VkPipelineInputAssemblyStateCreateInfo(3)

# VkPipelineInputAssemblyStateCreateInfo(3) Manual Page

## Name

VkPipelineInputAssemblyStateCreateInfo - Structure specifying parameters of a newly created pipeline input assembly state

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## 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

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

- `flags` is reserved for future use.

- `topology` is a VkPrimitiveTopology defining the primitive topology, as described below.

- `primitiveRestartEnable` controls whether a special vertex index value is treated as restarting the assembly of primitives. This enable only applies to indexed draws (vkCmdDrawIndexed and vkCmdDrawIndexedIndirect), and the special index value is either 0xFFFFFFFF when the `indexType` parameter of `vkCmdBindIndexBuffer` is equal to `VK_INDEX_TYPE_UINT32`, 0xFF when `indexType` is equal to `VK_INDEX_TYPE_UINT8_EXT`, or 0xFFFF when `indexType` is equal to `VK_INDEX_TYPE_UINT16`. Primitive restart is not allowed for “list” topologies.

## 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.

Valid Usage

- VUID-VkPipelineInputAssemblyStateCreateInfo-topology-00428
  If `topology` is `VK_PRIMITIVE_TOPOLOGY_POINT_LIST`, `VK_PRIMITIVE_TOPOLOGY_LINE_LIST`, `VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST`, `VK_PRIMITIVE_TOPOLOGY_LINE_LIST_WITH_ADJACENCY`, `VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST_WITH_ADJACENCY` or `VK_PRIMITIVE_TOPOLOGY_PATCH_LIST`, `primitiveRestartEnable` must be `VK_FALSE`

- VUID-VkPipelineInputAssemblyStateCreateInfo-topology-00429
  If the geometry shaders feature is not enabled, `topology` must not be any of `VK_PRIMITIVE_TOPOLOGY_LINE_LIST_WITH_ADJACENCY`, `VK_PRIMITIVE_TOPOLOGY_LINE_STRIP_WITH_ADJACENCY`, `VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST_WITH_ADJACENCY` or `VK_PRIMITIVE_TOPOLOGY_TRIANGLE_STRIP_WITH_ADJACENCY`

- VUID-VkPipelineInputAssemblyStateCreateInfo-topology-00430
  If the tessellation shaders feature is not enabled, `topology` must not be `VK_PRIMITIVE_TOPOLOGY_PATCH_LIST`

- VUID-VkPipelineInputAssemblyStateCreateInfo-triangleFans-04452
  If the `VK_KHR_portability_subset` extension is enabled, and VkPhysicalDevicePortabilitySubsetFeaturesKHR::`triangleFans` is `VK_FALSE`, `topology` must not be `VK_PRIMITIVE_TOPOLOGY_TRIANGLE_FAN`.

Valid Usage (Implicit)

- VUID-VkPipelineInputAssemblyStateCreateInfo-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_PIPELINE_INPUT_ASSEMBLY_STATE_CREATE_INFO`

- VUID-VkPipelineInputAssemblyStateCreateInfo-pNext-pNext
  `pNext` must be `NULL`

- VUID-VkPipelineInputAssemblyStateCreateInfo-flags-zerobitmask
  `flags` must be `0`

- VUID-VkPipelineInputAssemblyStateCreateInfo-topology-parameter
  `topology` must be a valid VkPrimitiveTopology value

## See Also

`VkBool32`, VkGraphicsPipelineCreateInfo, VkPipelineInputAssemblyStateCreateFlags, VkPrimitiveTopology, VkStructureType

## 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.

## Copyright

Copyright (c) 2014-2020 The Khronos Group Inc.

SPDX-License-Identifier: CC-BY-4.0