src/image-load-djvu.cc

   1 /*
   2  * Copyright (C) 20019 - The Geeqie Team
   3  *
   4  * Author: Colin Clark
   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 of the License, or
   9  * (at your option) 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 along
  17  * with this program; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  19  */
  20
  21 #include "image-load-djvu.h"
  22
  23 #include <config.h>
  24
  25 #if HAVE_DJVU
  26
  27 #include <cairo.h>
  28 #include <gdk-pixbuf/gdk-pixbuf.h>
  29 #include <glib-object.h>
  30 #include <glib.h>
  31 #include <libdjvu/ddjvuapi.h>
  32
  33 #include "image-load.h"
  34
  35 namespace
  36 {
  37
  38 struct ImageLoaderDJVU {
  39         ImageLoaderBackendCbAreaUpdated area_updated_cb;
  40         ImageLoaderBackendCbSize size_cb;
  41         ImageLoaderBackendCbAreaPrepared area_prepared_cb;
  42         gpointer data;
  43         GdkPixbuf *pixbuf;
  44         guint requested_width;
  45         guint requested_height;
  46         gboolean abort;
  47         gint page_num;
  48         gint page_total;
  49 };
  50
  51 void free_buffer(guchar *pixels, gpointer)
  52 {
  53         g_free (pixels);
  54 }
  55
  56 gboolean image_loader_djvu_write(gpointer loader, const guchar *buf, gsize &chunk_size, gsize count, GError **)
  57 {
  58         auto ld = static_cast<ImageLoaderDJVU *>(loader);
  59         ddjvu_context_t *ctx;
  60         ddjvu_document_t *doc;
  61         ddjvu_page_t *page;
  62         ddjvu_rect_t rrect;
  63         ddjvu_rect_t prect;
  64         ddjvu_format_t *fmt;
  65         gint width;
  66         gint height;
  67         gint stride;
  68         gboolean alpha = FALSE;
  69         cairo_surface_t *surface;
  70         guchar *pixels;
  71
  72         ctx = ddjvu_context_create(nullptr);
  73
  74         doc = ddjvu_document_create(ctx, nullptr, FALSE);
  75
  76         ddjvu_stream_write(doc, 0, reinterpret_cast<const char *>(buf), count );
  77         while (!ddjvu_document_decoding_done(doc));
  78
  79         ld->page_total = ddjvu_document_get_pagenum(doc);
  80
  81         page = ddjvu_page_create_by_pageno(doc, ld->page_num);
  82         while (!ddjvu_page_decoding_done(page));
  83
  84         fmt = ddjvu_format_create(DDJVU_FORMAT_RGB24, 0, nullptr);
  85
  86         width = ddjvu_page_get_width(page);
  87         height = ddjvu_page_get_height(page);
  88         stride = width * 4;
  89
  90         pixels = static_cast<guchar *>(g_malloc(height * stride));
  91
  92         prect.x = 0;
  93         prect.y = 0;
  94         prect.w = width;
  95         prect.h = height;
  96         rrect = prect;
  97
  98         surface = cairo_image_surface_create_for_data(pixels, CAIRO_FORMAT_RGB24, width, height, stride);
  99
 100         ddjvu_page_render(page, DDJVU_RENDER_COLOR, &prect, &rrect, fmt, stride, reinterpret_cast<char *>(pixels));
 101
 102         /**
 103          * @FIXME implementation of rotation is not correct */
 104         GdkPixbuf *tmp1;
 105         GdkPixbuf *tmp2;
 106         tmp1 = gdk_pixbuf_new_from_data(pixels, GDK_COLORSPACE_RGB, alpha, 8, width, height, stride, free_buffer, nullptr);
 107         tmp2 = gdk_pixbuf_flip(tmp1, TRUE);
 108         g_object_unref(tmp1);
 109
