2010
Khronos Group.
glPatchParameter
3G
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/.