Index for Section 3G

Alphabetical listing for G

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glGetMap(3G)
NAME
  glGetMap, glGetMapdv, glGetMapfv, glGetMapiv - return evaluator parameters

SYNOPSIS
  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 function. One-
      dimensional evaluators return order control points, and two-dimensional
      evaluators return uorder times 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 evaluator. The GL returns two-dimensional control
      points in row-major order, incrementing the uorder index quickly and
      the vorder index after each row. Integer values, when requested, are
      computed by rounding the internal floating-point values to the nearest
      integer values.

  GL_ORDER
      v returns the order of the evaluator function. One-dimensional
      evaluators return a single value, order. The initial value is 1.	Two-
      dimensional evaluators return two values, uorder and vorder. The
      initial value is 1,1.

  GL_DOMAIN
      v returns the linear u and v mapping parameters. One-dimensional
      evaluators return two values, u1 and u2, as specified by glMap1().
      Two-dimensional evaluators 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(3), glMap1(3), glMap2(3)

Index for Section 3G

Alphabetical listing for G

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