[gtk/path-work-rebased: 57/121] path: Add GskCurve
- From: Matthias Clasen <matthiasc src gnome org>
- To: commits-list gnome org
- Cc:
- Subject: [gtk/path-work-rebased: 57/121] path: Add GskCurve
- Date: Sun, 5 Dec 2021 03:58:57 +0000 (UTC)
commit eb04db32e0a470285bc66983b7f91df034a2f89c
Author: Benjamin Otte <otte redhat com>
Date: Sun Dec 6 18:46:08 2020 +0100
path: Add GskCurve
GskCurve is an abstraction for path operations. It's essentially a
collection of vfuncs per GskPathOperation.
GskStandardContour has been ported to use it where appropriate.
gsk/gskcontour.c | 240 ++++-------------
gsk/gskcurve.c | 705 +++++++++++++++++++++++++++++++++++++++++++++++++
gsk/gskcurveprivate.h | 108 ++++++++
gsk/gskpath.c | 69 ++---
gsk/gskpathopprivate.h | 1 +
gsk/gskpathprivate.h | 1 +
gsk/gskspline.c | 378 --------------------------
gsk/gsksplineprivate.h | 32 ---
gsk/meson.build | 3 +-
9 files changed, 900 insertions(+), 637 deletions(-)
---
diff --git a/gsk/gskcontour.c b/gsk/gskcontour.c
index e1f2853407..9f8796adc7 100644
--- a/gsk/gskcontour.c
+++ b/gsk/gskcontour.c
@@ -21,6 +21,7 @@
#include "gskcontourprivate.h"
+#include "gskcurveprivate.h"
#include "gskpathbuilder.h"
#include "gskpathprivate.h"
#include "gsksplineprivate.h"
@@ -1030,7 +1031,7 @@ typedef struct
GskStandardContourMeasure measure;
} LengthDecompose;
-static void
+static gboolean
gsk_standard_contour_measure_add_point (const graphene_point_t *from,
const graphene_point_t *to,
float from_progress,
@@ -1041,6 +1042,9 @@ gsk_standard_contour_measure_add_point (const graphene_point_t *from,
float seg_length;
seg_length = graphene_point_distance (from, to, NULL, NULL);
+ if (seg_length == 0)
+ return TRUE;
+
decomp->measure.end += seg_length;
decomp->measure.start_progress = from_progress;
decomp->measure.end_progress = to_progress;
@@ -1049,6 +1053,8 @@ gsk_standard_contour_measure_add_point (const graphene_point_t *from,
g_array_append_val (decomp->array, decomp->measure);
decomp->measure.start += seg_length;
+
+ return TRUE;
}
static gpointer
@@ -1058,7 +1064,7 @@ gsk_standard_contour_init_measure (const GskContour *contour,
{
const GskStandardContour *self = (const GskStandardContour *) contour;
gsize i;
- float length, seg_length;
+ float length;
GArray *array;
array = g_array_new (FALSE, FALSE, sizeof (GskStandardContourMeasure));
@@ -1066,50 +1072,12 @@ gsk_standard_contour_init_measure (const GskContour *contour,
for (i = 1; i < self->n_ops; i ++)
{
- const graphene_point_t *pt = gsk_pathop_points (self->ops[i]);
-
- switch (gsk_pathop_op (self->ops[i]))
- {
- case GSK_PATH_MOVE:
- break;
+ GskCurve curve;
+ LengthDecompose decomp = { array, { length, length, 0, 0, { }, i } };
- case GSK_PATH_CLOSE:
- case GSK_PATH_LINE:
- seg_length = graphene_point_distance (&pt[0], &pt[1], NULL, NULL);
- if (seg_length > 0)
- {
- g_array_append_vals (array,
- &(GskStandardContourMeasure) {
- length,
- length + seg_length,
- 0, 1,
- pt[1],
- i,
- }, 1);
- length += seg_length;
- }
- break;
-
- case GSK_PATH_CURVE:
- {
- LengthDecompose decomp = { array, { length, length, 0, 0, pt[0], i } };
- gsk_spline_decompose_cubic (pt, tolerance, gsk_standard_contour_measure_add_point, &decomp);
- length = decomp.measure.start;
- }
- break;
-
- case GSK_PATH_CONIC:
- {
- LengthDecompose decomp = { array, { length, length, 0, 0, pt[0], i } };
- gsk_spline_decompose_conic (pt, tolerance, gsk_standard_contour_measure_add_point, &decomp);
- length = decomp.measure.start;
- }
- break;
-
- default:
- g_assert_not_reached();
- return NULL;
- }
+ gsk_curve_init (&curve, self->ops[i]);
+ gsk_curve_decompose (&curve, tolerance, gsk_standard_contour_measure_add_point, &decomp);
+ length = decomp.measure.start;
}
*out_length = length;
@@ -1146,35 +1114,11 @@ gsk_standard_contour_measure_get_point (GskStandardContour *self,
graphene_point_t *pos,
graphene_vec2_t *tangent)
{
- const graphene_point_t *pts;
+ GskCurve curve;
- pts = gsk_pathop_points (self->ops[op]);
- switch (gsk_pathop_op (self->ops[op]))
- {
- case GSK_PATH_LINE:
- case GSK_PATH_CLOSE:
- if (pos)
- graphene_point_interpolate (&pts[0], &pts[1], progress, pos);
- if (tangent)
- {
- graphene_vec2_init (tangent, pts[1].x - pts[0].x, pts[1].y - pts[0].y);
- graphene_vec2_normalize (tangent, tangent);
- }
- break;
-
- case GSK_PATH_CURVE:
- gsk_spline_get_point_cubic (pts, progress, pos, tangent);
- break;
-
- case GSK_PATH_CONIC:
- gsk_spline_get_point_conic (pts, progress, pos, tangent);
- break;
-
- case GSK_PATH_MOVE:
- default:
- g_assert_not_reached ();
- return;
- }
+ gsk_curve_init (&curve, self->ops[op]);
+
+ gsk_curve_eval (&curve, progress, pos, tangent);
}
static void
@@ -1365,144 +1309,52 @@ gsk_standard_contour_add_segment (const GskContour *contour,
* taking care that first and last operation might be identical */
if (start_measure)
{
- switch (gsk_pathop_op (self->ops[start_measure->op]))
- {
- case GSK_PATH_CLOSE:
- case GSK_PATH_LINE:
- {
- const graphene_point_t *pts = gsk_pathop_points (self->ops[start_measure->op]);
- graphene_point_t point;
-
- graphene_point_interpolate (&pts[0], &pts[1], start_progress, &point);
- gsk_path_builder_move_to (builder, point.x, point.y);
- if (end_measure && end_measure->op == start_measure->op)
- {
- graphene_point_interpolate (&pts[0], &pts[1], end_progress, &point);
- gsk_path_builder_line_to (builder, point.x, point.y);
- return;
- }
- gsk_path_builder_line_to (builder, pts[1].x, pts[1].y);
- }
- break;
+ GskCurve curve, cut;
+ const graphene_point_t *start_point;
- case GSK_PATH_CURVE:
- {
- const graphene_point_t *pts = gsk_pathop_points (self->ops[start_measure->op]);
- graphene_point_t curve[4], discard[4];
-
- gsk_spline_split_cubic (pts, discard, curve, start_progress);
- if (end_measure && end_measure->op == start_measure->op)
- {
- graphene_point_t tiny[4];
- gsk_spline_split_cubic (curve, tiny, discard, (end_progress - start_progress) / (1 -
start_progress));
- gsk_path_builder_move_to (builder, tiny[0].x, tiny[0].y);
- gsk_path_builder_curve_to (builder, tiny[1].x, tiny[1].y, tiny[2].x, tiny[2].y, tiny[3].x,
