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gtk/gsk/gskpathopprivate.h

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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.
2023-07-08 14:15:22 +00:00
/*
* 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
#include "gskpath.h"
#include "gskpathbuilder.h"
G_BEGIN_DECLS
gskpathop: Introduce a type to represent an aligned graphene_point_t When we allocate a graphene_point_t on the stack, there's no guarantee that it will be aligned at an 8-byte boundary, which is an assumption made by gsk_pathop_encode() (which wants to use the lowest 3 bits to encode the operation). In the places where it matters, force the points on the stack and embedded in structs to be nicely aligned. By using a distinct type for this (a union with a suitable size and alignment), we ensure that the compiler will warn or error whenever we can't prove that a particular point is, in fact, suitably aligned. We can go from a `GskAlignedPoint *` to a `graphene_point_t *` (which is always valid, because the `GskAlignedPoint` is aligned) via &aligned_points[0].pt, but we cannot go back the other way (which is not always valid, because the `graphene_point_t` is not necessarily aligned nicely) without a cast. In practice, it seems that a graphene_point_t on x86_64 *is* usually placed at an 8-byte boundary, but this is not the case on 32-bit architectures or on s390x. In many cases we can avoid needing an explicit reference to the more complicated type by making use of a transparent union. There's already at least one transparent union in GSK's public API, so it's presumably portable enough to match GTK's requirements. Increasing the alignment of GskAlignedPoint also requires adjusting how a GskStandardContour is allocated and initialized. This data structure allocates extra memory to hold an array of GskAlignedPoint outside the bounds of the struct itself, and that array now needs to be aligned suitably. Previously the array started with at next byte after the flexible array of gskpathop, but the alignment of a gskpathop is only 4 bytes on 32-bit architectures, so depending on the number of gskpathop in the trailing flexible array, that pointer might be an unsuitable location to allocate a GskAlignedPoint. Resolves: https://gitlab.gnome.org/GNOME/gtk/-/issues/6395 Signed-off-by: Simon McVittie <smcv@debian.org>
2024-07-28 13:42:00 +00:00
/* We assume that arrays of graphene_point_t are aligned on an 8-byte
* boundary, which means we can use the lowest 3 bits to represent up
* to 8 distinct path operations. */
#define GSK_PATHOP_OPERATION_MASK (0x7)
/* graphene_point_t is a struct containing two floats, so an array of
* graphene_point_t on the stack is not necessarily 8-byte aligned
* unless we force it to be.
*
* Using a union for this means the compiler will warn or error if we
* have not handled these correctly: for example we can go from a
* GskAlignedPoint * to a graphene_point_t * (which is always OK) with:
*
* GskAlignedPoint *gap = ...;
* graphene_point_t *gpt;
* gpt = &gap[0].pt;
*
* but going back the other way is not possible without a cast or a
* compiler warning. */
typedef union
{
graphene_point_t pt;
/* On many platforms this will be enough to force the correct alignment. */
guint64 alignment;
/* Unfortunately not all platforms require guint64 to be naturally-aligned
* (for example on i386, only 4-byte alignment is required) so we have to
* try harder. */
#ifdef __GNUC__
__attribute__((aligned(8))) guint64 really_aligned;
#elif defined(_MSC_VER)
__declspec(align(8)) guint64 really_aligned;
#endif
} GskAlignedPoint;
G_STATIC_ASSERT (sizeof (GskAlignedPoint) == sizeof (graphene_point_t));
G_STATIC_ASSERT (G_ALIGNOF (GskAlignedPoint) >= GSK_PATHOP_OPERATION_MASK + 1);
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.
