANGLE_GET_TRANSITION_BIT(mScissor, offset.y));
-    transition->set(ANGLE_GET_TRANSITION_BIT(mScissor, extent.width));
-    transition->set(ANGLE_GET_TRANSITION_BIT(mScissor, extent.height));
+    setScissor(scissor);
+    transition->set(ANGLE_GET_TRANSITION_BIT(mScissor, x));
+    transition->set(ANGLE_GET_TRANSITION_BIT(mScissor, y));
+    transition->set(ANGLE_GET_TRANSITION_BIT(mScissor, width));
+    transition->set(ANGLE_GET_TRANSITION_BIT(mScissor, height));
 }
 
 void GraphicsPipelineDesc::updateSubpass(GraphicsPipelineTransitionBits *transition,

src/libANGLE/renderer/vulkan/vk_cache_utils.h

@@ -527,6 +527,16 @@ struct PackedInputAssemblyAndColorBlendStateInfo final
     PrimitiveState primitive;
 };
 
+struct PackedScissor final
+{
+    uint16_t x;
+    uint16_t y;
+    uint16_t width;
+    uint16_t height;
+};
+// This is invalid value for PackedScissor.x. It is used to indicate scissor is a dynamic state
+constexpr int32_t kDynamicScissorSentinel = std::numeric_limits<decltype(PackedScissor::x)>::max();
+
 constexpr size_t kPackedInputAssemblyAndColorBlendStateSize =
     sizeof(PackedInputAssemblyAndColorBlendStateInfo);
 static_assert(kPackedInputAssemblyAndColorBlendStateSize == 56, "Size check failed");
@@ -534,7 +544,7 @@ static_assert(kPackedInputAssemblyAndColorBlendStateSize == 56, "Size check fail
 constexpr size_t kGraphicsPipelineDescSumOfSizes =
     kVertexInputAttributesSize + kRenderPassDescSize + kPackedRasterizationAndMultisampleStateSize +
     kPackedDepthStencilStateSize + kPackedInputAssemblyAndColorBlendStateSize + sizeof(VkViewport) +
-    sizeof(VkRect2D);
+    sizeof(PackedScissor);
 
 // Number of dirty bits in the dirty bit set.
 constexpr size_t kGraphicsPipelineDirtyBitBytes = 4;
@@ -727,7 +737,7 @@ class GraphicsPipelineDesc final
     VkViewport mViewport;
     // The special value of .offset.x == INT_MIN for scissor implies dynamic scissor that needs to
     // be set through vkCmdSetScissor.
-    VkRect2D mScissor;
+    PackedScissor mScissor;
 };
 
 // Verify the packed pipeline description has no gaps in the packing.

src/libANGLE/renderer/vulkan/vk_caps_utils.cpp

@@ -17,6 +17,7 @@
 #include "libANGLE/renderer/driver_utils.h"
 #include "libANGLE/renderer/vulkan/DisplayVk.h"
 #include "libANGLE/renderer/vulkan/RendererVk.h"
+#include "libANGLE/renderer/vulkan/vk_cache_utils.h"
 #include "vk_format_utils.h"
 
 namespace
@@ -278,6 +279,19 @@ GLint LimitToInt(const LargerInt physicalDeviceValue)
         physicalDeviceValue, static_cast<LargerInt>(std::numeric_limits<int32_t>::max() / 2)));
 }
 
+template <typename LargerInt>
+uint16_t LimitToDynamicScissorSentinelMinusOne(const LargerInt physicalDeviceValue)
+{
+    static_assert(sizeof(LargerInt) >= sizeof(int32_t),
+                  "Incorrect usage of LimitToDynamicScissorSentinelMinusOne");
+
+    // Limit to kDynamicScissorSentinel-1. This is used to pack drawable offset/dimension to
+    // uint16_t for space conservation. The UINT16_MAX is reserved for special value like
+    // kDynamicScissorSentinel.
+    return static_cast<uint16_t>(
+        std::min<int32_t>(physicalDeviceValue, vk::kDynamicScissorSentinel - 1));
+}
+
 void RendererVk::ensureCapsInitialized() const
 {
     if (mCapsInitialized)
@@ -520,12 +534,16 @@ void RendererVk::ensureCapsInitialized() const
 
     mNativeCaps.maxDrawBuffers =
         std::min(limitsVk.maxColorAttachments, limitsVk.maxFragmentOutputAttachments);
-    mNativeCaps.maxFramebufferWidth  = LimitToInt(limitsVk.maxFramebufferWidth);
-    mNativeCaps.maxFramebufferHeight = LimitToInt(limitsVk.maxFramebufferHeight);
-    mNativeCaps.maxColorAttachments  = LimitToInt(limitsVk.maxColorAttachments);
-    mNativeCaps.maxViewportWidth     = LimitToInt(limitsVk.maxViewportDimensions[0]);
-    mNativeCaps.maxViewportHeight    = LimitToInt(limitsVk.maxViewportDimensions[1]);
-    mNativeCaps.maxSampleMaskWords   = LimitToInt(limitsVk.maxSampleMaskWords);
+    mNativeCaps.maxFramebufferWidth =
+        LimitToDynamicScissorSentinelMinusOne(limitsVk.maxFramebufferWidth);
+    mNativeCaps.maxFramebufferHeight =
+        LimitToDynamicScissorSentinelMinusOne(limitsVk.maxFramebufferHeight);
+    mNativeCaps.maxColorAttachments = LimitToInt(limitsVk.maxColorAttachments);
+    mNativeCaps.maxViewportWidth =
+        LimitToDynamicScissorSentinelMinusOne(limitsVk.maxViewportDimensions[0]);
+    mNativeCaps.maxViewportHeight =
+        LimitToDynamicScissorSentinelMinusOne(limitsVk.maxViewportDimensions[1]);
+    mNativeCaps.maxSampleMaskWords = LimitToInt(limitsVk.maxSampleMaskWords);
     mNativeCaps.maxColorTextureSamples =
         limitsVk.sampledImageColorSampleCounts & vk_gl::kSupportedSampleCounts;
     mNativeCaps.maxDepthTextureSamples =