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Add GskPathMeasure

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GskPathMeasure is an auxiliary object for
measuring path lengths.
This commit is contained in:
Matthias Clasen
2023-07-21 23:24:22 -04:00
parent 2bcc998e90
commit 2830d1725f
11 changed files with 817 additions and 39 deletions
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150
LOG Normal file
View File

@@ -0,0 +1,150 @@
TAP version 13
# random seed: R02S22611f6aefc1121b0ab2dc5286960449
# GLib-GIO-DEBUG: _g_io_module_get_default: Found default implementation dconf (DConfSettingsBackend) for ‘gsettings-backend’
# GLib-GIO-DEBUG: Using cross-namespace EXTERNAL authentication (this will deadlock if server is GDBus < 2.73.3)
# GLib-GIO-DEBUG: Using cross-namespace EXTERNAL authentication (this will deadlock if server is GDBus < 2.73.3)
1..1
# Start of ops tests
# testcase 0 op 0
collecting#
Cubic 0: # M 100.000000 100.000000 C 150.000000 100.000000 200.000000 100.000000 250.000000 100.000000
Cubic 1: # M 250.000000 100.000000 C 300.000000 100.000000 350.000000 100.000000 400.000000 100.000000
Line 2: # M 400 100 L 200 300
Line 3: # M 200 300 L 100 100
Cubic 4: # M 200.000000 100.000000 C 250.000000 100.000000 300.000000 100.000000 350.000000 100.000000
Cubic 5: # M 350.000000 100.000000 C 400.000000 100.000000 450.000000 100.000000 500.000000 100.000000
Line 6: # M 500 100 L 300 300
Line 7: # M 300 300 L 200 100
splitting#
1 intersections between Cubic 0 and Cubic 1#
1 intersections between Cubic 0 and Line 3#
9 intersections between Cubic 0 and Cubic 4#
# split Cubic 0.0 from Cubic 0 at 0.666666: M 100.000000 100.000000 C 133.333298 100.000000 166.666595 100.000000 199.999893 100.000000
split Cubic 0.1 from Cubic 0 at 0.666666: M 199.999893 100.000000 C 216.666595 100.000000 233.333298 100.000000 250.000000 100.000000split Cubic 0.4 from Cubic 0 at 0.00600814: M 200.300323 100.000000 C 216.866882 100.000000 233.433441 100.000000 250.000000 100.000000split Cubic 0.7 from Cubic 0 at 0.00604445: M 200.600708 100.000000 C 217.067139 100.000000 233.533569 100.000000 250.000000 100.000000# split Cubic 4.9 from Cubic 4 at 0.00533867: M 200.800812 100.000000 C 250.533875 100.000000 300.266937 100.000000 350.000000 100.000000
1 intersections between Cubic 0.1 and Line 7#
1 intersections between Cubic 1 and Line 2#
9 intersections between Cubic 1 and Cubic 4.9#
split Cubic 1.9 from Cubic 1 at 0.00534248: M 250.801361 100.000000 C 300.534241 100.000000 350.267120 100.000000 400.000000 100.000000# split Cubic 4.9.0 from Cubic 4.9 at 0.329756: M 200.800812 100.000000 C 217.200577 100.000000 233.600342 100.000000 250.000122 100.000000
# split Cubic 4.9.1 from Cubic 4.9 at 0.329756: M 250.000122 100.000000 C 283.333435 100.000000 316.666718 100.000000 350.000000 100.000000
# split Cubic 4.9.6 from Cubic 4.9 at 0.00500283: M 250.500412 100.000000 C 283.666931 100.000000 316.833466 100.000000 350.000000 100.000000
9 intersections between Cubic 1.9 and Cubic 5#
