glDrawArraysInstanced - OpenGL ES 3 Reference Pages

## Name

glDrawArraysInstanced — draw multiple instances of a range of elements

## C Specification

`void glDrawArraysInstanced(` | GLenum mode,
| GLint first,
| GLsizei count,
| GLsizei primcount`)`;

## Parameters

`mode`

  Specifies what kind of primitives to render. Symbolic constants `GL_POINTS`, `GL_LINE_STRIP`, `GL_LINE_LOOP`, `GL_LINES`, `GL_TRIANGLE_STRIP`, `GL_TRIANGLE_FAN` and `GL_TRIANGLES` are accepted.

`first`

  Specifies the starting index in the enabled arrays.

`count`

  Specifies the number of indices to be rendered.

`primcount`

  Specifies the number of instances of the specified range of indices to be rendered.

## Description

`glDrawArraysInstanced` behaves identically to glDrawArrays except that `primcount` instances of the range of elements are executed. Those attributes that have divisor N where N is other than zero (as specified by glVertexAttribDivisor) advance once every N instances. Thus, the element transferred from instanced vertex attributes is given by:

instance divisor

The value of `instance` may be read by a vertex shader as `gl_InstanceID`.

To enable and disable a generic vertex attribute array, call glEnableVertexAttribArray and glDisableVertexAttribArray.

If an array corresponding to a generic attribute required by a vertex shader is not enabled, then the corresponding element is taken from the current generic attribute state.

## Errors

`GL_INVALID_ENUM` is generated if `mode` is not one of the accepted values.

`GL_INVALID_VALUE` is generated if `count` or `primcount` are negative.

`GL_INVALID_OPERATION` is generated if a non-zero buffer object name is bound to an enabled array and the buffer object's data store is currently mapped.

`GL_INVALID_FRAMEBUFFER_OPERATION` is generated if the currently bound framebuffer is not framebuffer complete (i.e. the return value from glCheckFramebufferStatus is not `GL_FRAMEBUFFER_COMPLETE`).

`GL_INVALID_OPERATION` is generated if recording the vertices of a primitive to the buffer objects being used for transform feedback purposes would result in either exceeding the limits of any buffer object’s size, or in exceeding the end position `offset` + `size` - 1, as set by glBindBufferRange.

## API Version Support

| OpenGL ES API Version
--- | ---
Function Name | 2.0 | 3.0
glDrawArraysInstanced | - | ✔

## See Also

glCheckFramebufferStatus, glDisableVertexAttribArray, glDrawArrays, glDrawElements, glDrawElementsInstanced, glEnableVertexAttribArray , glVertexAttribDivisor

## Copyright

Copyright © 2010-2014 Khronos Group. This material may be distributed subject to the terms and conditions set forth in the Open Publication License, v 1.0, 8 June 1999. http://opencontent.org/openpub/.