GLDRAWELEMENTS(3gl)GLDRAWELEMENTS(3gl)NAME
glDrawElements - render primitives from array data
glDrawRangeElements - render primitives from array data
C SPECIFICATION
void glDrawElements( GLenum mode,
GLsizei count,
GLenum type,
const GLvoid *indices )
void glDrawRangeElements( GLenum mode,
GLunit start,
GLunit end,
GLsizei count,
GLenum type,
const GLvoid *indices)
PARAMETERS
mode Specifies what kind of primitives to render. Symbolic con‐
stants GL_POINTS, GL_LINE_STRIP, GL_LINE_LOOP, GL_LINES,
GL_TRIANGLE_STRIP, GL_TRIANGLE_FAN, GL_TRIANGLES,
GL_QUAD_STRIP, GL_QUADS, GL_POLYGON, and GL_TRIANGLE_LIST_SUN
are accepted.
start Specifies the minimum index value in the indices array.
end Specifies the maximum index value in the indices array.
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 indi‐
vidual vertex, normal, texture coordinate, edge flag, or color, you can
prespecify separate arrays of vertexes, normals, and so on and use them
to construct a sequence of primitives with a single call to glDrawEle‐
ments.
glDrawRangeElements is a restricted form of glDrawElements, with the
additional constraint that all values in the array indices must lie
between start and end inclusive.
When glDrawElements is called, it uses count sequential elements from
an enabled array, starting at indices to construct a sequence of geo‐
metric primitives. mode specifies what kind of primitives are con‐
structed, 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 unspeci‐
fied 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 remain well
defined.
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 glDrawElements is executed between
the execution of glBegin and the corresponding glEnd.
SEE ALSO
glArrayElement, glColorPointer, glDrawArrays, glEdgeFlagPointer,
glGetPointerv, glIndexPointer, glInterleavedArrays, glNormalPointer,
glTexCoordPointer, glVertexPointer, glReplacementCodePointerSUN
15 Mar 97 GLDRAWELEMENTS(3gl)