From 9a8263f465949f6484c859c2f7bbbbed6e253c6f Mon Sep 17 00:00:00 2001
From: Philip Rebohle <philip.rebohle@tu-dortmund.de>
Date: Tue, 17 Apr 2018 17:24:16 +0200
Subject: [PATCH] [dxvk] Implement vertex binding divisors

Uses VK_EXT_vertex_attribute_divisor when available.
---
 src/dxvk/dxvk_context.cpp     | 14 +-------------
 src/dxvk/dxvk_context_state.h |  9 ++-------
 src/dxvk/dxvk_graphics.cpp    | 27 ++++++++++++++++++++++++++-
 src/dxvk/dxvk_graphics.h      |  1 +
 4 files changed, 30 insertions(+), 21 deletions(-)

diff --git a/src/dxvk/dxvk_context.cpp b/src/dxvk/dxvk_context.cpp
index 25de161e..927d0366 100644
--- a/src/dxvk/dxvk_context.cpp
+++ b/src/dxvk/dxvk_context.cpp
@@ -1386,8 +1386,6 @@ namespace dxvk {
     m_flags.set(
       DxvkContextFlag::GpDirtyPipelineState,
       DxvkContextFlag::GpDirtyVertexBuffers);
-    m_flags.clr(
-      DxvkContextFlag::GpEmulateInstanceFetchRate);
     
     for (uint32_t i = 0; i < attributeCount; i++) {
       m_state.gp.state.ilAttributes[i].location = attributes[i].location;
@@ -1402,10 +1400,7 @@ namespace dxvk {
     for (uint32_t i = 0; i < bindingCount; i++) {
       m_state.gp.state.ilBindings[i].binding    = bindings[i].binding;
       m_state.gp.state.ilBindings[i].inputRate  = bindings[i].inputRate;
-      m_state.vi.vertexFetchRates[bindings[i].binding] = bindings[i].fetchRate;
-      
-      if (bindings[i].inputRate == VK_VERTEX_INPUT_RATE_INSTANCE && bindings[i].fetchRate != 1)
-        m_flags.set(DxvkContextFlag::GpEmulateInstanceFetchRate);
+      m_state.gp.state.ilDivisors[i]            = bindings[i].fetchRate;
     }
     
     for (uint32_t i = bindingCount; i < m_state.gp.state.ilBindingCount; i++)
@@ -1413,13 +1408,6 @@ namespace dxvk {
     
     m_state.gp.state.ilAttributeCount = attributeCount;
     m_state.gp.state.ilBindingCount   = bindingCount;
-    
-    if (m_flags.test(DxvkContextFlag::GpEmulateInstanceFetchRate)) {
-      static bool errorShown = false;
-      
-      if (!std::exchange(errorShown, true))
-        Logger::warn("Dxvk: GpEmulateInstanceFetchRate not handled yet");
-    }
   }
   
   
diff --git a/src/dxvk/dxvk_context_state.h b/src/dxvk/dxvk_context_state.h
index d28b0a11..0ebc1b31 100644
--- a/src/dxvk/dxvk_context_state.h
+++ b/src/dxvk/dxvk_context_state.h
@@ -27,7 +27,6 @@ namespace dxvk {
     GpDirtyResources,           ///< Graphics pipeline resource bindings are out of date
     GpDirtyVertexBuffers,       ///< Vertex buffer bindings are out of date
     GpDirtyIndexBuffer,         ///< Index buffer binding are out of date
-    GpEmulateInstanceFetchRate, ///< The current input layout uses fetch rates != 1
     
     CpDirtyPipeline,            ///< Compute pipeline binding are out of date
     CpDirtyPipelineState,       ///< Compute pipeline needs to be recompiled
@@ -42,12 +41,8 @@ namespace dxvk {
     VkIndexType     indexType   = VK_INDEX_TYPE_UINT32;
     uint32_t        bindingMask = 0;
     
