/**ColorOpt.c************************************************************ * * * SeePix -- by Hank Schafer * * * * SeePix is an IFF Picture Viewer. It works with Lo-Res, * * Med-Res, Hi-Res, HAM, and EHB formats. I'm working on support * * for X-Specs, and Anim5 formats. * * * * SeePix is based on a program by Olaf Barthel, called * * 'LoadImage'. As released, LoadImage had a couple of bugs. * * The Amiga-Key alternatives to menu use didn't all work. That's * * been fixed. There were two separate print functions in LoadImage * * which behaved exactly the same. The redundancy was eliminated. * * LoadImage used the Topaz ROMFONT, and made no allowances for a * * different system default font (under 2.04). I added a built-in * * font. I've reworked the code considerably from the original * * release, to allow for optimizations based on time and space. * * * * SeePix features a palette tool which allows "tweaking" of colors * * prior to printing, allowing you to modify the color printout to * * more closely resemble the original graphics (Blue is Blue, not * * Purple). SeePix can be Iconified. SeePix features an ARP * * interface. SeePix now uses the PathMaster File Selector. * * * ************************************************************************ * * * SeePix Copyright © 1992 by Hank Schafer; all rights reserved. * * * * This program is free software; you can redistribute it and/or * * modify it under the terms of the GNU General Public License as * * published by the Free Software Foundation, either version 1, or * * (at your option) any later version. * * * * This program is distributed in the hope that it will be useful, * * but WITHOUT ANY WARRANTY; without even the implied warranty of * * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * * General Public License for more details. * * * * You should have received a copy of the GNU General Public License * * along with this program; if not, write to: * * Free Software Foundation, Inc. * * 675 Massachusetts Ave. * * Cambridge MA 02139, USA * * * **************** Special Function Copyright Notices ******************** * * ****LoadImage Copyright Notice: * * * * LoadImage is © Copyright 1988, 1989, 1990 by MXM, all rights * * reserved, written by Olaf Barthel. No guarantees of any kind are * * made that this program is 100% reliable. Use this program on * * your own risk! * * * ****Iconify Copyright Notice: * * * * Copyright 1987 by Leo L. Schwab. * * Permission is hereby granted for use in any and all programs, * * both Public Domain and commercial in nature, provided this * * Copyright notice is left intact. * * * ****ColorWindow (Palette) Copyright Notice: * * * * ColorWindow Routine -- Color Window Routines * * from Book 1 of the Amiga Programmers' Suite by RJ Mical * * * * Copyright (C) 1986, 1987, Robert J. Mical * * All Rights Reserved. * * * ****PathMaster Copyright Notice: * * * * -------------------------------------------------------------------- * * Copyright © 1989 Justin V. McCormick. All Rights Reserved. * * -------------------------------------------------------------------- * * * * The PathMaster name is a trademark of Justin V. McCormick. * * * * PathMaster File Selector source and documentation written by: * * * * Justin V. McCormick. * * Copyright © 1989 by Justin V. McCormick. * * All Rights Reserved. * * * * -------------------------------------------------------------------- * ************************************************************************ * * * Hope this is something you can use and enjoy. * * * ************************************************************************/ /* * HSLToRGB(); RGBToHSL() : * * The functions controlling the HSL<->RGB conversions for the Color Palette. */ WORD HSLToRGB(hue, saturation, luminance) UWORD hue, saturation, luminance; /* * This actually doesn't do true HSL to RGB conversion, but it works close * enough. Also, this code could be optimized quite a bit, but I've left it * spread out like this so that several years from now I will be able to * figure out what the heck is going on. */ { LONG red, green, blue; LONG reddiff, greendiff, bluediff; LONG sixth, rising, falling, invertsaturation; /* * We're going to hold one color off, a second at full, and ramp the * third. This allows us to visit all two-color combinations. By * modifying saturation, all three-color combinations can be seen. */ sixth = hue / 0x2AAB; rising = (hue - (sixth * 0x2AAB)) * 6; falling = 0xFFFF - rising; switch (sixth) { case 0: red = 0xFFFF; green = rising; blue = 0; break; case 1: red = falling; green = 0xFFFF; blue = 0; break; case 2: red = 0; green = 0xFFFF; blue = rising; break; case 3: red = 0; green = falling; blue = 0xFFFF; break; case 4: red = rising; green = 0; blue = 0xFFFF; break; case 5: red = 0xFFFF; green = 0; blue = falling; break; } red = (red * luminance) >> 16; green = (green * luminance) >> 16; blue = (blue * luminance) >> 16; /* * The closer saturation is to zero, the closer red, green and blue * should be to luminance. */ invertsaturation = 0xFFFF - saturation; reddiff = luminance - red; red = red + ((reddiff * invertsaturation) >> 16); greendiff = luminance - green; green = green + ((greendiff * invertsaturation) >> 16); bluediff = luminance - blue; blue = blue + ((bluediff * invertsaturation) >> 16); red = (red >> 12) & 0xF; green = (green >> 12) & 0xF; blue = (blue >> 12) & 0xF; return ((WORD) ((red << 8) | (green << 4) | (blue))); } VOID RGBToHSL(rgb, returnhue, returnsat, returnlum) UWORD rgb; UWORD *returnhue, *returnsat, *returnlum; { LONG min, max, hue, saturation, luminance, differential; LONG redpart, greenpart, bluepart; LONG workred, workgreen, workblue; workred = ((rgb >> 8) & 0xF) * 0x111; workgreen = ((rgb >> 4) & 0xF) * 0x111; workblue = (rgb & 0xF) * 0x111; if (workred < workgreen) min = workred; else min = workgreen; if (workblue < min) min = workblue; if (workred > workgreen) max = workred; else max = workgreen; if (workblue > max) max = workblue; luminance = max; luminance <<= 4; differential = max - min; if (max != 0) { saturation = (differential << 16) / max; if (saturation > 0xFFFF) saturation = 0xFFFF; } else saturation = 0; if (saturation == 0) hue = 0; else { redpart = (((max - workred) << 16) / differential) >> 4; greenpart = (((max - workgreen) << 16) / differential) >> 4; bluepart = (((max - workblue) << 16) / differential) >> 4; if (workred == max) hue = bluepart - greenpart; else if (workgreen == max) hue = 0x2000 + redpart - bluepart; else if (workblue == max) hue = 0x4000 + greenpart - redpart; if (hue < 0) hue += 0x6000; hue = (hue * 2667) / 1000; } *returnhue = hue; *returnsat = saturation; *returnlum = luminance; }