NAME¶
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/.