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_TRIANGLE_STRIP
,
GL_TRIANGLE_FAN
,
GL_TRIANGLES
,
GL_QUAD_STRIP
,
GL_QUADS
,
and GL_POLYGON
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. If
GL_VERTEX_ARRAY
is not enabled, no geometric primitives are
constructed.
Vertex attributes that are modified by glDrawElements
have an
unspecified value after glDrawElements
returns. For example, if
GL_COLOR_ARRAY
is enabled, the value of the current color is
undefined after glDrawElements
executes. Attributes that aren't
modified maintain their previous values.
glDrawElements
is available only if the GL version is 1.1 or greater.
glDrawElements
is included in display lists. If glDrawElements
is entered into a
display list,
the necessary array data (determined by the array pointers and
enables) is also
entered into the display list. Because the array pointers and
enables are client-side state, their values affect display lists
when the lists are created, not when the lists are executed.
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 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.
GL_INVALID_OPERATION
is generated if glDrawElements
is executed between
the execution of glBegin and the corresponding glEnd.
glArrayElement, glColorPointer, glDrawArrays, glDrawRangeElements, glEdgeFlagPointer, glFogCoordPointer, glGetPointerv, glIndexPointer, glInterleavedArrays, glNormalPointer, glSecondaryColorPointer, glTexCoordPointer, glVertexPointer
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/.