1/*
2 * wrtarga.c
3 *
4 * This file was part of the Independent JPEG Group's software:
5 * Copyright (C) 1991-1996, Thomas G. Lane.
6 * libjpeg-turbo Modifications:
7 * Copyright (C) 2017, D. R. Commander.
8 * For conditions of distribution and use, see the accompanying README.ijg
9 * file.
10 *
11 * This file contains routines to write output images in Targa format.
12 *
13 * These routines may need modification for non-Unix environments or
14 * specialized applications.  As they stand, they assume output to
15 * an ordinary stdio stream.
16 *
17 * Based on code contributed by Lee Daniel Crocker.
18 */
19
20#include "cdjpeg.h"             /* Common decls for cjpeg/djpeg applications */
21
22#ifdef TARGA_SUPPORTED
23
24
25/*
26 * To support 12-bit JPEG data, we'd have to scale output down to 8 bits.
27 * This is not yet implemented.
28 */
29
30#if BITS_IN_JSAMPLE != 8
31  Sorry, this code only copes with 8-bit JSAMPLEs. /* deliberate syntax err */
32#endif
33
34
35/* Private version of data destination object */
36
37typedef struct {
38  struct djpeg_dest_struct pub; /* public fields */
39
40  char *iobuffer;               /* physical I/O buffer */
41  JDIMENSION buffer_width;      /* width of one row */
42} tga_dest_struct;
43
44typedef tga_dest_struct *tga_dest_ptr;
45
46
47LOCAL(void)
48write_header (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo, int num_colors)
49/* Create and write a Targa header */
50{
51  char targaheader[18];
52
53  /* Set unused fields of header to 0 */
54  MEMZERO(targaheader, sizeof(targaheader));
55
56  if (num_colors > 0) {
57    targaheader[1] = 1;         /* color map type 1 */
58    targaheader[5] = (char) (num_colors & 0xFF);
59    targaheader[6] = (char) (num_colors >> 8);
60    targaheader[7] = 24;        /* 24 bits per cmap entry */
61  }
62
63  targaheader[12] = (char) (cinfo->output_width & 0xFF);
64  targaheader[13] = (char) (cinfo->output_width >> 8);
65  targaheader[14] = (char) (cinfo->output_height & 0xFF);
66  targaheader[15] = (char) (cinfo->output_height >> 8);
67  targaheader[17] = 0x20;       /* Top-down, non-interlaced */
68
69  if (cinfo->out_color_space == JCS_GRAYSCALE) {
70    targaheader[2] = 3;         /* image type = uncompressed grayscale */
71    targaheader[16] = 8;        /* bits per pixel */
72  } else {                      /* must be RGB */
73    if (num_colors > 0) {
74      targaheader[2] = 1;       /* image type = colormapped RGB */
75      targaheader[16] = 8;
76    } else {
77      targaheader[2] = 2;       /* image type = uncompressed RGB */
78      targaheader[16] = 24;
79    }
80  }
81
82  if (JFWRITE(dinfo->output_file, targaheader, 18) != (size_t) 18)
83    ERREXIT(cinfo, JERR_FILE_WRITE);
84}
85
86
87/*
88 * Write some pixel data.
89 * In this module rows_supplied will always be 1.
90 */
91
92METHODDEF(void)
93put_pixel_rows (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
94                JDIMENSION rows_supplied)
95/* used for unquantized full-color output */
96{
97  tga_dest_ptr dest = (tga_dest_ptr) dinfo;
98  register JSAMPROW inptr;
99  register char *outptr;
100  register JDIMENSION col;
101
102  inptr = dest->pub.buffer[0];
103  outptr = dest->iobuffer;
104  for (col = cinfo->output_width; col > 0; col--) {
105    outptr[0] = (char) GETJSAMPLE(inptr[2]); /* RGB to BGR order */
106    outptr[1] = (char) GETJSAMPLE(inptr[1]);
107    outptr[2] = (char) GETJSAMPLE(inptr[0]);
108    inptr += 3, outptr += 3;
109  }
110  (void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width);
111}
112
113METHODDEF(void)
114put_gray_rows (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
115               JDIMENSION rows_supplied)
116/* used for grayscale OR quantized color output */
117{
118  tga_dest_ptr dest = (tga_dest_ptr) dinfo;
119  register JSAMPROW inptr;
120  register char *outptr;
121  register JDIMENSION col;
122
123  inptr = dest->pub.buffer[0];
124  outptr = dest->iobuffer;
125  for (col = cinfo->output_width; col > 0; col--) {
126    *outptr++ = (char) GETJSAMPLE(*inptr++);
127  }
128  (void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width);
129}
130
131
132/*
133 * Write some demapped pixel data when color quantization is in effect.
