libdocument/ev-document-misc.c

   1 /*
   2  *  Copyright (C) 2009 Juanjo Marín <juanj.marin@juntadeandalucia.es>
   3  *  Copyright (c) 2007 Carlos Garcia Campos <carlosgc@gnome.org>
   4  *  Copyright (C) 2000-2003 Marco Pesenti Gritti
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation; either version 2, or (at your option)
   9  *  any later version.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with this program; if not, write to the Free Software
  18  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  19  */
  20
  21 #include <config.h>
  22
  23 #include <string.h>
  24 #include <math.h>
  25
  26 #include <gtk/gtk.h>
  27
  28 #include "ev-document-misc.h"
  29
  30 /* Returns a new GdkPixbuf that is suitable for placing in the thumbnail view.
  31  * It is four pixels wider and taller than the source.  If source_pixbuf is not
  32  * NULL, then it will fill the return pixbuf with the contents of
  33  * source_pixbuf.
  34  */
  35 GdkPixbuf *
  36 ev_document_misc_get_thumbnail_frame (int        width,
  37                                       int        height,
  38                                       GdkPixbuf *source_pixbuf)
  39 {
  40         GdkPixbuf *retval;
  41         guchar *data;
  42         gint rowstride;
  43         int i;
  44         int width_r, height_r;
  45
  46         if (source_pixbuf)
  47                 g_return_val_if_fail (GDK_IS_PIXBUF (source_pixbuf), NULL);
  48
  49         if (source_pixbuf) {
  50                 width_r = gdk_pixbuf_get_width (source_pixbuf);
  51                 height_r = gdk_pixbuf_get_height (source_pixbuf);
  52         } else {
  53                 width_r = width;
  54                 height_r = height;
  55         }
  56
  57         /* make sure no one is passing us garbage */
  58         g_assert (width_r >= 0 && height_r >= 0);
  59
  60         retval = gdk_pixbuf_new (GDK_COLORSPACE_RGB,
  61                                  TRUE, 8,
  62                                  width_r + 4,
  63                                  height_r + 4);
  64
  65         /* make it black and fill in the middle */
  66         data = gdk_pixbuf_get_pixels (retval);
  67         rowstride = gdk_pixbuf_get_rowstride (retval);
  68
  69         gdk_pixbuf_fill (retval, 0x000000ff);
  70         for (i = 1; i < height_r + 1; i++)
  71                 memset (data + (rowstride * i) + 4, 0xffffffff, width_r * 4);
  72
  73         /* copy the source pixbuf */
  74         if (source_pixbuf)
  75                 gdk_pixbuf_copy_area (source_pixbuf, 0, 0,
  76                                       width_r,
  77                                       height_r,
  78                                       retval,
  79                                       1, 1);
  80         /* Add the corner */
  81         data [(width_r + 2) * 4 + 3] = 0;
  82         data [(width_r + 3) * 4 + 3] = 0;
  83         data [(width_r + 2) * 4 + (rowstride * 1) + 3] = 0;
  84         data [(width_r + 3) * 4 + (rowstride * 1) + 3] = 0;
  85
  86         data [(height_r + 2) * rowstride + 3] = 0;
  87         data [(height_r + 3) * rowstride + 3] = 0;
  88         data [(height_r + 2) * rowstride + 4 + 3] = 0;
  89         data [(height_r + 3) * rowstride + 4 + 3] = 0;
  90
  91         return retval;
  92 }
  93
  94 void
  95 ev_document_misc_get_page_border_size (gint       page_width,
  96                                        gint       page_height,
  97                                        GtkBorder *border)
  98 {
  99         g_assert (border);
 100
 101         border->left = 1;
 102         border->top = 1;
 103         if (page_width < 100) {
 104                 border->right = 2;
 105                 border->bottom = 2;
 106         } else if (page_width < 500) {
 107                 border->right = 3;
 108                 border->bottom = 3;
 109         } else {
 110                 border->right = 4;
 111                 border->bottom = 4;
 112         }
 113 }
 114
 115
 116 void
 117 ev_document_misc_paint_one_page (GdkDrawable  *drawable,
 118                                  GtkWidget    *widget,
 119                                  GdkRectangle *area,
 120                                  GtkBorder    *border,
 121                                  gboolean highlight)
 122 {
 123         GtkStyle    *style = gtk_widget_get_style (widget);
 124         GtkStateType state = gtk_widget_get_state (widget);
 125
 126         gdk_draw_rectangle (drawable,
 127                             highlight ? style->text_gc[state] : style->dark_gc[state],
 128                             TRUE,
 129                             area->x,
 130                             area->y,
 131                             area->width,
 132                             area->height);
 133         gdk_draw_rectangle (drawable,
 134                             style->white_gc,
 135                             TRUE,
 136                             area->x + border->left,
 137                             area->y + border->top,
 138                             area->width - (border->left + border->right),
 139                             area->height - (border->top + border->bottom));
 140         gdk_draw_rectangle (drawable,
 141                             style->mid_gc[state],
 142                             TRUE,
 143                             area->x,
 144                             area->y + area->height - (border->bottom - border->top),
 145                             border->bottom - border->top,
 146                             border->bottom - border->top);
 147         gdk_draw_rectangle (drawable,
 148                             style->mid_gc[state],
 149                             TRUE,
 150                             area->x + area->width - (border->right - border->left),
 151                             area->y,
 152                             border->right - border->left,
 153                             border->right - border->left);
 154
 155 }
 156
 157 cairo_surface_t *
 158 ev_document_misc_surface_from_pixbuf (GdkPixbuf *pixbuf)
 159 {
 160         cairo_surface_t *surface;
 161         cairo_t         *cr;
 162
 163         surface = cairo_image_surface_create (gdk_pixbuf_get_has_alpha (pixbuf) ?
