supported uint8_index_type

inc/hgl/graph/VK.h

@@ -138,8 +138,9 @@ inline const uint32_t GetMipLevel(const VkExtent3D &ext)
 /**
  * 索引类型,等同于VkIndexType
  */
-enum IndexType:uint
+enum IndexType:int
 {
+    AUTO=-1,
     U16=0,
     U32,
     U8=VK_INDEX_TYPE_UINT8_EXT,
@@ -147,6 +148,11 @@ enum IndexType:uint
     ERR=VK_INDEX_TYPE_MAX_ENUM
 };
 
+inline const bool IsIndexType(const IndexType it)
+{
+    return it>=U16&&it<=U8;
+}
+
 //Push Constant max-lengths:
 //
 //    256 bytes:  nvidia,arm

inc/hgl/graph/VKDevice.h

@@ -117,6 +117,9 @@ public: //Buffer相关
     VBO *           CreateVBO   (VkFormat format, uint32_t count,const void *data,    SharingMode sm=SharingMode::Exclusive);
     VBO *           CreateVBO   (VkFormat format, uint32_t count,                     SharingMode sm=SharingMode::Exclusive){return CreateVBO(format,count,nullptr,sm);}
 
+    const IndexType GetIndexType(const VkDeviceSize &vertex_count)const;     ///<求一个合适的索引类型
+    const bool      CheckIndexType(const IndexType,const VkDeviceSize &vertex_count)const;     ///<检测一个索引类型是否合适
+
     IndexBuffer *   CreateIBO   (IndexType type,  uint32_t count,const void *  data,  SharingMode sm=SharingMode::Exclusive);
     IndexBuffer *   CreateIBO8  (                 uint32_t count,const void *  data,  SharingMode sm=SharingMode::Exclusive){return CreateIBO(IndexType::U8,  count,(void *)data,sm);}
     IndexBuffer *   CreateIBO16 (                 uint32_t count,const uint16 *data,  SharingMode sm=SharingMode::Exclusive){return CreateIBO(IndexType::U16, count,(void *)data,sm);}

inc/hgl/graph/VKDeviceAttribute.h

@@ -39,6 +39,8 @@ struct GPUDeviceAttribute
     VkSurfaceTransformFlagBitsKHR       preTransform;
     VkCompositeAlphaFlagBitsKHR         compositeAlpha  =VK_COMPOSITE_ALPHA_OPAQUE_BIT_KHR;
 
+    bool                                uint8_index_type=false;
+
     VkDevice                            device          =VK_NULL_HANDLE;
     VkCommandPool                       cmd_pool        =VK_NULL_HANDLE;
 

src/SceneGraph/Vulkan/VKDeviceBuffer.cpp

@@ -77,6 +77,30 @@ VBO *GPUDevice::CreateVBO(VkFormat format,uint32_t count,const void *data,Sharin
     return(new VertexAttribBuffer(attr->device,buf,format,stride,count));
 }
 
+const IndexType GPUDevice::GetIndexType(const VkDeviceSize &vertex_count)const
+{
+    if(vertex_count<=0)return(IndexType::ERR);
+
+    if(attr->uint8_index_type&&                 vertex_count<=0xFF  )return IndexType::U8;  else
+    if(                                         vertex_count<=0xFFFF)return IndexType::U16; else
+    if(attr->physical_device->SupportU32Index()                     )return IndexType::U32; else
+
+    return IndexType::ERR;
+}
+
+const bool GPUDevice::CheckIndexType(const IndexType it,const VkDeviceSize &vertex_count)const
+{
+    if(vertex_count<=0)return(false);
+
+    if(it==IndexType::U16&&vertex_count<=0xFFFF)return(true);
+
+    if(it==IndexType::U32&&attr->physical_device->SupportU32Index())return(true);
+
+    if(it==IndexType::U8 &&vertex_count<=0xFF&&attr->uint8_index_type)return(true);
+
+    return(false);
+}
+
 IndexBuffer *GPUDevice::CreateIBO(IndexType index_type,uint32_t count,const void *data,SharingMode sharing_mode)
 {
     if(count==0)return(nullptr);

src/SceneGraph/Vulkan/VKDeviceCreater.cpp

@@ -229,6 +229,18 @@ VkDevice VulkanDeviceCreater::CreateDevice(const uint32_t graphics_family)
     create_info.ppEnabledLayerNames     =nullptr;
     create_info.pEnabledFeatures        =&features;
 
+    VkPhysicalDeviceIndexTypeUint8FeaturesEXT index_type_uint8_features;
+
+    if(physical_device->SupportU8Index()
+     &&require.fullDrawIndexUint8>=VulkanHardwareRequirement::SupportLevel::Want)
+    {
+        create_info.pNext=&index_type_uint8_features;
+
+        index_type_uint8_features.sType         =VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_INDEX_TYPE_UINT8_FEATURES_EXT;
+        index_type_uint8_features.pNext         =nullptr;
+        index_type_uint8_features.indexTypeUint8=VK_TRUE;
+    }
+
     VkDevice device;
 
     if(vkCreateDevice(*physical_device,&create_info,nullptr,&device)==VK_SUCCESS)
@@ -300,6 +312,12 @@ GPUDevice *VulkanDeviceCreater::CreateRenderDevice()
 
     ChooseSurfaceFormat();
 
+    if(physical_device->SupportU8Index()
+     &&require.fullDrawIndexUint8>=VulkanHardwareRequirement::SupportLevel::Want)
+    {
+        device_attr->uint8_index_type=true;
+    }
+
     device_attr->surface_format=surface_format;
 
     GetDeviceQueue(device_attr);