NAME¶
glPatchParameter - specifies the parameters for patch primitives
C SPECIFICATION¶
void
glPatchParameteri(GLenum pname,
GLint value);
void
glPatchParameterfv(GLenum pname,
const GLfloat *values);
PARAMETERS¶
pname
Specifies the name of the parameter to set.
The symbolc constants GL_PATCH_VERTICES,
GL_PATCH_DEFAULT_OUTER_LEVEL, and GL_PATCH_DEFAULT_INNER_LEVEL
are accepted.
value
Specifies the new value for the parameter
given by pname.
values
Specifies the address of an array containing
the new values for the parameter given by pname.
DESCRIPTION¶
glPatchParameter specifies the parameters that will be used for patch
primitives.
pname specifies the parameter to modify and must be either
GL_PATCH_VERTICES,
GL_PATCH_DEFAULT_OUTER_LEVEL or
GL_PATCH_DEFAULT_INNER_LEVEL. For
glPatchParameteri,
value specifies the new value for the parameter specified by
pname. For
glPatchParameterfv,
values specifies the
address of an array containing the new values for the parameter specified by
pname.
When
pname is
GL_PATCH_VERTICES,
value specifies the number
of vertices that will be used to make up a single patch primitive. Patch
primitives are consumed by the tessellation control shader (if present) and
subsequently used for tessellation. When primitives are specified using
glDrawArrays() or a similar function, each patch will be made from
parameter control points, each represented by a vertex taken from the
enabeld vertex arrays.
parameter must be greater than zero, and less
than or equal to the value of
GL_MAX_PATCH_VERTICES.
When
pname is
GL_PATCH_DEFAULT_OUTER_LEVEL or
GL_PATCH_DEFAULT_INNER_LEVEL,
values contains the address of an
array contiaining the default outer or inner tessellation levels,
respectively, to be used when no tessellation control shader is present.
ERRORS¶
GL_INVALID_ENUM is generated if
pname is not an accepted value.
GL_INVALID_VALUE is generated if
pname is
GL_PATCH_VERTICES
and
value is less than or equal to zero, or greater than the value of
GL_MAX_PATCH_VERTICES.
SEE ALSO¶
glDrawArrays(),
glDrawArraysInstanced(),
glDrawElements(),
glDrawRangeElements(),
COPYRIGHT¶
Copyright © 2010 Khronos Group. This material may be distributed subject to
the terms and conditions set forth in the Open Publication License, v 1.0, 8
June 1999.
http://opencontent.org/openpub/.