source: trunk/third/librsvg/rsvg-file-util.c @ 18609

/* vim: set sw=4: -*- Mode: C; tab-width: 4; indent-tabs-mode: t; c-basic-offset: 4 -*- */
/*
   rsvg-file-util.c: SAX-based renderer for SVG files into a GdkPixbuf.

   Copyright (C) 2000 Eazel, Inc.
   Copyright (C) 2002 Dom Lachowicz <cinamod@hotmail.com>

   This program is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public License as
   published by the Free Software Foundation; either version 2 of the
   License, or (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with this program; if not, write to the
   Free Software Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.

   Author: Raph Levien <raph@artofcode.com>
*/

#include "config.h"
#include "rsvg.h"

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

#if ENABLE_GNOME_VFS
#include <libgnomevfs/gnome-vfs.h>
#endif

#define SVG_BUFFER_SIZE (1024 * 8)

typedef enum {
        RSVG_SIZE_ZOOM,
        RSVG_SIZE_WH,
        RSVG_SIZE_WH_MAX,
        RSVG_SIZE_ZOOM_MAX
} RsvgSizeType;

struct RsvgSizeCallbackData
{
        RsvgSizeType type;
        double x_zoom;
        double y_zoom;
        gint width;
        gint height;
};

static void
rsvg_size_callback (int *width,
                                        int *height,
                                        gpointer  data)
{
        struct RsvgSizeCallbackData *real_data = (struct RsvgSizeCallbackData *) data;
        double zoomx, zoomy, zoom;
        
        switch (real_data->type) {
        case RSVG_SIZE_ZOOM:
                if (*width < 0 || *height < 0)
                        return;
                
                *width = floor (real_data->x_zoom * *width + 0.5);
                *height = floor (real_data->y_zoom * *height + 0.5);
                return;
                
        case RSVG_SIZE_ZOOM_MAX:
                if (*width < 0 || *height < 0)
                        return;
                
                *width = floor (real_data->x_zoom * *width + 0.5);
                *height = floor (real_data->y_zoom * *height + 0.5);
                
                if (*width > real_data->width || *height > real_data->height)
                        {
                                zoomx = (double) real_data->width / *width;
                                zoomy = (double) real_data->height / *height;
                                zoom = MIN (zoomx, zoomy);
                                
                                *width = floor (zoom * *width + 0.5);
                                *height = floor (zoom * *height + 0.5);
                        }
                return;
                
        case RSVG_SIZE_WH_MAX:
                if (*width < 0 || *height < 0)
                        return;
                
                zoomx = (double) real_data->width / *width;
                zoomy = (double) real_data->height / *height;
                zoom = MIN (zoomx, zoomy);
                
                *width = floor (zoom * *width + 0.5);
                *height = floor (zoom * *height + 0.5);
                return;
                
        case RSVG_SIZE_WH:
                
                if (real_data->width != -1)
                        *width = real_data->width;
                if (real_data->height != -1)
                        *height = real_data->height;
                return;
        }
        
        g_assert_not_reached ();
}

static GdkPixbuf *
rsvg_pixbuf_from_file_with_size_data (const gchar * file_name,
                                                                          struct RsvgSizeCallbackData * data,
                                                                          GError ** error)
{
        char chars[SVG_BUFFER_SIZE];
        gint result;
        GdkPixbuf *retval;
        RsvgHandle *handle;
        
#if ENABLE_GNOME_VFS
        GnomeVFSHandle * f = NULL;
        if (GNOME_VFS_OK != gnome_vfs_open (&handle, file_name, GNOME_VFS_OPEN_READ))
                {
                        /* FIXME: Set up error. */
                        return NULL;
                }
#else
        FILE *f = fopen (file_name, "r");
        if (!f)
                {
                        /* FIXME: Set up error. */
                        return NULL;
                }
#endif
        
        handle = rsvg_handle_new ();
        
        rsvg_handle_set_size_callback (handle, rsvg_size_callback, data, NULL);

#if ENABLE_GNOME_VFS
        while (GNOME_VFS_OK == gnome_vfs_read (f,chars, SVG_BUFFER_SIZE, &result))
                rsvg_handle_write (handle, chars, result, error);
#else
        while ((result = fread (chars, 1, SVG_BUFFER_SIZE, f)) > 0)
                rsvg_handle_write (handle, chars, result, error);
#endif
        
        rsvg_handle_close (handle, error);
        retval = rsvg_handle_get_pixbuf (handle);
        
#if ENABLE_GNOME_VFS
        gnome_vfs_close (f);
#else
        fclose (f);
#endif
        
        rsvg_handle_free (handle);
        
        return retval;
}

/**
 * rsvg_pixbuf_from_file:
 * @file_name: A file name
 * @error: return location for errors
 * 
 * Loads a new #GdkPixbuf from @file_name and returns it.  The caller must
 * assume the reference to the reurned pixbuf. If an error occurred, @error is
 * set and %NULL is returned.
 * 
 * Return value: A newly allocated #GdkPixbuf, or %NULL
 **/
GdkPixbuf *
rsvg_pixbuf_from_file (const gchar *file_name,
                                           GError     **error)
{
        return rsvg_pixbuf_from_file_at_size (file_name, -1, -1, error);
}

