glDrawElements — render primitives from array data
void glDrawElements( | GLenum mode, |
GLsizei count, | |
GLenum type, | |
const GLvoid * indices) ; |
mode
Specifies what kind of primitives to render.
Symbolic constants
GL_POINTS
,
GL_LINE_STRIP
,
GL_LINE_LOOP
,
GL_LINES
,
GL_LINE_STRIP_ADJACENCY
,
GL_LINES_ADJACENCY
,
GL_TRIANGLE_STRIP
,
GL_TRIANGLE_FAN
,
GL_TRIANGLES
,
GL_TRIANGLE_STRIP_ADJACENCY
,
GL_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_BYTE
, GL_UNSIGNED_SHORT
, or
GL_UNSIGNED_INT
.
indices
Specifies a pointer to the location where the indices are stored.
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.
GL_LINE_STRIP_ADJACENCY
,
GL_LINES_ADJACENCY
,
GL_TRIANGLE_STRIP_ADJACENCY
and
GL_TRIANGLES_ADJACENCY
are available only if the GL version is 3.2 or greater.
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.
Copyright © 1991-2006 Silicon Graphics, Inc. This document is licensed under the SGI Free Software B License. For details, see http://oss.sgi.com/projects/FreeB/.