netsurf/desktop/thumbnail.c
2013-05-28 14:16:10 +01:00

107 lines
2.6 KiB
C

/*
* Copyright 2011 Michael Drake <tlsa@netsurf-browser.org>
*
* This file is part of NetSurf, http://www.netsurf-browser.org/
*
* NetSurf 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; version 2 of the License.
*
* NetSurf 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, see <http://www.gnu.org/licenses/>.
*/
/** \file
* Core thumbnail handling (implementation).
*/
#include <assert.h>
#include <stdbool.h>
#include "content/content.h"
#include "content/hlcache.h"
#include "desktop/browser.h"
#include "desktop/knockout.h"
#include "utils/nsoption.h"
#include "desktop/plotters.h"
#include "desktop/thumbnail.h"
#include "utils/log.h"
/**
* Get scale at which thumbnail will be rendered for a given content and
* thumbnail size.
*
* \param content The content to redraw for thumbnail
* \param width The thumbnail width
* \return scale thumbnail will be rendered at
*
* Units for width and height are pixels.
*/
static float thumbnail_get_redraw_scale(struct hlcache_handle *content,
int width)
{
assert(content);
if (content_get_width(content))
return (float)width / (float)content_get_width(content);
else
return 1.0;
}
/* exported interface, documented in thumbnail.h */
bool thumbnail_redraw(struct hlcache_handle *content,
int width, int height, const struct redraw_context *ctx)
{
struct redraw_context new_ctx = *ctx;
struct rect clip;
struct content_redraw_data data;
float scale;
bool plot_ok = true;
assert(content);
if (ctx->plot->option_knockout)
knockout_plot_start(ctx, &new_ctx);
/* Set clip rectangle to required thumbnail size */
clip.x0 = 0;
clip.y0 = 0;
clip.x1 = width;
clip.y1 = height;
new_ctx.plot->clip(&clip);
/* Plot white background */
plot_ok &= new_ctx.plot->rectangle(clip.x0, clip.y0, clip.x1, clip.y1,
plot_style_fill_white);
/* Find the scale we're using */
scale = thumbnail_get_redraw_scale(content, width);
/* Set up content redraw data */
data.x = 0;
data.y = 0;
data.width = width;
data.height = height;
data.background_colour = 0xFFFFFF;
data.scale = scale;
data.repeat_x = false;
data.repeat_y = false;
/* Render the content */
plot_ok &= content_redraw(content, &data, &clip, &new_ctx);
if (ctx->plot->option_knockout)
knockout_plot_end();
return plot_ok;
}