File: tga.c

package info (click to toggle)
xli 1.17.0+20061110-5
  • links: PTS, VCS
  • area: main
  • in suites: bullseye, buster, sid
  • size: 1,540 kB
  • sloc: ansic: 25,840; makefile: 11
file content (405 lines) | stat: -rw-r--r-- 9,815 bytes parent folder | download | duplicates (6)
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
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
/* #ident   "@(#)x11:contrib/clients/xloadimage/tga.c 1.2 93/07/28 Labtam" */
/*
 * Read a TrueVision Targa file.
 *
 * Created for xli by Graeme Gill,
 *
 * partially based on tgatoppm Copyright by Jef Poskanzer,
 *
 * which was partially based on tga2rast, version 1.0, by Ian MacPhedran.
 *
 */

#include "xli.h"
#include "imagetypes.h"
#include "tga.h"

/* Read the header of the file, and */
/* Return TRUE if this looks like a tga file */
/* Note that since Targa files don't have a magic number, */
/* we have to be pickey about this. */
static boolean
read_tgaHeader(ZFILE *zf, tgaHeader *hp, char *name)
{
	unsigned char buf[18];

	if(zread(zf, buf, TGA_HEADER_LEN) != TGA_HEADER_LEN)
		return FALSE;

	hp->IDLength = (unsigned int)buf[0];
	hp->CoMapType = (unsigned int)buf[1];
	hp->ImgType = (unsigned int)buf[2];
	hp->Index = (unsigned int)buf[3] + 256 * (unsigned int)buf[4];
	hp->Length = (unsigned int)buf[5] + 256 * (unsigned int)buf[6];
	hp->CoSize = (unsigned int)buf[7];
	hp->X_org = (int)buf[8] + 256 * (int)buf[9];
	hp->Y_org = (int)buf[10] + 256 * (int)buf[11];
	hp->Width = (unsigned int)buf[12] + 256 * (unsigned int)buf[13];
	hp->Height = (unsigned int)buf[14] + 256 * (unsigned int)buf[15];
	hp->PixelSize = (unsigned int)buf[16];
	hp->AttBits = (unsigned int)buf[17] & 0xf;
	hp->Rsrvd = ( (unsigned int)buf[17] & 0x10 ) >> 4;
	hp->OrgBit = ( (unsigned int)buf[17] & 0x20 ) >> 5;
	hp->IntrLve = ( (unsigned int)buf[17] & 0xc0 ) >> 6;

	/* See if it is consistent with a tga files */

	if(   hp->CoMapType != 0
	   && hp->CoMapType != 1)
		return FALSE;

	if(   hp->ImgType != 1
	   && hp->ImgType != 2
	   && hp->ImgType != 3
	   && hp->ImgType != 9
	   && hp->ImgType != 10
	   && hp->ImgType != 11)
		return FALSE;

	if(   hp->CoSize != 0
	   && hp->CoSize != 15
	   && hp->CoSize != 16
	   && hp->CoSize != 24
	   && hp->CoSize != 32)
		return FALSE;

	if(   hp->PixelSize != 8
	   && hp->PixelSize != 16
	   && hp->PixelSize != 24
	   && hp->PixelSize != 32)
		return FALSE;

	if(   hp->IntrLve != 0
	   && hp->IntrLve != 1
	   && hp->IntrLve != 2)
		return FALSE;

	/* Do a few more consistency checks */
	if(hp->ImgType == TGA_Map ||
		hp->ImgType == TGA_RLEMap)
		{
		if(hp->CoMapType != 1 || hp->CoSize == 0)
			return FALSE;	/* map types must have map */
		}
	else
		{
		if(hp->CoMapType != 0 || hp->CoSize != 0)
			return FALSE;	/* non-map types must not have map */
		}

	/* can only handle 8 or 16 bit pseudo color images */
	if(hp->CoMapType != 0 && hp->PixelSize > 16)
		return FALSE;

	/* other numbers mustn't be silly */
	if(   (hp->Index + hp->Length) > 65535	
	   || (hp->X_org + hp->Width) > 65535
	   || (hp->Y_org + hp->Height) > 65535)
		return FALSE;

