glGetMap(3G)		       OpenGL Reference			  glGetMap(3G)



NAME
     glGetMapdv, glGetMapfv, glGetMapiv	- return evaluator parameters


C SPECIFICATION
     void glGetMapdv( GLenum target,
		      GLenum query,
		      GLdouble *v )
     void glGetMapfv( GLenum target,
		      GLenum query,
		      GLfloat *v )
     void glGetMapiv( GLenum target,
		      GLenum query,
		      GLint *v )


PARAMETERS
     target  Specifies the symbolic name of a map.  Accepted values are
	     GL_MAP1_COLOR_4, GL_MAP1_INDEX, GL_MAP1_NORMAL,
	     GL_MAP1_TEXTURE_COORD_1, GL_MAP1_TEXTURE_COORD_2,
	     GL_MAP1_TEXTURE_COORD_3, GL_MAP1_TEXTURE_COORD_4,
	     GL_MAP1_VERTEX_3, GL_MAP1_VERTEX_4, GL_MAP2_COLOR_4,
	     GL_MAP2_INDEX, GL_MAP2_NORMAL, GL_MAP2_TEXTURE_COORD_1,
	     GL_MAP2_TEXTURE_COORD_2, GL_MAP2_TEXTURE_COORD_3,
	     GL_MAP2_TEXTURE_COORD_4, GL_MAP2_VERTEX_3,	and GL_MAP2_VERTEX_4.

     query   Specifies which parameter to return.  Symbolic names GL_COEFF,
	     GL_ORDER, and GL_DOMAIN are accepted.

     v	     Returns the requested data.


DESCRIPTION
     glMap1 and	glMap2 define evaluators.  glGetMap returns evaluator
     parameters.  target chooses a map,	query selects a	specific parameter,
     and v points to storage where the values will be returned.

     The acceptable values for the target parameter are	described in the
     glMap1 and	glMap2 reference pages.

     query can assume the following values:

     GL_COEFF	       v returns the control points for	the evaluator map.
		       One-dimensional maps return order control points, and
		       two-dimensional maps return uorder*vorder control
		       points.	Each control point consists of one, two,
		       three, or four integer, single-precision	floating-
		       point, or double-precision floating-point values,
		       depending on the	type of	the map.  Two-dimensional
		       control points are returned in row-major	order,
		       incrementing the	uorder index quickly, and the vorder
		       index after each	row.  Integer values, when requested,



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glGetMap(3G)		       OpenGL Reference			  glGetMap(3G)



		       are computed by rounding	the internal floating-point
		       values to the nearest integer values.

     GL_ORDER	       v returns the order of the map.	One-dimensional	maps
		       return a	single value, order.  Two-dimensional maps
		       return two values, uorder and vorder.

     GL_DOMAIN	       v returns the linear u and v mapping parameters.	 One-
		       dimensional maps	return two values, u1 and u2, as
		       specified by glMap1.  Two-dimensional maps return four
		       values (u1, u2, v1, and v2) as specified	by glMap2.
		       Integer values, when requested, are computed by
		       rounding	the internal floating-point values to the
		       nearest integer values.

NOTES
     If	an error is generated, no change is made to the	contents of v.

ERRORS
     GL_INVALID_ENUM is	generated if either target or query is not an accepted
     value.

     GL_INVALID_OPERATION is generated if glGetMap is executed between the
     execution of glBegin and the corresponding	execution of glEnd.


SEE ALSO
     glEvalCoord, glMap1, glMap2



























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