glDrawElements

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Render primitives from array data.

C Specification[edit]

void glDrawElements( GLenum mode, GLsizei count, GLenum type, const void * indices );


Parameters[edit]

mode - Specifies what kind of primitives to render. Symbolic constants GL_POINTSGL_LINE_STRIPGL_LINE_LOOPGL_LINESGL_LINE_STRIP_ADJACENCYGL_LINES_ADJACENCYGL_TRIANGLE_STRIPGL_TRIANGLE_FANGL_TRIANGLESGL_TRIANGLE_STRIP_ADJACENCYGL_TRIANGLES_ADJACENCY and GL_PATCHES are accepted.
count - Specifies the number of elements to be rendered.
type - Specifies the type of the values in indices. Must be one of GL_UNSIGNED_BYTEGL_UNSIGNED_SHORT, or GL_UNSIGNED_INT.
indices - Specifies a pointer to the location where the indices are stored.


Description[edit]

glDrawElements specifies multiple geometric primitives with very few subroutine calls. Instead of calling a GL function to pass each individual vertex, normal, texture coordinate, edge flag, or color, you can prespecify separate arrays of vertices, normals, and so on, and use them to construct a sequence of primitives with a single call to glDrawElements.

When glDrawElements is called, it uses count sequential elements from an enabled array, starting at indices to construct a sequence of geometric primitives. mode specifies what kind of primitives are constructed and how the array elements construct these primitives. If more than one array is enabled, each is used.

Vertex attributes that are modified by glDrawElements have an unspecified value after glDrawElements returns. Attributes that aren't modified maintain their previous values.


Notes[edit]

GL_LINE_STRIP_ADJACENCYGL_LINES_ADJACENCYGL_TRIANGLE_STRIP_ADJACENCY and GL_TRIANGLES_ADJACENCY are available only if the GL version is 3.2 or greater.


Errors[edit]

GL_INVALID_ENUM is generated if mode is not an accepted value.

GL_INVALID_VALUE is generated if count is negative.

GL_INVALID_OPERATION is generated if a geometry shader is active and mode is incompatible with the input primitive type of the geometry shader in the currently installed program object.

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


Version Support[edit]

 glDrawElements  2.0+

See Also[edit]

glDrawArraysglDrawElementsInstancedglDrawElementsBaseVertexglDrawRangeElements 


Copyright[edit]

Copyright© 1991-2006 Silicon Graphics, Inc. Copyright© 2010-2014 Khronos Group. This document is licensed under the SGI Free Software B License. For details, see http://oss.sgi.com/projects/FreeB/.