Function glMapGrid2d

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 + 𝐯1

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

Summary

define a one- or two-dimensional mesh

See

glMapGrid