Parameters

Description

glMapGrid and glEvalMesh are used in tandem to efficiently generate and evaluate a series of evenly spaced map domain values. glEvalPoint can be used to evaluate a single grid point in the same gridspace that is traversed by glEvalMesh. Calling glEvalPoint1 is equivalent to calling

glEvalCoord1( $\mathrm{i}·\Delta \mathit{u}+{\mathit{u}}_1$ );
         

where

and $\mathit{n}$, ${\mathit{u}}_1$, and ${\mathit{u}}_2$ are the arguments to the most recent glMapGrid1 command. The one absolute numeric requirement is that if $\mathit{i}=\mathit{n}$, then the value computed from $\mathit{i}·\Delta \mathit{u}+{\mathit{u}}_1$ is exactly ${\mathit{u}}_2$.

In the two-dimensional case, glEvalPoint2, let

where $\mathit{n}$, ${\mathit{u}}_1$, ${\mathit{u}}_2$, $\mathit{m}$, ${\mathit{v}}_1$, and ${\mathit{v}}_2$ are the arguments to the most recent glMapGrid2 command. Then the glEvalPoint2 command is equivalent to calling

glEvalCoord2( $\mathrm{i}·\Delta \mathit{u}+{\mathit{u}}_1,\mathrm{j}·\Delta \mathit{v}+{\mathit{v}}_1$ );
            

The only absolute numeric requirements are that if $\mathit{i}=\mathit{n}$, then the value computed from $\mathit{i}·\Delta \mathit{u}+{\mathit{u}}_1$ is exactly ${\mathit{u}}_2$, and if $\mathit{j}=\mathit{m}$, then the value computed from $\mathit{j}·\Delta \mathit{v}+{\mathit{v}}_1$ is exactly ${\mathit{v}}_2$.

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, glMap1, glMap2, glMapGrid