# split Cubic 1.9.0 from Cubic 1.9 at 0.664877: M 250.801361 100.000000 C 283.867615 100.000000 316.933868 100.000000 350.000122 100.000000
split Cubic 1.9.1 from Cubic 1.9 at 0.664877: M 350.000122 100.000000 C 366.666748 100.000000 383.333374 100.000000 400.000000 100.000000split Cubic 1.9.4 from Cubic 1.9 at 0.00601021: M 350.300598 100.000000 C 366.867065 100.000000 383.433533 100.000000 400.000000 100.000000split Cubic 1.9.7 from Cubic 1.9 at 0.00604655: M 350.601074 100.000000 C 367.067383 100.000000 383.533691 100.000000 400.000000 100.000000# split Cubic 5.9 from Cubic 5 at 0.00534248: M 350.801361 100.000000 C 400.534241 100.000000 450.267120 100.000000 500.000000 100.000000
1 intersections between Line 2 and Line 3#
1 intersections between Line 2 and Line 7#
# split Line 2.0 from Line 2 at 0.666667: M 400 100 L 266.667 233.333
split Line 2.1 from Line 2 at 0.666667: M 266.667 233.333 L 200 300# split Line 7.0 from Line 7 at 0.333333: M 300 300 L 266.667 233.333
# split Line 7.1 from Line 7 at 0.333333: M 266.667 233.333 L 200 100
1 intersections between Cubic 4 and Cubic 4.9.0#
1 intersections between Cubic 4 and Line 7.1#
1 intersections between Cubic 4.9.0 and Cubic 4.9.1#
1 intersections between Cubic 4.9.1 and Cubic 4.9.6#
1 intersections between Cubic 4.9.6 and Cubic 5#
1 intersections between Cubic 5 and Cubic 5.9#
1 intersections between Cubic 5.9 and Line 6#
1 intersections between Line 6 and Line 7.0#
Cubic 0.0: # M 100.000000 100.000000 C 133.333298 100.000000 166.666595 100.000000 199.999893 100.000000
Cubic 0.1: # M 199.999893 100.000000 C 200.100037 100.000000 200.200180 100.000000 200.300323 100.000000
Cubic 0.4: # M 200.300323 100.000000 C 200.400452 100.000000 200.500580 100.000000 200.600708 100.000000
Cubic 0.7: # M 200.600708 100.000000 C 217.067139 100.000000 233.533569 100.000000 250.000000 100.000000
Cubic 1: # M 250.000000 100.000000 C 250.267120 100.000000 250.534241 100.000000 250.801361 100.000000
Cubic 1.9.0: # M 250.801361 100.000000 C 283.867615 100.000000 316.933868 100.000000 350.000122 100.000000
Cubic 1.9.1: # M 350.000122 100.000000 C 350.100281 100.000000 350.200439 100.000000 350.300598 100.000000
Cubic 1.9.4: # M 350.300598 100.000000 C 350.400757 100.000000 350.500916 100.000000 350.601074 100.000000
Cubic 1.9.7: # M 350.601074 100.000000 C 367.067383 100.000000 383.533691 100.000000 400.000000 100.000000
Line 2.0: # M 400 100 L 266.667 233.333
Line 2.1: # M 266.667 233.333 L 200 300
Line 3: # M 200 300 L 100 100
Cubic 4: # M 200.000000 100.000000 C 200.266937 100.000000 200.533875 100.000000 200.800812 100.000000
Cubic 4.9.0: # M 200.800812 100.000000 C 217.200577 100.000000 233.600342 100.000000 250.000122 100.000000
Cubic 4.9.1: # M 250.000122 100.000000 C 250.166885 100.000000 250.333649 100.000000 250.500412 100.000000
Cubic 4.9.6: # M 250.500412 100.000000 C 283.666931 100.000000 316.833466 100.000000 350.000000 100.000000
Cubic 5: # M 350.000000 100.000000 C 350.267120 100.000000 350.534241 100.000000 350.801361 100.000000
Cubic 5.9: # M 350.801361 100.000000 C 400.534241 100.000000 450.267120 100.000000 500.000000 100.000000
Line 6: # M 500 100 L 300 300
Line 7.0: # M 300 300 L 266.667 233.333
Line 7.1: # M 266.667 233.333 L 200 100
classifying#
01 Cubic 0.0: # M 100.000000 100.000000 C 133.333298 100.000000 166.666595 100.000000 199.999893 100.000000
[11 Cubic 0.7: # M 200.600708 100.000000 C 217.067139 100.000000 233.533569 100.000000 250.000000 100.000000 ]
