ev-render-context.c

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/* this file is part of evince, a gnome document viewer
 *
 *  Copyright (C) 2005 Jonathan Blandford <jrb@gnome.org>
 *
 * Evince is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * Evince 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
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 */

#include <config.h>
#include "ev-render-context.h"

static void ev_render_context_init       (EvRenderContext      *rc);
static void ev_render_context_class_init (EvRenderContextClass *class);

G_DEFINE_TYPE (EvRenderContext, ev_render_context, G_TYPE_OBJECT);

#define FLIP_DIMENSIONS(rc) ((rc)->rotation == 90 || (rc)->rotation == 270)

static void ev_render_context_init (EvRenderContext *rc) { /* Do Nothing */ }

static void
ev_render_context_dispose (GObject *object)
{
    EvRenderContext *rc;

    rc = (EvRenderContext *) object;

    if (rc->page) {
        g_object_unref (rc->page);
        rc->page = NULL;
    }

    (* G_OBJECT_CLASS (ev_render_context_parent_class)->dispose) (object);
}

static void
ev_render_context_class_init (EvRenderContextClass *class)
{
    GObjectClass *oclass;

    oclass = G_OBJECT_CLASS (class);

    oclass->dispose = ev_render_context_dispose;
}

EvRenderContext *
ev_render_context_new (EvPage *page,
               gint    rotation,
               gdouble scale)
{
    EvRenderContext *rc;

    rc = (EvRenderContext *) g_object_new (EV_TYPE_RENDER_CONTEXT, NULL);

    rc->page = page ? g_object_ref (page) : NULL;
    rc->rotation = rotation;
    rc->scale = scale;
    rc->target_width = -1;
    rc->target_height = -1;

    return rc;
}

void
ev_render_context_set_page (EvRenderContext *rc,
                EvPage          *page)
{
    g_return_if_fail (rc != NULL);
    g_return_if_fail (EV_IS_PAGE (page));

    if (rc->page)
        g_object_unref (rc->page);
    rc->page = g_object_ref (page);
}

void
ev_render_context_set_rotation (EvRenderContext *rc,
                int              rotation)
{
    g_return_if_fail (rc != NULL);

    rc->rotation = rotation;
}

void
ev_render_context_set_scale (EvRenderContext *rc,
                 gdouble          scale)
{
    g_return_if_fail (rc != NULL);

    rc->scale = scale;
}

void
ev_render_context_set_target_size (EvRenderContext *rc,
                   int          target_width,
                   int          target_height)
{
    g_return_if_fail (rc != NULL);

    rc->target_width = target_width;
    rc->target_height = target_height;
}

void
ev_render_context_compute_scaled_size (EvRenderContext *rc,
                       double       width_points,
                       double       height_points,
                       int         *scaled_width,
                       int         *scaled_height)
{
    g_return_if_fail (rc != NULL);

    if (scaled_width) {
        if (rc->target_width >= 0) {
            *scaled_width = FLIP_DIMENSIONS (rc) ? rc->target_height : rc->target_width;
        } else {
            *scaled_width = (int) (width_points * rc->scale + 0.5);
        }
    }

    if (scaled_height) {
        if (rc->target_height >= 0) {
            *scaled_height = FLIP_DIMENSIONS (rc) ? rc->target_width : rc->target_height;
        } else {
            *scaled_height = (int) (height_points * rc->scale + 0.5);
        }
    }
}

void
ev_render_context_compute_transformed_size (EvRenderContext *rc,
                        double       width_points,
                        double       height_points,
                        int             *transformed_width,
                        int             *transformed_height)
{
    int scaled_width, scaled_height;

    g_return_if_fail (rc != NULL);

    ev_render_context_compute_scaled_size (rc, width_points, height_points,
                           &scaled_width, &scaled_height);

    if (transformed_width)
        *transformed_width = FLIP_DIMENSIONS (rc) ? scaled_height : scaled_width;

    if (transformed_height)
        *transformed_height = FLIP_DIMENSIONS (rc) ? scaled_width : scaled_height;
}

void
ev_render_context_compute_scales (EvRenderContext *rc,
                  double       width_points,
                  double       height_points,
                  double      *scale_x,
                  double      *scale_y)
{
    int scaled_width, scaled_height;

    g_return_if_fail (rc != NULL);

    ev_render_context_compute_scaled_size (rc, width_points, height_points,
                           &scaled_width, &scaled_height);

    if (scale_x)
        *scale_x = scaled_width / width_points;

    if (scale_y)
        *scale_y = scaled_height / height_points;
}