1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
|
/* 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;
}
|