[11 Cubic 1.9.0: # M 250.801361 100.000000 C 283.867615 100.000000 316.933868 100.000000 350.000122 100.000000 ]
[11 Cubic 1.9.7: # M 350.601074 100.000000 C 367.067383 100.000000 383.533691 100.000000 400.000000 100.000000 ]
[11 Line 2.0: # M 400 100 L 266.667 233.333 ]
01 Line 2.1: # M 266.667 233.333 L 200 300
01 Line 3: # M 200 300 L 100 100
[11 Cubic 4: # M 200.000000 100.000000 C 200.266937 100.000000 200.533875 100.000000 200.800812 100.000000 ]
[11 Cubic 4.9.0: # M 200.800812 100.000000 C 217.200577 100.000000 233.600342 100.000000 250.000122 100.000000 ]
[11 Cubic 4.9.6: # M 250.500412 100.000000 C 283.666931 100.000000 316.833466 100.000000 350.000000 100.000000 ]
[11 Cubic 5: # M 350.000000 100.000000 C 350.267120 100.000000 350.534241 100.000000 350.801361 100.000000 ]
01 Cubic 5.9: # M 350.801361 100.000000 C 400.534241 100.000000 450.267120 100.000000 500.000000 100.000000
01 Line 6: # M 500 100 L 300 300
01 Line 7.0: # M 300 300 L 266.667 233.333
[11 Line 7.1: # M 266.667 233.333 L 200 100 ]
fixups#
# found 3 bad nodes
# split Cubic 0/Cubic 4 BAD 200.600723 100.000000
# [11 Line 7.1 ] 116.565
# [11 Cubic 0.7 ] 180
# [11 Cubic 4 ] 180
# [11 Cubic 4 ] 180
# [11 Cubic 4.9.0 ] 180
# >01 Cubic 0.0 360
# split Cubic 1/Cubic 4.9 BAD 250.801376 100.000000
# [11 Cubic 1.9.0 ] 180
# [11 Cubic 4.9.6 ] 180
# [11 Cubic 0.7 ] 360
# [11 Cubic 4.9.0 ] 360
# split Cubic 1.9/Cubic 5 BAD 350.601105 100.000000
# [11 Cubic 1.9.7 ] 180
# [11 Cubic 5 ] 180
# [11 Cubic 5 ] 180
# <01 Cubic 5.9 180
# [11 Cubic 1.9.0 ] 360
# [11 Cubic 4.9.6 ] 360
reassembling#
start new contour Cubic 0.0#
# Cubic 0.0 ends at:
# start 0 100.000000 100.000000
# >01 Line 3 116.565
# (10 Cubic 0.0 ) 180
picking cw#
append Line 3#
# Line 3 ends at:
# end 2 200.000000 300.000000
# >01 Line 2.1 225
# (10 Line 3 ) 296.565
picking cw#
append Line 2.1#
# Line 2.1 ends at:
# split Line 2/Line 7 266.666656 233.333344
# (10 Line 2.1 ) 45
# >01 Line 7.0 116.565
# [11 Line 2.0 ] 225
# [11 Line 7.1 ] 296.565
picking cw#
append Line 7.0#
# Line 7.0 ends at:
# end 6 300.000000 300.000000
# >01 Line 6 225
# (10 Line 7.0 ) 296.565
picking cw#
append Line 6#
# Line 6 ends at:
# end 5 500.000000 100.000000
# (10 Line 6 ) 45
# >01 Cubic 5.9 360
picking cw#
append Cubic 5.9#
# Cubic 5.9 ends at:
# split Cubic 1.9/Cubic 5 BAD 350.601105 100.000000
# [11 Cubic 1.9.7 ] 180
# [11 Cubic 5 ] 180
# [11 Cubic 5 ] 180
# (10 Cubic 5.9 ) 180
# [11 Cubic 1.9.0 ] 360
# [11 Cubic 4.9.6 ] 360
picking cw#
**
ERROR:../testsuite/gsk/path-ops.c:359:test_ops_simple: assertion failed (s == tests[i].out): ("M 354.60110473632812 100 A 4 4 0 0 0 346.60110473632812 100 A 4 4 0 0 0 354.60110473632812 100 z M 252.80137634277344 100 A 2 2 0 0 0 248.80137634277344 100 A 2 2 0 0 0 252.80137634277344 100 z M 204.60072326660156 100 A 4 4 0 0 0 196.60072326660156 100 A 4 4 0 0 0 204.60072326660156 100 z" == "M 100 100 z")
not ok /ops/simple - ERROR:../testsuite/gsk/path-ops.c:359:test_ops_simple: assertion failed (s == tests[i].out): ("M 354.60110473632812 100 A 4 4 0 0 0 346.60110473632812 100 A 4 4 0 0 0 354.60110473632812 100 z M 252.80137634277344 100 A 2 2 0 0 0 248.80137634277344 100 A 2 2 0 0 0 252.80137634277344 100 z M 204.60072326660156 100 A 4 4 0 0 0 196.60072326660156 100 A 4 4 0 0 0 204.60072326660156 100 z" == "M 100 100 z")
Bail out!