tiny[3].y);
- return;
- }
- gsk_path_builder_move_to (builder, curve[0].x, curve[0].y);
- gsk_path_builder_curve_to (builder, curve[1].x, curve[1].y, curve[2].x, curve[2].y, curve[3].x,
curve[3].y);
- }
- break;
+ gsk_curve_init (&curve, self->ops[start_measure->op]);
- case GSK_PATH_CONIC:
- {
- const graphene_point_t *pts = gsk_pathop_points (self->ops[start_measure->op]);
- graphene_point_t curve[4], discard[4];
-
- gsk_spline_split_conic (pts, discard, curve, start_progress);
- if (end_measure && end_measure->op == start_measure->op)
- {
- graphene_point_t tiny[4];
- gsk_spline_split_conic (curve, tiny, discard, (end_progress - start_progress) / (1 -
start_progress));
- gsk_path_builder_move_to (builder, tiny[0].x, tiny[0].y);
- gsk_path_builder_conic_to (builder, tiny[1].x, tiny[1].y, tiny[3].x, tiny[3].y, tiny[2].x);
- return;
- }
- gsk_path_builder_move_to (builder, curve[0].x, curve[0].y);
- gsk_path_builder_conic_to (builder, curve[1].x, curve[1].y, curve[3].x, curve[3].y, curve[2].x);
- }
- break;
+ gsk_curve_split (&curve, start_progress, NULL, &cut);
+ start_point = gsk_curve_get_start_point (&cut);
+ gsk_path_builder_move_to (builder, start_point->x, start_point->y);
- case GSK_PATH_MOVE:
- default:
- g_assert_not_reached();
+ if (end_measure && end_measure->op == start_measure->op)
+ {
+ GskCurve cut2;
+
+ gsk_curve_split (&cut, (end_progress - start_progress) / (1 - start_progress), &cut2, NULL);
+ gsk_curve_builder_to (&cut2, builder);
return;
- }
+ }
+
+ gsk_curve_builder_to (&cut, builder);
i = start_measure->op + 1;
}
else
i = 0;
- for (; i < (end_measure ? end_measure->op : self->n_ops); i++)
+ for (; i < (end_measure ? end_measure->op : self->n_ops - 1); i++)
{
- const graphene_point_t *pt = gsk_pathop_points (self->ops[i]);
-
- switch (gsk_pathop_op (self->ops[i]))
- {
- case GSK_PATH_MOVE:
- gsk_path_builder_move_to (builder, pt[0].x, pt[0].y);
- break;
-
- case GSK_PATH_LINE:
- case GSK_PATH_CLOSE:
- gsk_path_builder_line_to (builder, pt[1].x, pt[1].y);
- break;
-
- case GSK_PATH_CURVE:
- gsk_path_builder_curve_to (builder, pt[1].x, pt[1].y, pt[2].x, pt[2].y, pt[3].x, pt[3].y);
- break;
-
- case GSK_PATH_CONIC:
- gsk_path_builder_conic_to (builder, pt[1].x, pt[1].y, pt[3].x, pt[3].y, pt[2].x);
- break;
-
- default:
- g_assert_not_reached();
- return;
- }
+ gsk_path_builder_pathop_to (builder, self->ops[i]);
}
/* Add the last partial operation */
if (end_measure)
{
- switch (gsk_pathop_op (self->ops[end_measure->op]))
- {
- case GSK_PATH_CLOSE:
- case GSK_PATH_LINE:
- {
- const graphene_point_t *pts = gsk_pathop_points (self->ops[end_measure->op]);
- graphene_point_t point;
-
- graphene_point_interpolate (&pts[0], &pts[1], end_progress, &point);
- gsk_path_builder_line_to (builder, point.x, point.y);
- }
- break;
+ GskCurve curve, cut;
- case GSK_PATH_CURVE:
- {
- const graphene_point_t *pts = gsk_pathop_points (self->ops[end_measure->op]);
- graphene_point_t curve[4], discard[4];
-
- gsk_spline_split_cubic (pts, curve, discard, end_progress);
- gsk_path_builder_curve_to (builder, curve[1].x, curve[1].y, curve[2].x, curve[2].y, curve[3].x,
curve[3].y);
- }
- break;
-
- case GSK_PATH_CONIC:
- {
- const graphene_point_t *pts = gsk_pathop_points (self->ops[end_measure->op]);
- graphene_point_t curve[4], discard[4];
+ gsk_curve_init (&curve, self->ops[end_measure->op]);
- gsk_spline_split_conic (pts, curve, discard, end_progress);
- gsk_path_builder_conic_to (builder, curve[1].x, curve[1].y, curve[3].x, curve[3].y, curve[2].x);
- }
- break;
-
- case GSK_PATH_MOVE:
- default:
- g_assert_not_reached();
- return;
- }
+ gsk_curve_split (&curve, end_progress, &cut, NULL);
+ gsk_curve_builder_to (&cut, builder);
+ }
+ else if (i == self->n_ops - 1)
+ {
+ gskpathop op = self->ops[i];
+ if (gsk_pathop_op (op) == GSK_PATH_CLOSE)
+ gsk_path_builder_pathop_to (builder, gsk_pathop_encode (GSK_PATH_LINE, gsk_pathop_points (op)));
+ else
+ gsk_path_builder_pathop_to (builder, op);
}
}
diff --git a/gsk/gskcurve.c b/gsk/gskcurve.c
new file mode 100644
index 0000000000..36a08a130e
--- /dev/null
+++ b/gsk/gskcurve.c
@@ -0,0 +1,705 @@
+/*
+ * 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>
+ */
+
+#include "config.h"
+
+#include "gskcurveprivate.h"
+
+#define MIN_PROGRESS (1/1024.f)
+
+typedef struct _GskCurveClass GskCurveClass;
+
+struct _GskCurveClass
+{
+ void (* init) (GskCurve *curve,
+ gskpathop op);
+ void (* eval) (const GskCurve *curve,
+ float progress,
+ graphene_point_t *pos,
+ graphene_vec2_t *tangent);
+ void (* split) (const GskCurve *curve,
+ float progress,
+ GskCurve *result1,
+ GskCurve *result2);
+ gboolean (* decompose) (const GskCurve *curve,
+ float tolerance,
+ GskCurveAddLineFunc add_line_func,
+ gpointer user_data);
+ gskpathop (* pathop) (const GskCurve *curve);
+ const graphene_point_t * (* get_start_point) (const GskCurve *curve);
+ const graphene_point_t * (* get_end_point) (const GskCurve *curve);
+};
+
+/** LINE **/
+
+static void
+gsk_line_curve_init_from_points (GskLineCurve *self,
+ GskPathOperation op,
+ const graphene_point_t *start,
+ const graphene_point_t *end)
+{
+ self->op = op;
+ self->points[0] = *start;
+ self->points[1] = *end;
+}
+
+static void
+gsk_line_curve_init (GskCurve *curve,
+ gskpathop op)
+{
+ GskLineCurve *self = &curve->line;
+ const graphene_point_t *pts = gsk_pathop_points (op);
+
+ gsk_line_curve_init_from_points (self, gsk_pathop_op (op), &pts[0], &pts[1]);
+}
+
+static void
+gsk_line_curve_eval (const GskCurve *curve,
+ float progress,
+ graphene_point_t *pos,
+ graphene_vec2_t *tangent)
+{
+ const GskLineCurve *self = &curve->line;
+
+ if (pos)
+ graphene_point_interpolate (&self->points[0], &self->points[1], progress, pos);
+
+ if (tangent)
+ {
+ graphene_vec2_init (tangent, self->points[1].x - self->points[0].x, self->points[1].y -
self->points[0].y);
+ graphene_vec2_normalize (tangent, tangent);
+ }
+}
+
+static void
+gsk_line_curve_split (const GskCurve *curve,
+ float progress,
+ GskCurve *start,
+ GskCurve *end)
