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<STRONG>NAME</STRONG>
<STRONG>glGetMapdv,</STRONG> <STRONG>glGetMapfv,</STRONG> <STRONG>glGetMapiv</STRONG> - return evaluator
parameters
<STRONG>C</STRONG> <STRONG>SPECIFICATION</STRONG>
void <STRONG>glGetMapdv</STRONG>( GLenum <EM>target</EM>,
GLenum <EM>query</EM>,
GLdouble *<EM>v</EM> )
void <STRONG>glGetMapfv</STRONG>( GLenum <EM>target</EM>,
GLenum <EM>query</EM>,
GLfloat *<EM>v</EM> )
void <STRONG>glGetMapiv</STRONG>( GLenum <EM>target</EM>,
GLenum <EM>query</EM>,
GLint *<EM>v</EM> )
<STRONG>PARAMETERS</STRONG>
<EM>target</EM> Specifies the symbolic name of a map. Accepted
values are <STRONG>GL_MAP1_COLOR_4</STRONG>, <STRONG>GL_MAP1_INDEX</STRONG>,
<STRONG>GL_MAP1_NORMAL</STRONG>, <STRONG>GL_MAP1_TEXTURE_COORD_1</STRONG>,
<STRONG>GL_MAP1_TEXTURE_COORD_2</STRONG>, <STRONG>GL_MAP1_TEXTURE_COORD_3</STRONG>,
<STRONG>GL_MAP1_TEXTURE_COORD_4</STRONG>, <STRONG>GL_MAP1_VERTEX_3</STRONG>,
<STRONG>GL_MAP1_VERTEX_4</STRONG>, <STRONG>GL_MAP2_COLOR_4</STRONG>, <STRONG>GL_MAP2_INDEX</STRONG>,
<STRONG>GL_MAP2_NORMAL</STRONG>, <STRONG>GL_MAP2_TEXTURE_COORD_1</STRONG>,
<STRONG>GL_MAP2_TEXTURE_COORD_2</STRONG>, <STRONG>GL_MAP2_TEXTURE_COORD_3</STRONG>,
<STRONG>GL_MAP2_TEXTURE_COORD_4</STRONG>, <STRONG>GL_MAP2_VERTEX_3</STRONG>, and
<STRONG>GL_MAP2_VERTEX_4</STRONG>.
<EM>query</EM> Specifies which parameter to return. Symbolic names
<STRONG>GL_COEFF</STRONG>, <STRONG>GL_ORDER</STRONG>, and <STRONG>GL_DOMAIN</STRONG> are accepted.
<EM>v</EM> Returns the requested data.
<STRONG>DESCRIPTION</STRONG>
<STRONG>glMap1</STRONG> and <STRONG>glMap2</STRONG> define evaluators. <STRONG>glGetMap</STRONG> returns
evaluator parameters. <EM>target</EM> chooses a map, <EM>query</EM> selects a
specific parameter, and <EM>v</EM> points to storage where the values
will be returned.
The acceptable values for the <EM>target</EM> parameter are described
in the <STRONG>glMap1</STRONG> and <STRONG>glMap2</STRONG> reference pages.
<EM>query</EM> can assume the following values:
<STRONG>GL_COEFF</STRONG> <EM>v</EM> 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.
<STRONG>GL_ORDER</STRONG> <EM>v</EM> 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.
<STRONG>GL_DOMAIN</STRONG> <EM>v</EM> returns the linear u and v mapping
parameters. One-dimensional evaluators
return two values, u1 and u2, as specified by
<STRONG>glMap1</STRONG>. Two-dimensional evaluators return
four values (u1, u2, v1, and v2) as specified
by <STRONG>glMap2</STRONG>. Integer values, when requested,
are computed by rounding the internal
floating-point values to the nearest integer
values.
<STRONG>NOTES</STRONG>
If an error is generated, no change is made to the contents
of <EM>v</EM>.
<STRONG>ERRORS</STRONG>
<STRONG>GL_INVALID_ENUM</STRONG> is generated if either <EM>target</EM> or <EM>query</EM> is
not an accepted value.
<STRONG>GL_INVALID_OPERATION</STRONG> is generated if <STRONG>glGetMap</STRONG> is executed
between the execution of <STRONG>glBegin</STRONG> and the corresponding
execution of <STRONG>glEnd</STRONG>.
<STRONG>SEE</STRONG> <STRONG>ALSO</STRONG>
<STRONG>glEvalCoord</STRONG>, <STRONG>glMap1</STRONG>, <STRONG>glMap2</STRONG>
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