2023-07-08 14:15:22 +00:00
typedef gpointer gskpathop;
static inline
gskpathop gsk_pathop_encode (GskPathOperation op,
gskpathop: Introduce a type to represent an aligned graphene_point_t When we allocate a graphene_point_t on the stack, there's no guarantee that it will be aligned at an 8-byte boundary, which is an assumption made by gsk_pathop_encode() (which wants to use the lowest 3 bits to encode the operation). In the places where it matters, force the points on the stack and embedded in structs to be nicely aligned. By using a distinct type for this (a union with a suitable size and alignment), we ensure that the compiler will warn or error whenever we can't prove that a particular point is, in fact, suitably aligned. We can go from a `GskAlignedPoint *` to a `graphene_point_t *` (which is always valid, because the `GskAlignedPoint` is aligned) via &aligned_points[0].pt, but we cannot go back the other way (which is not always valid, because the `graphene_point_t` is not necessarily aligned nicely) without a cast. In practice, it seems that a graphene_point_t on x86_64 *is* usually placed at an 8-byte boundary, but this is not the case on 32-bit architectures or on s390x. In many cases we can avoid needing an explicit reference to the more complicated type by making use of a transparent union. There's already at least one transparent union in GSK's public API, so it's presumably portable enough to match GTK's requirements. Increasing the alignment of GskAlignedPoint also requires adjusting how a GskStandardContour is allocated and initialized. This data structure allocates extra memory to hold an array of GskAlignedPoint outside the bounds of the struct itself, and that array now needs to be aligned suitably. Previously the array started with at next byte after the flexible array of gskpathop, but the alignment of a gskpathop is only 4 bytes on 32-bit architectures, so depending on the number of gskpathop in the trailing flexible array, that pointer might be an unsuitable location to allocate a GskAlignedPoint. Resolves: https://gitlab.gnome.org/GNOME/gtk/-/issues/6395 Signed-off-by: Simon McVittie <smcv@debian.org>
2024-07-28 13:42:00 +00:00
const GskAlignedPoint *pts);
static inline
const GskAlignedPoint *gsk_pathop_aligned_points (gskpathop pop);
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.
2023-07-08 14:15:22 +00:00
static inline
const graphene_point_t *gsk_pathop_points (gskpathop pop);
static inline
GskPathOperation gsk_pathop_op (gskpathop pop);
static inline
gboolean gsk_pathop_foreach (gskpathop pop,
GskPathForeachFunc func,
gpointer user_data);
/* included inline so tests can use them */
static inline
void gsk_path_builder_pathop_to (GskPathBuilder *builder,
gskpathop op);
static inline
void gsk_path_builder_pathop_reverse_to (GskPathBuilder *builder,
gskpathop op);
/* IMPLEMENTATION */
path: Switch back to conics Arcs were appealing, but they have a fatal flaw: we can't split our arcs without changing the ellipse they trace. That could be fixed by adding an extra parameter, but then it is no longer any better than conics. So switch back to conics, which have the advantage that they are used elsewhere.
2023-08-25 02:16:08 +00:00
/* Note:
*
* The weight of conics is encoded as p[2].x, and the endpoint is p[3].
* This is important, since contours store the points of adjacent
* operations overlapping, so we can't put the weight at the end.
*/
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.
2023-07-08 14:15:22 +00:00
static inline gskpathop
gsk_pathop_encode (GskPathOperation op,
gskpathop: Introduce a type to represent an aligned graphene_point_t When we allocate a graphene_point_t on the stack, there's no guarantee that it will be aligned at an 8-byte boundary, which is an assumption made by gsk_pathop_encode() (which wants to use the lowest 3 bits to encode the operation). In the places where it matters, force the points on the stack and embedded in structs to be nicely aligned. By using a distinct type for this (a union with a suitable size and alignment), we ensure that the compiler will warn or error whenever we can't prove that a particular point is, in fact, suitably aligned. We can go from a `GskAlignedPoint *` to a `graphene_point_t *` (which is always valid, because the `GskAlignedPoint` is aligned) via &aligned_points[0].pt, but we cannot go back the other way (which is not always valid, because the `graphene_point_t` is not necessarily aligned nicely) without a cast. In practice, it seems that a graphene_point_t on x86_64 *is* usually placed at an 8-byte boundary, but this is not the case on 32-bit architectures or on s390x. In many cases we can avoid needing an explicit reference to the more complicated type by making use of a transparent union. There's already at least one transparent union in GSK's public API, so it's presumably portable enough to match GTK's requirements. Increasing the alignment of GskAlignedPoint also requires adjusting how a GskStandardContour is allocated and initialized. This data structure allocates extra memory to hold an array of GskAlignedPoint outside the bounds of the struct itself, and that array now needs to be aligned suitably. Previously the array started with at next byte after the flexible array of gskpathop, but the alignment of a gskpathop is only 4 bytes on 32-bit architectures, so depending on the number of gskpathop in the trailing flexible array, that pointer might be an unsuitable location to allocate a GskAlignedPoint. Resolves: https://gitlab.gnome.org/GNOME/gtk/-/issues/6395 Signed-off-by: Simon McVittie <smcv@debian.org>
2024-07-28 13:42:00 +00:00
const GskAlignedPoint *pts)
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.
