Index for Section 3G

Alphabetical listing for G

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glMapGrid(3G)
NAME
  glMapGrid, glMapGrid1d, glMapGrid1f, glMapGrid2d, glMapGrid2f - define a
  one- or two-dimensional mesh

SYNOPSIS
  void glMapGrid1d(
	  GLint un,
	  GLdouble u1,
	  GLdouble u2 );

  void glMapGrid1f(
	  GLint un,
	  GLfloat u1,
	  GLfloat u2 );

  void glMapGrid2d(
	  GLint un,
	  GLdouble u1,
	  GLdouble u2,
	  GLint vn,
	  GLdouble v1,
	  GLdouble v2 );

  void glMapGrid2f(
	  GLint un,
	  GLfloat u1,
	  GLfloat u2,
	  GLint vn,
	  GLfloat v1,
	  GLfloat v2 );

PARAMETERS
  un  Specifies the number of partitions in the grid range interval [u1, u2].
      Must be positive.

  u1, u2
      Specify the mappings for integer grid domain values i=0 and i="un".

  vn  Specifies the number of partitions in the grid range interval [v1, v2]
      (glMapGrid2() only).

  v1, v2
      Specify the mappings for integer grid domain values j=0 and j="vn"
      (glMapGrid2() only).

DESCRIPTION
  glMapGrid() and glEvalMesh() are used together to efficiently generate and
  evaluate a series of evenly-spaced map domain values.	 glEvalMesh() steps
  through the integer domain of a one- or two-dimensional grid, whose range
  is the domain of the evaluation maps specified by glMap1() and glMap2().

  glMapGrid1() and glMapGrid2() specify the linear grid mappings between the
  i (or i and j) integer grid coordinates, to the u (or u and v) floating-
  point evaluation map coordinates.  See glMap1() and glMap2() for details of
  how u and v coordinates are evaluated.

  glMapGrid1() specifies a single linear mapping such that integer grid
  coordinate 0 maps exactly to u1, and integer grid coordinate un maps
  exactly to u2. All other integer grid coordinates i are mapped so that

       u = i(u2-u1/un + u1

  glMapGrid2() specifies two such linear mappings. One maps integer grid
  coordinate i=0 exactly to u1, and integer grid coordinate i="un" exactly to
  u2. The other maps integer grid coordinate j=0 exactly to v1, and integer
  grid coordinate j="vn" exactly to v2. Other integer grid coordinates i and
  j are mapped such that

       u = i(u2-u1/un + u1
       v = j(v2-v1/vn + uv1

  The mappings specified by glMapGrid() are used identically by glEvalMesh()
  and glEvalPoint().

ERRORS
  GL_INVALID_VALUE is generated if either un or vn is not positive.

  GL_INVALID_OPERATION is generated if glMapGrid() is executed between the
  execution of glBegin() and the corresponding execution of glEnd().

ASSOCIATED GETS
       glGet() with argument GL_MAP1_GRID_DOMAIN
       glGet() with argument GL_MAP2_GRID_DOMAIN
       glGet() with argument GL_MAP1_GRID_SEGMENTS
       glGet() with argument GL_MAP2_GRID_SEGMENTS

SEE ALSO
  glEvalCoord(3), glEvalMesh(3), glEvalPoint(3), glMap1(3), glMap2(3)

Index for Section 3G

Alphabetical listing for G

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