glGetMap

NAME

glGetMapdv, glGetMapfv, glGetMapiv - return evaluator parameters

C SPECIFICATION

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

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 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 uorderxvorder 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.