pango-view/viewer-pangocairo.c

   1 /* viewer-pangocairo.c: PangoCairo viewer backend.
   2  *
   3  * Copyright (C) 1999,2004,2005 Red Hat, Inc.
   4  * Copyright (C) 2001 Sun Microsystems
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Library General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This library 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 GNU
  14  * Library General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Library General Public
  17  * License along with this library; if not, write to the
  18  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19  * Boston, MA 02111-1307, USA.
  20  */
  21
  22 #include "config.h"
  23
  24 #include "viewer-render.h"
  25 #include "viewer-cairo.h"
  26
  27 #include <pango/pangocairo.h>
  28
  29 static int opt_annotate = 0;
  30
  31 typedef struct
  32 {
  33   const CairoViewerIface *iface;
  34
  35   gpointer backend;
  36
  37   PangoFontMap *fontmap;
  38   cairo_font_options_t *font_options;
  39 } CairoViewer;
  40
  41 static gpointer
  42 pangocairo_view_create (const PangoViewer *klass G_GNUC_UNUSED)
  43 {
  44   CairoViewer *instance;
  45
  46   instance = g_slice_new (CairoViewer);
  47
  48   instance->backend = cairo_viewer_iface_create (&instance->iface);
  49
  50   instance->fontmap = pango_cairo_font_map_new ();
  51   pango_cairo_font_map_set_resolution (PANGO_CAIRO_FONT_MAP (instance->fontmap), opt_dpi);
  52
  53   instance->font_options = cairo_font_options_create ();
  54   if (opt_hinting != HINT_DEFAULT)
  55     {
  56       if (opt_hinting == HINT_NONE)
  57         cairo_font_options_set_hint_style (instance->font_options, CAIRO_HINT_STYLE_NONE);
  58       else if (opt_hinting == HINT_FULL)
  59         cairo_font_options_set_hint_style (instance->font_options, CAIRO_HINT_STYLE_FULL);
  60     }
  61
  62   return instance;
  63 }
  64
  65 static void
  66 pangocairo_view_destroy (gpointer instance)
  67 {
  68   CairoViewer *c = (CairoViewer *) instance;
  69
  70   cairo_font_options_destroy (c->font_options);
  71
  72   g_object_unref (c->fontmap);
  73
  74   c->iface->backend_class->destroy (c->backend);
  75
  76   cairo_debug_reset_static_data ();
  77
  78   g_slice_free (CairoViewer, c);
  79 }
  80
  81 static PangoContext *
  82 pangocairo_view_get_context (gpointer instance)
  83 {
  84   CairoViewer *c = (CairoViewer *) instance;
  85   PangoContext *context;
  86
  87   context = pango_font_map_create_context (c->fontmap);
  88   pango_cairo_context_set_font_options (context, c->font_options);
  89
  90   return context;
  91 }
  92
  93 typedef struct
  94 {
  95   gpointer backend;
  96
  97   cairo_surface_t *cairo;
  98 } CairoSurface;
  99
 100 static gpointer
 101 pangocairo_view_create_surface (gpointer instance,
 102                                 int      width,
 103                                 int      height)
 104 {
 105   CairoViewer *c = (CairoViewer *) instance;
 106   CairoSurface *surface;
 107
 108   surface = g_slice_new (CairoSurface);
 109
 110   surface->backend = c->iface->backend_class->create_surface (c->backend,
 111                                                               width, height);
 112
 113   surface->cairo = c->iface->create_surface (c->backend,
 114                                              surface->backend,
 115                                              width, height);
 116
 117   return surface;
 118 }
 119
 120 static void
 121 pangocairo_view_destroy_surface (gpointer instance,
 122                                  gpointer surface)
 123 {
 124   CairoViewer *c = (CairoViewer *) instance;
 125   CairoSurface *c_surface = (CairoSurface *) surface;
 126
 127   c->iface->backend_class->destroy_surface (c->backend, c_surface->backend);
 128   cairo_surface_destroy (c_surface->cairo);
 129
 130   g_slice_free (CairoSurface, surface);
 131 }
 132
 133 static void
 134 render_callback (PangoLayout *layout,
 135                  int          x,
 136                  int          y,
 137                  gpointer     context,