1
gsk/gsk.h
View File

@@ -22,6 +22,7 @@
#include <gsk/gskenums.h>
#include <gsk/gskpath.h>
#include <gsk/gskpathbuilder.h>
#include <gsk/gskpathmeasure.h>
#include <gsk/gskpathpoint.h>
#include <gsk/gskrenderer.h>
#include <gsk/gskrendernode.h>

284
gsk/gskcontour.c
View File

@@ -82,6 +82,18 @@ struct _GskContourClass
gboolean emit_move_to,
GskRealPathPoint *start,
GskRealPathPoint *end);
gpointer (* init_measure) (const GskContour *contour,
float tolerance,
float *out_length);
void (* free_measure) (const GskContour *contour,
gpointer measure_data);
void (* get_point) (const GskContour *contour,
gpointer measure_data,
float offset,
GskRealPathPoint *result);
float (* get_distance) (const GskContour *contour,
GskRealPathPoint *point,
gpointer measure_data);
};
/* {{{ Utilities */
@@ -230,6 +242,38 @@ gsk_standard_contour_reverse (const GskContour *contour)
return res;
}
static int
gsk_standard_contour_get_winding (const GskContour *contour,
const graphene_point_t *point)
{
GskStandardContour *self = (GskStandardContour *) contour;
int winding = 0;
for (gsize i = 0; i < self->n_ops; i ++)
{
GskCurve c;
if (gsk_pathop_op (self->ops[i]) == GSK_PATH_MOVE)
continue;
gsk_curve_init (&c, self->ops[i]);
winding += gsk_curve_get_crossing (&c, point);
}
if ((self->flags & GSK_PATH_CLOSED) == 0)
{
GskCurve c;
gsk_curve_init (&c, gsk_pathop_encode (GSK_PATH_CLOSE,
(const graphene_point_t[]) { self->points[self->n_points - 1],
self->points[0] }));
winding += gsk_curve_get_crossing (&c, point);
}
return winding;
}
static GskPathFlags
gsk_standard_contour_get_flags (const GskContour *contour)
{
@@ -373,38 +417,6 @@ gsk_standard_contour_get_start_end (const GskContour *contour,
*end = self->points[self->n_points - 1];
}
static int
gsk_standard_contour_get_winding (const GskContour *contour,
const graphene_point_t *point)
{
GskStandardContour *self = (GskStandardContour *) contour;
int winding = 0;
for (gsize i = 0; i < self->n_ops; i ++)
{
GskCurve c;
if (gsk_pathop_op (self->ops[i]) == GSK_PATH_MOVE)
continue;
gsk_curve_init (&c, self->ops[i]);
winding += gsk_curve_get_crossing (&c, point);
}
if ((self->flags & GSK_PATH_CLOSED) == 0)
{
GskCurve c;
gsk_curve_init (&c, gsk_pathop_encode (GSK_PATH_CLOSE,
(const graphene_point_t[]) { self->points[self->n_points - 1],
self->points[0] }));
winding += gsk_curve_get_crossing (&c, point);
}
return winding;
}
static gsize
gsk_standard_contour_get_n_points (const GskContour *contour)
{
@@ -621,6 +633,166 @@ gsk_standard_contour_add_segment (const GskContour *contour,
}
}
typedef struct
{
float start;
float end;
float start_progress;
float end_progress;
GskCurveLineReason reason;
graphene_point_t start_point;
graphene_point_t end_point;
gsize op;
} GskStandardContourMeasure;
typedef struct
{
GArray *array;
GskStandardContourMeasure measure;
} LengthDecompose;
static gboolean
gsk_standard_contour_measure_add_point (const graphene_point_t *from,
const graphene_point_t *to,
float from_progress,
float to_progress,
GskCurveLineReason reason,
gpointer user_data)
{
LengthDecompose *decomp = user_data;
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;
decomp->measure.start_point = *from;
decomp->measure.end_point = *to;
decomp->measure.reason = reason;
g_array_append_val (decomp->array, decomp->measure);
decomp->measure.start += seg_length;
return TRUE;
}
static gpointer
gsk_standard_contour_init_measure (const GskContour *contour,
float tolerance,
float *out_length)
{
const GskStandardContour *self = (const GskStandardContour *) contour;
gsize i;
float length;
GArray *array;
array = g_array_new (FALSE, FALSE, sizeof (GskStandardContourMeasure));
length = 0;
for (i = 1; i < self->n_ops; i ++)
{
GskCurve curve;
LengthDecompose decomp = { array, { length, length, 0, 0, GSK_CURVE_LINE_REASON_SHORT, { 0, 0 }, { 0, 0 }, i } };
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;