	/* setup run-length encoding flag */
	if(   hp->ImgType == TGA_RLEMap 
	   || hp->ImgType == TGA_RLERGB
	   || hp->ImgType == TGA_RLEMono)
		hp->RLE = TRUE;
	else
		hp->RLE = FALSE;

	hp->name = name;
	return TRUE;
	}

/* Print a brief description of the image */
static void
tell_about_tga(tgaHeader *hp)
{
	char colors[40];

	if (hp->ImgType == TGA_Map || hp->ImgType == TGA_RLEMap)
		sprintf(colors," with %d colors",hp->Length);
	else
		colors[0] = '\000';

	printf("%s is a %dx%d %sTarga %simage%s\n",
	    hp->name,
	    hp->Width, hp->Height,
		TGA_IL_TYPE(hp->IntrLve),
		TGA_IMAGE_TYPE(hp->ImgType),
		colors);
	}

int tgaIdent(char *fullname, char *name)
{
	ZFILE *zf;
	tgaHeader hdr;

	if(!(zf = zopen(fullname)))
		{
		perror("tgaIdent");
		return(0);
		}
	if (!read_tgaHeader(zf,&hdr,name))
		{
		zclose(zf);
		return 0;		/* Nope, not a Targa file */
		}
	tell_about_tga(&hdr);
	zclose(zf);
	return 1;
	}

Image *tgaLoad(char *fullname, ImageOptions *image_ops, boolean verbose)
{
	ZFILE  *zf;
	tgaHeader hdr;
	Image  *image;
	int span,hretrace,vretrace,nopix,x,y;
	byte *data,*eoi;
	unsigned int rd_count,wr_count;

	if(!(zf = zopen(fullname)))
		{
		perror("tgaIdent");
		return(0);
		}
	if(!read_tgaHeader(zf,&hdr,image_ops->name))
		{
		zclose(zf);
		return NULL;		/* Nope, not a Targa file */
		}
	if(verbose)
		tell_about_tga(&hdr);
	znocache(zf);

	/* Skip the identifier string */
	if(hdr.IDLength)
		{
		byte buf[256];
		if(zread(zf, buf, hdr.IDLength) != hdr.IDLength)
			{
			fprintf(stderr, "tgaLoad: %s - Short read within Identifier String\n",hdr.name);
			zclose(zf);
			return NULL;
			}
		}

	/* Create the appropriate image and colormap */
	if(hdr.CoMapType != 0)	/* must be 8 or 16 bit mapped type */
		{
		int i,n=0;
		byte buf[4];
		int used = (1 << hdr.PixelSize);	/* maximum numnber of colors */

		image= newRGBImage(hdr.Width, hdr.Height, hdr.PixelSize);
  		image->title= dupString(hdr.name);
		for(i = 0; i < hdr.Index; i++)	/* init bottom of colormap */
			{
			image->rgb.red[i]=
			image->rgb.green[i]=
			image->rgb.blue[i]= 0;
			}
		switch (hdr.CoSize)
			{
			case 8:		/* Gray scale color map */
				for(; i < ( hdr.Index + hdr.Length ); i++)
					{
					if(zread(zf, buf, 1) != 1)
						{
						fprintf(stderr, "tgaLoad: %s - Short read within Colormap\n",hdr.name);
						freeImage(image);
						zclose(zf);
						return NULL;
						}
					image->rgb.red[i]=
					image->rgb.green[i]=
					image->rgb.blue[i]= buf[0] << 8;
					}
			break;
	
			case 16:	/* 5 bits of RGB */
			case 15:
				for(i = hdr.Index; i < ( hdr.Index + hdr.Length ); i++)
					{
					if(zread(zf, buf, 2) != 2)
						{
						fprintf(stderr, "tgaLoad: %s - Short read within Colormap\n",hdr.name);
						freeImage(image);
						zclose(zf);
						return NULL;
						}
					image->rgb.red[i]= (buf[1] & 0x7c) << 6;
					image->rgb.green[i]= ((buf[1] & 0x03)<< 11) + ((buf[0] & 0xe0)<< 3);
					image->rgb.blue[i]= (buf[0] & 0x1f)<< 8;
					}
				break;
	
			case 32:	/* 8 bits of RGB */
				n = 1;
			case 24:
				n += 3;
				for(i = hdr.Index; i < ( hdr.Index + hdr.Length ); i++)
					{
					if(zread(zf, buf, n) != n)
						{
						fprintf(stderr, "tgaLoad: %s - Short read within Colormap\n",hdr.name);
						freeImage(image);
						zclose(zf);
						return NULL;
						}
					image->rgb.red[i]= buf[2] << 8;
					image->rgb.green[i]= buf[1] << 8;
					image->rgb.blue[i]= buf[0] << 8;
					}
				break;
			}
		for(; i < used; i++)	/* init rest of colormap */
			{
			image->rgb.red[i]=
			image->rgb.green[i]=
			image->rgb.blue[i]= 0;
			}
		/* Don't know how many colors are actually used. */
		/* (believing the header caould cause a fault) */
		/* compress() will figure it out. */
  		image->rgb.used= used;		/* so use max possible */
		}
	else if(hdr.PixelSize == 8)		/* Have to handle gray as pseudocolor */
		{
		int i;