+{
+ const GskLineCurve *self = &curve->line;
+ graphene_point_t point;
+
+ graphene_point_interpolate (&self->points[0], &self->points[1], progress, &point);
+
+ if (start)
+ gsk_line_curve_init_from_points (&start->line, GSK_PATH_LINE, &self->points[0], &point);
+ if (end)
+ gsk_line_curve_init_from_points (&end->line, GSK_PATH_LINE, &point, &self->points[1]);
+}
+
+static gboolean
+gsk_line_curve_decompose (const GskCurve *curve,
+ float tolerance,
+ GskCurveAddLineFunc add_line_func,
+ gpointer user_data)
+{
+ const GskLineCurve *self = &curve->line;
+
+ return add_line_func (&self->points[0], &self->points[1], 0.0f, 1.0f, user_data);
+}
+
+static gskpathop
+gsk_line_curve_pathop (const GskCurve *curve)
+{
+ const GskLineCurve *self = &curve->line;
+
+ return gsk_pathop_encode (self->op, self->points);
+}
+
+static const graphene_point_t *
+gsk_line_curve_get_start_point (const GskCurve *curve)
+{
+ const GskLineCurve *self = &curve->line;
+
+ return &self->points[0];
+}
+
+static const graphene_point_t *
+gsk_line_curve_get_end_point (const GskCurve *curve)
+{
+ const GskLineCurve *self = &curve->line;
+
+ return &self->points[1];
+}
+
+static const GskCurveClass GSK_LINE_CURVE_CLASS = {
+ gsk_line_curve_init,
+ gsk_line_curve_eval,
+ gsk_line_curve_split,
+ gsk_line_curve_decompose,
+ gsk_line_curve_pathop,
+ gsk_line_curve_get_start_point,
+ gsk_line_curve_get_end_point,
+};
+
+/** CURVE **/
+
+static void
+gsk_curve_curve_init_from_points (GskCurveCurve *self,
+ const graphene_point_t pts[4])
+{
+ self->op = GSK_PATH_CURVE;
+ self->has_coefficients = FALSE;
+ memcpy (self->points, pts, sizeof (graphene_point_t) * 4);
+}
+
+static void
+gsk_curve_curve_init (GskCurve *curve,
+ gskpathop op)
+{
+ GskCurveCurve *self = &curve->curve;
+
+ gsk_curve_curve_init_from_points (self, gsk_pathop_points (op));
+}
+
+static void
+gsk_curve_curve_ensure_coefficients (const GskCurveCurve *curve)
+{
+ GskCurveCurve *self = (GskCurveCurve *) curve;
+ const graphene_point_t *pts = &self->points[0];
+
+ if (self->has_coefficients)
+ return;
+
+ self->coeffs[0] = GRAPHENE_POINT_INIT (pts[3].x - 3.0f * pts[2].x + 3.0f * pts[1].x - pts[0].x,
+ pts[3].y - 3.0f * pts[2].y + 3.0f * pts[1].y - pts[0].y);
+ self->coeffs[1] = GRAPHENE_POINT_INIT (3.0f * pts[2].x - 6.0f * pts[1].x + 3.0f * pts[0].x,
+ 3.0f * pts[2].y - 6.0f * pts[1].y + 3.0f * pts[0].y);
+ self->coeffs[2] = GRAPHENE_POINT_INIT (3.0f * pts[1].x - 3.0f * pts[0].x,
+ 3.0f * pts[1].y - 3.0f * pts[0].y);
+ self->coeffs[3] = pts[0];
+
+ self->has_coefficients = TRUE;
+}
+
+static void
+gsk_curve_curve_eval (const GskCurve *curve,
+ float progress,
+ graphene_point_t *pos,
+ graphene_vec2_t *tangent)
+{
+ const GskCurveCurve *self = &curve->curve;
+ const graphene_point_t *c = self->coeffs;
+
+ gsk_curve_curve_ensure_coefficients (self);
+
+ if (pos)
+ *pos = GRAPHENE_POINT_INIT (((c[0].x * progress + c[1].x) * progress +c[2].x) * progress + c[3].x,
+ ((c[0].y * progress + c[1].y) * progress +c[2].y) * progress + c[3].y);
+ if (tangent)
+ {
+ graphene_vec2_init (tangent,
+ (3.0f * c[0].x * progress + 2.0f * c[1].x) * progress + c[2].x,
+ (3.0f * c[0].y * progress + 2.0f * c[1].y) * progress + c[2].y);
+ graphene_vec2_normalize (tangent, tangent);
+ }
+}
+
+static void
+gsk_curve_curve_split (const GskCurve *curve,
+ float progress,
+ GskCurve *start,
+ GskCurve *end)
+{
+ const GskCurveCurve *self = &curve->curve;
+ const graphene_point_t *pts = self->points;
+ graphene_point_t ab, bc, cd;
+ graphene_point_t abbc, bccd;
+ graphene_point_t final;
+
+ graphene_point_interpolate (&pts[0], &pts[1], progress, &ab);
+ graphene_point_interpolate (&pts[1], &pts[2], progress, &bc);
+ graphene_point_interpolate (&pts[2], &pts[3], progress, &cd);
+ graphene_point_interpolate (&ab, &bc, progress, &abbc);
+ graphene_point_interpolate (&bc, &cd, progress, &bccd);
+ graphene_point_interpolate (&abbc, &bccd, progress, &final);
+
+ if (start)
+ gsk_curve_curve_init_from_points (&start->curve, (graphene_point_t[4]) { pts[0], ab, abbc, final });
+ if (end)
+ gsk_curve_curve_init_from_points (&end->curve, (graphene_point_t[4]) { final, bccd, cd, pts[3] });
+}
+
+/* taken from Skia, including the very descriptive name */
+static gboolean
+gsk_curve_curve_too_curvy (const GskCurveCurve *self,
+ float tolerance)
+{
+ const graphene_point_t *pts = self->points;
+ graphene_point_t p;
+
+ graphene_point_interpolate (&pts[0], &pts[3], 1.0f / 3, &p);
+ if (ABS (p.x - pts[1].x) + ABS (p.y - pts[1].y) > tolerance)
+ return TRUE;
+
+ graphene_point_interpolate (&pts[0], &pts[3], 2.0f / 3, &p);
+ if (ABS (p.x - pts[2].x) + ABS (p.y - pts[2].y) > tolerance)
+ return TRUE;
+
+ return FALSE;
+}
+
+static gboolean
+gsk_curce_curve_decompose_step (const GskCurve *curve,
+ float start_progress,
+ float end_progress,
+ float tolerance,
+ GskCurveAddLineFunc add_line_func,
+ gpointer user_data)
+{
+ const GskCurveCurve *self = &curve->curve;
+ GskCurve left, right;
+ float mid_progress;
+
+ if (!gsk_curve_curve_too_curvy (self, tolerance) || end_progress - start_progress <= MIN_PROGRESS)
+ return add_line_func (&self->points[0], &self->points[3], start_progress, end_progress, user_data);
+
+ gsk_curve_curve_split ((const GskCurve *) self, 0.5, &left, &right);
+ mid_progress = (start_progress + end_progress) / 2;
+
+ return gsk_curce_curve_decompose_step (&left, start_progress, mid_progress, tolerance, add_line_func,
user_data)
+ && gsk_curce_curve_decompose_step (&right, mid_progress, end_progress, tolerance, add_line_func,
user_data);
+}
+
+static gboolean
+gsk_curve_curve_decompose (const GskCurve *curve,
+ float tolerance,
+ GskCurveAddLineFunc add_line_func,
+ gpointer user_data)
+{
+ return gsk_curce_curve_decompose_step (curve, 0.0, 1.0, tolerance, add_line_func, user_data);
+}
+
+static gskpathop
+gsk_curve_curve_pathop (const GskCurve *curve)
+{
+ const GskCurveCurve *self = &curve->curve;
+
+ return gsk_pathop_encode (self->op, self->points);
+}
+
+static const graphene_point_t *
+gsk_curve_curve_get_start_point (const GskCurve *curve)