return array;
}
static void
gsk_standard_contour_free_measure (const GskContour *contour,
gpointer data)
{
g_array_free (data, TRUE);
}
static int
gsk_standard_contour_find_measure (gconstpointer m,
gconstpointer l)
{
const GskStandardContourMeasure *measure = m;
float length = *(const float *) l;
if (measure->start > length)
return 1;
else if (measure->end <= length)
return -1;
else
return 0;
}
static void
gsk_standard_contour_get_point (const GskContour *contour,
gpointer measure_data,
float distance,
GskRealPathPoint *result)
{
GArray *array = measure_data;
unsigned int idx;
GskStandardContourMeasure *measure;
float fraction, t;
if (array->len == 0)
{
result->idx = 0;
result->t = 0;
return;
}
if (!g_array_binary_search (array, &distance, gsk_standard_contour_find_measure, &idx))
idx = array->len - 1;
measure = &g_array_index (array, GskStandardContourMeasure, idx);
fraction = (distance - measure->start) / (measure->end - measure->start);
t = measure->start_progress + fraction * (measure->end_progress - measure->start_progress);
g_assert (t >= 0 && t <= 1);
result->idx = measure->op;
result->t = t;
}
static float
gsk_standard_contour_get_distance (const GskContour *contour,
GskRealPathPoint *point,
gpointer measure_data)
{
GArray *array = measure_data;
if (G_UNLIKELY (point->idx == 0))
return 0;
for (unsigned int i = 0; i < array->len; i++)
{
GskStandardContourMeasure *measure = &g_array_index (array, GskStandardContourMeasure, i);
float fraction;
if (measure->op != point->idx)
continue;
if (measure->end_progress < point->t)
continue;
g_assert (measure->op == point->idx);
g_assert (measure->start_progress <= point->t && point->t <= measure->end_progress);
fraction = (point->t - measure->start_progress) / (measure->end_progress - measure->start_progress);
return measure->start + fraction * (measure->end - measure->start);
}
return 0;
}
static const GskContourClass GSK_STANDARD_CONTOUR_CLASS =
{
sizeof (GskStandardContour),
@@ -641,6 +813,10 @@ static const GskContourClass GSK_STANDARD_CONTOUR_CLASS =
gsk_standard_contour_get_tangent,
gsk_standard_contour_get_curvature,
gsk_standard_contour_add_segment,
gsk_standard_contour_init_measure,
gsk_standard_contour_free_measure,
gsk_standard_contour_get_point,
gsk_standard_contour_get_distance,
};
/* You must ensure the contour has enough size allocated,
@@ -777,6 +953,12 @@ gsk_contour_get_winding (const GskContour *self,
return self->klass->get_winding (self, point);
}
gsize
gsk_contour_get_n_points (const GskContour *self)
{
return self->klass->get_n_points (self);
}
gboolean
gsk_contour_get_closest_point (const GskContour *self,
const graphene_point_t *point,
@@ -787,12 +969,6 @@ gsk_contour_get_closest_point (const GskContour *self,
return self->klass->get_closest_point (self, point, threshold, result, out_dist);
}
gsize
gsk_contour_get_n_points (const GskContour *self)
{
return self->klass->get_n_points (self);
}
void
gsk_contour_get_position (const GskContour *self,
GskRealPathPoint *point,
@@ -828,6 +1004,38 @@ gsk_contour_add_segment (const GskContour *self,
self->klass->add_segment (self, builder, emit_move_to, start, end);
}
gpointer
gsk_contour_init_measure (const GskContour *self,
float tolerance,
float *out_length)
{
return self->klass->init_measure (self, tolerance, out_length);
}
void
gsk_contour_free_measure (const GskContour *self,
gpointer data)
{
self->klass->free_measure (self, data);
}
void
gsk_contour_get_point (const GskContour *self,
gpointer measure_data,
float offset,
GskRealPathPoint *result)
{
self->klass->get_point (self, measure_data, offset, result);
}
float
gsk_contour_get_distance (const GskContour *self,
GskRealPathPoint *point,
gpointer measure_data)
{
return self->klass->get_distance (self, point, measure_data);
}
/* }}} */
/* vim:set foldmethod=marker expandtab: */

