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