render primitives from array data
Signature
glDrawElements(
GLenum (
mode
)
,
GLsizei (
count
)
,
GLenum (
type
)
,
const GLvoid * (
indices
)
)-> void
glDrawElements(
mode
,
count
,
type
,
indices
)
glDrawElements( GLenum(mode), GLsizei(count), GLenum(type), POINTER(GLvoid)(indices) ) -> None
Parameters
| Variables | Description |
|---|---|
| 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.
|
Description
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.
Notes
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.
Errors
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
.
See Also
Copyright
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/
.
Sample Code References
The following code samples have been found which appear to reference the functions described here. Take care that the code may be old, broken or not even use PyOpenGL.
glDrawElements