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/* ScummVM - Scumm Interpreter
* Copyright (C) 2002 The ScummVM project
*
* 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 2
* of the License, 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 the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* $Header$
*/
#include "stdafx.h"
#include "util.h"
//
// 8-bit alpha blending routines
//
static int BlendCache[256][256];
//
// Find the entry in the given palette which matches the color defined by
// the tripel (r,b,g) most closely.
//
int RGBMatch(byte *palette, int r, int g, int b)
{
int i, bestidx = 0, besterr = 0xFFFFFF;
int error = 0;
for (i = 0;i < 256;i++) {
byte *pal = palette + (i * 3);
int r_diff = r - (int)*pal++;
int g_diff = g - (int)*pal++;
int b_diff = b - (int)*pal++;
r_diff *= r_diff; g_diff *= g_diff; b_diff *= b_diff;
error = r_diff + g_diff + b_diff;
if (error < besterr) {
besterr = error;
bestidx = i;
}
}
return bestidx;
}
//
// Blend two 8 bit colors into a third, all colors being defined by palette indices.
//
int Blend(int src, int dst, byte *palette)
{
int r, g, b;
int alpha = 128; // Level of transparency [0-256]
byte *srcpal = palette + (dst * 3);
byte *dstpal = palette + (src * 3);
if (BlendCache[dst][src] > -1)
return BlendCache[dst][src];
r = (*srcpal++ * alpha);
r += (*dstpal++ * (256-alpha));
r /= 256;
g = (*srcpal++ * alpha);
g += (*dstpal++ * (256-alpha));
g /= 256;
b = (*srcpal++ * alpha);
b += (*dstpal++ * (256-alpha));
b /= 256;
return (BlendCache[dst][src] = RGBMatch(palette, r , g , b ));
}
//
// Reset the blending cache
//
void ClearBlendCache(byte *palette, int weight)
{
for (int i = 0; i < 256; i++)
for (int j = 0 ; j < 256 ; j++)
// BlendCache[i][j] = i; // No alphablending
// BlendCache[i][j] = j; // 100% translucent
BlendCache[i][j] = -1; // Enable alphablending
}
//
// Print hexdump of the data passed in, 8 bytes a row
//
void hexdump(const byte * data, int len)
{
int i;
byte c;
while (len >= 8) {
for (i = 0; i < 8; i++)
printf("%02x ", data[i]);
printf(" |");
for (i = 0; i < 8; i++) {
c = data[i];
if (c < 32 || c >= 127)
c = '.';
printf("%c", c);
}
printf("|\n");
data += 8;
len -= 8;
}
if (len <= 0)
return;
for (i = 0; i < len; i++)
printf("%02x ", data[i]);
for (; i < 8; i++)
printf(" ");
printf(" |");
for (i = 0; i < len; i++) {
c = data[i];
if (c < 32 || c >= 127)
c = '.';
printf("%c", c);
}
for (; i < 8; i++)
printf(" ");
printf("|\n");
}
//
// Given a pointer to a Scumm resource, this function returns the length
// of the (string) data in that resource. To do so it understands certain
// special chars starting with FF. The reason for this function is that
// sometimes resource data will contain 0 bytes, thus we can't just use strlen.
//
int resStrLen(const char *src)
{
int num = 0;
byte chr;
while ((chr = *src++) != 0) {
num++;
if (chr == 255) {
chr = *src++;
num++;
if (chr != 1 && chr != 2 && chr != 3 && chr != 8) {
src += 2;
num += 2;
}
}
}
return num;
}
RandomSource::RandomSource(uint32 seed)
{
_randSeed = seed;
}
void RandomSource::setSeed(uint32 seed)
{
_randSeed = seed;
}
uint RandomSource::getRandomNumber(uint max)
{
/* TODO: my own random number generator */
_randSeed = 0xDEADBF03 * (_randSeed + 1);
_randSeed = (_randSeed >> 13) | (_randSeed << 19);
return _randSeed % (max + 1);
}
uint RandomSource::getRandomNumberRng(uint min, uint max)
{
return getRandomNumber(max - min) + min;
}
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