plgcol0a: Returns 8-bit RGB values and double alpha transparency value for given color index from cmap0

plgcol0a (icol0,
 r,
 g,
 b,
 alpha);
 

Returns 8-bit RGB values (0-255) and double alpha transparency value (0.0 - 1.0) for given color from cmap0 (see the section called “Color Map0”). Values are negative if an invalid color id is given.

icol0 (PLINT, input)

Index of desired cmap0 color.

r (PLINT *, output)

Pointer to 8-bit red value.

g (PLINT *, output)

Pointer to 8-bit green value.

b (PLINT *, output)

Pointer to 8-bit blue value.

alpha (PLFLT *, output)

Pointer to PLFLT alpha transparency value.

This function is used in example 30.