c3f, c3i, c3s, c4f, c4i, c4s - sets the RGB (or RGBA) values for the
current color vector
The subroutines above are functionally the same but declare their
cv For the c4 routines, this parameter expects a four element array
containing RGBA (red, green, blue, and alpha) values. If you use
the c3 routines, this parameter expects a three element array
containing RGB values.
Array components 0, 1, 2, and 3 are red, green, blue, and alpha,
respectively. Floating point RGBA values range from 0.0 through 1.0.
Integer RGBA values range from 0 through 255. Values that exceed
the upper limit are clamped to it. Values that exceed the lower
limit are not clamped, and therefore result in unpredictable
c4 sets the red, green, blue, and alpha color components of the currently
active GL framebuffer, one of normal, popup, overlay, or underlay (see
drawmode). c3 sets red, green, and blue to the specified values, and
sets alpha to the maximum value. The current framebuffer must be in RGB
mode (see RGBmode) for the c command to be applicable. Most drawing
commands copy the current RGBA color components into the color bitplanes
of the current framebuffer. Color components are retained in each draw
mode, so when a draw mode is re-entered, red, green, blue, and alpha are
reset to the last values specified in that draw mode.
Integer color component values range from 0, specifying no intensity,
through 255, specifying maximum intensity. Floating point color
component values range from 0.0, specifying no intensity, through 1.0,
specifying maximum intensity.
It is an error to call c while the current framebuffer is in color map
The color components of all framebuffers in RGB mode are set to zero when
gconfig is called.
cpack, drawmode, lmcolor, gRGBcolor
These routines can also be used to modify the current material while
lighting is active (see lmcolor). Note that clamping to 1.0 is disabled
in this case.
Because only the normal framebuffer currently supports RGB mode, c should
be called only while draw mode is NORMALDRAW. Use getgdesc to determine
whether RGB mode is available in draw mode NORMALDRAW.
On the IRIS-4D/120GTX and IRIS-4D/140GTX, there is problem with the
graphics DMA hardware that can cause data to be sent to the hardware
after the subroutine call has returned. If the data is modified
immediately after the subroutine call, the modified data may get sent
down. To avoid this, don't modify the data until after another n, v, or
c call has been made.
This is an example of the bug:
vertex = 1.0;
v3f(vertex); /* 4D/1x0 GTX hardware may receive 3.0 for the z value */
vertex = 3.0;
This is one way to work around the problem:
vertexA = 1.0;
vertexB = 3.0;
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