libpurple/purplegdkpixbuf.c

/*
 * Purple - Internet Messaging Library
 * Copyright (C) Pidgin Developers <devel@pidgin.im>
 *
 * Purple is the legal property of its developers, whose names are too numerous
 * to list here. Please refer to the COPYRIGHT file distributed with this
 * source distribution.
 *
 * This library 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.
 *
 * This library 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 library; if not, see <https://www.gnu.org/licenses/>.
 */

#include "libpurple/purplegdkpixbuf.h"

#include "debug.h"

void purple_gdk_pixbuf_make_round(GdkPixbuf *pixbuf) {
	gint width, height, rowstride;
	guchar *pixels;

	if (!gdk_pixbuf_get_has_alpha(pixbuf)) {
		return;
	}

	width = gdk_pixbuf_get_width(pixbuf);
	height = gdk_pixbuf_get_height(pixbuf);
	rowstride = gdk_pixbuf_get_rowstride(pixbuf);
	pixels = gdk_pixbuf_get_pixels(pixbuf);

	if (width < 6 || height < 6) {
		return;
	}

	/* The following code will convert the alpha of the pixel data in all
	 * corners to look something like the following diagram.
	 *
	 * 00 80 c0 FF FF c0 80 00
	 * 80 FF FF FF FF FF FF 80
	 * c0 FF FF FF FF FF FF c0
	 * FF FF FF FF FF FF FF FF
	 * FF FF FF FF FF FF FF FF
	 * c0 FF FF FF FF FF FF c0
	 * 80 FF FF FF FF FF FF 80
	 * 00 80 c0 FF FF c0 80 00
	 */

	/* Top left */
	pixels[3] = 0;
	pixels[7] = 0x80;
	pixels[11] = 0xC0;
	pixels[rowstride + 3] = 0x80;
	pixels[rowstride * 2 + 3] = 0xC0;

	/* Top right */
	pixels[width * 4 - 1] = 0;
	pixels[width * 4 - 5] = 0x80;
	pixels[width * 4 - 9] = 0xC0;
	pixels[rowstride + (width * 4) - 1] = 0x80;
	pixels[(2 * rowstride) + (width * 4) - 1] = 0xC0;

	/* Bottom left */
	pixels[(height - 1) * rowstride + 3] = 0;
	pixels[(height - 1) * rowstride + 7] = 0x80;
	pixels[(height - 1) * rowstride + 11] = 0xC0;
	pixels[(height - 2) * rowstride + 3] = 0x80;
	pixels[(height - 3) * rowstride + 3] = 0xC0;

	/* Bottom right */
	pixels[height * rowstride - 1] = 0;
	pixels[(height - 1) * rowstride - 1] = 0x80;
	pixels[(height - 2) * rowstride - 1] = 0xC0;
	pixels[height * rowstride - 5] = 0x80;
	pixels[height * rowstride - 9] = 0xC0;
}

gboolean
purple_gdk_pixbuf_is_opaque(GdkPixbuf *pixbuf) {
	gint height, rowstride, i;
	guchar *pixels;
	guchar *row;

	if (!gdk_pixbuf_get_has_alpha(pixbuf)) {
		return TRUE;
	}

	height = gdk_pixbuf_get_height (pixbuf);
	rowstride = gdk_pixbuf_get_rowstride (pixbuf);
	pixels = gdk_pixbuf_get_pixels (pixbuf);

	/* check the top row */
	row = pixels;
	for (i = 3; i < rowstride; i+=4) {
		if (row[i] < 0xfe) {
			return FALSE;
		}
	}

	/* check the left and right sides */
	for (i = 1; i < height - 1; i++) {
		row = pixels + (i * rowstride);
		if (row[3] < 0xfe || row[rowstride - 1] < 0xfe) {
			return FALSE;
		}
	}

	/* check the bottom */
	row = pixels + ((height - 1) * rowstride);
	for (i = 3; i < rowstride; i += 4) {
		if (row[i] < 0xfe) {
			return FALSE;
		}
	}

	return TRUE;
}

static GObject *purple_gdk_pixbuf_from_data_helper(const guchar *buf, gsize count, gboolean animated)
{
	GObject *pixbuf;
	GdkPixbufLoader *loader;
	GError *error = NULL;

	loader = gdk_pixbuf_loader_new();

	if (!gdk_pixbuf_loader_write(loader, buf, count, &error) || error) {
		purple_debug_warning("gtkutils", "gdk_pixbuf_loader_write() "
				"failed with size=%" G_GSIZE_FORMAT ": %s\n", count,
				error ? error->message : "(no error message)");
		g_clear_error(&error);
		g_object_unref(loader);
		return NULL;
	}

	if (!gdk_pixbuf_loader_close(loader, &error) || error) {
		purple_debug_warning("gtkutils", "gdk_pixbuf_loader_close() "
				"failed for image of size %" G_GSIZE_FORMAT ": %s\n", count,
				error ? error->message : "(no error message)");
		g_clear_error(&error);
		g_object_unref(loader);
		return NULL;
	}

	if (animated)
		pixbuf = G_OBJECT(gdk_pixbuf_loader_get_animation(loader));
	else
		pixbuf = G_OBJECT(gdk_pixbuf_loader_get_pixbuf(loader));
	if (!pixbuf) {
		purple_debug_warning("gtkutils", "%s() returned NULL for image "
				"of size %" G_GSIZE_FORMAT "\n",
				animated ? "gdk_pixbuf_loader_get_animation"
					: "gdk_pixbuf_loader_get_pixbuf", count);
		g_object_unref(loader);
		return NULL;
	}

	g_object_ref(pixbuf);
	g_object_unref(loader);

	return pixbuf;
}

GdkPixbuf *purple_gdk_pixbuf_from_data(const guchar *buf, gsize count)
{
	return GDK_PIXBUF(purple_gdk_pixbuf_from_data_helper(buf, count, FALSE));
}

GdkPixbuf *
purple_gdk_pixbuf_from_image(PurpleImage *image)
{
	return purple_gdk_pixbuf_from_data(purple_image_get_data(image),
		purple_image_get_data_size(image));
}

GdkPixbuf *purple_gdk_pixbuf_new_from_file(const gchar *filename)
{
	GdkPixbuf *pixbuf;
	GError *error = NULL;

	g_return_val_if_fail(filename != NULL, NULL);
	g_return_val_if_fail(filename[0] != '\0', NULL);

	pixbuf = gdk_pixbuf_new_from_file(filename, &error);
	if (!pixbuf || error) {
		purple_debug_warning("gtkutils", "gdk_pixbuf_new_from_file() "
				"returned %s for file %s: %s\n",
				pixbuf ? "something" : "nothing",
				filename,
				error ? error->message : "(no error message)");
		g_clear_error(&error);
		g_clear_object(&pixbuf);
		return NULL;
	}

	return pixbuf;
}

GdkPixbuf *purple_gdk_pixbuf_new_from_file_at_size(const char *filename, int width, int height)
{
	GdkPixbuf *pixbuf;
	GError *error = NULL;

	g_return_val_if_fail(filename != NULL, NULL);
	g_return_val_if_fail(filename[0] != '\0', NULL);

	pixbuf = gdk_pixbuf_new_from_file_at_size(filename,
			width, height, &error);
	if (!pixbuf || error) {
		purple_debug_warning("gtkutils", "gdk_pixbuf_new_from_file_at_size() "
				"returned %s for file %s: %s\n",
				pixbuf ? "something" : "nothing",
				filename,
				error ? error->message : "(no error message)");
		g_clear_error(&error);
		g_clear_object(&pixbuf);
		return NULL;
	}

	return pixbuf;
}