/**
 * rsvg_pixbuf_from_file_at_zoom:
 * @file_name: A file name
 * @x_zoom: The horizontal zoom factor
 * @y_zoom: The vertical zoom factor
 * @error: return location for errors
 * 
 * Loads a new #GdkPixbuf from @file_name and returns it.  This pixbuf is scaled
 * from the size indicated by the file by a factor of @x_zoom and @y_zoom.  The
 * caller must assume the reference to the returned pixbuf. If an error
 * occurred, @error is set and %NULL is returned.
 * 
 * Return value: A newly allocated #GdkPixbuf, or %NULL
 **/
GdkPixbuf *
rsvg_pixbuf_from_file_at_zoom (const gchar *file_name,
                                                           double       x_zoom,
                                                           double       y_zoom,
                                                           GError     **error)
{
        struct RsvgSizeCallbackData data;
        
        g_return_val_if_fail (file_name != NULL, NULL);
        g_return_val_if_fail (x_zoom > 0.0 && y_zoom > 0.0, NULL);
        
        data.type = RSVG_SIZE_ZOOM;
        data.x_zoom = x_zoom;
        data.y_zoom = y_zoom;
        
        return rsvg_pixbuf_from_file_with_size_data (file_name, &data, error);
}

/**
 * rsvg_pixbuf_from_file_at_zoom_with_max:
 * @file_name: A file name
 * @x_zoom: The horizontal zoom factor
 * @y_zoom: The vertical zoom factor
 * @max_width: The requested max width
 * @max_height: The requested max heigh
 * @error: return location for errors
 * 
 * Loads a new #GdkPixbuf from @file_name and returns it.  This pixbuf is scaled
 * from the size indicated by the file by a factor of @x_zoom and @y_zoom. If the
 * resulting pixbuf would be larger than max_width/max_heigh it is uniformly scaled
 * down to fit in that rectangle. The caller must assume the reference to the
 * returned pixbuf. If an error occurred, @error is set and %NULL is returned.
 * 
 * Return value: A newly allocated #GdkPixbuf, or %NULL
 **/
GdkPixbuf  *
rsvg_pixbuf_from_file_at_zoom_with_max (const gchar  *file_name,
                                                                                double        x_zoom,
                                                                                double        y_zoom,
                                                                                gint          max_width,
                                                                                gint          max_height,
                                                                                GError      **error)
{
        struct RsvgSizeCallbackData data;
        
        g_return_val_if_fail (file_name != NULL, NULL);
        g_return_val_if_fail (x_zoom > 0.0 && y_zoom > 0.0, NULL);
        
        data.type = RSVG_SIZE_ZOOM_MAX;
        data.x_zoom = x_zoom;
        data.y_zoom = y_zoom;
        data.width = max_width;
        data.height = max_height;
        
        return rsvg_pixbuf_from_file_with_size_data (file_name, &data, error);
}

/**
 * rsvg_pixbuf_from_file_at_size:
 * @file_name: A file name
 * @width: The new width, or -1
 * @height: The new height, or -1
 * @error: return location for errors
 * 
 * Loads a new #GdkPixbuf from @file_name and returns it.  This pixbuf is scaled
 * from the size indicated to the new size indicated by @width and @height.  If
 * either of these are -1, then the default size of the image being loaded is
 * used.  The caller must assume the reference to the returned pixbuf. If an
 * error occurred, @error is set and %NULL is returned.
 * 
 * Return value: A newly allocated #GdkPixbuf, or %NULL
 **/
GdkPixbuf *
rsvg_pixbuf_from_file_at_size (const gchar *file_name,
                                                           gint         width,
                                                           gint         height,
                                                           GError     **error)
{
        struct RsvgSizeCallbackData data;
        
        data.type = RSVG_SIZE_WH;
        data.width = width;
        data.height = height;
        
        return rsvg_pixbuf_from_file_with_size_data (file_name, &data, error);
}

/**
 * rsvg_pixbuf_from_file_at_max_size:
 * @file_name: A file name
 * @max_width: The requested max width
 * @max_height: The requested max heigh
 * @error: return location for errors
 * 
 * Loads a new #GdkPixbuf from @file_name and returns it.  This pixbuf is uniformly
 * scaled so that the it fits into a rectangle of size max_width * max_height. The
 * caller must assume the reference to the returned pixbuf. If an error occurred,
 * @error is set and %NULL is returned.
 * 
 * Return value: A newly allocated #GdkPixbuf, or %NULL
 **/
GdkPixbuf  *
rsvg_pixbuf_from_file_at_max_size (const gchar     *file_name,
                                                                   gint             max_width,
                                                                   gint             max_height,
                                                                   GError         **error)
{
        struct RsvgSizeCallbackData data;
        
        data.type = RSVG_SIZE_WH_MAX;
        data.width = max_width;
        data.height = max_height;
        
        return rsvg_pixbuf_from_file_with_size_data (file_name, &data, error);
}