+{
+ const GskCurveCurve *self = &curve->curve;
+
+ return &self->points[0];
+}
+
+static const graphene_point_t *
+gsk_curve_curve_get_end_point (const GskCurve *curve)
+{
+ const GskCurveCurve *self = &curve->curve;
+
+ return &self->points[3];
+}
+
+static const GskCurveClass GSK_CURVE_CURVE_CLASS = {
+ gsk_curve_curve_init,
+ gsk_curve_curve_eval,
+ gsk_curve_curve_split,
+ gsk_curve_curve_decompose,
+ gsk_curve_curve_pathop,
+ gsk_curve_curve_get_start_point,
+ gsk_curve_curve_get_end_point,
+};
+
+/** CONIC **/
+
+static void
+gsk_conic_curve_init_from_points (GskConicCurve *self,
+ const graphene_point_t pts[4])
+{
+ self->op = GSK_PATH_CONIC;
+ self->has_coefficients = FALSE;
+
+ memcpy (self->points, pts, sizeof (graphene_point_t) * 4);
+}
+
+static void
+gsk_conic_curve_init (GskCurve *curve,
+ gskpathop op)
+{
+ GskConicCurve *self = &curve->conic;
+
+ gsk_conic_curve_init_from_points (self, gsk_pathop_points (op));
+}
+
+static inline float
+gsk_conic_curve_get_weight (const GskConicCurve *self)
+{
+ return self->points[2].x;
+}
+
+static void
+gsk_conic_curve_ensure_coefficents (const GskConicCurve *curve)
+{
+ GskConicCurve *self = (GskConicCurve *) curve;
+ float w = gsk_conic_curve_get_weight (self);
+ const graphene_point_t *pts = self->points;
+ graphene_point_t pw = GRAPHENE_POINT_INIT (w * pts[1].x, w * pts[1].y);
+
+ if (self->has_coefficients)
+ return;
+
+ self->num[2] = pts[0];
+ self->num[1] = GRAPHENE_POINT_INIT (2 * (pw.x - pts[0].x),
+ 2 * (pw.y - pts[0].y));
+ self->num[0] = GRAPHENE_POINT_INIT (pts[3].x - 2 * pw.x + pts[0].x,
+ pts[3].y - 2 * pw.y + pts[0].y);
+
+ self->denom[2] = GRAPHENE_POINT_INIT (1, 1);
+ self->denom[1] = GRAPHENE_POINT_INIT (2 * (w - 1), 2 * (w - 1));
+ self->denom[0] = GRAPHENE_POINT_INIT (-self->denom[1].x, -self->denom[1].y);
+
+ self->has_coefficients = TRUE;
+}
+
+static inline void
+gsk_curve_eval_quad (const graphene_point_t quad[3],
+ float progress,
+ graphene_point_t *result)
+{
+ *result = GRAPHENE_POINT_INIT ((quad[0].x * progress + quad[1].x) * progress + quad[2].x,
+ (quad[0].y * progress + quad[1].y) * progress + quad[2].y);
+}
+
+static inline void
+gsk_conic_curve_eval_point (const GskConicCurve *self,
+ float progress,
+ graphene_point_t *point)
+{
+ graphene_point_t num, denom;
+
+ gsk_curve_eval_quad (self->num, progress, &num);
+ gsk_curve_eval_quad (self->denom, progress, &denom);
+
+ *point = GRAPHENE_POINT_INIT (num.x / denom.x, num.y / denom.y);
+}
+
+static void
+gsk_conic_curve_eval (const GskCurve *curve,
+ float progress,
+ graphene_point_t *pos,
+ graphene_vec2_t *tangent)
+{
+ const GskConicCurve *self = &curve->conic;
+
+ gsk_conic_curve_ensure_coefficents (self);
+
+ if (pos)
+ gsk_conic_curve_eval_point (self, progress, pos);
+
+ if (tangent)
+ {
+ graphene_point_t tmp;
+ float w = gsk_conic_curve_get_weight (self);
+ const graphene_point_t *pts = self->points;
+
+ /* The tangent will be 0 in these corner cases, just
+ * treat it like a line here. */
+ if ((progress <= 0.f && graphene_point_equal (&pts[0], &pts[1])) ||
+ (progress >= 1.f && graphene_point_equal (&pts[1], &pts[3])))
+ {
+ graphene_vec2_init (tangent, pts[3].x - pts[0].x, pts[3].y - pts[0].y);
+ return;
+ }
+
+ gsk_curve_eval_quad ((graphene_point_t[3]) {
+ GRAPHENE_POINT_INIT ((w - 1) * (pts[3].x - pts[0].x),
+ (w - 1) * (pts[3].y - pts[0].y)),
+ GRAPHENE_POINT_INIT (pts[3].x - pts[0].x - 2 * w * (pts[1].x - pts[0].x),
+ pts[3].y - pts[0].y - 2 * w * (pts[1].y - pts[0].y)),
+ GRAPHENE_POINT_INIT (w * (pts[1].x - pts[0].x),
+ w * (pts[1].y - pts[0].y))
+ },
+ progress,
+ &tmp);
+ graphene_vec2_init (tangent, tmp.x, tmp.y);
+ graphene_vec2_normalize (tangent, tangent);
+ }
+}
+
+static void
+split_bezier3d_recurse (const graphene_point3d_t *p,
+ int l,
+ float t,
+ graphene_point3d_t *left,
+ graphene_point3d_t *right,
+ int *lpos,
+ int *rpos)
+{
+ if (l == 1)
+ {
+ left[*lpos] = p[0];
+ right[*rpos] = p[0];
+ }
+ else
+ {
+ graphene_point3d_t *np;
+ int i;
+
+ np = g_alloca (sizeof (graphene_point3d_t) * (l - 1));
+ for (i = 0; i < l - 1; i++)
+ {
+ if (i == 0)
+ {
+ left[*lpos] = p[i];
+ (*lpos)++;
+ }
+ if (i + 1 == l - 1)
+ {
+ right[*rpos] = p[i + 1];
+ (*rpos)--;
+ }
+ graphene_point3d_interpolate (&p[i], &p[i + 1], t, &np[i]);
+ }
+ split_bezier3d_recurse (np, l - 1, t, left, right, lpos, rpos);
+ }
+}
+
+static void
+split_bezier3d (const graphene_point3d_t *p,
+ int l,
+ float t,
+ graphene_point3d_t *left,
+ graphene_point3d_t *right)
+{
+ int lpos = 0;
+ int rpos = l - 1;
+ split_bezier3d_recurse (p, l, t, left, right, &lpos, &rpos);
+}
+
+static void
+gsk_conic_curve_split (const GskCurve *curve,
+ float progress,
+ GskCurve *start,
+ GskCurve *end)
+{
+ const GskConicCurve *self = &curve->conic;
+ graphene_point3d_t p[3];
+ graphene_point3d_t l[3], r[3];
+ graphene_point_t left[4], right[4];
+ float w;
+
+ /* do de Casteljau in homogeneous coordinates... */
+ w = self->points[2].x;
+ p[0] = GRAPHENE_POINT3D_INIT (self->points[0].x, self->points[0].y, 1);
+ p[1] = GRAPHENE_POINT3D_INIT (self->points[1].x * w, self->points[1].y * w, w);
+ p[2] = GRAPHENE_POINT3D_INIT (self->points[3].x, self->points[3].y, 1);
+
+ split_bezier3d (p, 3, progress, l, r);
+
+ /* then project the control points down */
+ left[0] = GRAPHENE_POINT_INIT (l[0].x / l[0].z, l[0].y / l[0].z);
+ left[1] = GRAPHENE_POINT_INIT (l[1].x / l[1].z, l[1].y / l[1].z);
+ left[3] = GRAPHENE_POINT_INIT (l[2].x / l[2].z, l[2].y / l[2].z);
+
+ right[0] = GRAPHENE_POINT_INIT (r[0].x / r[0].z, r[0].y / r[0].z);
+ right[1] = GRAPHENE_POINT_INIT (r[1].x / r[1].z, r[1].y / r[1].z);
+ right[3] = GRAPHENE_POINT_INIT (r[2].x / r[2].z, r[2].y / r[2].z);
+
+ /* normalize the outer weights to be 1 by using
+ * the fact that weights w_i and c*w_i are equivalent
+ * for any nonzero constant c
+ */
+ for (int i = 0; i < 3; i++)
+ {
+ l[i].z /= l[0].z;
+ r[i].z /= r[2].z;
+ }
+
+ /* normalize the inner weight to be 1 by using
+ * the fact that w_0*w_2/w_1^2 is a constant for
+ * all equivalent weights.