16
gsk/gskcontourprivate.h
View File

@@ -63,9 +63,11 @@ gboolean gsk_contour_get_closest_point (const GskContou
float threshold,
GskRealPathPoint *result,
float *out_dist);
void gsk_contour_get_position (const GskContour *self,
GskRealPathPoint *point,
graphene_point_t *pos);
void gsk_contour_get_tangent (const GskContour *self,
GskRealPathPoint *point,
GskPathDirection direction,
@@ -73,6 +75,7 @@ void gsk_contour_get_tangent (const GskContou
float gsk_contour_get_curvature (const GskContour *self,
GskRealPathPoint *point,
graphene_point_t *center);
void gsk_contour_add_segment (const GskContour *self,
GskPathBuilder *builder,
gboolean emit_move_to,
@@ -80,4 +83,17 @@ void gsk_contour_add_segment (const GskContou
GskRealPathPoint *end);
gpointer gsk_contour_init_measure (const GskContour *self,
float tolerance,
float *out_length);
void gsk_contour_free_measure (const GskContour *self,
gpointer data);
void gsk_contour_get_point (const GskContour *self,
gpointer measure_data,
float offset,
GskRealPathPoint *result);
float gsk_contour_get_distance (const GskContour *self,
GskRealPathPoint *point,
gpointer measure_data);
G_END_DECLS

1
gsk/gskpathbuilder.h
View File

@@ -73,6 +73,7 @@ void gsk_path_builder_add_segment (GskPathBuilder
GskPath *path,
const GskPathPoint *start,
const GskPathPoint *end);
GDK_AVAILABLE_IN_4_14
void gsk_path_builder_move_to (GskPathBuilder *self,
float x,

