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
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
|
/*
render/tgafile.cc
This file is part of the Osirion project and is distributed under
the terms of the GNU General Public License version 2
*/
/*
Documentation and examples on the TGA file format:
http://www.dca.fee.unicamp.br/~martino/disciplinas/ea978/tgaffs.pdf
http://www.fileformat.info/format/tga/egff.htm
http://www.morrowland.com/apron/tut_gl.php
Notes
TGA image type Colormap RLE
0 No image data included in file No No
1 Colormapped image data Yes No
2 Truecolor image data No No
3 Monochrome image data No No
9 Colormapped image data Yes Yes
10 Truecolor image data No Yes
11 Monochrome image data No Yes
TGA multi-byte integer values have LSB first
*/
#include <string.h>
#include <fstream>
#include <sstream>
#include <string>
#include "sys/sys.h"
#include "filesystem/filesystem.h"
#include "render/tgafile.h"
const unsigned char TGA_NONE = 0;
const unsigned char TGA_TRUECOLOR = 2;
const unsigned char TGA_TRUECOLOR_RLE = 10;
namespace render
{
Image *TGA::load(const char *filename)
{
Image *image = 0;
if (!filename)
return 0;
filesystem::File *tga_file = filesystem::open(filename);
if (!tga_file) {
//con_warn << "Could not open " << filename << std::endl;
return 0;
}
// TGA header
unsigned char header[18];
memset(header, 0, sizeof(header));
if (!tga_file->read(header, 18)) {
con_warn << "Error reading " << filename << std::endl;
filesystem::close(tga_file);
return 0;
}
// byte 0 - image ID field length
unsigned int tga_idlength = header[0];
// byte 1 - color map type
unsigned int tga_colormap = header[1];
// byte 2 - image type
unsigned int tga_type = header[2];
// byte 3+4 - color map first entry index
//unsigned int tga_colormap_first = header[3] + (header[4] << 8 );
// byte 5+6 - color map length (in bits)
unsigned int tga_color_map_length = header[5] + (header[6] << 8);
// byte 7 - color map entry length
unsigned int tga_colormap_entry = header[7];
// byte 8+9 - image x origin
// byte 10+11 - image y origin
// byte 12+13 - image width (LSB first)
unsigned int tga_width = header[12] + (header[13] << 8);
// byte 14+15 - image height (LSB first)
unsigned int tga_height = header[14] + (header[15] << 8);
// byte 16 - image color depth (in bits)
unsigned int tga_depth = header[16];
// byte 17 - image descriptor byte
unsigned int tga_descriptor = header[17];
// read the image id if there is one
if (tga_idlength)
tga_file->skip(tga_idlength);
// read color map data (even for non-color mapped images)
if (tga_colormap) {
if (tga_colormap > 1)
con_warn << filename << ": invalid color map type!" << std::endl;
tga_file->skip(tga_color_map_length*tga_colormap_entry);
}
// FIXME channels should be a sane value
unsigned int index = 0;
unsigned int channels = tga_depth / 8;
switch (tga_type) {
case TGA_NONE:
con_warn << "Error reading " << filename
<< ": no image data!" << std::endl;
filesystem::close(tga_file);
return 0;
break;
case TGA_TRUECOLOR:
if ((tga_depth == 24) || (tga_depth == 32)) {
image = new Image(tga_width, tga_height, channels);
for (size_t i = 0; i < tga_width * tga_height; i++) {
tga_file->read((void *)(*image)[i*(size_t)channels], channels);
}
image->swap_channels();
} else if (tga_depth == 16) {
channels = 3;
image = new Image(tga_width, tga_height, channels);
for (size_t i = 0; i < tga_width * tga_height; i++) {
// unpack one pixel
unsigned char pixel_data[2];
tga_file->read((void *)pixel_data, 2);
unsigned int unpacked = pixel_data[0] + pixel_data[1] * 0xff;
unsigned int b = (unpacked & 0x1f) << 3;
unsigned int g = ((unpacked >> 5) & 0x1f) << 3;
unsigned int r = ((unpacked >> 10) & 0x1f) << 3;
// store it
image->ptr()[i * channels] = (unsigned char) b;
image->ptr()[i * channels+1] = (unsigned char) g;
image->ptr()[i * channels+2] = (unsigned char) r;
}
} else {
con_warn << "Error reading " << filename
<< ": unsupported image depth '" << tga_depth << "'!" << std::endl;
filesystem::close(tga_file);
return 0;
}
break;
case TGA_TRUECOLOR_RLE:
image = new Image(tga_width, tga_height, channels);
while (index < tga_width * tga_height) {
unsigned char rle = 0;
unsigned char pixel_data[4];
// read RLE packet byte
tga_file->read(&rle, 1);
if (rle < 128) {
rle++; // rle contains the number of pixels-1
tga_file->read((void *)(*image)[index*channels], rle*channels);
index += rle;
} else {
rle -= 127; // rle contains 128 + the number of identical pixels-1
tga_file->read(pixel_data, channels);
while (rle > 0) {
memcpy((void *)(*image)[index*channels], (void *)pixel_data, channels);