 138                  gpointer     state)
 139 {
 140   cairo_t *cr = (cairo_t *) context;
 141   int annotate = (GPOINTER_TO_INT (state) + opt_annotate) % 3;
 142
 143   cairo_save (cr);
 144   cairo_translate (cr, x, y);
 145
 146   if (annotate)
 147     {
 148       cairo_pattern_t *pattern;
 149       PangoRectangle ink, logical;
 150       double lw = cairo_get_line_width (cr);
 151       PangoLayoutIter* iter;
 152
 153       pango_layout_get_extents (layout, &ink, &logical);
 154
 155       if (annotate >= 2)
 156         {
 157           /* draw resolved gravity "roof" in blue */
 158           cairo_save (cr);
 159           cairo_translate (cr,
 160                            (double)logical.x / PANGO_SCALE,
 161                            (double)logical.y / PANGO_SCALE);
 162           cairo_scale     (cr,
 163                            (double)logical.width / PANGO_SCALE * 0.5,
 164                            (double)logical.height / PANGO_SCALE * 0.5);
 165           cairo_translate   (cr,  1.0,  1.0);
 166           cairo_rotate (cr,
 167             pango_gravity_to_rotation (
 168               pango_context_get_gravity (
 169                 pango_layout_get_context (layout))));
 170           cairo_move_to     (cr, -1.0, -1.0);
 171           cairo_rel_line_to (cr, +1.0, -0.2); /* /   */
 172           cairo_rel_line_to (cr, +1.0, +0.2); /*   \ */
 173           cairo_close_path  (cr);             /*  -  */
 174           pattern = cairo_pattern_create_linear (0, -1.0, 0, -1.2);
 175           cairo_pattern_add_color_stop_rgba (pattern, 0.0, 0.0, 0.0, 1.0, 0.0);
 176           cairo_pattern_add_color_stop_rgba (pattern, 1.0, 0.0, 0.0, 1.0, 0.15);
 177           cairo_set_source (cr, pattern);
 178           cairo_fill (cr);
 179           /* once more, without close_path this time */
 180           cairo_move_to     (cr, -1.0, -1.0);
 181           cairo_rel_line_to (cr, +1.0, -0.2); /* /   */
 182           cairo_rel_line_to (cr, +1.0, +0.2); /*   \ */
 183           /* silly line_width is not locked :(. get rid of scale. */
 184           cairo_restore (cr);
 185           cairo_save (cr);
 186           cairo_set_source_rgba (cr, 0.0, 0.0, 0.7, 0.2);
 187           cairo_stroke (cr);
 188           cairo_restore (cr);
 189
 190
 191           /* draw block progression arrow in green */
 192           cairo_save (cr);
 193           cairo_translate (cr,
 194                            (double)logical.x / PANGO_SCALE,
 195                            (double)logical.y / PANGO_SCALE);
 196           cairo_scale     (cr,
 197                            (double)logical.width / PANGO_SCALE * 0.5,
 198                            (double)logical.height / PANGO_SCALE * 0.5);
 199           cairo_translate   (cr,  1.0,  1.0);
 200           cairo_move_to     (cr, -0.4, -0.7);
 201           cairo_rel_line_to (cr, +0.8,  0.0); /*  --   */
 202           cairo_rel_line_to (cr,  0.0, +0.9); /*    |  */
 203           cairo_rel_line_to (cr, +0.4,  0.0); /*     - */
 204           cairo_rel_line_to (cr, -0.8, +0.5); /*    /  */
 205           cairo_rel_line_to (cr, -0.8, -0.5); /*  \    */
 206           cairo_rel_line_to (cr, +0.4,  0.0); /* -     */
 207           cairo_close_path  (cr);             /*  |    */
 208           pattern = cairo_pattern_create_linear (0, -0.7, 0, 0.7);
 209           cairo_pattern_add_color_stop_rgba (pattern, 0.0, 0.0, 1.0, 0.0, 0.0);
 210           cairo_pattern_add_color_stop_rgba (pattern, 1.0, 0.0, 1.0, 0.0, 0.15);
 211           cairo_set_source (cr, pattern);
 212           cairo_fill_preserve (cr);
 213           /* silly line_width is not locked :(. get rid of scale. */
 214           cairo_restore (cr);
 215           cairo_save (cr);
 216           cairo_set_source_rgba (cr, 0.0, 0.7, 0.0, 0.2);
 217           cairo_stroke (cr);
 218           cairo_restore (cr);
 219         }
 220
 221       /* draw baselines with line direction arrow in orange */
 222       cairo_save (cr);
 223       cairo_set_source_rgba (cr, 1.0, 0.5, 0.0, 0.5);