328
gsk/gskpathmeasure.c Normal file
View File

@@ -0,0 +1,328 @@
/*
* 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 "gskpathmeasure.h"
#include "gskpathbuilder.h"
#include "gskpathpointprivate.h"
#include "gskpathprivate.h"
/**
* GskPathMeasure:
*
* `GskPathMeasure` is an object that allows measurements
* on `GskPath`s such as determining the length of the path.
*
* Many measuring operations require approximating the path
* with simpler shapes. Therefore, a `GskPathMeasure` has
* a tolerance that determines what precision is required
* for such approximations.
*
* A `GskPathMeasure` struct is a reference counted struct
* and should be treated as opaque.
*/
typedef struct _GskContourMeasure GskContourMeasure;
struct _GskContourMeasure
{
float length;
gpointer contour_data;
};
struct _GskPathMeasure
{
/*< private >*/
guint ref_count;
GskPath *path;
float tolerance;
float length;
gsize n_contours;
GskContourMeasure measures[];
};
G_DEFINE_BOXED_TYPE (GskPathMeasure, gsk_path_measure,
gsk_path_measure_ref,
gsk_path_measure_unref)
/**
* gsk_path_measure_new:
* @path: the path to measure
*
* Creates a measure object for the given @path.
*
* Returns: a new `GskPathMeasure` representing @path
*
* Since: 4.14
*/
GskPathMeasure *
gsk_path_measure_new (GskPath *path)
{
return gsk_path_measure_new_with_tolerance (path, GSK_PATH_TOLERANCE_DEFAULT);
}
/**
* gsk_path_measure_new_with_tolerance:
* @path: the path to measure
* @tolerance: the tolerance for measuring operations
*
* Creates a measure object for the given @path and @tolerance.
*
* Returns: a new `GskPathMeasure` representing @path
*
* Since: 4.14
*/
GskPathMeasure *
gsk_path_measure_new_with_tolerance (GskPath *path,
float tolerance)
{
GskPathMeasure *self;
gsize i, n_contours;
g_return_val_if_fail (path != NULL, NULL);
g_return_val_if_fail (tolerance > 0, NULL);
n_contours = gsk_path_get_n_contours (path);
self = g_malloc0 (sizeof (GskPathMeasure) + n_contours * sizeof (GskContourMeasure));
self->ref_count = 1;
self->path = gsk_path_ref (path);
self->tolerance = tolerance;
self->n_contours = n_contours;
for (i = 0; i < n_contours; i++)
{
self->measures[i].contour_data = gsk_contour_init_measure (gsk_path_get_contour (path, i),
self->tolerance,
&self->measures[i].length);
self->length += self->measures[i].length;
}
return self;
}
/**
* gsk_path_measure_ref:
* @self: a `GskPathMeasure`
*
* Increases the reference count of a `GskPathMeasure` by one.
*
* Returns: the passed in `GskPathMeasure`.
*
* Since: 4.14
*/
GskPathMeasure *
gsk_path_measure_ref (GskPathMeasure *self)
{
g_return_val_if_fail (self != NULL, NULL);
self->ref_count++;
return self;
}
/**
* gsk_path_measure_unref:
* @self: a `GskPathMeasure`
*
* Decreases the reference count of a `GskPathMeasure` by one.
*
* If the resulting reference count is zero, frees the object.
*
* Since: 4.14
*/
void
gsk_path_measure_unref (GskPathMeasure *self)
{
gsize i;
g_return_if_fail (self != NULL);
g_return_if_fail (self->ref_count > 0);
self->ref_count--;
if (self->ref_count > 0)
return;
for (i = 0; i < self->n_contours; i++)
{
gsk_contour_free_measure (gsk_path_get_contour (self->path, i),
self->measures[i].contour_data);
}
gsk_path_unref (self->path);
g_free (self);
}
/**
* gsk_path_measure_get_path:
* @self: a `GskPathMeasure`
*
* Returns the path that the measure was created for.
*
* Returns: (transfer none): the path of @self
*
* Since: 4.14
*/
GskPath *
gsk_path_measure_get_path (GskPathMeasure *self)
{
return self->path;
}
/**
* gsk_path_measure_get_tolerance:
* @self: a `GskPathMeasure`
*
* Returns the tolerance that the measure was created with.
*
* Returns: the tolerance of @self
*
* Since: 4.14
*/
float
gsk_path_measure_get_tolerance (GskPathMeasure *self)
{
return self->tolerance;
}
/**
* gsk_path_measure_get_length:
* @self: a `GskPathMeasure`
*
* Gets the length of the path being measured.
*
* The length is cached, so this function does not do any work.
*
* Returns: The length of the path measured by @self
*
* Since: 4.14
*/
float
gsk_path_measure_get_length (GskPathMeasure *self)
{
g_return_val_if_fail (self != NULL, 0);
return self->length;
}
static float
gsk_path_measure_clamp_distance (GskPathMeasure *self,
float distance)
{
if (isnan (distance))
return 0;
return CLAMP (distance, 0, self->length);
}
/**
* gsk_path_measure_get_point:
* @self: a `GskPathMeasure`
* @distance: the distance
* @result: (out caller-allocates): return location for the result
*
* Sets @result to the point at the given distance into the path.
*
* An empty path has no points, so `FALSE` is returned in that case.
*
* Returns: `TRUE` if @result was set
*
* Since: 4.14
*/
gboolean
gsk_path_measure_get_point (GskPathMeasure *self,
float distance,
GskPathPoint *result)
{
GskRealPathPoint *res = (GskRealPathPoint *) result;
gsize i;
float offset;
const GskContour *contour;
g_return_val_if_fail (self != NULL, FALSE);
g_return_val_if_fail (result != NULL, FALSE);
if (self->n_contours == 0)
return FALSE;
offset = gsk_path_measure_clamp_distance (self, distance);
for (i = 0; i < self->n_contours - 1; i++)
{
if (offset < self->measures[i].length)
break;
offset -= self->measures[i].length;
}
g_assert (0 <= i && i < self->n_contours);
offset = CLAMP (offset, 0, self->measures[i].length);
contour = gsk_path_get_contour (self->path, i);
gsk_contour_get_point (contour, self->measures[i].contour_data, offset, res);
res->contour = i;
return TRUE;
}
/**
* gsk_path_point_get_distance:
* @measure: a `GskPathMeasure`
* @point: a `GskPathPoint on the path of @self
*
* Returns the distance from the beginning of the path
* to @point.
*
* Returns: the distance of @point
*
* Since: 4.14
*/
float
gsk_path_point_get_distance (GskPathMeasure *measure,
const GskPathPoint *point)
{
GskRealPathPoint *p = (GskRealPathPoint *)point;
const GskContour *contour;
float contour_offset = 0;
g_return_val_if_fail (measure != NULL, 0);
g_return_val_if_fail (point != NULL, 0);
g_return_val_if_fail (p->contour < measure->n_contours, 0);
contour = gsk_path_get_contour (measure->path, p->contour);
for (gsize i = 0; i < measure->n_contours; i++)
{
if (contour == gsk_path_get_contour (measure->path, i))
return contour_offset + gsk_contour_get_distance (contour,
p,
measure->measures[i].contour_data);
contour_offset += measure->measures[i].length;
}
g_return_val_if_reached (0);
}