index++;
rle--;
}
}
}
image->swap_channels();
break;
default:
con_warn << "Error reading " << filename
<< ": unsupported TGA type '" << (int) tga_type << "'!" << std::endl;
filesystem::close(tga_file);
return 0;
}
filesystem::close(tga_file);
if ((tga_descriptor & 0x20) == 0x0) {
// origin at bottom left
image->flip_vertical();
}
if ((tga_descriptor & 0x10) == 0x10) {
con_warn << filename << ": descriptor bit 4 (left-right) set!" << std::endl;
}
con_debug << " " << filename << " " << image->width() << "x" << image->height() << "x" << image->bpp() << "bpp" << std::endl;
return image;
}
void TGA::save(const char *filename, Image & image)
{
if (!filename)
return;
std::ofstream ofs(filename, std::ios_base::out | std::ios_base::binary);
if (!ofs.is_open()) {
con_warn << "Could not write " << filename << std::endl;
return;
}
// write TGA header
unsigned char header[18];
memset(header, 0, sizeof(header));
// byte 0 - image ID field length = 0 (no image ID field present)
// byte 1 - color map type = 0 (no palette present)
// byte 2 - image type = 10 (truecolor RLE encoded)
header[2] = TGA_TRUECOLOR_RLE;
// byte 3-11 - palette data (not used)
// byte 12+13 - image width
header[12] = (image.width() & 0xff);
header[13] = ((image.width() >> 8) & 0xff);
// byte 14+15 - image height
header[14] = (image.height() & 0xff);
header[15] = ((image.height() >> 8) & 0xff);
// byte 16 - image color depth = 24 (RGB) or 32 (RGBA)
header[16] = image.channels() * 8;
// byte 17 - image descriptor byte = 0x20 (origin at bottom left)
header[17] = 0x20;
// write header
ofs.write((char *)header, sizeof(header));
// write image data
// TGA has the R and B channels switched
unsigned char pixel_data[image.channels()];
unsigned char block_data[image.channels()*128];
unsigned char rle_packet;
bool compress = false;
size_t block_length = 0;
for (int y = image.height() - 1; y >= 0; y--) {
for (size_t x = 0; x < image.width(); x++) {
size_t index = y * image.width() * image.channels() + x * image.channels();
pixel_data[0] = *image[index+2];
pixel_data[1] = *image[index+1];
pixel_data[2] = *image[index];
if (image.channels() == 4)
pixel_data[3] = *image[index+3];
if (block_length == 0) {
// if the block is empty, copy the first pixel
memcpy(block_data, pixel_data, image.channels());
block_length++;
// by default, the block is not compressed
compress = false;
} else {
// if the current block is not compressed
if (!compress) {
// if the previous pixel differs from the pixel data
if (memcmp(&block_data[(block_length-1)*image.channels()], pixel_data, image.channels()) != 0) {
// append pixel
memcpy(&block_data[block_length*image.channels()], pixel_data, image.channels());
block_length++;
} else {
// uncompressed block and pixel data is identical
if (block_length > 1) {
// write the uncompressed block
rle_packet = block_length - 2;
ofs.write((char *)&rle_packet, 1);
ofs.write((char *)block_data, (block_length - 1) * image.channels());
block_length = 1;
}
// create a commpressed block
memcpy(block_data, pixel_data, image.channels());
block_length++;
compress = true;
}
// if the current block is compressed
} else {
// if the previous pixel and the pixel data are identical
if (memcmp(block_data, pixel_data, image.channels()) == 0) {
block_length++;
} else {
// compressed block and pixel data differs
if (block_length > 1) {
// write the compressed block
rle_packet = block_length + 127;
ofs.write((char *)&rle_packet, 1);
ofs.write((char *)block_data, image.channels());
block_length = 0;
}
memcpy(&block_data[block_length * image.channels()], pixel_data, image.channels());
block_length++;
compress = false;
}
}
}
if (block_length == 128) {
rle_packet = block_length - 1;
if (!compress) {
ofs.write((char *)&rle_packet, 1);
ofs.write((char *)block_data, 128 * image.channels());
} else {
rle_packet += 128;
ofs.write((char *)&rle_packet, 1);
ofs.write((char *)block_data, image.channels());
}
block_length = 0;
compress = false;
}
}
}
// write remaining bytes
if (block_length) {
rle_packet = block_length - 1;
if (!compress) {
ofs.write((char *)&rle_packet, 1);
ofs.write((char *)block_data, block_length * image.channels());
} else {
rle_packet += 128;
ofs.write((char *)&rle_packet, 1);
ofs.write((char *)block_data, image.channels());
}
}
// write footer (optional, but the specification recommends it)
char footer[26];
memset(footer, 0, sizeof(footer));
strncpy(&footer[8] , "TRUEVISION-XFILE", 16);
footer[24] = '.';
footer[25] = 0;
ofs.write(footer, sizeof(footer));
// close file
ofs.close();
}
}
|