2023-07-08 14:15:22 +00:00
{
/* g_assert (op & GSK_PATHOP_OPERATION_MASK == op); */
g_assert ((GPOINTER_TO_SIZE (pts) & GSK_PATHOP_OPERATION_MASK) == 0);
return GSIZE_TO_POINTER (GPOINTER_TO_SIZE (pts) | op);
}
gskpathop: Introduce a type to represent an aligned graphene_point_t When we allocate a graphene_point_t on the stack, there's no guarantee that it will be aligned at an 8-byte boundary, which is an assumption made by gsk_pathop_encode() (which wants to use the lowest 3 bits to encode the operation). In the places where it matters, force the points on the stack and embedded in structs to be nicely aligned. By using a distinct type for this (a union with a suitable size and alignment), we ensure that the compiler will warn or error whenever we can't prove that a particular point is, in fact, suitably aligned. We can go from a `GskAlignedPoint *` to a `graphene_point_t *` (which is always valid, because the `GskAlignedPoint` is aligned) via &aligned_points[0].pt, but we cannot go back the other way (which is not always valid, because the `graphene_point_t` is not necessarily aligned nicely) without a cast. In practice, it seems that a graphene_point_t on x86_64 *is* usually placed at an 8-byte boundary, but this is not the case on 32-bit architectures or on s390x. In many cases we can avoid needing an explicit reference to the more complicated type by making use of a transparent union. There's already at least one transparent union in GSK's public API, so it's presumably portable enough to match GTK's requirements. Increasing the alignment of GskAlignedPoint also requires adjusting how a GskStandardContour is allocated and initialized. This data structure allocates extra memory to hold an array of GskAlignedPoint outside the bounds of the struct itself, and that array now needs to be aligned suitably. Previously the array started with at next byte after the flexible array of gskpathop, but the alignment of a gskpathop is only 4 bytes on 32-bit architectures, so depending on the number of gskpathop in the trailing flexible array, that pointer might be an unsuitable location to allocate a GskAlignedPoint. Resolves: https://gitlab.gnome.org/GNOME/gtk/-/issues/6395 Signed-off-by: Simon McVittie <smcv@debian.org>
2024-07-28 13:42:00 +00:00
static inline const GskAlignedPoint *
gsk_pathop_aligned_points (gskpathop pop)
{
return GSIZE_TO_POINTER (GPOINTER_TO_SIZE (pop) & ~GSK_PATHOP_OPERATION_MASK);
}
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.