+ */
+ left[2] = GRAPHENE_POINT_INIT (l[1].z / sqrt (l[2].z), 0);
+ right[2] = GRAPHENE_POINT_INIT (r[1].z / sqrt (r[0].z), 0);
+
+ if (start)
+ gsk_curve_init (start, gsk_pathop_encode (GSK_PATH_CONIC, left));
+ if (end)
+ gsk_curve_init (end, gsk_pathop_encode (GSK_PATH_CONIC, right));
+}
+
+/* taken from Skia, including the very descriptive name */
+static gboolean
+gsk_conic_curve_too_curvy (const graphene_point_t *start,
+ const graphene_point_t *mid,
+ const graphene_point_t *end,
+ float tolerance)
+{
+ return fabs ((start->x + end->x) * 0.5 - mid->x) > tolerance
+ || fabs ((start->y + end->y) * 0.5 - mid->y) > tolerance;
+}
+
+static gboolean
+gsk_conic_curve_decompose_subdivide (const GskConicCurve *self,
+ float tolerance,
+ const graphene_point_t *start,
+ float start_progress,
+ const graphene_point_t *end,
+ float end_progress,
+ GskCurveAddLineFunc add_line_func,
+ gpointer user_data)
+{
+ graphene_point_t mid;
+ float mid_progress;
+
+ mid_progress = (start_progress + end_progress) / 2;
+ gsk_conic_curve_eval_point (self, mid_progress, &mid);
+
+ if (end_progress - start_progress <= MIN_PROGRESS ||
+ !gsk_conic_curve_too_curvy (start, &mid, end, tolerance))
+ {
+ return add_line_func (start, end, start_progress, end_progress, user_data);
+ }
+
+ return gsk_conic_curve_decompose_subdivide (self, tolerance,
+ start, start_progress, &mid, mid_progress,
+ add_line_func, user_data)
+ && gsk_conic_curve_decompose_subdivide (self, tolerance,
+ &mid, mid_progress, end, end_progress,
+ add_line_func, user_data);
+}
+
+static gboolean
+gsk_conic_curve_decompose (const GskCurve *curve,
+ float tolerance,
+ GskCurveAddLineFunc add_line_func,
+ gpointer user_data)
+{
+ const GskConicCurve *self = &curve->conic;
+
+ gsk_conic_curve_ensure_coefficents (self);
+
+ return gsk_conic_curve_decompose_subdivide (self,
+ tolerance,
+ &self->points[0],
+ 0.0f,
+ &self->points[3],
+ 1.0f,
+ add_line_func,
+ user_data);
+}
+
+static gskpathop
+gsk_conic_curve_pathop (const GskCurve *curve)
+{
+ const GskConicCurve *self = &curve->conic;
+
+ return gsk_pathop_encode (self->op, self->points);
+}
+
+static const graphene_point_t *
+gsk_conic_curve_get_start_point (const GskCurve *curve)
+{
+ const GskConicCurve *self = &curve->conic;
+
+ return &self->points[0];
+}
+
+static const graphene_point_t *
+gsk_conic_curve_get_end_point (const GskCurve *curve)
+{
+ const GskConicCurve *self = &curve->conic;
+
+ return &self->points[3];
+}
+
+static const GskCurveClass GSK_CONIC_CURVE_CLASS = {
+ gsk_conic_curve_init,
+ gsk_conic_curve_eval,
+ gsk_conic_curve_split,
+ gsk_conic_curve_decompose,
+ gsk_conic_curve_pathop,
+ gsk_conic_curve_get_start_point,
+ gsk_conic_curve_get_end_point,
+};
+
+/** API **/
+
+static const GskCurveClass *
+get_class (GskPathOperation op)
+{
+ const GskCurveClass *klasses[] = {
+ [GSK_PATH_CLOSE] = &GSK_LINE_CURVE_CLASS,
+ [GSK_PATH_LINE] = &GSK_LINE_CURVE_CLASS,
+ [GSK_PATH_CURVE] = &GSK_CURVE_CURVE_CLASS,
+ [GSK_PATH_CONIC] = &GSK_CONIC_CURVE_CLASS,
+ };
+
+ g_assert (op < G_N_ELEMENTS (klasses) && klasses[op] != NULL);
+
+ return klasses[op];
+}
+
+void
+gsk_curve_init (GskCurve *curve,
+ gskpathop op)
+{
+ get_class (gsk_pathop_op (op))->init (curve, op);
+}
+
+void
+gsk_curve_eval (const GskCurve *curve,
+ float progress,
+ graphene_point_t *pos,
+ graphene_vec2_t *tangent)
+{
+ get_class (curve->op)->eval (curve, progress, pos, tangent);
+}
+
+void
+gsk_curve_split (const GskCurve *curve,
+ float progress,
+ GskCurve *start,
+ GskCurve *end)
+{
+ get_class (curve->op)->split (curve, progress, start, end);
+}
+
+gboolean
+gsk_curve_decompose (const GskCurve *curve,
+ float tolerance,
+ GskCurveAddLineFunc add_line_func,
+ gpointer user_data)
+{
+ return get_class (curve->op)->decompose (curve, tolerance, add_line_func, user_data);
+}
+
+gskpathop
+gsk_curve_pathop (const GskCurve *curve)
+{
+ return get_class (curve->op)->pathop (curve);
+}
+
+const graphene_point_t *
+gsk_curve_get_start_point (const GskCurve *curve)
+{
+ return get_class (curve->op)->get_start_point (curve);
+}
+
+const graphene_point_t *
+gsk_curve_get_end_point (const GskCurve *curve)
+{
+ return get_class (curve->op)->get_end_point (curve);
+}
+
diff --git a/gsk/gskcurveprivate.h b/gsk/gskcurveprivate.h
new file mode 100644
index 0000000000..720ee71f1c
--- /dev/null
+++ b/gsk/gskcurveprivate.h
@@ -0,0 +1,108 @@
+/*
+ * 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>
+ */
+
+
+#ifndef __GSK_CURVE_PRIVATE_H__
+#define __GSK_CURVE_PRIVATE_H__
+
+#include "gskpathopprivate.h"
+
+G_BEGIN_DECLS
+
+typedef gpointer gskpathop;
+
+typedef union _GskCurve GskCurve;
+
+typedef struct _GskLineCurve GskLineCurve;
+typedef struct _GskCurveCurve GskCurveCurve;
+typedef struct _GskConicCurve GskConicCurve;
+
+struct _GskLineCurve
+{
+ GskPathOperation op;
+
+ gboolean padding;
+
+ graphene_point_t points[2];
+};
+
+struct _GskCurveCurve
+{
+ GskPathOperation op;
+
+ gboolean has_coefficients;
+
+ graphene_point_t points[4];
+
+ graphene_point_t coeffs[4];
+};
+
+struct _GskConicCurve
+{
+ GskPathOperation op;
+
+ gboolean has_coefficients;
+
+ graphene_point_t points[4];
+
+ graphene_point_t num[3];
+ graphene_point_t denom[3];
+};
+
+union _GskCurve
+{
+ GskPathOperation op;
+ GskLineCurve line;
+ GskCurveCurve curve;
+ GskConicCurve conic;
+};
+
+typedef gboolean (* GskCurveAddLineFunc) (const graphene_point_t *from,
+ const graphene_point_t *to,
+ float from_progress,
+ float to_progress,
+ gpointer user_data);
+
+void gsk_curve_init (GskCurve *curve,
+ gskpathop op);
+