134 * For Targa, this is only applied to grayscale data.
135 */
136
137METHODDEF(void)
138put_demapped_gray (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
139                   JDIMENSION rows_supplied)
140{
141  tga_dest_ptr dest = (tga_dest_ptr) dinfo;
142  register JSAMPROW inptr;
143  register char *outptr;
144  register JSAMPROW color_map0 = cinfo->colormap[0];
145  register JDIMENSION col;
146
147  inptr = dest->pub.buffer[0];
148  outptr = dest->iobuffer;
149  for (col = cinfo->output_width; col > 0; col--) {
150    *outptr++ = (char) GETJSAMPLE(color_map0[GETJSAMPLE(*inptr++)]);
151  }
152  (void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width);
153}
154
155
156/*
157 * Startup: write the file header.
158 */
159
160METHODDEF(void)
161start_output_tga (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo)
162{
163  tga_dest_ptr dest = (tga_dest_ptr) dinfo;
164  int num_colors, i;
165  FILE *outfile;
166
167  if (cinfo->out_color_space == JCS_GRAYSCALE) {
168    /* Targa doesn't have a mapped grayscale format, so we will */
169    /* demap quantized gray output.  Never emit a colormap. */
170    write_header(cinfo, dinfo, 0);
171    if (cinfo->quantize_colors)
172      dest->pub.put_pixel_rows = put_demapped_gray;
173    else
174      dest->pub.put_pixel_rows = put_gray_rows;
175  } else if (cinfo->out_color_space == JCS_RGB) {
176    if (cinfo->quantize_colors) {
177      /* We only support 8-bit colormap indexes, so only 256 colors */
178      num_colors = cinfo->actual_number_of_colors;
179      if (num_colors > 256)
180        ERREXIT1(cinfo, JERR_TOO_MANY_COLORS, num_colors);
181      write_header(cinfo, dinfo, num_colors);
182      /* Write the colormap.  Note Targa uses BGR byte order */
183      outfile = dest->pub.output_file;
184      for (i = 0; i < num_colors; i++) {
185        putc(GETJSAMPLE(cinfo->colormap[2][i]), outfile);
186        putc(GETJSAMPLE(cinfo->colormap[1][i]), outfile);
187        putc(GETJSAMPLE(cinfo->colormap[0][i]), outfile);
188      }
189      dest->pub.put_pixel_rows = put_gray_rows;
190    } else {
191      write_header(cinfo, dinfo, 0);
192      dest->pub.put_pixel_rows = put_pixel_rows;
193    }
194  } else {
195    ERREXIT(cinfo, JERR_TGA_COLORSPACE);
196  }
197}
198
199
200/*
201 * Finish up at the end of the file.
202 */
203
204METHODDEF(void)
205finish_output_tga (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo)
206{
207  /* Make sure we wrote the output file OK */
208  fflush(dinfo->output_file);
209  if (ferror(dinfo->output_file))
210    ERREXIT(cinfo, JERR_FILE_WRITE);
211}
212
213
214/*
215 * Re-calculate buffer dimensions based on output dimensions.
216 */
217
218METHODDEF(void)
219calc_buffer_dimensions_tga (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo)
220{
221  tga_dest_ptr dest = (tga_dest_ptr) dinfo;
222
223  dest->buffer_width = cinfo->output_width * cinfo->output_components;
224}
225
226
227/*
228 * The module selection routine for Targa format output.
229 */
230
231GLOBAL(djpeg_dest_ptr)
232jinit_write_targa (j_decompress_ptr cinfo)
233{
234  tga_dest_ptr dest;
235
236  /* Create module interface object, fill in method pointers */
237  dest = (tga_dest_ptr)
238      (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
239                                  sizeof(tga_dest_struct));
240  dest->pub.start_output = start_output_tga;
241  dest->pub.finish_output = finish_output_tga;
242  dest->pub.calc_buffer_dimensions = calc_buffer_dimensions_tga;
243
244  /* Calculate output image dimensions so we can allocate space */
245  jpeg_calc_output_dimensions(cinfo);
246
247  /* Create I/O buffer. */
248  dest->pub.calc_buffer_dimensions (cinfo, (djpeg_dest_ptr) dest);
249  dest->iobuffer = (char *)
250    (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
251                                (size_t) (dest->buffer_width * sizeof(char)));
252
253  /* Create decompressor output buffer. */
254  dest->pub.buffer = (*cinfo->mem->alloc_sarray)
255    ((j_common_ptr) cinfo, JPOOL_IMAGE, dest->buffer_width, (JDIMENSION) 1);
256  dest->pub.buffer_height = 1;
257
258  return (djpeg_dest_ptr) dest;
259}
260
261#endif /* TARGA_SUPPORTED */
262