754372f23b35e40b22d22c2d2961c0a96090dac4
1 #define __SP_PNG_WRITE_C__
3 /*
4 * PNG file format utilities
5 *
6 * Authors:
7 * Lauris Kaplinski <lauris@kaplinski.com>
8 * Whoever wrote this example in libpng documentation
9 *
10 * Copyright (C) 1999-2002 authors
11 *
12 * Released under GNU GPL, read the file 'COPYING' for more information
13 */
15 #ifdef HAVE_CONFIG_H
16 # include "config.h"
17 #endif
19 #include <interface.h>
20 #include <libnr/nr-pixops.h>
21 #include <libnr/nr-translate-scale-ops.h>
22 #include <2geom/rect.h>
23 #include <glib/gmessages.h>
24 #include <png.h>
25 #include "png-write.h"
26 #include "io/sys.h"
27 #include <display/nr-arena-item.h>
28 #include <display/nr-arena.h>
29 #include <document.h>
30 #include <sp-item.h>
31 #include <sp-root.h>
32 #include <sp-defs.h>
33 #include "preferences.h"
34 #include "rdf.h"
36 /* This is an example of how to use libpng to read and write PNG files.
37 * The file libpng.txt is much more verbose then this. If you have not
38 * read it, do so first. This was designed to be a starting point of an
39 * implementation. This is not officially part of libpng, and therefore
40 * does not require a copyright notice.
41 *
42 * This file does not currently compile, because it is missing certain
43 * parts, like allocating memory to hold an image. You will have to
44 * supply these parts to get it to compile. For an example of a minimal
45 * working PNG reader/writer, see pngtest.c, included in this distribution.
46 */
48 static unsigned int const MAX_STRIPE_SIZE = 1024*1024;
50 struct SPEBP {
51 unsigned long int width, height, sheight;
52 guchar r, g, b, a;
53 NRArenaItem *root; // the root arena item to show; it is assumed that all unneeded items are hidden
54 guchar *px;
55 unsigned (*status)(float, void *);
56 void *data;
57 };
59 /* write a png file */
61 typedef struct SPPNGBD {
62 guchar const *px;
63 int rowstride;
64 } SPPNGBD;
66 /**
67 * A simple wrapper to list png_text.
68 */
69 class PngTextList {
70 public:
71 PngTextList() : count(0), textItems(0) {}
72 ~PngTextList();
74 void add(gchar const* key, gchar const* text);
75 gint getCount() {return count;}
76 png_text* getPtext() {return textItems;}
78 private:
79 gint count;
80 png_text* textItems;
81 };
83 PngTextList::~PngTextList() {
84 for (gint i = 0; i < count; i++) {
85 if (textItems[i].key) {
86 g_free(textItems[i].key);
87 }
88 if (textItems[i].text) {
89 g_free(textItems[i].text);
90 }
91 }
92 }
94 void PngTextList::add(gchar const* key, gchar const* text)
95 {
96 if (count < 0) {
97 count = 0;
98 textItems = 0;
99 }
100 png_text* tmp = (count > 0) ? g_try_renew(png_text, textItems, count + 1): g_try_new(png_text, 1);
101 if (tmp) {
102 textItems = tmp;
103 count++;
105 png_text* item = &(textItems[count - 1]);
106 item->compression = PNG_TEXT_COMPRESSION_NONE;
107 item->key = g_strdup(key);
108 item->text = g_strdup(text);
109 item->text_length = 0;
110 #ifdef PNG_iTXt_SUPPORTED
111 item->itxt_length = 0;
112 item->lang = 0;
113 item->lang_key = 0;
114 #endif // PNG_iTXt_SUPPORTED
115 } else {
116 g_warning("Unable to allocate arrary for %d PNG text data.", count);
117 textItems = 0;
118 count = 0;
119 }
120 }
122 static bool
123 sp_png_write_rgba_striped(SPDocument *doc,
124 gchar const *filename, unsigned long int width, unsigned long int height, double xdpi, double ydpi,
125 int (* get_rows)(guchar const **rows, int row, int num_rows, void *data),
126 void *data)
127 {
128 struct SPEBP *ebp = (struct SPEBP *) data;
129 FILE *fp;
130 png_structp png_ptr;
131 png_infop info_ptr;
132 png_color_8 sig_bit;
133 png_uint_32 r;
135 g_return_val_if_fail(filename != NULL, false);
136 g_return_val_if_fail(data != NULL, false);
138 /* open the file */
140 Inkscape::IO::dump_fopen_call(filename, "M");
141 fp = Inkscape::IO::fopen_utf8name(filename, "wb");
142 g_return_val_if_fail(fp != NULL, false);
144 /* Create and initialize the png_struct with the desired error handler
145 * functions. If you want to use the default stderr and longjump method,
146 * you can supply NULL for the last three parameters. We also check that
147 * the library version is compatible with the one used at compile time,
148 * in case we are using dynamically linked libraries. REQUIRED.