+void gsk_curve_eval (const GskCurve *curve,
+ float progress,
+ graphene_point_t *pos,
+ graphene_vec2_t *tangent);
+void gsk_curve_split (const GskCurve *curve,
+ float progress,
+ GskCurve *start,
+ GskCurve *end);
+gboolean gsk_curve_decompose (const GskCurve *curve,
+ float tolerance,
+ GskCurveAddLineFunc add_line_func,
+ gpointer user_data);
+gskpathop gsk_curve_pathop (const GskCurve *curve);
+#define gsk_curve_builder_to(curve, builder) gsk_path_builder_pathop_to ((builder), gsk_curve_pathop (curve))
+const graphene_point_t *gsk_curve_get_start_point (const GskCurve *curve);
+const graphene_point_t *gsk_curve_get_end_point (const GskCurve *curve);
+
+
+
+
+G_END_DECLS
+
+#endif /* __GSK_CURVE_PRIVATE_H__ */
+
diff --git a/gsk/gskpath.c b/gsk/gskpath.c
index c25cb6b8e0..9073d9155b 100644
--- a/gsk/gskpath.c
+++ b/gsk/gskpath.c
@@ -21,8 +21,8 @@
#include "gskpathprivate.h"
+#include "gskcurveprivate.h"
#include "gskpathbuilder.h"
-#include "gsksplineprivate.h"
typedef struct _GskContour GskContour;
@@ -447,26 +447,22 @@ struct _GskPathForeachTrampoline
double tolerance;
GskPathForeachFunc func;
gpointer user_data;
- gboolean retval;
};
-static void
-gsk_path_foreach_trampoline_add_point (const graphene_point_t *from,
- const graphene_point_t *to,
- float from_progress,
- float to_progress,
- gpointer data)
+static gboolean
+gsk_path_foreach_trampoline_add_line (const graphene_point_t *from,
+ const graphene_point_t *to,
+ float from_progress,
+ float to_progress,
+ gpointer data)
{
GskPathForeachTrampoline *trampoline = data;
- if (!trampoline->retval)
- return;
-
- trampoline->retval = trampoline->func (GSK_PATH_LINE,
- (graphene_point_t[2]) { *from, *to },
- 2,
- 0.0f,
- trampoline->user_data);
+ return trampoline->func (GSK_PATH_LINE,
+ (graphene_point_t[2]) { *from, *to },
+ 2,
+ 0.0f,
+ trampoline->user_data);
}
static gboolean
@@ -486,25 +482,34 @@ gsk_path_foreach_trampoline (GskPathOperation op,
return trampoline->func (op, pts, n_pts, weight, trampoline->user_data);
case GSK_PATH_CURVE:
- if (trampoline->flags & GSK_PATH_FOREACH_ALLOW_CURVE)
- return trampoline->func (op, pts, n_pts, weight, trampoline->user_data);
+ {
+ GskCurve curve;
- gsk_spline_decompose_cubic (pts,
- trampoline->tolerance,
- gsk_path_foreach_trampoline_add_point,
- trampoline);
- return trampoline->retval;
+ if (trampoline->flags & GSK_PATH_FOREACH_ALLOW_CURVE)
+ return trampoline->func (op, pts, n_pts, weight, trampoline->user_data);
+
+ gsk_curve_init (&curve, gsk_pathop_encode (GSK_PATH_CURVE, pts));
+ return gsk_curve_decompose (&curve,
+ trampoline->tolerance,
+ gsk_path_foreach_trampoline_add_line,
+ trampoline);
+ }
case GSK_PATH_CONIC:
- if (trampoline->flags & GSK_PATH_FOREACH_ALLOW_CONIC)
- return trampoline->func (op, pts, n_pts, weight, trampoline->user_data);
+ {
+ GskCurve curve;
+
+ if (trampoline->flags & GSK_PATH_FOREACH_ALLOW_CONIC)
+ return trampoline->func (op, pts, n_pts, weight, trampoline->user_data);
+
+ /* XXX: decompose into curves if allowed */
+ gsk_curve_init (&curve, gsk_pathop_encode (GSK_PATH_CONIC, (graphene_point_t[4]) { pts[0], pts[1], {
weight, }, pts[2] } ));
+ return gsk_curve_decompose (&curve,
+ trampoline->tolerance,
+ gsk_path_foreach_trampoline_add_line,
+ trampoline);
+ }
- /* XXX: decompose into curves if allowed */
- gsk_spline_decompose_conic ((graphene_point_t[4]) { pts[0], pts[1], { weight, }, pts[2] },
- trampoline->tolerance,
- gsk_path_foreach_trampoline_add_point,
- trampoline);
- return trampoline->retval;
default:
g_assert_not_reached ();
@@ -525,7 +530,7 @@ gsk_path_foreach_with_tolerance (GskPath *self,
/* If we need to massage the data, set up a trampoline here */
if (flags != (GSK_PATH_FOREACH_ALLOW_CURVE | GSK_PATH_FOREACH_ALLOW_CONIC))
{
- trampoline = (GskPathForeachTrampoline) { flags, tolerance, func, user_data, TRUE };
+ trampoline = (GskPathForeachTrampoline) { flags, tolerance, func, user_data };
func = gsk_path_foreach_trampoline;
user_data = &trampoline;
}
diff --git a/gsk/gskpathopprivate.h b/gsk/gskpathopprivate.h
index 864e97e2ea..da1c3e63e4 100644
--- a/gsk/gskpathopprivate.h
+++ b/gsk/gskpathopprivate.h
@@ -58,6 +58,7 @@ gsk_pathop_encode (GskPathOperation op,
const graphene_point_t *pts)
{
/* 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);
}
diff --git a/gsk/gskpathprivate.h b/gsk/gskpathprivate.h
index e9d9c386d9..4b403acbd6 100644
--- a/gsk/gskpathprivate.h
+++ b/gsk/gskpathprivate.h
@@ -24,6 +24,7 @@
#include "gskpath.h"
#include "gskcontourprivate.h"
+#include "gskpathopprivate.h"
G_BEGIN_DECLS
diff --git a/gsk/gskspline.c b/gsk/gskspline.c
index 711226229c..5590c7f7e0 100644
--- a/gsk/gskspline.c
+++ b/gsk/gskspline.c
@@ -25,384 +25,6 @@
#include <math.h>
-#define MIN_PROGRESS (1/1024.f)
-
-typedef struct
-{
- graphene_point_t last_point;
- float last_progress;
- GskSplineAddPointFunc func;
- gpointer user_data;
-} GskSplineDecompose;
-
-static void
-gsk_spline_decompose_add_point (GskSplineDecompose *decomp,
- const graphene_point_t *pt,
- float progress)
-{
- if (graphene_point_equal (&decomp->last_point, pt))
- return;
-
- decomp->func (&decomp->last_point, pt, decomp->last_progress, decomp->last_progress + progress,
decomp->user_data);
- decomp->last_point = *pt;
- decomp->last_progress += progress;
-}
-
-static void
-gsk_spline_decompose_finish (GskSplineDecompose *decomp,
- const graphene_point_t *end_point)
-{
- g_assert (graphene_point_equal (&decomp->last_point, end_point));
- g_assert (decomp->last_progress == 1.0f || decomp->last_progress == 0.0f);
-}
-
-typedef struct
-{
- GskSplineDecompose decomp;
