1991-2006
Silicon Graphics, Inc.
glDrawRangeElements
3G
glDrawRangeElements
render primitives from array data
C Specification
void glDrawRangeElements
GLenum mode
GLuint start
GLuint end
GLsizei count
GLenum type
const GLvoid * indices
Parameters
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.
start
Specifies the minimum array index contained in indices.
end
Specifies the maximum array index contained in indices.
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
glDrawRangeElements is a restricted form of glDrawElements. mode, start, end,
and count match the corresponding arguments to glDrawElements, with
the additional constraint that all values in the arrays count must lie
between start and end, inclusive.
Implementations denote recommended maximum amounts of vertex and
index data,
which may be queried by calling glGet with argument
GL_MAX_ELEMENTS_VERTICES and GL_MAX_ELEMENTS_INDICES.
If
end
-
start
+
1
is greater than the value of
GL_MAX_ELEMENTS_VERTICES, or if count is greater than the value of
GL_MAX_ELEMENTS_INDICES, then the call may operate at reduced
performance. There is no requirement that all vertices in the range
start
end
be referenced. However, the implementation may
partially process unused vertices, reducing performance from what could
be achieved with an optimal index set.
When glDrawRangeElements is called, it uses count sequential elements from an
enabled array, starting at start 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 glDrawRangeElements have an
unspecified value after glDrawRangeElements returns. Attributes that aren't
modified maintain their previous values.
Notes
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.
Errors
It is an error for indices to lie outside the range
start
end
,
but implementations may not check for this situation. Such indices
cause implementation-dependent behavior.
GL_INVALID_ENUM is generated if mode is not an accepted value.
GL_INVALID_VALUE is generated if count is negative.
GL_INVALID_VALUE is generated if
end
<
start
.
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.
Associated Gets
glGet with argument GL_MAX_ELEMENTS_VERTICES
glGet with argument GL_MAX_ELEMENTS_INDICES
See Also
glDrawArrays,
glDrawElements,
glDrawElementsBaseVertex
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/.