-    std::array<DxvkBufferSlice,
-      DxvkLimits::MaxNumVertexBindings> vertexBuffers = { };
-    std::array<uint32_t,
-      DxvkLimits::MaxNumVertexBindings> vertexStrides = { };
-    std::array<uint32_t,
-      DxvkLimits::MaxNumVertexBindings> vertexFetchRates = { };
+    std::array<DxvkBufferSlice, DxvkLimits::MaxNumVertexBindings> vertexBuffers = { };
+    std::array<uint32_t,        DxvkLimits::MaxNumVertexBindings> vertexStrides = { };
   };
   
   
diff --git a/src/dxvk/dxvk_graphics.cpp b/src/dxvk/dxvk_graphics.cpp
index 611c5053..554434d4 100644
--- a/src/dxvk/dxvk_graphics.cpp
+++ b/src/dxvk/dxvk_graphics.cpp
@@ -135,15 +135,40 @@ namespace dxvk {
     if (m_gs  != nullptr) stages.push_back(m_gs->stageInfo(&specInfo));
     if (m_fs  != nullptr) stages.push_back(m_fs->stageInfo(&specInfo));
     
+    std::array<VkVertexInputBindingDivisorDescriptionEXT, MaxNumVertexBindings> viDivisorDesc;
+    uint32_t                                                                    viDivisorCount = 0;
+    
+    for (uint32_t i = 0; i < state.ilBindingCount; i++) {
+      if (state.ilBindings[i].inputRate == VK_VERTEX_INPUT_RATE_INSTANCE) {
+        const uint32_t id = viDivisorCount++;
+        
+        viDivisorDesc[id].binding = state.ilBindings[i].binding;
+        viDivisorDesc[id].divisor = state.ilDivisors[i];
+      }
+    }
+    
+    VkPipelineVertexInputDivisorStateCreateInfoEXT viDivisorInfo;
+    viDivisorInfo.sType                     = VK_STRUCTURE_TYPE_PIPELINE_VERTEX_INPUT_DIVISOR_STATE_CREATE_INFO_EXT;
+    viDivisorInfo.pNext                     = nullptr;
+    viDivisorInfo.vertexBindingDivisorCount = viDivisorCount;
+    viDivisorInfo.pVertexBindingDivisors    = viDivisorDesc.data();
+    
     VkPipelineVertexInputStateCreateInfo viInfo;
     viInfo.sType                            = VK_STRUCTURE_TYPE_PIPELINE_VERTEX_INPUT_STATE_CREATE_INFO;
-    viInfo.pNext                            = nullptr;
+    viInfo.pNext                            = &viDivisorInfo;
     viInfo.flags                            = 0;
     viInfo.vertexBindingDescriptionCount    = state.ilBindingCount;
     viInfo.pVertexBindingDescriptions       = state.ilBindings;
     viInfo.vertexAttributeDescriptionCount  = state.ilAttributeCount;
     viInfo.pVertexAttributeDescriptions     = state.ilAttributes;
     
+    if (viDivisorCount == 0)
+      viInfo.pNext = viDivisorInfo.pNext;
+    
+    // TODO make this extension required when widely supported
+    if (!m_device->extensions().extVertexAttributeDivisor.enabled())
+      viInfo.pNext = viDivisorInfo.pNext;
+    
     VkPipelineInputAssemblyStateCreateInfo iaInfo;
     iaInfo.sType                  = VK_STRUCTURE_TYPE_PIPELINE_INPUT_ASSEMBLY_STATE_CREATE_INFO;
     iaInfo.pNext                  = nullptr;
diff --git a/src/dxvk/dxvk_graphics.h b/src/dxvk/dxvk_graphics.h
index 67d620ee..8b6f56a4 100644
--- a/src/dxvk/dxvk_graphics.h
+++ b/src/dxvk/dxvk_graphics.h
@@ -43,6 +43,7 @@ namespace dxvk {
     uint32_t                            ilBindingCount;
     VkVertexInputAttributeDescription   ilAttributes[DxvkLimits::MaxNumVertexAttributes];
     VkVertexInputBindingDescription     ilBindings[DxvkLimits::MaxNumVertexBindings];
+    uint32_t                            ilDivisors[DxvkLimits::MaxNumVertexBindings];
     
     VkBool32                            rsEnableDepthClamp;
     VkBool32                            rsEnableDiscard;