 224       iter = pango_layout_get_iter (layout);
 225       do
 226         {
 227           PangoLayoutLine *line = pango_layout_iter_get_line (iter);
 228           double width = (double)logical.width / PANGO_SCALE;
 229
 230           y = pango_layout_iter_get_baseline (iter);
 231           cairo_save (cr);
 232           cairo_translate (cr,
 233                          (double)logical.x / PANGO_SCALE + width * 0.5,
 234                          (double)y / PANGO_SCALE);
 235           if (line->resolved_dir)
 236             cairo_scale (cr, -1, 1);
 237           cairo_move_to     (cr, -width * .5, -lw*0.2);
 238           cairo_rel_line_to (cr, +width * .9, -lw*0.3);
 239           cairo_rel_line_to (cr,  0,          -lw);
 240           cairo_rel_line_to (cr, +width * .1, +lw*1.5);
 241           cairo_rel_line_to (cr, -width * .1, +lw*1.5);
 242           cairo_rel_line_to (cr, 0,           -lw);
 243           cairo_rel_line_to (cr, -width * .9, -lw*0.3);
 244           cairo_close_path (cr);
 245           cairo_fill (cr);
 246           cairo_restore (cr);
 247         }
 248       while (pango_layout_iter_next_line (iter));
 249       pango_layout_iter_free (iter);
 250       cairo_restore (cr);
 251
 252       /* draw the logical rect in red */
 253       cairo_save (cr);
 254       cairo_set_source_rgba (cr, 1.0, 0.0, 0.0, 0.5);
 255       cairo_rectangle (cr,
 256                        (double)logical.x / PANGO_SCALE - lw / 2,
 257                        (double)logical.y / PANGO_SCALE - lw / 2,
 258                        (double)logical.width / PANGO_SCALE + lw,
 259                        (double)logical.height / PANGO_SCALE + lw);
 260       cairo_stroke (cr);
 261       cairo_restore (cr);
 262
 263       /* draw the ink rect in green */
 264       cairo_save (cr);
 265       cairo_set_source_rgba (cr, 0.0, 1.0, 0.0, 0.5);
 266       cairo_rectangle (cr,
 267                        (double)ink.x / PANGO_SCALE - lw / 2,
 268                        (double)ink.y / PANGO_SCALE - lw / 2,
 269                        (double)ink.width / PANGO_SCALE + lw,
 270                        (double)ink.height / PANGO_SCALE + lw);
 271       cairo_stroke (cr);
 272       cairo_restore (cr);
 273     }
 274
 275   cairo_move_to (cr, 0, 0);
 276   pango_cairo_show_layout (cr, layout);
 277
 278   cairo_restore (cr);
 279 }
 280
 281 static void
 282 transform_callback (PangoContext *context,
 283                     PangoMatrix  *matrix,
 284                     gpointer      cr_context,
 285                     gpointer      state G_GNUC_UNUSED)
 286 {
 287   cairo_t *cr = (cairo_t *)cr_context;
 288   cairo_matrix_t cairo_matrix;
 289
 290   if (matrix)
 291     {
 292       cairo_matrix.xx = matrix->xx;
 293       cairo_matrix.yx = matrix->yx;
 294       cairo_matrix.xy = matrix->xy;
 295       cairo_matrix.yy = matrix->yy;
 296       cairo_matrix.x0 = matrix->x0;
 297       cairo_matrix.y0 = matrix->y0;
 298     }
 299   else
 300     {
 301       cairo_matrix_init_identity (&cairo_matrix);
 302     }
 303
 304   cairo_set_matrix (cr, &cairo_matrix);
 305
 306   pango_cairo_update_context (cr, context);
 307 }
 308
 309 static void
 310 pangocairo_view_render (gpointer      instance,
 311                         gpointer      surface,
 312                         PangoContext *context,
 313                         int          *width,
 314                         int          *height,
 315                         gpointer      state)
 316 {
 317   CairoViewer *c = (CairoViewer *) instance;
 318   cairo_t *cr;
 319   CairoSurface *c_surface = (CairoSurface *) surface;
 320
 321   g_assert (surface);
 322
 323   cr = cairo_create (c_surface->cairo);
 324
 325   transform_callback (context, NULL, cr, state);
 326
 327   c->iface->paint_background (instance, cr);
 328
 329   cairo_set_operator (cr, CAIRO_OPERATOR_OVER);
 330   cairo_set_source_rgba (cr,
 331                          opt_fg_color.red / 65535.,
 332                          opt_fg_color.green / 65535.,
 333                          opt_fg_color.blue / 65535.,
