gcpBlendColor - Color blending
#include <ggi/gcp.h> gcp_pixel gcpBlendColor(ggi_visual_t vis, const gcp_pixel *pix1, const gcp_pixel *pix2, uint16_t alpha);
gcpBlendColor blends pix2 over pix1 with the translucency alpha, with pix1 as the background, pix2 the forground. alpha is a 16bit translucency channel.
gcpBlendColor returns the resulting gcp_pixel(3) value.