Add gsk_path_get_stroke_bounds

This is a helper to compute the bounds for
stroke nodes. We keep it private for now.
This commit is contained in:
Matthias Clasen 2023-07-21 23:35:14 -04:00
parent db71c07f8f
commit c37c29422a
6 changed files with 129 additions and 7 deletions

View File

@ -26,6 +26,7 @@
#include "gskpathprivate.h" #include "gskpathprivate.h"
#include "gskpathpointprivate.h" #include "gskpathpointprivate.h"
#include "gsksplineprivate.h" #include "gsksplineprivate.h"
#include "gskstrokeprivate.h"
typedef struct _GskContourClass GskContourClass; typedef struct _GskContourClass GskContourClass;
@ -47,6 +48,9 @@ struct _GskContourClass
GString *string); GString *string);
gboolean (* get_bounds) (const GskContour *contour, gboolean (* get_bounds) (const GskContour *contour,
GskBoundingBox *bounds); GskBoundingBox *bounds);
gboolean (* get_stroke_bounds) (const GskContour *contour,
const GskStroke *stroke,
GskBoundingBox *bounds);
void (* get_start_end) (const GskContour *self, void (* get_start_end) (const GskContour *self,
graphene_point_t *start, graphene_point_t *start,
graphene_point_t *end); graphene_point_t *end);
@ -295,6 +299,60 @@ gsk_standard_contour_get_bounds (const GskContour *contour,
return bounds->max.x > bounds->min.x && bounds->max.y > bounds->min.y; return bounds->max.x > bounds->min.x && bounds->max.y > bounds->min.y;
} }
static gboolean
add_stroke_bounds (GskPathOperation op,
const graphene_point_t *pts,
gsize n_pts,
gpointer user_data)
{
struct {
GskBoundingBox *bounds;
float lw;
float mw;
} *data = user_data;
GskBoundingBox bounds;
for (int i = 1; i < n_pts - 1; i++)
{
gsk_bounding_box_init (&bounds,
&GRAPHENE_POINT_INIT (pts[i].x - data->lw/2, pts[i].y - data->lw/2),
&GRAPHENE_POINT_INIT (pts[i].x + data->lw/2, pts[i].y + data->lw/2));
gsk_bounding_box_union (&bounds, data->bounds, data->bounds);
}
gsk_bounding_box_init (&bounds,
&GRAPHENE_POINT_INIT (pts[n_pts - 1].x - data->mw/2, pts[n_pts - 1].y - data->mw/2),
&GRAPHENE_POINT_INIT (pts[n_pts - 1].x + data->mw/2, pts[n_pts - 1].y + data->mw/2));
gsk_bounding_box_union (&bounds, data->bounds, data->bounds);
return TRUE;
}
static gboolean
gsk_standard_contour_get_stroke_bounds (const GskContour *contour,
const GskStroke *stroke,
GskBoundingBox *bounds)
{
GskStandardContour *self = (GskStandardContour *) contour;
struct {
GskBoundingBox *bounds;
float lw;
float mw;
} data;
data.bounds = bounds;
data.lw = stroke->line_width;
data.mw = gsk_stroke_get_join_width (stroke);
gsk_bounding_box_init (bounds,
&GRAPHENE_POINT_INIT (self->points[0].x - data.mw/2, self->points[0].y - data.mw/2),
&GRAPHENE_POINT_INIT (self->points[0].x + data.mw/2, self->points[0].y + data.mw/2));
gsk_standard_contour_foreach (contour, GSK_PATH_TOLERANCE_DEFAULT, add_stroke_bounds, &data);
return TRUE;
}
static void static void
gsk_standard_contour_get_start_end (const GskContour *contour, gsk_standard_contour_get_start_end (const GskContour *contour,
graphene_point_t *start, graphene_point_t *start,
@ -493,6 +551,7 @@ static const GskContourClass GSK_STANDARD_CONTOUR_CLASS =
gsk_standard_contour_get_flags, gsk_standard_contour_get_flags,
gsk_standard_contour_print, gsk_standard_contour_print,
gsk_standard_contour_get_bounds, gsk_standard_contour_get_bounds,
gsk_standard_contour_get_stroke_bounds,
gsk_standard_contour_get_start_end, gsk_standard_contour_get_start_end,
gsk_standard_contour_foreach, gsk_standard_contour_foreach,
gsk_standard_contour_reverse, gsk_standard_contour_reverse,
@ -605,6 +664,14 @@ gsk_contour_get_bounds (const GskContour *self,
return self->klass->get_bounds (self, bounds); return self->klass->get_bounds (self, bounds);
} }
gboolean
gsk_contour_get_stroke_bounds (const GskContour *self,
const GskStroke *stroke,
GskBoundingBox *bounds)
{
return self->klass->get_stroke_bounds (self, stroke, bounds);
}
gboolean gboolean
gsk_contour_foreach (const GskContour *self, gsk_contour_foreach (const GskContour *self,
float tolerance, float tolerance,

