From 481fe3553decff35fcd039aee54ff1b5ec266355 Mon Sep 17 00:00:00 2001
From: Chip Davis <cdavis@codeweavers.com>
Date: Sun, 27 Sep 2020 14:46:46 -0500
Subject: [PATCH] MVKPipeline: Don't rely on the index buffer to tell apart
 indexed draws.

This was a good heuristic, because the index buffer must be bound for
indexed draws. However, it may also be bound for non-indexed draws--for
example, if an indexed draw were immediately followed by a non-indexed
draw, as happens in some `dEQP-VK.synchronization.*` tests. Therefore,
we can't tell from the presence or absence of the index buffer what kind
of draw we're in. We'll have to keep track of this state in the command
encoder.
---
 MoltenVK/MoltenVK/Commands/MVKCmdDraw.mm      | 8 ++++++++
 MoltenVK/MoltenVK/Commands/MVKCommandBuffer.h | 3 +++
 MoltenVK/MoltenVK/GPUObjects/MVKPipeline.mm   | 2 +-
 3 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/MoltenVK/MoltenVK/Commands/MVKCmdDraw.mm b/MoltenVK/MoltenVK/Commands/MVKCmdDraw.mm
index bd63403c..57819360 100644
--- a/MoltenVK/MoltenVK/Commands/MVKCmdDraw.mm
+++ b/MoltenVK/MoltenVK/Commands/MVKCmdDraw.mm
@@ -108,6 +108,8 @@ void MVKCmdDraw::encode(MVKCommandEncoder* cmdEncoder) {
         return;
     }
 
+    cmdEncoder->_isIndexedDraw = false;
+
     auto* pipeline = (MVKGraphicsPipeline*)cmdEncoder->_graphicsPipelineState.getPipeline();
 
 	MVKPiplineStages stages;
@@ -302,6 +304,8 @@ void MVKCmdDrawIndexed::encode(MVKCommandEncoder* cmdEncoder) {
         return;
     }
 
+    cmdEncoder->_isIndexedDraw = true;
+
     auto* pipeline = (MVKGraphicsPipeline*)cmdEncoder->_graphicsPipelineState.getPipeline();
 
 	MVKPiplineStages stages;
@@ -510,6 +514,8 @@ static const uint32_t kMVKDrawIndirectVertexCountUpperBound = 131072;
 
 void MVKCmdDrawIndirect::encode(MVKCommandEncoder* cmdEncoder) {
 
+    cmdEncoder->_isIndexedDraw = false;
+
     auto* pipeline = (MVKGraphicsPipeline*)cmdEncoder->_graphicsPipelineState.getPipeline();
     bool needsInstanceAdjustment = cmdEncoder->getSubpass()->isMultiview() &&
                                    cmdEncoder->getDevice()->getPhysicalDevice()->canUseInstancingForMultiview();
@@ -820,6 +826,8 @@ VkResult MVKCmdDrawIndexedIndirect::setContent(MVKCommandBuffer* cmdBuff,
 
 void MVKCmdDrawIndexedIndirect::encode(MVKCommandEncoder* cmdEncoder) {
 
+    cmdEncoder->_isIndexedDraw = true;
+
     MVKIndexMTLBufferBinding& ibb = cmdEncoder->_graphicsResourcesState._mtlIndexBufferBinding;
     auto* pipeline = (MVKGraphicsPipeline*)cmdEncoder->_graphicsPipelineState.getPipeline();
     bool needsInstanceAdjustment = cmdEncoder->getSubpass()->isMultiview() &&
diff --git a/MoltenVK/MoltenVK/Commands/MVKCommandBuffer.h b/MoltenVK/MoltenVK/Commands/MVKCommandBuffer.h
index 9002d59e..9bcbd524 100644
--- a/MoltenVK/MoltenVK/Commands/MVKCommandBuffer.h
+++ b/MoltenVK/MoltenVK/Commands/MVKCommandBuffer.h
@@ -449,6 +449,9 @@ public:
 	/** Indicates whether the current render subpass is able to render to an array (layered) framebuffer. */
 	bool _canUseLayeredRendering;
 
+	/** Indicates whether the current draw is an indexed draw. */
+	bool _isIndexedDraw;
+
 
 #pragma mark Construction
 
diff --git a/MoltenVK/MoltenVK/GPUObjects/MVKPipeline.mm b/MoltenVK/MoltenVK/GPUObjects/MVKPipeline.mm
index aa7f30d3..1e072849 100644
--- a/MoltenVK/MoltenVK/GPUObjects/MVKPipeline.mm
+++ b/MoltenVK/MoltenVK/GPUObjects/MVKPipeline.mm
@@ -207,7 +207,7 @@ void MVKGraphicsPipeline::encode(MVKCommandEncoder* cmdEncoder, uint32_t stage)
 
             id<MTLComputePipelineState> plState;
 			const MVKIndexMTLBufferBinding& indexBuff = cmdEncoder->_graphicsResourcesState._mtlIndexBufferBinding;
-            if (!indexBuff.mtlBuffer) {
+            if (!cmdEncoder->_isIndexedDraw) {
                 plState = getTessVertexStageState();
             } else if (indexBuff.mtlIndexType == MTLIndexTypeUInt16) {
                 plState = getTessVertexStageIndex16State();