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/*
* Copyright (c) 1995 The Regents of the University of California.
* All rights reserved.
*
* Permission to use, copy, modify, and distribute this software and its
* documentation for any purpose, without fee, and without written agreement is
* hereby granted, provided that the above copyright notice and the following
* two paragraphs appear in all copies of this software.
*
* IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR
* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT
* OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE UNIVERSITY OF
* CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
* ON AN "AS IS" BASIS, AND THE UNIVERSITY OF CALIFORNIA HAS NO OBLIGATION TO
* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
*/
/* This file contains C code to implement an ordered dither. */
#include "video.h"
#include "proto.h"
#include "rgbl.h"
int r_values[R_RANGE];
int b_values[B_RANGE];
int g_values[G_RANGE];
void
InitRGBLColor()
{
int i;
for (i=0; i<R_RANGE; i++) {
r_values[i] = ((i * 256) / (R_RANGE)) + (256/(R_RANGE*2));
}
for (i=0; i<G_RANGE; i++) {
g_values[i] = ((i * 256) / (G_RANGE)) + (256/(G_RANGE*2));
}
for (i=0; i<B_RANGE; i++) {
b_values[i] = ((i * 256) / (B_RANGE)) + (256/(B_RANGE*2));
}
}
static unsigned char *r_pix_a;
static unsigned char *g_pix_a;
static unsigned char *b_pix_a;
double chrom_mult;
double lum_mult;
double chrom_add;
double lum_add;
void
InitRGBLDither()
{
int y, ch, indx, r, b, g;
double fl, fch, fr, fb, fcr, fcb, fg;
r_pix_a = (unsigned char *) malloc(256*256*sizeof(char));
g_pix_a = (unsigned char *) malloc(256*256*sizeof(char));
b_pix_a = (unsigned char *) malloc(256*256*sizeof(char));
for (y = 0; y<256; y++) {
for (ch = 0; ch<256; ch++) {
indx = ((y << 8) | ch);
fl = (double) y;
fl *= lum_mult;
fl += lum_add;
fch = ((double) ch) - 128.0;
fch *= chrom_mult;
fch += chrom_add;
fr = fl + (1.40200 * fch);
fb = fl + (1.77200 * fch);
if (fr < 0.0) fr = 0.0;
else if (fr > 255.0) fr = 255.0;
if (fb < 0.0) fb = 0.0;
else if (fb > 255.0) fb = 255.0;
r = ((int) fr);
b = ((int) fb);
r = (r * R_RANGE) / 256;
b = (b * B_RANGE) / 256;
r_pix_a[indx] = r_values[r];
b_pix_a[indx] = b_values[b];
r = ch & 0xf0;
b = (ch & 0x0f) << 4;
fcr = ((double) r) - 128.0;
fcb = ((double) b) - 128.0;
fcr *= chrom_mult;
fcb *= chrom_mult;
fcr += chrom_add;
fcb += chrom_add;
fg = fl - (0.71414 * fcb) - (0.34414 * fcr);
if (fg < 0.0) fg = 0.0;
else if (fg > 255.0) fg = 255.0;
g = ((int) fg);
g = (g * G_RANGE) / 256;
g_pix_a[indx] = g_values[g];
}
}
}
void RGBLDitherImage(lum, cr, cb, out, h, w)
unsigned char *lum;
unsigned char *cr;
unsigned char *cb;
unsigned char *out;
int w, h;
{
unsigned char *o1, *o2, *o3, *o4, *o5, *o6, *l1, *l2;
int i, j, l1_val, l2_val, g_val;
int wadd;
wadd = 15*w;
o1 = out;
o2 = (out + (3*w));
o3 = (out + (6*w));
o4 = (out + (9*w));
o5 = (out + (12*w));
o6 = (out + (15*w));
l1 = lum;
l2 = lum+w;
for (i=0; i<h; i+=2) {
for (j=0; j<w; j+= 2) {
l1_val = (*l1++) << 8;
l2_val = (*l2++) << 8;
g_val = ((*cr) & 0xf0) | ((*cb) >> 4);
o2[0] = o1[2] = o3[2] = r_pix_a[(l1_val | (*cb))];
o2[1] = o2[2] = g_pix_a[(l1_val | g_val)];
o1[0] = o1[1] = o3[0] = o3[1] = b_pix_a[(l1_val | (*cr))];
o4[0] = o5[2] = o6[0] = r_pix_a[(l2_val | (*cb))];
o4[1] = o4[2] = o6[1] = o6[2] = g_pix_a[(l2_val | g_val)];
o5[0] = o5[1] = b_pix_a[(l2_val | (*cr))];
l1_val = (*l1++) << 8;
l2_val = (*l2++) << 8;
o1[3] = o2[5] = o3[3] = r_pix_a[(l1_val | (*cb))];
o1[4] = o1[5] = o3[4] = o3[5] = g_pix_a[(l1_val | g_val)];
o2[3] = o2[4] = b_pix_a[(l1_val | (*cr))];
o4[5] = o5[3] = o6[5] = r_pix_a[(l2_val | (*cb++))];
o5[4] = o5[5] = g_pix_a[(l2_val | g_val)];
o4[3] = o4[4] = o6[3] = o6[4] = b_pix_a[(l2_val | (*cr++))];
o1 +=6; o2 +=6; o3 += 6; o4 += 6; o5 += 6; o6 += 6;
}
l1 += w;
l2 += w;
o1 += wadd;
o2 += wadd;
o3 += wadd;
o4 += wadd;
o5 += wadd;
o6 += wadd;
}
}
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