HP b2600 Reference Manual page 281

Each control point is two floating-point values representing the s and t texture
coordinates. Internal glTexCoord2 commands are generated when the map is evaluated
but the current texture coordinates are not updated with the value of these glTexCoord
commands.
GL_MAP2_TEXTURE_COORD_3
Each control point is three floating-point values representing the s, t, and r texture
coordinates. Internal glTexCoord3 commands are generated when the map is evaluated
but the current texture coordinates are not updated with the value of these glTexCoord
commands.
GL_MAP2_TEXTURE_COORD_4
Each control point is four floating-point values representing the s, t, r, and q texture
coordinates. Internal glTexCoord4 commands are generated when the map is evaluated
but the current texture coordinates are not updated with the value of these glTexCoord
commands.
ustride, uorder, vstride, vorder, and points define the array addressing for accessing the
control points. points is the location of the first control point, which occupies one, two,
three, or four contiguous memory locations, depending on which map is being defined.
There are uorder vorder control points in the array. ustride specifies how many float or
double locations are skipped to advance the internal memory pointer from control point
R
ij
skipped to advance the internal memory pointer from control point R
R
i(j+1)
Notes
As is the case with all GL commands that accept pointers to data, it is as if the contents
of points were copied by glMap2 before glMap2 returns. Changes to the contents of
points have no effect after glMap2 is called.
Initially, GL_AUTO_NORMAL is enabled. If GL_AUTO_NORMAL is enabled, normal
vectors are generated when either GL_MAP2_VERTEX_3 or GL_MAP2_VERTEX_4 is
used to generate vertices.
Errors
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•
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Chapter 11
to control point R . vstride specifies how many float or double locations are
(i+1)j
.
GL_INVALID_ENUM is generated if target is not an accepted value.
GL_INVALID_VALUE is generated if u1 is equal to u2, or if v1 is equal to v2.
GL_INVALID_VALUE is generated if either ustride or vstride is less than the
number of values in a control point.
GL_INVALID_VALUE is generated if either uorder or vorder is less than 1 or
greater than the return value of GL_MAX_EVAL_ORDER.
GL_INVALID_OPERATION is generated if glMap2 is executed between the
execution of glBegin and the corresponding execution of glEnd.
M
glMap2
to control point
ij
281