MirOS Manual: glGetMap(3), glGetMapdv(3), glGetMapfv(3), glGetMapiv(3)


GLGETMAP(3G)        UNIX Programmer's Manual         GLGETMAP(3G)

NAME

     glGetMapdv, glGetMapfv, glGetMapiv - return evaluator param-
     eters

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

     glMap1 and 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 glMap1 and glMap2 reference pages.

     query can assume the following values:

     GL_COEFF       v returns the control points for the evalua-
                    tor function. One-dimensional evaluators
                    return order control points, and two-
                    dimensional evaluators return uorder x vorder
                    control points. Each control point consists
                    of one, two, three, or four integer, single-
                    precision floating-point, or double-precision

MirOS BSD #10-current  Printed 03.04.2017                       1

GLGETMAP(3G)        UNIX Programmer's Manual         GLGETMAP(3G)

                    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 func-
                    tion. 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 parame-
                    ters. 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 exe-
     cution of glEnd.

SEE ALSO

     glEvalCoord(3G), glMap1(3G), glMap2(3G)

MirOS BSD #10-current  Printed 03.04.2017                       2

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