gtk/gsk/gskpath.h
Matthias Clasen 1b5dfcba7e gsk: Add GskPath
This commit adds the basic infrastructure for paths.
The public APIs consists of GskPath, GskPathPoint and
GskPathBuilder.

GskPath is a data structure for paths that consists
of contours, which in turn might contain Bézier curves.
The Bezier data structure is inspired by Skia, with separate
arrays for points and operations. One advantage of this
arrangement is that start and end points are shared
between adjacent curves.

A GskPathPoint represents a point on a path, which can
be queried for various properties.

GskPathBuilder is an auxiliary builder object for paths.
2023-08-06 20:48:09 -04:00

123 lines
5.1 KiB
C

/*
* Copyright © 2020 Benjamin Otte
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see <http://www.gnu.org/licenses/>.
*
* Authors: Benjamin Otte <otte@gnome.org>
*/
#pragma once
#if !defined (__GSK_H_INSIDE__) && !defined (GTK_COMPILATION)
#error "Only <gsk/gsk.h> can be included directly."
#endif
#include <gsk/gsktypes.h>
G_BEGIN_DECLS
/**
* GskPathForeachFlags:
* @GSK_PATH_FOREACH_ALLOW_ONLY_LINES: The default behavior, only allow lines.
* @GSK_PATH_FOREACH_ALLOW_QUAD: Allow emission of `GSK_PATH_QUAD` operations
* @GSK_PATH_FOREACH_ALLOW_CUBIC: Allow emission of `GSK_PATH_CUBIC` operations.
* @GSK_PATH_FOREACH_ALLOW_ANY: Allow emission of any kind of operation.
*
* Flags that can be passed to gsk_path_foreach() to enable additional
* features.
*
* By default, [method@Gsk.Path.foreach] will only emit a path with all operations
* flattened to straight lines to allow for maximum compatibility. The only
* operations emitted will be `GSK_PATH_MOVE`, `GSK_PATH_LINE` and `GSK_PATH_CLOSE`.
*/
typedef enum
{
GSK_PATH_FOREACH_ALLOW_ONLY_LINES = 0,
GSK_PATH_FOREACH_ALLOW_QUAD = (1 << 0),
GSK_PATH_FOREACH_ALLOW_CUBIC = (1 << 1),
} GskPathForeachFlags;
/**
* GskPathForeachFunc:
* @op: The operation to perform
* @pts: The points of the operation
* @n_pts: The number of points
* @user_data: The user data provided with the function
*
* Prototype of the callback to iterate throught the operations of
* a path.
*
* Returns: %TRUE to continue evaluating the path, %FALSE to
* immediately abort and not call the function again.
*/
typedef gboolean (* GskPathForeachFunc) (GskPathOperation op,
const graphene_point_t *pts,
gsize n_pts,
gpointer user_data);
#define GSK_TYPE_PATH (gsk_path_get_type ())
GDK_AVAILABLE_IN_4_14
GType gsk_path_get_type (void) G_GNUC_CONST;
GDK_AVAILABLE_IN_4_14
GskPath * gsk_path_ref (GskPath *self);
GDK_AVAILABLE_IN_4_14
void gsk_path_unref (GskPath *self);
GDK_AVAILABLE_IN_4_14
void gsk_path_print (GskPath *self,
GString *string);
GDK_AVAILABLE_IN_4_14
char * gsk_path_to_string (GskPath *self);
GDK_AVAILABLE_IN_4_14
GskPath * gsk_path_parse (const char *string);
GDK_AVAILABLE_IN_4_14
void gsk_path_to_cairo (GskPath *self,
cairo_t *cr);
GDK_AVAILABLE_IN_4_14
gboolean gsk_path_is_empty (GskPath *self);
GDK_AVAILABLE_IN_4_14
gboolean gsk_path_is_closed (GskPath *self);
GDK_AVAILABLE_IN_4_14
gboolean gsk_path_get_bounds (GskPath *self,
graphene_rect_t *bounds);
GDK_AVAILABLE_IN_4_14
gboolean gsk_path_in_fill (GskPath *self,
const graphene_point_t *point,
GskFillRule fill_rule);
GDK_AVAILABLE_IN_4_14
gboolean gsk_path_get_closest_point (GskPath *self,
const graphene_point_t *point,
float threshold,
GskPathPoint *result);
GDK_AVAILABLE_IN_4_14
gboolean gsk_path_foreach (GskPath *self,
GskPathForeachFlags flags,
GskPathForeachFunc func,
gpointer user_data);
G_DEFINE_AUTOPTR_CLEANUP_FUNC(GskPath, gsk_path_unref)
G_END_DECLS