GLMAPGRID() GLMAPGRID() NAME glMapGrid1d, glMapGrid1f, glMapGrid2d, glMapGrid2f - define a one- or two- dimensional mesh C SPECIFICATION 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 ) delim $$ 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 de- tails of how $u$ and $v$ coordinates are evaluated. glMapGrid1 specifies a single linear mapping such that integer grid coordi- nate 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 coor- dinate $i=0$ exactly to u1, and integer grid coordinate $i="un"$ exactly to u2. The other maps integer grid coordinate $j=0$ exactly to v1, and inte- ger 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" ~+~ "v1" 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 exe- cution 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, glEvalMesh, glEvalPoint, glMap1, glMap2 GLMAPGRID()
NAME | C SPECIFICATION | PARAMETERS | DESCRIPTION | ERRORS | ASSOCIATED GETS | SEE ALSO
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