 164                                               CAIRO_FORMAT_ARGB32 : CAIRO_FORMAT_RGB24,
 165                                               gdk_pixbuf_get_width (pixbuf),
 166                                               gdk_pixbuf_get_height (pixbuf));
 167         cr = cairo_create (surface);
 168         gdk_cairo_set_source_pixbuf (cr, pixbuf, 0, 0);
 169         cairo_paint (cr);
 170         cairo_destroy (cr);
 171
 172         return surface;
 173 }
 174
 175 GdkPixbuf *
 176 ev_document_misc_pixbuf_from_surface (cairo_surface_t *surface)
 177 {
 178         GdkPixbuf       *pixbuf;
 179         cairo_surface_t *image;
 180         cairo_t         *cr;
 181         gboolean         has_alpha;
 182         gint             width, height;
 183         cairo_format_t   surface_format;
 184         gint             pixbuf_n_channels;
 185         gint             pixbuf_rowstride;
 186         guchar          *pixbuf_pixels;
 187         gint             x, y;
 188
 189         width = cairo_image_surface_get_width (surface);
 190         height = cairo_image_surface_get_height (surface);
 191
 192         surface_format = cairo_image_surface_get_format (surface);
 193         has_alpha = (surface_format == CAIRO_FORMAT_ARGB32);
 194
 195         pixbuf = gdk_pixbuf_new (GDK_COLORSPACE_RGB,
 196                                  TRUE, 8,
 197                                  width, height);
 198         pixbuf_n_channels = gdk_pixbuf_get_n_channels (pixbuf);
 199         pixbuf_rowstride = gdk_pixbuf_get_rowstride (pixbuf);
 200         pixbuf_pixels = gdk_pixbuf_get_pixels (pixbuf);
 201
 202         image = cairo_image_surface_create_for_data (pixbuf_pixels,
 203                                                      surface_format,
 204                                                      width, height,
 205                                                      pixbuf_rowstride);
 206         cr = cairo_create (image);
 207         cairo_set_source_surface (cr, surface, 0, 0);
 208
 209         if (has_alpha)
 210                 cairo_mask_surface (cr, surface, 0, 0);
 211         else
 212                 cairo_paint (cr);
 213
 214         cairo_destroy (cr);
 215         cairo_surface_destroy (image);
 216
 217         for (y = 0; y < height; y++) {
 218                 guchar *p = pixbuf_pixels + y * pixbuf_rowstride;
 219
 220                 for (x = 0; x < width; x++) {
 221                         guchar tmp;
 222
 223 #if G_BYTE_ORDER == G_LITTLE_ENDIAN
 224                         tmp = p[0];
 225                         p[0] = p[2];
 226                         p[2] = tmp;
 227                         p[3] = (has_alpha) ? p[3] : 0xff;
 228 #else
 229                         tmp = p[0];
 230                         p[0] = p[1];
 231                         p[1] = p[2];
 232                         p[2] = p[3];
 233                         p[3] = (has_alpha) ? tmp : 0xff;
 234 #endif
 235                         p += pixbuf_n_channels;
 236                 }
 237         }
 238
 239         return pixbuf;
 240 }
 241
 242 cairo_surface_t *
 243 ev_document_misc_surface_rotate_and_scale (cairo_surface_t *surface,
 244                                            gint             dest_width,
 245                                            gint             dest_height,
 246                                            gint             dest_rotation)
 247 {
 248         cairo_surface_t *new_surface;
 249         cairo_t         *cr;
 250         gint             width, height;
 251         gint             new_width = dest_width;
 252         gint             new_height = dest_height;
 253
 254         width = cairo_image_surface_get_width (surface);
 255         height = cairo_image_surface_get_height (surface);
 256
 257         if (dest_width == width &&
 258             dest_height == height &&
 259             dest_rotation == 0) {
 260                 return cairo_surface_reference (surface);
 261         }
 262
 263         if (dest_rotation == 90 || dest_rotation == 270) {
 264                 new_width = dest_height;
 265                 new_height = dest_width;
 266         }
 267
 268         new_surface = cairo_surface_create_similar (surface,
