---
title: "drawIndexedPrimitives(primitiveType:indexCount:indexType:indexBuffer:indexBufferLength:instanceCount:)"
framework: metal
role: symbol
role_heading: Instance Method
path: "metal/mtl4rendercommandencoder/drawindexedprimitives(primitivetype:indexcount:indextype:indexbuffer:indexbufferlength:instancecount:)"
---

# drawIndexedPrimitives(primitiveType:indexCount:indexType:indexBuffer:indexBufferLength:instanceCount:)

Encodes a draw command that renders multiple instances of a geometric primitive with indexed vertices.

## Declaration

```swift
func drawIndexedPrimitives(primitiveType: MTLPrimitiveType, indexCount: Int, indexType: MTLIndexType, indexBuffer: MTLGPUAddress, indexBufferLength: Int, instanceCount: Int)
```

## Parameters

- `primitiveType`: A doc://com.apple.metal/documentation/Metal/MTLPrimitiveType representing how the command interprets vertex argument data.
- `indexCount`: An integer that represents the number of vertices the command reads from indexBuffer.
- `indexType`: A doc://com.apple.metal/documentation/Metal/MTLIndexType instance that represents the index format.
- `indexBuffer`: GPUAddress of a doc://com.apple.metal/documentation/Metal/MTLBuffer instance that contains indexCount indices of indexType format. You are responsible for ensuring this address is aligned to 2 bytes if the indexType format is doc://com.apple.metal/documentation/Metal/MTLIndexType/uint16, and aligned to 4 bytes if the format is doc://com.apple.metal/documentation/Metal/MTLIndexType/uint32.
- `indexBufferLength`: An integer that represents the length of indexBuffer, in bytes. You are responsible for ensuring this this size is a multiple of 2 if the indexType format is doc://com.apple.metal/documentation/Metal/MTLIndexType/uint16, and a multiple of 4 if the format is doc://com.apple.metal/documentation/Metal/MTLIndexType/uint32. Metal disregards this value and assigns 0 to the vertex_id attribute for all primitives that require loading indices at a byte offset of indexBufferLength or greater.
- `instanceCount`: An integer that represents the number of times the command draws primitiveType with indexCount vertices.

## Discussion

Discussion Use this method to perform instanced indexed drawing, where an index buffer determines how Metal assembles primitives. The command assigns each drawing instance a unique instance_id value that increases from 0 through (instanceCount - 1). Your shader can use this value to identify which instance the vertex belongs to. Metal imposes some restrictions on the index buffer’s address, which needs to be 2- or 4-byte aligned, and its length in bytes, which needs to be a multiple of 2 or 4, depending on whether the format of the index is MTLIndexType.uint16 or MTLIndexType.uint32. Use an instance of MTLResidencySet to mark residency of the index buffer the indexBuffer parameter references.

## See Also

### Drawing with indexed vertices

- [drawIndexedPrimitives(primitiveType:indexCount:indexType:indexBuffer:indexBufferLength:)](metal/mtl4rendercommandencoder/drawindexedprimitives(primitivetype:indexcount:indextype:indexbuffer:indexbufferlength:).md)
- [drawIndexedPrimitives(primitiveType:indexCount:indexType:indexBuffer:indexBufferLength:instanceCount:baseVertex:baseInstance:)](metal/mtl4rendercommandencoder/drawindexedprimitives(primitivetype:indexcount:indextype:indexbuffer:indexbufferlength:instancecount:basevertex:baseinstance:).md)
- [drawIndexedPrimitives(primitiveType:indexType:indexBuffer:indexBufferLength:indirectBuffer:)](metal/mtl4rendercommandencoder/drawindexedprimitives(primitivetype:indextype:indexbuffer:indexbufferlength:indirectbuffer:).md)