66
gsk/gskpathmeasure.h Normal file
View File

@@ -0,0 +1,66 @@
/*
* 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/gskpath.h>
#include <gsk/gskpathpoint.h>
G_BEGIN_DECLS
#define GSK_TYPE_PATH_MEASURE (gsk_path_measure_get_type ())
GDK_AVAILABLE_IN_4_14
GType gsk_path_measure_get_type (void) G_GNUC_CONST;
GDK_AVAILABLE_IN_4_14
GskPathMeasure * gsk_path_measure_new (GskPath *path);
GDK_AVAILABLE_IN_4_14
GskPathMeasure * gsk_path_measure_new_with_tolerance (GskPath *path,
float tolerance);
GDK_AVAILABLE_IN_4_14
GskPathMeasure * gsk_path_measure_ref (GskPathMeasure *self);
GDK_AVAILABLE_IN_4_14
void gsk_path_measure_unref (GskPathMeasure *self);
GDK_AVAILABLE_IN_4_14
GskPath * gsk_path_measure_get_path (GskPathMeasure *self) G_GNUC_PURE;
GDK_AVAILABLE_IN_4_14
float gsk_path_measure_get_tolerance (GskPathMeasure *self) G_GNUC_PURE;
GDK_AVAILABLE_IN_4_14
float gsk_path_measure_get_length (GskPathMeasure *self);
GDK_AVAILABLE_IN_4_14
gboolean gsk_path_measure_get_point (GskPathMeasure *self,
float distance,
GskPathPoint *result);
GDK_AVAILABLE_IN_4_14
float gsk_path_measure_get_distance (GskPathMeasure *self,
const GskPathPoint *point);
G_DEFINE_AUTOPTR_CLEANUP_FUNC(GskPathMeasure, gsk_path_measure_unref)
G_END_DECLS

4
gsk/gskpathpoint.c
View File

@@ -22,6 +22,7 @@
#include "gskpathpointprivate.h"
#include "gskcontourprivate.h"
#include "gskpathmeasure.h"
#include "gdk/gdkprivate.h"
@@ -33,7 +34,8 @@
* It can be queried for properties of the path at that point, such as its
* tangent or its curvature.
*
* To obtain a `GskPathPoint`, use [method@Gsk.Path.get_closest_point].
* To obtain a `GskPathPoint`, use [method@Gsk.Path.get_closest_point]
* or [method@Gsk.PathMeasure.get_point].
*
* Note that `GskPathPoint` structs are meant to be stack-allocated, and
* don't a reference to the path object they are obtained from. It is the

3
gsk/gskpathpoint.h
View File

@@ -72,5 +72,8 @@ float gsk_path_point_get_curvature (GskPath *path
const GskPathPoint *point,
graphene_point_t *center);
GDK_AVAILABLE_IN_4_14
float gsk_path_point_get_distance (GskPathMeasure *measure,
const GskPathPoint *point);
G_END_DECLS

1
gsk/gsktypes.h
View File

@@ -27,6 +27,7 @@
typedef struct _GskPath GskPath;
typedef struct _GskPathBuilder GskPathBuilder;
typedef struct _GskPathMeasure GskPathMeasure;
typedef struct _GskPathPoint GskPathPoint;
typedef struct _GskRenderer GskRenderer;
typedef struct _GskStroke GskStroke;

2
gsk/meson.build
View File

@@ -28,6 +28,7 @@ gsk_public_sources = files([
'gskglshader.c',
'gskpath.c',
'gskpathbuilder.c',
'gskpathmeasure.c',
'gskpathpoint.c',
'gskrenderer.c',
'gskrendernode.c',
@@ -75,6 +76,7 @@ gsk_public_headers = files([
'gskglshader.h',
'gskpath.h',
'gskpathbuilder.h',
'gskpathmeasure.h',
'gskpathpoint.h',
'gskrenderer.h',
'gskrendernode.h',