149 */
150 png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
152 if (png_ptr == NULL) {
153 fclose(fp);
154 return false;
155 }
157 /* Allocate/initialize the image information data. REQUIRED */
158 info_ptr = png_create_info_struct(png_ptr);
159 if (info_ptr == NULL) {
160 fclose(fp);
161 png_destroy_write_struct(&png_ptr, NULL);
162 return false;
163 }
165 /* Set error handling. REQUIRED if you aren't supplying your own
166 * error hadnling functions in the png_create_write_struct() call.
167 */
168 if (setjmp(png_ptr->jmpbuf)) {
169 /* If we get here, we had a problem reading the file */
170 fclose(fp);
171 png_destroy_write_struct(&png_ptr, &info_ptr);
172 return false;
173 }
175 /* set up the output control if you are using standard C streams */
176 png_init_io(png_ptr, fp);
178 /* Set the image information here. Width and height are up to 2^31,
179 * bit_depth is one of 1, 2, 4, 8, or 16, but valid values also depend on
180 * the color_type selected. color_type is one of PNG_COLOR_TYPE_GRAY,
181 * PNG_COLOR_TYPE_GRAY_ALPHA, PNG_COLOR_TYPE_PALETTE, PNG_COLOR_TYPE_RGB,
182 * or PNG_COLOR_TYPE_RGB_ALPHA. interlace is either PNG_INTERLACE_NONE or
183 * PNG_INTERLACE_ADAM7, and the compression_type and filter_type MUST
184 * currently be PNG_COMPRESSION_TYPE_BASE and PNG_FILTER_TYPE_BASE. REQUIRED
185 */
186 png_set_IHDR(png_ptr, info_ptr,
187 width,
188 height,
189 8, /* bit_depth */
190 PNG_COLOR_TYPE_RGB_ALPHA,
191 PNG_INTERLACE_NONE,
192 PNG_COMPRESSION_TYPE_BASE,
193 PNG_FILTER_TYPE_BASE);
195 /* otherwise, if we are dealing with a color image then */
196 sig_bit.red = 8;
197 sig_bit.green = 8;
198 sig_bit.blue = 8;
199 /* if the image has an alpha channel then */
200 sig_bit.alpha = 8;
201 png_set_sBIT(png_ptr, info_ptr, &sig_bit);
203 PngTextList textList;
205 textList.add("Software", "www.inkscape.org"); // Made by Inkscape comment
206 {
207 const gchar* pngToDc[] = {"Title", "title",
208 "Author", "creator",
209 "Description", "description",
210 //"Copyright", "",
211 "Creation Time", "date",
212 //"Disclaimer", "",
213 //"Warning", "",
214 "Source", "source"
215 //"Comment", ""
216 };
217 for (size_t i = 0; i < G_N_ELEMENTS(pngToDc); i += 2) {
218 struct rdf_work_entity_t * entity = rdf_find_entity ( pngToDc[i + 1] );
219 if (entity) {
220 gchar const* data = rdf_get_work_entity(doc, entity);
221 if (data && *data) {
222 textList.add(pngToDc[i], data);
223 }
224 } else {
225 g_warning("Unable to find entity [%s]", pngToDc[i + 1]);
226 }
227 }
230 struct rdf_license_t *license = rdf_get_license(doc);
231 if (license) {
232 if (license->name && license->uri) {
233 gchar* tmp = g_strdup_printf("%s %s", license->name, license->uri);
234 textList.add("Copyright", tmp);
235 g_free(tmp);
236 } else if (license->name) {
237 textList.add("Copyright", license->name);
238 } else if (license->uri) {
239 textList.add("Copyright", license->uri);
240 }
241 }
242 }
243 if (textList.getCount() > 0) {
244 png_set_text(png_ptr, info_ptr, textList.getPtext(), textList.getCount());
245 }
247 /* other optional chunks like cHRM, bKGD, tRNS, tIME, oFFs, pHYs, */
248 /* note that if sRGB is present the cHRM chunk must be ignored
249 * on read and must be written in accordance with the sRGB profile */
250 png_set_pHYs(png_ptr, info_ptr, unsigned(xdpi / 0.0254 + 0.5), unsigned(ydpi / 0.0254 + 0.5), PNG_RESOLUTION_METER);
252 /* Write the file header information. REQUIRED */
253 png_write_info(png_ptr, info_ptr);
255 /* Once we write out the header, the compression type on the text
256 * chunks gets changed to PNG_TEXT_COMPRESSION_NONE_WR or
257 * PNG_TEXT_COMPRESSION_zTXt_WR, so it doesn't get written out again
258 * at the end.
259 */
261 /* set up the transformations you want. Note that these are
262 * all optional. Only call them if you want them.
