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
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
|
/* This file is part of the GNU plotutils package. Copyright (C) 1995,
1996, 1997, 1998, 1999, 2000, 2005, 2008, Free Software Foundation, Inc.
The GNU plotutils package is free software. You may 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, or (at your
option) any later version.
The GNU plotutils package 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 the GNU plotutils package; see the file COPYING. If not, write to
the Free Software Foundation, Inc., 51 Franklin St., Fifth Floor,
Boston, MA 02110-1301, USA. */
/* This file contains device-specific color database access routines.
These routines are called by various GIFPlotter methods, before drawing
objects. They set the appropriate GIFPlotter-specific fields in the
drawing state. */
#include "sys-defines.h"
#include "extern.h"
/* forward references */
static int bit_depth (int colors);
/* we call this routine to evaluate _plotter->drawstate->i_pen_color_index
lazily, i.e. only when needed (just before a drawing operation) */
void
_pl_i_set_pen_color(S___(Plotter *_plotter))
{
int red_long, green_long, blue_long;
int red, green, blue;
/* 48-bit RGB */
red_long = _plotter->drawstate->fgcolor.red;
green_long = _plotter->drawstate->fgcolor.green;
blue_long = _plotter->drawstate->fgcolor.blue;
/* 24-bit RGB (as used in GIFs) */
red = (((unsigned int)red_long) >> 8) & 0xff;
green = (((unsigned int)green_long) >> 8) & 0xff;
blue = (((unsigned int)blue_long) >> 8) & 0xff;
if (!(_plotter->drawstate->i_pen_color_status
&& _plotter->drawstate->i_pen_color.red == red
&& _plotter->drawstate->i_pen_color.green == green
&& _plotter->drawstate->i_pen_color.blue == blue))
/* need another color index: search table, expand if necessary */
{
unsigned char index;
index = _pl_i_new_color_index (R___(_plotter) red, green, blue);
/* set new 24-bit RGB and color index in the drawing state */
_plotter->drawstate->i_pen_color.red = red;
_plotter->drawstate->i_pen_color.green = green;
_plotter->drawstate->i_pen_color.blue = blue;
_plotter->drawstate->i_pen_color_index = index;
/* flag this color index as genuine */
_plotter->drawstate->i_pen_color_status = true;
}
}
/* we call this routine to evaluate _plotter->drawstate->i_fill_color_index
lazily, i.e. only when needed (just before a filling operation) */
void
_pl_i_set_fill_color(S___(Plotter *_plotter))
{
int red_long, green_long, blue_long;
int red, green, blue;
if (_plotter->drawstate->fill_type == 0)
/* don't do anything, fill color will be ignored when writing objects */
return;
/* 48-bit RGB */
red_long = _plotter->drawstate->fillcolor.red;
green_long = _plotter->drawstate->fillcolor.green;
blue_long = _plotter->drawstate->fillcolor.blue;
/* 24-bit RGB (as used in GIFs) */
red = (((unsigned int)red_long) >> 8) & 0xff;
green = (((unsigned int)green_long) >> 8) & 0xff;
blue = (((unsigned int)blue_long) >> 8) & 0xff;
if (!(_plotter->drawstate->i_fill_color_status
&& _plotter->drawstate->i_fill_color.red == red
&& _plotter->drawstate->i_fill_color.green == green
&& _plotter->drawstate->i_fill_color.blue == blue))
/* need another color index: search table, expand if necessary */
{
unsigned char index;
index = _pl_i_new_color_index (R___(_plotter) red, green, blue);
/* set new 24-bit RGB and color index in the drawing state */
_plotter->drawstate->i_fill_color.red = red;
_plotter->drawstate->i_fill_color.green = green;
_plotter->drawstate->i_fill_color.blue = blue;
_plotter->drawstate->i_fill_color_index = index;
}
}
/* we call this routine to compute and set
_plotter->drawstate->i_bg_color_index, e.g. in _pl_i_new_image */
void
_pl_i_set_bg_color(S___(Plotter *_plotter))
{
int red_long, green_long, blue_long;
int red, green, blue;
/* 48-bit RGB */
red_long = _plotter->drawstate->bgcolor.red;
green_long = _plotter->drawstate->bgcolor.green;
blue_long = _plotter->drawstate->bgcolor.blue;
/* 24-bit RGB (as used in GIFs) */
red = (((unsigned int)red_long) >> 8) & 0xff;
green = (((unsigned int)green_long) >> 8) & 0xff;
blue = (((unsigned int)blue_long) >> 8) & 0xff;
if (!(_plotter->drawstate->i_bg_color_status
&& _plotter->drawstate->i_bg_color.red == red
&& _plotter->drawstate->i_bg_color.green == green
&& _plotter->drawstate->i_bg_color.blue == blue))
/* need another color index: search table, expand if necessary */
{
unsigned char index;
index = _pl_i_new_color_index (R___(_plotter) red, green, blue);
/* set new 24-bit RGB and color index in the drawing state */
_plotter->drawstate->i_bg_color.red = red;
_plotter->drawstate->i_bg_color.green = green;
_plotter->drawstate->i_bg_color.blue = blue;
_plotter->drawstate->i_bg_color_index = index;
/* flag this color index as genuine */
_plotter->drawstate->i_bg_color_status = true;
}
}
/* Internal function, called by each of the above. It searches for a
24-bit RGB in the color table. If not found, it's added to table,
unless table can't be expanded, in which case index with closest RGB is
returned. */
unsigned char
_pl_i_new_color_index (R___(Plotter *_plotter) int red, int green, int blue)
{
int i, j;
int sqdist;
bool found = false;
for (i = 0; i < _plotter->i_num_color_indices; i++)
if (_plotter->i_colormap[i].red == red
&& _plotter->i_colormap[i].green == green
&& _plotter->i_colormap[i].blue == blue)
{
found = true;
break;
}
if (found)
return (unsigned char)i;
/* not found, try to allocate new index */
i = _plotter->i_num_color_indices;
if (i < 256)
{
_plotter->i_colormap[i].red = red;
_plotter->i_colormap[i].green = green;
_plotter->i_colormap[i].blue = blue;
_plotter->i_num_color_indices = i + 1;
/* New bit depth of colormap, e.g. sizes 129..256 get mapped to 8.
In effect the colormap for any of these sizes will be of size 256. */
_plotter->i_bit_depth = bit_depth (i + 1);
return (unsigned char)i;
}
/* table full, do our best */
sqdist = INT_MAX;
i = 0;
for (j = 0; j < 256; j++)
{
int new_sqdist;
int a_red, a_green, a_blue;
a_red = _plotter->i_colormap[j].red;
a_green = _plotter->i_colormap[j].green;
a_blue = _plotter->i_colormap[j].blue;
new_sqdist = ((a_red - red) * (a_red - red)
+ (a_green - green) * (a_green - green)
+ (a_blue - blue) * (a_blue - blue));
if (new_sqdist <= sqdist)
{
sqdist = new_sqdist;
i = j; /* best to date */
}
}
return (unsigned char)i;
}
/* compute number of bits needed to represent all color indices
(when this is called, colors >= 1) */
static int
bit_depth (int colors)
{
int size;
unsigned int ucolors;
/* subtract 1, see how many bits needed to represent result */
size = 0;
for (ucolors = colors - 1; ucolors; ucolors = ucolors >> 1)
size++;
return size;
}
|