 110         ld->pixbuf = gdk_pixbuf_rotate_simple(tmp2,GDK_PIXBUF_ROTATE_UPSIDEDOWN);
 111
 112         ld->area_updated_cb(loader, 0, 0, width, height, ld->data);
 113
 114
 115         cairo_surface_destroy(surface);
 116         ddjvu_page_release(page);
 117         ddjvu_document_release(doc);
 118         ddjvu_context_release(ctx);
 119
 120         chunk_size = count;
 121         return TRUE;
 122 }
 123
 124 gpointer image_loader_djvu_new(ImageLoaderBackendCbAreaUpdated area_updated_cb, ImageLoaderBackendCbSize size_cb, ImageLoaderBackendCbAreaPrepared area_prepared_cb, gpointer data)
 125 {
 126         auto loader = g_new0(ImageLoaderDJVU, 1);
 127         loader->area_updated_cb = area_updated_cb;
 128         loader->size_cb = size_cb;
 129         loader->area_prepared_cb = area_prepared_cb;
 130         loader->data = data;
 131         return loader;
 132 }
 133
 134 void image_loader_djvu_set_size(gpointer loader, int width, int height)
 135 {
 136         auto ld = static_cast<ImageLoaderDJVU *>(loader);
 137         ld->requested_width = width;
 138         ld->requested_height = height;
 139 }
 140
 141 GdkPixbuf* image_loader_djvu_get_pixbuf(gpointer loader)
 142 {
 143         auto ld = static_cast<ImageLoaderDJVU *>(loader);
 144         return ld->pixbuf;
 145 }
 146
 147 gchar* image_loader_djvu_get_format_name(gpointer)
 148 {
 149         return g_strdup("djvu");
 150 }
 151
 152 gchar** image_loader_djvu_get_format_mime_types(gpointer)
 153 {
 154         static const gchar *mime[] = {"image/vnd.djvu", nullptr};
 155         return g_strdupv(const_cast<gchar **>(mime));
 156 }
 157
 158 void image_loader_djvu_set_page_num(gpointer loader, gint page_num)
 159 {
 160         auto ld = static_cast<ImageLoaderDJVU *>(loader);
 161
 162         ld->page_num = page_num;
 163 }
 164
 165 gint image_loader_djvu_get_page_total(gpointer loader)
 166 {
 167         auto ld = static_cast<ImageLoaderDJVU *>(loader);
 168
 169         return ld->page_total;
 170 }
 171
 172 gboolean image_loader_djvu_close(gpointer, GError **)
 173 {
 174         return TRUE;
 175 }
 176
 177 void image_loader_djvu_abort(gpointer loader)
 178 {
 179         auto ld = static_cast<ImageLoaderDJVU *>(loader);
 180         ld->abort = TRUE;
 181 }
 182
 183 void image_loader_djvu_free(gpointer loader)
 184 {
 185         auto ld = static_cast<ImageLoaderDJVU *>(loader);
 186         if (ld->pixbuf) g_object_unref(ld->pixbuf);
 187         g_free(ld);
 188 }
 189
 190 } // namespace
 191
 192 void image_loader_backend_set_djvu(ImageLoaderBackend *funcs)
 193 {
 194         funcs->loader_new = image_loader_djvu_new;
 195         funcs->set_size = image_loader_djvu_set_size;
 196         funcs->write = image_loader_djvu_write;
 197         funcs->get_pixbuf = image_loader_djvu_get_pixbuf;
 198         funcs->close = image_loader_djvu_close;
 199         funcs->abort = image_loader_djvu_abort;
 200         funcs->free = image_loader_djvu_free;
 201         funcs->get_format_name = image_loader_djvu_get_format_name;
 202         funcs->get_format_mime_types = image_loader_djvu_get_format_mime_types;
 203         funcs->set_page_num = image_loader_djvu_set_page_num;
 204         funcs->get_page_total = image_loader_djvu_get_page_total;
 205 }
 206
 207 #endif
 208 /* vim: set shiftwidth=8 softtabstop=0 cindent cinoptions={1s: */