2023-07-08 14:15:22 +00:00
static inline const graphene_point_t *
gsk_pathop_points (gskpathop pop)
{
gskpathop: Introduce a type to represent an aligned graphene_point_t When we allocate a graphene_point_t on the stack, there's no guarantee that it will be aligned at an 8-byte boundary, which is an assumption made by gsk_pathop_encode() (which wants to use the lowest 3 bits to encode the operation). In the places where it matters, force the points on the stack and embedded in structs to be nicely aligned. By using a distinct type for this (a union with a suitable size and alignment), we ensure that the compiler will warn or error whenever we can't prove that a particular point is, in fact, suitably aligned. We can go from a `GskAlignedPoint *` to a `graphene_point_t *` (which is always valid, because the `GskAlignedPoint` is aligned) via &aligned_points[0].pt, but we cannot go back the other way (which is not always valid, because the `graphene_point_t` is not necessarily aligned nicely) without a cast. In practice, it seems that a graphene_point_t on x86_64 *is* usually placed at an 8-byte boundary, but this is not the case on 32-bit architectures or on s390x. In many cases we can avoid needing an explicit reference to the more complicated type by making use of a transparent union. There's already at least one transparent union in GSK's public API, so it's presumably portable enough to match GTK's requirements. Increasing the alignment of GskAlignedPoint also requires adjusting how a GskStandardContour is allocated and initialized. This data structure allocates extra memory to hold an array of GskAlignedPoint outside the bounds of the struct itself, and that array now needs to be aligned suitably. Previously the array started with at next byte after the flexible array of gskpathop, but the alignment of a gskpathop is only 4 bytes on 32-bit architectures, so depending on the number of gskpathop in the trailing flexible array, that pointer might be an unsuitable location to allocate a GskAlignedPoint. Resolves: https://gitlab.gnome.org/GNOME/gtk/-/issues/6395 Signed-off-by: Simon McVittie <smcv@debian.org>
2024-07-28 13:42:00 +00:00
return &(gsk_pathop_aligned_points (pop)->pt);
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.
2023-07-08 14:15:22 +00:00
}
static inline
GskPathOperation gsk_pathop_op (gskpathop pop)
{
return GPOINTER_TO_SIZE (pop) & GSK_PATHOP_OPERATION_MASK;
}
static inline gboolean
gsk_pathop_foreach (gskpathop pop,
GskPathForeachFunc func,
gpointer user_data)
{
switch (gsk_pathop_op (pop))
{
case GSK_PATH_MOVE:
path: Switch back to conics Arcs were appealing, but they have a fatal flaw: we can't split our arcs without changing the ellipse they trace. That could be fixed by adding an extra parameter, but then it is no longer any better than conics. So switch back to conics, which have the advantage that they are used elsewhere.
2023-08-25 02:16:08 +00:00
return func (gsk_pathop_op (pop), gsk_pathop_points (pop), 1, 0, user_data);
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.
2023-07-08 14:15:22 +00:00
case GSK_PATH_CLOSE:
case GSK_PATH_LINE:
path: Switch back to conics Arcs were appealing, but they have a fatal flaw: we can't split our arcs without changing the ellipse they trace. That could be fixed by adding an extra parameter, but then it is no longer any better than conics. So switch back to conics, which have the advantage that they are used elsewhere.
2023-08-25 02:16:08 +00:00
return func (gsk_pathop_op (pop), gsk_pathop_points (pop), 2, 0, user_data);
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.
2023-07-08 14:15:22 +00:00
case GSK_PATH_QUAD:
path: Switch back to conics Arcs were appealing, but they have a fatal flaw: we can't split our arcs without changing the ellipse they trace. That could be fixed by adding an extra parameter, but then it is no longer any better than conics. So switch back to conics, which have the advantage that they are used elsewhere.
2023-08-25 02:16:08 +00:00
return func (gsk_pathop_op (pop), gsk_pathop_points (pop), 3, 0, user_data);
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.
2023-07-08 14:15:22 +00:00
case GSK_PATH_CUBIC:
path: Switch back to conics Arcs were appealing, but they have a fatal flaw: we can't split our arcs without changing the ellipse they trace. That could be fixed by adding an extra parameter, but then it is no longer any better than conics. So switch back to conics, which have the advantage that they are used elsewhere.
2023-08-25 02:16:08 +00:00
return func (gsk_pathop_op (pop), gsk_pathop_points (pop), 4, 0, user_data);
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.
2023-07-08 14:15:22 +00:00
path: Switch back to conics Arcs were appealing, but they have a fatal flaw: we can't split our arcs without changing the ellipse they trace. That could be fixed by adding an extra parameter, but then it is no longer any better than conics. So switch back to conics, which have the advantage that they are used elsewhere.
