MVKGraphicsPipeline: Fix applying divisors to instanced vertex attributes.
Use the Vulkan binding index to check that the binding is used.
Previously, we were erroneously using the Metal binding index. This
allows vertex binding divisor info to actually be used, and fixes some
tests in the CTS.
Fixes #1041.
diff --git a/MoltenVK/MoltenVK/GPUObjects/MVKPipeline.mm b/MoltenVK/MoltenVK/GPUObjects/MVKPipeline.mm
index 0f7e1cb..0a0ddc3 100644
--- a/MoltenVK/MoltenVK/GPUObjects/MVKPipeline.mm
+++ b/MoltenVK/MoltenVK/GPUObjects/MVKPipeline.mm
@@ -1139,8 +1139,8 @@
vbCnt = pVertexInputDivisorState->vertexBindingDivisorCount;
for (uint32_t i = 0; i < vbCnt; i++) {
const VkVertexInputBindingDivisorDescriptionEXT* pVKVB = &pVertexInputDivisorState->pVertexBindingDivisors[i];
- uint32_t vbIdx = getMetalBufferIndexForVertexAttributeBinding(pVKVB->binding);
- if (shaderContext.isVertexBufferUsed(vbIdx)) {
+ if (shaderContext.isVertexBufferUsed(pVKVB->binding)) {
+ uint32_t vbIdx = getMetalBufferIndexForVertexAttributeBinding(pVKVB->binding);
if ((NSUInteger)inputDesc.layouts[vbIdx].stepFunction == MTLStepFunctionPerInstance ||
(NSUInteger)inputDesc.layouts[vbIdx].stepFunction == MTLStepFunctionThreadPositionInGridY) {
if (pVKVB->divisor == 0)
