Vulkan: Reduce the amount of redundant stencil parameter sets

hrydgard · Aug 12, 2019 · ddb5208 · ddb5208
1 parent cf06b4a
commit ddb5208
Showing 1 changed file with 22 additions and 6 deletions.
diff --git a/ext/native/thin3d/VulkanQueueRunner.cpp b/ext/native/thin3d/VulkanQueueRunner.cpp
@@ -869,9 +869,11 @@ void VulkanQueueRunner::PerformRenderPass(const VKRStep &step, VkCommandBuffer c
 
 	auto &commands = step.commands;
 
-	// TODO: Dynamic state commands (SetViewport, SetScissor, SetBlendConstants, SetStencil*) are only
+	// We can do a little bit of state tracking here to eliminate some calls into the driver.
-	// valid when a pipeline is bound with those as dynamic state. So we need to add some state tracking here
+	// The stencil ones are very commonly mostly redundant so let's eliminate them where possible.
-	// for this to be correct. This is a bit of a pain but also will let us eliminate redundant calls.
+	int lastStencilWriteMask = -1;
+	int lastStencilCompareMask = -1;
+	int lastStencilReference = -1;
 
 	for (const auto &c : commands) {
 		switch (c.cmd) {
@@ -882,6 +884,10 @@ void VulkanQueueRunner::PerformRenderPass(const VKRStep &step, VkCommandBuffer c
 			if (c.pipeline.pipeline != lastPipeline) {
 				vkCmdBindPipeline(cmd, VK_PIPELINE_BIND_POINT_GRAPHICS, c.pipeline.pipeline);
 				lastPipeline = c.pipeline.pipeline;
+				// Reset dynamic state so it gets refreshed with the new pipeline.
+				lastStencilWriteMask = -1;
+				lastStencilCompareMask = -1;
+				lastStencilReference = -1;
 			}
 			break;
 
@@ -902,9 +908,18 @@ void VulkanQueueRunner::PerformRenderPass(const VKRStep &step, VkCommandBuffer c
 			break;
 
 		case VKRRenderCommand::STENCIL:
-			vkCmdSetStencilWriteMask(cmd, VK_STENCIL_FRONT_AND_BACK, c.stencil.stencilWriteMask);
+			if (lastStencilReference != c.stencil.stencilWriteMask) {
-			vkCmdSetStencilCompareMask(cmd, VK_STENCIL_FRONT_AND_BACK, c.stencil.stencilCompareMask);
+				lastStencilReference = (int)c.stencil.stencilWriteMask;
-			vkCmdSetStencilReference(cmd, VK_STENCIL_FRONT_AND_BACK, c.stencil.stencilRef);
+				vkCmdSetStencilWriteMask(cmd, VK_STENCIL_FRONT_AND_BACK, c.stencil.stencilWriteMask);
+			}
+			if (lastStencilCompareMask != c.stencil.stencilCompareMask) {
+				lastStencilCompareMask = c.stencil.stencilCompareMask;
+				vkCmdSetStencilCompareMask(cmd, VK_STENCIL_FRONT_AND_BACK, c.stencil.stencilCompareMask);
+			}
+			if (lastStencilReference != c.stencil.stencilRef) {
+				lastStencilReference = c.stencil.stencilRef;
+				vkCmdSetStencilReference(cmd, VK_STENCIL_FRONT_AND_BACK, c.stencil.stencilRef);
+			}
 			break;
 
 		case VKRRenderCommand::DRAW_INDEXED:
@@ -924,6 +939,7 @@ void VulkanQueueRunner::PerformRenderPass(const VKRStep &step, VkCommandBuffer c
 
 		case VKRRenderCommand::CLEAR:
 		{
+			// If we get here, we failed to merge a clear into a render pass load op. This is bad for perf.
 			int numAttachments = 0;
 			VkClearRect rc{};
 			rc.baseArrayLayer = 0;