2023-08-25 02:16:08 +00:00
case GSK_PATH_CONIC:
{
const graphene_point_t *pts = gsk_pathop_points (pop);
return func (gsk_pathop_op (pop), (graphene_point_t[3]) { pts[0], pts[1], pts[3] }, 3, pts[2].x, user_data);
}
path: Add elliptical arcs Add a new curve type for elliptical arcs and use it for rounded rectangles and circles. We use the 'E' command to represent elliptical arcs in serialized paths.
2023-08-18 17:32:37 +00:00
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.
2023-07-08 14:15:22 +00:00
default:
g_assert_not_reached ();
return TRUE;
}
}
static inline void
gsk_path_builder_pathop_to (GskPathBuilder *builder,
gskpathop op)
{
const graphene_point_t *pts = gsk_pathop_points (op);
switch (gsk_pathop_op (op))
{
case GSK_PATH_MOVE:
gsk_path_builder_move_to (builder, pts[0].x, pts[0].y);
break;
case GSK_PATH_CLOSE:
gsk_path_builder_close (builder);
break;
case GSK_PATH_LINE:
gsk_path_builder_line_to (builder, pts[1].x, pts[1].y);
break;
case GSK_PATH_QUAD:
gsk_path_builder_quad_to (builder, pts[1].x, pts[1].y, pts[2].x, pts[2].y);
break;
case GSK_PATH_CUBIC:
gsk_path_builder_cubic_to (builder, pts[1].x, pts[1].y, pts[2].x, pts[2].y, pts[3].x, pts[3].y);
break;
path: Switch back to conics Arcs were appealing, but they have a fatal flaw: we can't split our arcs without changing the ellipse they trace. That could be fixed by adding an extra parameter, but then it is no longer any better than conics. So switch back to conics, which have the advantage that they are used elsewhere.
2023-08-25 02:16:08 +00:00
case GSK_PATH_CONIC:
gsk_path_builder_conic_to (builder, pts[1].x, pts[1].y, pts[3].x, pts[3].y, pts[2].x);
path: Add elliptical arcs Add a new curve type for elliptical arcs and use it for rounded rectangles and circles. We use the 'E' command to represent elliptical arcs in serialized paths.
2023-08-18 17:32:37 +00:00
break;
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.
2023-07-08 14:15:22 +00:00
default:
g_assert_not_reached ();
break;
}
}
static inline void
gsk_path_builder_pathop_reverse_to (GskPathBuilder *builder,
gskpathop op)
{
const graphene_point_t *pts = gsk_pathop_points (op);
switch (gsk_pathop_op (op))
{
case GSK_PATH_MOVE:
gsk_path_builder_move_to (builder, pts[0].x, pts[0].y);
break;
case GSK_PATH_CLOSE:
gsk_path_builder_line_to (builder, pts[0].x, pts[0].y);
break;
case GSK_PATH_LINE:
gsk_path_builder_line_to (builder, pts[1].x, pts[1].y);
break;
case GSK_PATH_QUAD:
gsk_path_builder_quad_to (builder, pts[1].x, pts[1].y, pts[0].x, pts[0].y);
break;
case GSK_PATH_CUBIC:
gsk_path_builder_cubic_to (builder, pts[2].x, pts[2].y, pts[1].x, pts[1].y, pts[0].x, pts[0].y);
break;
path: Switch back to conics Arcs were appealing, but they have a fatal flaw: we can't split our arcs without changing the ellipse they trace. That could be fixed by adding an extra parameter, but then it is no longer any better than conics. So switch back to conics, which have the advantage that they are used elsewhere.
2023-08-25 02:16:08 +00:00
case GSK_PATH_CONIC:
gsk_path_builder_conic_to (builder, pts[1].x, pts[1].y, pts[0].x, pts[0].y, pts[2].x);
path: Add elliptical arcs Add a new curve type for elliptical arcs and use it for rounded rectangles and circles. We use the 'E' command to represent elliptical arcs in serialized paths.
2023-08-18 17:32:37 +00:00
break;
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.
2023-07-08 14:15:22 +00:00
default:
g_assert_not_reached ();
break;
}
}
G_END_DECLS
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