		image= newRGBImage(hdr.Width, hdr.Height, 8);
  		image->title= dupString(hdr.name);
		for(i = 0; i < 256; i++)
			{
			image->rgb.red[i]=
			image->rgb.green[i]=
			image->rgb.blue[i]= i << 8;
			}
  		image->rgb.used= 256;
		}
	else	/* else must be a true color image */
		{
		image= newTrueImage(hdr.Width, hdr.Height);
  		image->title= dupString(hdr.name);
		}

	/* work out virtical advance and retrace */
	if(hdr.OrgBit)	/* if upper left */
		span = hdr.Width;
	else
		span = -hdr.Width;

	if (hdr.IntrLve == TGA_IL_Four )
		hretrace = 4 * span - hdr.Width;	
	else if(hdr.IntrLve == TGA_IL_Two )
		hretrace = 2 * span - hdr.Width;	
	else
		hretrace = span - hdr.Width;	
	vretrace = (hdr.Height-1) * -span;

	nopix = (hdr.Width * hdr.Height);	/* total number of pixels */

	hretrace *= image->pixlen;	/* scale for byes per pixel */
	vretrace *= image->pixlen;
	span *= image->pixlen;

	if(hdr.OrgBit)	/* if upper left */
		{
		data = image->data;
		eoi = image->data + (nopix * image->pixlen);
		}
	else
		{
		eoi = image->data + span;
		data = image->data + (nopix * image->pixlen) + span;
		}

	/* Now read in the image data */
	rd_count = wr_count = 0;
	if (!hdr.RLE)	/* If not rle, all are literal */
		wr_count = rd_count = nopix;
	for(y = hdr.Height; y > 0; y--, data += hretrace)
		{
		byte buf[6];	/* 0, 1 for pseudo, 2, 3, 4 for BGR */

		if (data == eoi)		/* adjust for possible retrace */
			{
			data += vretrace;
			eoi += span;
			}

		/* Do another line of pixels */
		for(x = hdr.Width; x > 0; x--)
			{
			if(wr_count == 0)
				{ /* Deal with run length encoded. */
				if(zread(zf, buf, 1) != 1)
					goto data_short;
				if(buf[0] & 0x80)
					{	/* repeat count */
					wr_count = (unsigned int)buf[0] - 127;	/* no. */
					rd_count = 1;	/* need to read pixel to repeat */
					}
				else	/* number of literal pixels */
					{
					wr_count = 
					rd_count = buf[0] + 1;
					}
				}
			if(rd_count != 0)
				{		/* read a pixel and decode into RGB */
				switch (hdr.PixelSize)
					{
					case 8:	/* Pseudo or Gray */
						if(zread(zf, buf, 1) != 1)
							goto data_short;
					break;
			
					case 16:	/* 5 bits of RGB or 16 pseudo color */
					case 15:
						if(zread(zf, buf, 2) != 2)
							goto data_short;
						buf[2] = buf[0] & 0x1F;		/* B */
						buf[3] = ((buf[1] & 0x03) << 3) + ((unsigned)(buf[0] & 0xE0) >> 5);	/* G */
						buf[4] = (unsigned)(buf[1] & 0x7C) >> 2;	/* R */
					break;
			
					case 24:	/* 8 bits of B G R */
						if(zread(zf, &buf[2], 3) != 3)
							goto data_short;
					break;

					case 32:	/* 8 bits of B G R + alpha */
						if(zread(zf, &buf[2], 4) != 4)
							goto data_short;
					break;
					}
				rd_count--;
				}
			switch (image->pixlen)
				{
				case 1:					/* 8 bit pseudo or gray */
					*data++ = buf[0];
					break;
				case 2:					/* 16 bit pseudo */
					*data++ = buf[1];	/* tga is little endian, */
					*data++ = buf[0];	/* xli is big endian */
					break;
				case 3:					/* True color */
					*data++ = buf[4];	/* R */
					*data++ = buf[3];	/* G */
					*data++ = buf[2];	/* B */
					break;
				}
			wr_count--;
			}
		}
	zclose(zf);
	return image;

data_short:
	fprintf(stderr, "tgaLoad: %s - Short read within Data\n",hdr.name);
	zclose(zf);
	return image;
	}