263 */
265 /* --- CUT --- */
267 /* The easiest way to write the image (you may have a different memory
268 * layout, however, so choose what fits your needs best). You need to
269 * use the first method if you aren't handling interlacing yourself.
270 */
272 png_bytep* row_pointers = new png_bytep[ebp->sheight];
274 r = 0;
275 while (r < static_cast< png_uint_32 > (height) ) {
276 int n = get_rows((unsigned char const **) row_pointers, r, height-r, data);
277 if (!n) break;
278 png_write_rows(png_ptr, row_pointers, n);
279 r += n;
280 }
282 delete[] row_pointers;
284 /* You can write optional chunks like tEXt, zTXt, and tIME at the end
285 * as well.
286 */
288 /* It is REQUIRED to call this to finish writing the rest of the file */
289 png_write_end(png_ptr, info_ptr);
291 /* if you allocated any text comments, free them here */
293 /* clean up after the write, and free any memory allocated */
294 png_destroy_write_struct(&png_ptr, &info_ptr);
296 /* close the file */
297 fclose(fp);
299 /* that's it */
300 return true;
301 }
304 /**
305 *
306 */
307 static int
308 sp_export_get_rows(guchar const **rows, int row, int num_rows, void *data)
309 {
310 struct SPEBP *ebp = (struct SPEBP *) data;
312 if (ebp->status) {
313 if (!ebp->status((float) row / ebp->height, ebp->data)) return 0;
314 }
316 num_rows = MIN(num_rows, static_cast<int>(ebp->sheight));
317 num_rows = MIN(num_rows, static_cast<int>(ebp->height - row));
319 /* Set area of interest */
320 // bbox is now set to the entire image to prevent discontinuities
321 // in the image when blur is used (the borders may still be a bit
322 // off, but that's less noticeable).
323 NRRectL bbox;
324 bbox.x0 = 0;
325 bbox.y0 = row;
326 bbox.x1 = ebp->width;
327 bbox.y1 = row + num_rows;
328 /* Update to renderable state */
329 NRGC gc(NULL);
330 gc.transform.setIdentity();
332 nr_arena_item_invoke_update(ebp->root, &bbox, &gc,
333 NR_ARENA_ITEM_STATE_ALL, NR_ARENA_ITEM_STATE_NONE);
335 NRPixBlock pb;
336 nr_pixblock_setup_extern(&pb, NR_PIXBLOCK_MODE_R8G8B8A8N,
337 bbox.x0, bbox.y0, bbox.x1, bbox.y1,
338 ebp->px, 4 * ebp->width, FALSE, FALSE);
340 for (int r = 0; r < num_rows; r++) {
341 guchar *p = NR_PIXBLOCK_PX(&pb) + r * pb.rs;
342 for (int c = 0; c < static_cast<int>(ebp->width); c++) {
343 *p++ = ebp->r;
344 *p++ = ebp->g;
345 *p++ = ebp->b;
346 *p++ = ebp->a;
347 }
348 }
350 /* Render */
351 nr_arena_item_invoke_render(NULL, ebp->root, &bbox, &pb, 0);
353 for (int r = 0; r < num_rows; r++) {
354 rows[r] = NR_PIXBLOCK_PX(&pb) + r * pb.rs;
355 }
357 nr_pixblock_release(&pb);
359 return num_rows;
360 }
362 /**
363 * Hide all items that are not listed in list, recursively, skipping groups and defs.
364 */
365 static void
366 hide_other_items_recursively(SPObject *o, GSList *list, unsigned dkey)
367 {
368 if ( SP_IS_ITEM(o)
369 && !SP_IS_DEFS(o)
370 && !SP_IS_ROOT(o)
371 && !SP_IS_GROUP(o)
372 && !g_slist_find(list, o) )
373 {
374 sp_item_invoke_hide(SP_ITEM(o), dkey);
375 }
377 // recurse
378 if (!g_slist_find(list, o)) {
379 for (SPObject *child = sp_object_first_child(o) ; child != NULL; child = SP_OBJECT_NEXT(child) ) {
380 hide_other_items_recursively(child, list, dkey);
381 }
382 }
383 }
386 /**
387 * Export the given document as a Portable Network Graphics (PNG) file.
388 *
389 * \return true if succeeded (or if no action was taken), false if an error occurred.