View File

@ -45,6 +45,9 @@ void gsk_contour_print (const GskContou
GString *string); GString *string);
gboolean gsk_contour_get_bounds (const GskContour *self, gboolean gsk_contour_get_bounds (const GskContour *self,
GskBoundingBox *bounds); GskBoundingBox *bounds);
gboolean gsk_contour_get_stroke_bounds (const GskContour *self,
const GskStroke *stroke,
GskBoundingBox *bounds);
gboolean gsk_contour_foreach (const GskContour *self, gboolean gsk_contour_foreach (const GskContour *self,
float tolerance, float tolerance,
GskPathForeachFunc func, GskPathForeachFunc func,

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@ -379,7 +379,6 @@ gsk_path_get_bounds (GskPath *self,
graphene_rect_t *bounds) graphene_rect_t *bounds)
{ {
GskBoundingBox b; GskBoundingBox b;
gsize i;
g_return_val_if_fail (self != NULL, FALSE); g_return_val_if_fail (self != NULL, FALSE);
g_return_val_if_fail (bounds != NULL, FALSE); g_return_val_if_fail (bounds != NULL, FALSE);
@ -392,12 +391,60 @@ gsk_path_get_bounds (GskPath *self,
gsk_contour_get_bounds (self->contours[0], &b); gsk_contour_get_bounds (self->contours[0], &b);
for (i = 1; i < self->n_contours; i++) for (gsize i = 1; i < self->n_contours; i++)
{ {
GskBoundingBox bb; GskBoundingBox tmp;
gsk_contour_get_bounds (self->contours[i], &bb); gsk_contour_get_bounds (self->contours[i], &tmp);
gsk_bounding_box_union (&b, &bb, &b); gsk_bounding_box_union (&b, &tmp, &b);
}
gsk_bounding_box_to_rect (&b, bounds);
return TRUE;
}
/**
* gsk_path_get_stroke_bounds:
* @self: a #GtkPath
* @stroke: stroke parameters
* @bounds: (out caller-allocates): the bounds to fill in
*
* Computes the bounds for stroking the given path with the
* parameters in @stroke.
*
* The returned bounds may be larger than necessary, because this
* function aims to be fast, not accurate. The bounds are guaranteed
* to contain the area affected by the stroke, including protrusions
* like miters.
*
* Returns: `TRUE` if the path has bounds, `FALSE` if the path is known
* to be empty and have no bounds.
*/
gboolean
gsk_path_get_stroke_bounds (GskPath *self,
const GskStroke *stroke,
graphene_rect_t *bounds)
{
GskBoundingBox b;
g_return_val_if_fail (self != NULL, FALSE);
g_return_val_if_fail (bounds != NULL, FALSE);
if (self->n_contours == 0)
{
graphene_rect_init_from_rect (bounds, graphene_rect_zero ());
return FALSE;
}
gsk_contour_get_stroke_bounds (self->contours[0], stroke, &b);
for (gsize i = 1; i < self->n_contours; i++)
{
GskBoundingBox tmp;
if (gsk_contour_get_stroke_bounds (self->contours[i], stroke, &tmp))
gsk_bounding_box_union (&b, &tmp, &b);
} }
gsk_bounding_box_to_rect (&b, bounds); gsk_bounding_box_to_rect (&b, bounds);

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@ -100,6 +100,11 @@ GDK_AVAILABLE_IN_4_14
gboolean gsk_path_get_bounds (GskPath *self, gboolean gsk_path_get_bounds (GskPath *self,
graphene_rect_t *bounds); graphene_rect_t *bounds);
GDK_AVAILABLE_IN_4_14
gboolean gsk_path_get_stroke_bounds (GskPath *self,
const GskStroke *stroke,
graphene_rect_t *bounds);
GDK_AVAILABLE_IN_4_14 GDK_AVAILABLE_IN_4_14
gboolean gsk_path_in_fill (GskPath *self, gboolean gsk_path_in_fill (GskPath *self,
const graphene_point_t *point, const graphene_point_t *point,

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@ -498,7 +498,7 @@ gsk_stroke_get_dash_offset (const GskStroke *self)
* Returns: the join width * Returns: the join width
*/ */
float float
gsk_stroke_get_join_width (GskStroke *stroke) gsk_stroke_get_join_width (const GskStroke *stroke)
{ {
float width; float width;

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@ -53,6 +53,6 @@ gsk_stroke_clear (GskStroke *stroke)
stroke->n_dash = 0; /* better safe than sorry */ stroke->n_dash = 0; /* better safe than sorry */
} }
float gsk_stroke_get_join_width (GskStroke); float gsk_stroke_get_join_width (const GskStroke *stroke);
G_END_DECLS G_END_DECLS