- float tolerance;
-} GskCubicDecomposition;
-
-static void
-gsk_spline_cubic_get_coefficients (graphene_point_t coeffs[4],
- const graphene_point_t pts[4])
-{
- coeffs[0] = GRAPHENE_POINT_INIT (pts[3].x - 3.0f * pts[2].x + 3.0f * pts[1].x - pts[0].x,
- pts[3].y - 3.0f * pts[2].y + 3.0f * pts[1].y - pts[0].y);
- coeffs[1] = GRAPHENE_POINT_INIT (3.0f * pts[2].x - 6.0f * pts[1].x + 3.0f * pts[0].x,
- 3.0f * pts[2].y - 6.0f * pts[1].y + 3.0f * pts[0].y);
- coeffs[2] = GRAPHENE_POINT_INIT (3.0f * pts[1].x - 3.0f * pts[0].x,
- 3.0f * pts[1].y - 3.0f * pts[0].y);
- coeffs[3] = pts[0];
-}
-
-void
-gsk_spline_get_point_cubic (const graphene_point_t pts[4],
- float progress,
- graphene_point_t *pos,
- graphene_vec2_t *tangent)
-{
- graphene_point_t c[4];
-
- gsk_spline_cubic_get_coefficients (c, pts);
-
- if (pos)
- *pos = GRAPHENE_POINT_INIT (((c[0].x * progress + c[1].x) * progress +c[2].x) * progress + c[3].x,
- ((c[0].y * progress + c[1].y) * progress +c[2].y) * progress + c[3].y);
- if (tangent)
- {
- graphene_vec2_init (tangent,
- (3.0f * c[0].x * progress + 2.0f * c[1].x) * progress + c[2].x,
- (3.0f * c[0].y * progress + 2.0f * c[1].y) * progress + c[2].y);
- graphene_vec2_normalize (tangent, tangent);
- }
-}
-
-void
-gsk_spline_split_cubic (const graphene_point_t pts[4],
- graphene_point_t result1[4],
- graphene_point_t result2[4],
- float progress)
-{
- graphene_point_t ab, bc, cd;
- graphene_point_t abbc, bccd;
- graphene_point_t final;
-
- graphene_point_interpolate (&pts[0], &pts[1], progress, &ab);
- graphene_point_interpolate (&pts[1], &pts[2], progress, &bc);
- graphene_point_interpolate (&pts[2], &pts[3], progress, &cd);
- graphene_point_interpolate (&ab, &bc, progress, &abbc);
- graphene_point_interpolate (&bc, &cd, progress, &bccd);
- graphene_point_interpolate (&abbc, &bccd, progress, &final);
-
- memcpy (result1, (graphene_point_t[4]) { pts[0], ab, abbc, final }, sizeof (graphene_point_t[4]));
- memcpy (result2, (graphene_point_t[4]) { final, bccd, cd, pts[3] }, sizeof (graphene_point_t[4]));
-}
-
-#if 0
-/* Return an upper bound on the error (squared) that could result from
- * approximating a spline as a line segment connecting the two endpoints. */
-static float
-gsk_spline_error_squared (const graphene_point_t pts[4])
-{
- float bdx, bdy, berr;
- float cdx, cdy, cerr;
-
- /* We are going to compute the distance (squared) between each of the the b
- * and c control points and the segment a-b. The maximum of these two
- * distances will be our approximation error. */
-
- bdx = pts[1].x - pts[0].x;
- bdy = pts[1].y - pts[0].y;
-
- cdx = pts[2].x - pts[0].x;
- cdy = pts[2].y - pts[0].y;
-
- if (!graphene_point_equal (&pts[0], &pts[3]))
- {
- float dx, dy, u, v;
-
- /* Intersection point (px):
- * px = p1 + u(p2 - p1)
- * (p - px) ∙ (p2 - p1) = 0
- * Thus:
- * u = ((p - p1) ∙ (p2 - p1)) / ∥p2 - p1∥²;
- */
-
- dx = pts[3].x - pts[0].x;
- dy = pts[3].y - pts[0].y;
- v = dx * dx + dy * dy;
-
- u = bdx * dx + bdy * dy;
- if (u <= 0)
- {
- /* bdx -= 0;
- * bdy -= 0;
- */
- }
- else if (u >= v)
- {
- bdx -= dx;
- bdy -= dy;
- }
- else
- {
- bdx -= u/v * dx;
- bdy -= u/v * dy;
- }
-
- u = cdx * dx + cdy * dy;
- if (u <= 0)
- {
- /* cdx -= 0;
- * cdy -= 0;
- */
- }
- else if (u >= v)
- {
- cdx -= dx;
- cdy -= dy;
- }
- else
- {
- cdx -= u/v * dx;
- cdy -= u/v * dy;
- }
- }
-
- berr = bdx * bdx + bdy * bdy;
- cerr = cdx * cdx + cdy * cdy;
- if (berr > cerr)
- return berr;
- else
- return cerr;
-}
-#endif
-
-/* taken from Skia, including the very descriptive name */
-static gboolean
-gsk_spline_cubic_too_curvy (const graphene_point_t pts[4],
- float tolerance)
-{
- graphene_point_t p;
-
- graphene_point_interpolate (&pts[0], &pts[3], 1.0f / 3, &p);
- if (ABS (p.x - pts[1].x) + ABS (p.y - pts[1].y) > tolerance)
- return TRUE;
-
- graphene_point_interpolate (&pts[0], &pts[3], 2.0f / 3, &p);
- if (ABS (p.x - pts[2].x) + ABS (p.y - pts[2].y) > tolerance)
- return TRUE;
-
- return FALSE;
-}
-
-static void
-gsk_spline_cubic_decompose (GskCubicDecomposition *d,
- const graphene_point_t pts[4],
- float progress)
-{
- graphene_point_t left[4], right[4];
-
- if (!gsk_spline_cubic_too_curvy (pts, d->tolerance) || progress < MIN_PROGRESS)
- {
- gsk_spline_decompose_add_point (&d->decomp, &pts[3], progress);
- return;
- }
-
- gsk_spline_split_cubic (pts, left, right, 0.5);
-
- gsk_spline_cubic_decompose (d, left, progress / 2);
- gsk_spline_cubic_decompose (d, right, progress / 2);
-}
-
-void
-gsk_spline_decompose_cubic (const graphene_point_t pts[4],
- float tolerance,
- GskSplineAddPointFunc add_point_func,
- gpointer user_data)
-{
- GskCubicDecomposition decomp = { { pts[0], 0.0f, add_point_func, user_data }, tolerance };
-
- gsk_spline_cubic_decompose (&decomp, pts, 1.0f);
-
- gsk_spline_decompose_finish (&decomp.decomp, &pts[3]);
-}
-
-/* CONIC */
-
-typedef struct {
- graphene_point_t num[3];
- graphene_point_t denom[3];
-} ConicCoefficients;
-
-typedef struct
-{
- GskSplineDecompose decomp;
- float tolerance;
- ConicCoefficients c;
-} GskConicDecomposition;
-
-
-static void
-gsk_spline_conic_get_coefficents (ConicCoefficients *c,
- const graphene_point_t pts[4])
-{
- float w = pts[2].x;
- graphene_point_t pw = GRAPHENE_POINT_INIT (w * pts[1].x, w * pts[1].y);
-
- c->num[2] = pts[0];
- c->num[1] = GRAPHENE_POINT_INIT (2 * (pw.x - pts[0].x),
- 2 * (pw.y - pts[0].y));
- c->num[0] = GRAPHENE_POINT_INIT (pts[3].x - 2 * pw.x + pts[0].x,
- pts[3].y - 2 * pw.y + pts[0].y);
-
- c->denom[2] = GRAPHENE_POINT_INIT (1, 1);
- c->denom[1] = GRAPHENE_POINT_INIT (2 * (w - 1), 2 * (w - 1));
