[dxvk] Enable VK_KHR_draw_indirect_count if available

Useful to implement a corresponding D3D11 extension.

src/dxvk/dxvk_adapter.cpp

@@ -240,7 +240,7 @@ namespace dxvk {
   Rc<DxvkDevice> DxvkAdapter::createDevice(std::string clientApi, DxvkDeviceFeatures enabledFeatures) {
     DxvkDeviceExtensions devExtensions;
 
-    std::array<DxvkExt*, 19> devExtensionList = {{
+    std::array<DxvkExt*, 20> devExtensionList = {{
       &devExtensions.amdMemoryOverallocationBehaviour,
       &devExtensions.amdShaderFragmentMask,
       &devExtensions.extConditionalRendering,
@@ -252,6 +252,7 @@ namespace dxvk {
       &devExtensions.extVertexAttributeDivisor,
       &devExtensions.khrDedicatedAllocation,
       &devExtensions.khrDescriptorUpdateTemplate,
+      &devExtensions.khrDrawIndirectCount,
       &devExtensions.khrDriverProperties,
       &devExtensions.khrGetMemoryRequirements2,
       &devExtensions.khrImageFormatList,

src/dxvk/dxvk_cmdlist.h

@@ -463,6 +463,18 @@ namespace dxvk {
     }
     
     
+    void cmdDrawIndirectCount(
+            VkBuffer                buffer,
+            VkDeviceSize            offset,
+            VkBuffer                countBuffer,
+            VkDeviceSize            countOffset,
+            uint32_t                maxDrawCount,
+            uint32_t                stride) {
+      m_vkd->vkCmdDrawIndirectCountKHR(m_execBuffer,
+        buffer, offset, countBuffer, countOffset, maxDrawCount, stride);
+    }
+    
+    
     void cmdDrawIndexed(
             uint32_t                indexCount,
             uint32_t                instanceCount,
@@ -486,6 +498,18 @@ namespace dxvk {
     }
 
 
+    void cmdDrawIndexedIndirectCount(
+            VkBuffer                buffer,
+            VkDeviceSize            offset,
+            VkBuffer                countBuffer,
+            VkDeviceSize            countOffset,
+            uint32_t                maxDrawCount,
+            uint32_t                stride) {
+      m_vkd->vkCmdDrawIndexedIndirectCountKHR(m_execBuffer,
+        buffer, offset, countBuffer, countOffset, maxDrawCount, stride);
+    }
+    
+    
     void cmdDrawIndirectVertexCount(
             uint32_t                instanceCount,
             uint32_t                firstInstance,

src/dxvk/dxvk_extensions.h

@@ -268,6 +268,7 @@ namespace dxvk {
     DxvkExt extVertexAttributeDivisor       = { VK_EXT_VERTEX_ATTRIBUTE_DIVISOR_EXTENSION_NAME,         DxvkExtMode::Optional };
     DxvkExt khrDedicatedAllocation          = { VK_KHR_DEDICATED_ALLOCATION_EXTENSION_NAME,             DxvkExtMode::Required };
     DxvkExt khrDescriptorUpdateTemplate     = { VK_KHR_DESCRIPTOR_UPDATE_TEMPLATE_EXTENSION_NAME,       DxvkExtMode::Required };
+    DxvkExt khrDrawIndirectCount            = { VK_KHR_DRAW_INDIRECT_COUNT_EXTENSION_NAME,              DxvkExtMode::Optional };
     DxvkExt khrDriverProperties             = { VK_KHR_DRIVER_PROPERTIES_EXTENSION_NAME,                DxvkExtMode::Optional };
     DxvkExt khrGetMemoryRequirements2       = { VK_KHR_GET_MEMORY_REQUIREMENTS_2_EXTENSION_NAME,        DxvkExtMode::Required };
     DxvkExt khrImageFormatList              = { VK_KHR_IMAGE_FORMAT_LIST_EXTENSION_NAME,                DxvkExtMode::Required };

src/vulkan/vulkan_loader.h

@@ -273,6 +273,11 @@ namespace dxvk::vk {
     VULKAN_FN(vkUpdateDescriptorSetWithTemplateKHR);
     VULKAN_FN(vkCmdPushDescriptorSetWithTemplateKHR);
     #endif
+
+    #ifdef VK_KHR_draw_indirect_count
+    VULKAN_FN(vkCmdDrawIndirectCountKHR);
+    VULKAN_FN(vkCmdDrawIndexedIndirectCountKHR);
+    #endif
     
     #ifdef VK_KHR_swapchain
     VULKAN_FN(vkCreateSwapchainKHR);