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/.