 334                          opt_fg_alpha / 65535.);
 335
 336   do_output (context, render_callback, transform_callback, cr, state, width, height);
 337
 338   cairo_destroy (cr);
 339 }
 340
 341 #ifdef HAVE_CAIRO_PNG
 342 static cairo_status_t
 343 write_func (void                *closure,
 344             const unsigned char *data,
 345             unsigned int         length)
 346 {
 347   FILE *stream = (FILE *) closure;
 348   unsigned int l;
 349
 350   l = fwrite (data, 1, length, stream);
 351
 352   return l == length ? CAIRO_STATUS_SUCCESS : CAIRO_STATUS_WRITE_ERROR;
 353 }
 354
 355 static void
 356 pangocairo_view_write (gpointer instance G_GNUC_UNUSED,
 357                        gpointer surface,
 358                        FILE    *stream,
 359                        int      width G_GNUC_UNUSED,
 360                        int      height G_GNUC_UNUSED)
 361 {
 362   CairoSurface *c_surface = (CairoSurface *) surface;
 363
 364   cairo_surface_write_to_png_stream (c_surface->cairo, write_func, stream);
 365 }
 366 #endif
 367
 368 static gpointer
 369 pangocairo_view_create_window (gpointer    instance,
 370                                const char *title,
 371                                int         width,
 372                                int         height)
 373 {
 374   CairoViewer *c = (CairoViewer *) instance;
 375
 376   if (!c->iface->backend_class->create_window)
 377     return NULL;
 378
 379   return c->iface->backend_class->create_window (c->backend,
 380                                                  title,
 381                                                  width, height);
 382 }
 383
 384 static void
 385 pangocairo_view_destroy_window (gpointer instance,
 386                                 gpointer window)
 387 {
 388   CairoViewer *c = (CairoViewer *) instance;
 389
 390   c->iface->backend_class->destroy_window (c->backend,
 391                                            window);
 392 }
 393
 394 static gpointer
 395 pangocairo_view_display (gpointer instance,
 396                          gpointer surface,
 397                          gpointer window,
 398                          int width, int height,
 399                          gpointer state)
 400 {
 401   CairoViewer *c = (CairoViewer *) instance;
 402   CairoSurface *c_surface = (CairoSurface *) surface;
 403
 404   return c->iface->backend_class->display (c->backend,
 405                                            c_surface->backend,
 406                                            window,
 407                                            width, height,
 408                                            state);
 409 }
 410
 411 static GOptionGroup *
 412 pangocairo_view_get_option_group (const PangoViewer *klass G_GNUC_UNUSED)
 413 {
 414   GOptionEntry entries[] =
 415   {
 416     {"annotate",        0, 0, G_OPTION_ARG_INT, &opt_annotate,
 417      "Annotate the output",                             "1 or 2"},
 418     {NULL}
 419   };
 420   GOptionGroup *group;
 421
 422   group = g_option_group_new ("cairo",
 423                               "Cairo backend options:",
 424                               "Options understood by the cairo backend",
 425                               NULL,
 426                               NULL);
 427
 428   g_option_group_add_entries (group, entries);
 429
 430   cairo_viewer_add_options (group);
 431
 432   return group;
 433 }
 434
 435 const PangoViewer pangocairo_viewer = {
 436   "PangoCairo",
 437   "cairo",
 438 #ifdef HAVE_CAIRO_PNG
 439   "png",
 440 #else
 441   NULL,
 442 #endif
 443   pangocairo_view_create,
 444   pangocairo_view_destroy,
 445   pangocairo_view_get_context,
 446   pangocairo_view_create_surface,
 447   pangocairo_view_destroy_surface,
 448   pangocairo_view_render,
 449 #ifdef HAVE_CAIRO_PNG
 450   pangocairo_view_write,
 451 #else
 452   NULL,
 453 #endif
 454   pangocairo_view_create_window,
 455   pangocairo_view_destroy_window,
 456   pangocairo_view_display,
 457   NULL,
 458   NULL,
 459   pangocairo_view_get_option_group
 460 };