390 */
391 bool sp_export_png_file (SPDocument *doc, gchar const *filename,
392 double x0, double y0, double x1, double y1,
393 unsigned long int width, unsigned long int height, double xdpi, double ydpi,
394 unsigned long bgcolor,
395 unsigned int (*status) (float, void *),
396 void *data, bool force_overwrite,
397 GSList *items_only)
398 {
399 return sp_export_png_file(doc, filename, Geom::Rect(Geom::Point(x0,y0),Geom::Point(x1,y1)),
400 width, height, xdpi, ydpi, bgcolor, status, data, force_overwrite, items_only);
401 }
402 bool
403 sp_export_png_file(SPDocument *doc, gchar const *filename,
404 Geom::Rect const &area,
405 unsigned long width, unsigned long height, double xdpi, double ydpi,
406 unsigned long bgcolor,
407 unsigned (*status)(float, void *),
408 void *data, bool force_overwrite,
409 GSList *items_only)
410 {
411 g_return_val_if_fail(doc != NULL, false);
412 g_return_val_if_fail(filename != NULL, false);
413 g_return_val_if_fail(width >= 1, false);
414 g_return_val_if_fail(height >= 1, false);
415 g_return_val_if_fail(!area.hasZeroArea(), false);
417 if (!force_overwrite && !sp_ui_overwrite_file(filename)) {
418 /* Remark: We return true so as not to invoke an error dialog in case export is cancelled
419 by the user; currently this is safe because the callers only act when false is returned.
420 If this changes in the future we need better distinction of return types (e.g., use int)
421 */
422 return true;
423 }
425 sp_document_ensure_up_to_date(doc);
427 /* Calculate translation by transforming to document coordinates (flipping Y)*/
428 Geom::Point translation = Geom::Point(-area[Geom::X][0], area[Geom::Y][1] - sp_document_height(doc));
430 /* This calculation is only valid when assumed that (x0,y0)= area.corner(0) and (x1,y1) = area.corner(2)
431 * 1) a[0] * x0 + a[2] * y1 + a[4] = 0.0
432 * 2) a[1] * x0 + a[3] * y1 + a[5] = 0.0
433 * 3) a[0] * x1 + a[2] * y1 + a[4] = width
434 * 4) a[1] * x0 + a[3] * y0 + a[5] = height
435 * 5) a[1] = 0.0;
436 * 6) a[2] = 0.0;
437 *
438 * (1,3) a[0] * x1 - a[0] * x0 = width
439 * a[0] = width / (x1 - x0)
440 * (2,4) a[3] * y0 - a[3] * y1 = height
441 * a[3] = height / (y0 - y1)
442 * (1) a[4] = -a[0] * x0
443 * (2) a[5] = -a[3] * y1
444 */
446 Geom::Matrix const affine(Geom::Translate(translation)
447 * Geom::Scale(width / area.width(),
448 height / area.height()));
450 //SP_PRINT_MATRIX("SVG2PNG", &affine);
452 struct SPEBP ebp;
453 ebp.width = width;
454 ebp.height = height;
455 ebp.r = NR_RGBA32_R(bgcolor);
456 ebp.g = NR_RGBA32_G(bgcolor);
457 ebp.b = NR_RGBA32_B(bgcolor);
458 ebp.a = NR_RGBA32_A(bgcolor);
460 /* Create new arena */
461 NRArena *const arena = NRArena::create();
462 // export with maximum blur rendering quality
463 nr_arena_set_renderoffscreen(arena);
464 unsigned const dkey = sp_item_display_key_new(1);
466 /* Create ArenaItems and set transform */
467 ebp.root = sp_item_invoke_show(SP_ITEM(sp_document_root(doc)), arena, dkey, SP_ITEM_SHOW_DISPLAY);
468 nr_arena_item_set_transform(NR_ARENA_ITEM(ebp.root), affine);
470 // We show all and then hide all items we don't want, instead of showing only requested items,
471 // because that would not work if the shown item references something in defs
472 if (items_only) {
473 hide_other_items_recursively(sp_document_root(doc), items_only, dkey);
474 }
476 ebp.status = status;
477 ebp.data = data;
479 bool write_status;
480 if ((width < 256) || ((width * height) < 32768)) {
481 ebp.px = nr_pixelstore_64K_new(FALSE, 0);
482 ebp.sheight = 65536 / (4 * width);
483 write_status = sp_png_write_rgba_striped(doc, filename, width, height, xdpi, ydpi, sp_export_get_rows, &ebp);
484 nr_pixelstore_64K_free(ebp.px);
485 } else {
486 ebp.sheight = 64;
487 ebp.px = g_try_new(guchar, 4 * ebp.sheight * width);
488 write_status = sp_png_write_rgba_striped(doc, filename, width, height, xdpi, ydpi, sp_export_get_rows, &ebp);
489 g_free(ebp.px);
490 }
492 // Hide items, this releases arenaitem
493 sp_item_invoke_hide(SP_ITEM(sp_document_root(doc)), dkey);
495 /* Free arena */
496 nr_object_unref((NRObject *) arena);
498 return write_status;
499 }
502 /*
503 Local Variables:
504 mode:c++
505 c-file-style:"stroustrup"
506 c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
507 indent-tabs-mode:nil
508 fill-column:99
509 End:
510 */
511 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :