C Specification
Drawing can be achieved in two modes:
-
Programmable Mesh Shading, the mesh shader assembles primitives, or
-
Programmable Primitive Shading, the input primitives are assembled as follows.
Each draw is made up of zero or more vertices and zero or more instances,
which are processed by the device and result in the assembly of primitives.
Primitives are assembled according to the pInputAssemblyState member
of the VkGraphicsPipelineCreateInfo structure, which is of type
VkPipelineInputAssemblyStateCreateInfo:
// Provided by VK_VERSION_1_0
typedef struct VkPipelineInputAssemblyStateCreateInfo {
VkStructureType sType;
const void* pNext;
VkPipelineInputAssemblyStateCreateFlags flags;
VkPrimitiveTopology topology;
VkBool32 primitiveRestartEnable;
} VkPipelineInputAssemblyStateCreateInfo;Members
-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
flagsis reserved for future use. -
topologyis a VkPrimitiveTopology defining the primitive topology, as described below. -
primitiveRestartEnablecontrols whether a special vertex index value is treated as restarting the assembly of primitives. This enable only applies to indexed draws (vkCmdDrawIndexed, vkCmdDrawMultiIndexedEXT, and vkCmdDrawIndexedIndirect), and the special index value is either 0xFFFFFFFF when theindexTypeparameter ofvkCmdBindIndexBuffer2KHRorvkCmdBindIndexBufferis equal toVK_INDEX_TYPE_UINT32, 0xFF whenindexTypeis equal toVK_INDEX_TYPE_UINT8_EXT, or 0xFFFF whenindexTypeis equal toVK_INDEX_TYPE_UINT16. Primitive restart is not allowed for “list” topologies, unless one of the featuresprimitiveTopologyPatchListRestart(forVK_PRIMITIVE_TOPOLOGY_PATCH_LIST) orprimitiveTopologyListRestart(for all other list topologies) is enabled.
Description
Restarting the assembly of primitives discards the most recent index values
if those elements formed an incomplete primitive, and restarts the primitive
assembly using the subsequent indices, but only assembling the immediately
following element through the end of the originally specified elements.
The primitive restart index value comparison is performed before adding the
vertexOffset value to the index value.
Document Notes
For more information, see the Vulkan Specification
This page is extracted from the Vulkan Specification. Fixes and changes should be made to the Specification, not directly.