- c->denom[0] = GRAPHENE_POINT_INIT (-c->denom[1].x, -c->denom[1].y);
-}
-
-static inline void
-gsk_spline_eval_quad (const graphene_point_t quad[3],
- float progress,
- graphene_point_t *result)
-{
- *result = GRAPHENE_POINT_INIT ((quad[0].x * progress + quad[1].x) * progress + quad[2].x,
- (quad[0].y * progress + quad[1].y) * progress + quad[2].y);
-}
-
-static inline void
-gsk_spline_eval_conic (const ConicCoefficients *c,
- float progress,
- graphene_point_t *result)
-{
- graphene_point_t num, denom;
-
- gsk_spline_eval_quad (c->num, progress, &num);
- gsk_spline_eval_quad (c->denom, progress, &denom);
- *result = GRAPHENE_POINT_INIT (num.x / denom.x, num.y / denom.y);
-}
-
-void
-gsk_spline_get_point_conic (const graphene_point_t pts[4],
- float progress,
- graphene_point_t *pos,
- graphene_vec2_t *tangent)
-{
- ConicCoefficients c;
-
- gsk_spline_conic_get_coefficents (&c, pts);
-
- if (pos)
- gsk_spline_eval_conic (&c, progress, pos);
-
- if (tangent)
- {
- graphene_point_t tmp;
- float w = pts[2].x;
-
- /* The tangent will be 0 in these corner cases, just
- * treat it like a line here. */
- if ((progress <= 0.f && graphene_point_equal (&pts[0], &pts[1])) ||
- (progress >= 1.f && graphene_point_equal (&pts[1], &pts[3])))
- {
- graphene_vec2_init (tangent, pts[3].x - pts[0].x, pts[3].y - pts[0].y);
- return;
- }
-
- gsk_spline_eval_quad ((graphene_point_t[3]) {
- GRAPHENE_POINT_INIT ((w - 1) * (pts[3].x - pts[0].x),
- (w - 1) * (pts[3].y - pts[0].y)),
- GRAPHENE_POINT_INIT (pts[3].x - pts[0].x - 2 * w * (pts[1].x - pts[0].x),
- pts[3].y - pts[0].y - 2 * w * (pts[1].y - pts[0].y)),
- GRAPHENE_POINT_INIT (w * (pts[1].x - pts[0].x),
- w * (pts[1].y - pts[0].y))
- },
- progress,
- &tmp);
- graphene_vec2_init (tangent, tmp.x, tmp.y);
- graphene_vec2_normalize (tangent, tangent);
- }
-}
-
-void
-gsk_spline_split_conic (const graphene_point_t pts[4],
- graphene_point_t result1[4],
- graphene_point_t result2[4],
- float progress)
-{
- g_warning ("FIXME: Stop treating conics as lines");
-}
-
-/* taken from Skia, including the very descriptive name */
-static gboolean
-gsk_spline_conic_too_curvy (const graphene_point_t *start,
- const graphene_point_t *mid,
- const graphene_point_t *end,
- float tolerance)
-{
- return fabs ((start->x + end->x) * 0.5 - mid->x) > tolerance
- || fabs ((start->y + end->y) * 0.5 - mid->y) > tolerance;
-}
-
-static void
-gsk_spline_decompose_conic_subdivide (GskConicDecomposition *d,
- const graphene_point_t *start,
- float start_progress,
- const graphene_point_t *end,
- float end_progress)
-{
- graphene_point_t mid;
- float mid_progress;
-
- mid_progress = (start_progress + end_progress) / 2;
- gsk_spline_eval_conic (&d->c, mid_progress, &mid);
-
- if (end_progress - start_progress < MIN_PROGRESS ||
- !gsk_spline_conic_too_curvy (start, &mid, end, d->tolerance))
- {
- gsk_spline_decompose_add_point (&d->decomp, end, end_progress - start_progress);
- return;
- }
-
- gsk_spline_decompose_conic_subdivide (d, start, start_progress, &mid, mid_progress);
- gsk_spline_decompose_conic_subdivide (d, &mid, mid_progress, end, end_progress);
-}
-
-void
-gsk_spline_decompose_conic (const graphene_point_t pts[4],
- float tolerance,
- GskSplineAddPointFunc add_point_func,
- gpointer user_data)
-{
- GskConicDecomposition d = { { pts[0], 0.0f, add_point_func, user_data }, tolerance, };
-
- gsk_spline_conic_get_coefficents (&d.c, pts);
-
- gsk_spline_decompose_conic_subdivide (&d, &pts[0], 0.0f, &pts[3], 1.0f);
-
- gsk_spline_decompose_finish (&d.decomp, &pts[3]);
-}
-
/* Spline deviation from the circle in radius would be given by:
error = sqrt (x**2 + y**2) - 1
diff --git a/gsk/gsksplineprivate.h b/gsk/gsksplineprivate.h
index 02556937ce..c9da32734c 100644
--- a/gsk/gsksplineprivate.h
+++ b/gsk/gsksplineprivate.h
@@ -25,38 +25,6 @@
G_BEGIN_DECLS
-typedef void (* GskSplineAddPointFunc) (const graphene_point_t *from,
- const graphene_point_t *to,
- float from_progress,
- float to_progress,
- gpointer user_data);
-
-void gsk_spline_get_point_cubic (const graphene_point_t pts[4],
- float progress,
- graphene_point_t *pos,
- graphene_vec2_t *tangent);
-void gsk_spline_split_cubic (const graphene_point_t pts[4],
- graphene_point_t result1[4],
- graphene_point_t result2[4],
- float progress);
-void gsk_spline_decompose_cubic (const graphene_point_t pts[4],
- float tolerance,
- GskSplineAddPointFunc add_point_func,
- gpointer user_data);
-
-void gsk_spline_get_point_conic (const graphene_point_t pts[4],
- float progress,
- graphene_point_t *pos,
- graphene_vec2_t *tangent);
-void gsk_spline_split_conic (const graphene_point_t pts[4],
- graphene_point_t result1[4],
- graphene_point_t result2[4],
- float progress);
-void gsk_spline_decompose_conic (const graphene_point_t pts[4],
- float tolerance,
- GskSplineAddPointFunc add_point_func,
- gpointer user_data);
-
typedef gboolean (* GskSplineAddCurveFunc) (const graphene_point_t curve[4],
gpointer user_data);
gboolean gsk_spline_decompose_arc (const graphene_point_t *center,
diff --git a/gsk/meson.build b/gsk/meson.build
index 791ee23809..11f7abae67 100644
--- a/gsk/meson.build
+++ b/gsk/meson.build
@@ -22,8 +22,8 @@ gsk_private_gl_shaders = [
]
gsk_public_sources = files([
- 'gskdiff.c',
'gskcairorenderer.c',
+ 'gskdiff.c',
'gskglshader.c',
'gskpath.c',
'gskpathbuilder.c',
@@ -41,6 +41,7 @@ gsk_public_sources = files([
gsk_private_sources = files([
'gskcairoblur.c',
'gskcontour.c',
+ 'gskcurve.c',
'gskdebug.c',
'gskprivate.c',
'gskprofiler.c',
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