setColorRgbB method
Implementation
void setColorRgbB(PvrtcColorRgb c) {
final r = BitUtility.BITSCALE_8_TO_5_CEIL[c.r];
final g = BitUtility.BITSCALE_8_TO_5_CEIL[c.g];
final b = BitUtility.BITSCALE_8_TO_5_CEIL[c.b];
colorB = r << 10 | g << 5 | b;
colorBIsOpaque = 1;
}