 269                                                     cairo_surface_get_content (surface),
 270                                                     new_width, new_height);
 271
 272         cr = cairo_create (new_surface);
 273         switch (dest_rotation) {
 274                 case 90:
 275                         cairo_translate (cr, new_width, 0);
 276                         break;
 277                 case 180:
 278                         cairo_translate (cr, new_width, new_height);
 279                         break;
 280                 case 270:
 281                         cairo_translate (cr, 0, new_height);
 282                         break;
 283                 default:
 284                         cairo_translate (cr, 0, 0);
 285         }
 286
 287         if (dest_width != width || dest_height != height) {
 288                 cairo_pattern_set_filter (cairo_get_source (cr), CAIRO_FILTER_BILINEAR);
 289                 cairo_scale (cr,
 290                              (gdouble)dest_width / width,
 291                              (gdouble)dest_height / height);
 292         }
 293
 294         cairo_rotate (cr, dest_rotation * G_PI / 180.0);
 295         cairo_set_source_surface (cr, surface, 0, 0);
 296         cairo_paint (cr);
 297         cairo_destroy (cr);
 298
 299         return new_surface;
 300 }
 301
 302 void
 303 ev_document_misc_invert_surface (cairo_surface_t *surface) {
 304 #if CAIRO_VERSION > CAIRO_VERSION_ENCODE(1, 9, 2)
 305         cairo_t *cr;
 306
 307         cr = cairo_create (surface);
 308
 309         /* white + DIFFERENCE -> invert */
 310         cairo_set_operator (cr, CAIRO_OPERATOR_DIFFERENCE);
 311         cairo_set_source_rgb (cr, 1., 1., 1.);
 312         cairo_paint(cr);
 313         cairo_destroy (cr);
 314 #else
 315         guchar *data;
 316         gint    rowstride;
 317         gint    width, height;
 318         gint    x, y;
 319
 320         data = cairo_image_surface_get_data (surface);
 321         rowstride = cairo_image_surface_get_stride (surface);
 322         width = cairo_image_surface_get_width (surface);
 323         height = cairo_image_surface_get_height (surface);
 324
 325         for (y = 0; y < height; y++) {
 326                 guchar *p = data + y * rowstride;
 327
 328                 for (x = 0; x < width; x++) {
 329                         p[0] = 255 - p[0];
 330                         p[1] = 255 - p[1];
 331                         p[2] = 255 - p[2];
 332                         p += 4;
 333                 }
 334         }
 335
 336         cairo_surface_mark_dirty (surface);
 337 #endif
 338 }
 339
 340 void
 341 ev_document_misc_invert_pixbuf (GdkPixbuf *pixbuf)
 342 {
 343         guchar *data, *p;
 344         guint   width, height, x, y, rowstride, n_channels;
 345
 346         n_channels = gdk_pixbuf_get_n_channels (pixbuf);
 347         g_assert (gdk_pixbuf_get_colorspace (pixbuf) == GDK_COLORSPACE_RGB);
 348         g_assert (gdk_pixbuf_get_bits_per_sample (pixbuf) == 8);
 349
 350         /* First grab a pointer to the raw pixel data. */
 351         data = gdk_pixbuf_get_pixels (pixbuf);
 352
 353         /* Find the number of bytes per row (could be padded). */
 354         rowstride = gdk_pixbuf_get_rowstride (pixbuf);
 355
 356         width = gdk_pixbuf_get_width (pixbuf);
 357         height = gdk_pixbuf_get_height (pixbuf);
 358         for (x = 0; x < width; x++) {
 359                 for (y = 0; y < height; y++) {
 360                         /* Calculate pixel's offset into the data array. */
 361                         p = data + x * n_channels + y * rowstride;
 362                         /* Change the RGB values*/
 363                         p[0] = 255 - p[0];
 364                         p[1] = 255 - p[1];
 365                         p[2] = 255 - p[2];
 366                 }
 367         }
 368 }
 369
 370 gdouble
 371 ev_document_misc_get_screen_dpi (GdkScreen *screen)
 372 {
 373         gdouble dp, di;
 374
 375         /*diagonal in pixels*/
 376         dp = hypot (gdk_screen_get_width (screen), gdk_screen_get_height (screen));
 377
 378         /*diagonal in inches*/
 379         di = hypot (gdk_screen_get_width_mm(screen), gdk_screen_get_height_mm (screen)) / 25.4;
 380
 381         return (dp / di);
 382 }