[PATCH 3/4] d2d1: Calculate intersections in a more robust way in d2d_geometry_intersect_self().
Henri Verbeet
hverbeet at codeweavers.com
Wed Nov 18 15:23:24 CST 2015
Signed-off-by: Henri Verbeet <hverbeet at codeweavers.com>
---
dlls/d2d1/geometry.c | 109 +++++++++++++++++++++++++++++++++++++++------------
1 file changed, 83 insertions(+), 26 deletions(-)
diff --git a/dlls/d2d1/geometry.c b/dlls/d2d1/geometry.c
index ed69a1e..9fa1783 100644
--- a/dlls/d2d1/geometry.c
+++ b/dlls/d2d1/geometry.c
@@ -82,6 +82,21 @@ struct d2d_cdt
const D2D1_POINT_2F *vertices;
};
+struct d2d_geometry_intersection
+{
+ size_t figure_idx;
+ size_t segment_idx;
+ float t;
+ D2D1_POINT_2F p;
+};
+
+struct d2d_geometry_intersections
+{
+ struct d2d_geometry_intersection *intersections;
+ size_t intersections_size;
+ size_t intersection_count;
+};
+
struct d2d_fp_two_vec2
{
float x[2];
@@ -1458,6 +1473,41 @@ static BOOL d2d_cdt_insert_segments(struct d2d_cdt *cdt, struct d2d_geometry *ge
return TRUE;
}
+static BOOL d2d_geometry_intersections_add(struct d2d_geometry_intersections *i,
+ size_t figure_idx, size_t segment_idx, float t, D2D1_POINT_2F p)
+{
+ struct d2d_geometry_intersection *intersection;
+
+ if (!d2d_array_reserve((void **)&i->intersections, &i->intersections_size,
+ i->intersection_count + 1, sizeof(*i->intersections)))
+ {
+ ERR("Failed to grow intersections array.\n");
+ return FALSE;
+ }
+
+ intersection = &i->intersections[i->intersection_count++];
+ intersection->figure_idx = figure_idx;
+ intersection->segment_idx = segment_idx;
+ intersection->t = t;
+ intersection->p = p;
+
+ return TRUE;
+}
+
+static int d2d_geometry_intersections_compare(const void *a, const void *b)
+{
+ const struct d2d_geometry_intersection *i0 = a;
+ const struct d2d_geometry_intersection *i1 = b;
+
+ if (i0->figure_idx != i1->figure_idx)
+ return i0->figure_idx - i1->figure_idx;
+ if (i0->segment_idx != i1->segment_idx)
+ return i0->segment_idx - i1->segment_idx;
+ if (i0->t != i1->t)
+ return i0->t > i1->t ? 1 : -1;
+ return 0;
+}
+
/* Intersect the geometry's segments with themselves. This uses the
* straightforward approach of testing everything against everything, but
* there certainly exist more scalable algorithms for this. */
@@ -1465,21 +1515,21 @@ static BOOL d2d_cdt_insert_segments(struct d2d_cdt *cdt, struct d2d_geometry *ge
static BOOL d2d_geometry_intersect_self(struct d2d_geometry *geometry)
{
D2D1_POINT_2F p0, p1, q0, q1, v_p, v_q, v_qp, intersection;
+ struct d2d_geometry_intersections intersections = {0};
struct d2d_figure *figure_p, *figure_q;
- size_t i, j, k, l, min_j, min_l, max_l;
+ size_t i, j, k, l, max_l;
+ BOOL ret = FALSE;
float s, t, det;
for (i = 0; i < geometry->u.path.figure_count; ++i)
{
figure_p = &geometry->u.path.figures[i];
p0 = figure_p->vertices[figure_p->vertex_count - 1];
- min_j = 0;
- min_l = 0;
for (k = 0; k < figure_p->vertex_count; p0 = p1, ++k)
{
p1 = figure_p->vertices[k];
d2d_point_subtract(&v_p, &p1, &p0);
- for (j = min_j, min_j = 0, l = min_l, min_l = 0; j < i || (j == i && k); ++j, l = 0)
+ for (j = 0; j < i || (j == i && k); ++j)
{
figure_q = &geometry->u.path.figures[j];
@@ -1490,8 +1540,8 @@ static BOOL d2d_geometry_intersect_self(struct d2d_geometry *geometry)
continue;
max_l = j == i ? k - 1 : figure_q->vertex_count;
- q0 = figure_q->vertices[l == 0 ? figure_q->vertex_count - 1 : l - 1];
- for (; l < max_l; q0 = q1, ++l)
+ q0 = figure_q->vertices[figure_q->vertex_count - 1];
+ for (l = 0; l < max_l; q0 = q1, ++l)
{
q1 = figure_q->vertices[l];
d2d_point_subtract(&v_q, &q1, &q0);
@@ -1510,31 +1560,38 @@ static BOOL d2d_geometry_intersect_self(struct d2d_geometry *geometry)
intersection.x = p0.x + v_p.x * s;
intersection.y = p0.y + v_p.y * s;
- if (t > 0.0f && t < 1.0f)
- {
- if (!d2d_figure_insert_vertex(figure_q, l, intersection))
- return FALSE;
- if (j == i)
- ++k;
- ++max_l;
- ++l;
- }
-
- if (s > 0.0f && s < 1.0f)
- {
- if (!d2d_figure_insert_vertex(figure_p, k, intersection))
- return FALSE;
- min_j = j;
- min_l = l+1;
- p1 = intersection;
- d2d_point_subtract(&v_p, &p1, &p0);
- }
+ if (t > 0.0f && t < 1.0f
+ && !d2d_geometry_intersections_add(&intersections, j, l, t, intersection))
+ goto done;
+
+ if (s > 0.0f && s < 1.0f
+ && !d2d_geometry_intersections_add(&intersections, i, k, s, intersection))
+ goto done;
}
}
}
}
- return TRUE;
+ qsort(intersections.intersections, intersections.intersection_count,
+ sizeof(*intersections.intersections), d2d_geometry_intersections_compare);
+ for (i = 0; i < intersections.intersection_count; ++i)
+ {
+ const struct d2d_geometry_intersection *inter = &intersections.intersections[i];
+
+ if (!i || inter->figure_idx != intersections.intersections[i - 1].figure_idx)
+ j = 0;
+
+ if (!d2d_figure_insert_vertex(&geometry->u.path.figures[inter->figure_idx],
+ inter->segment_idx + j, inter->p))
+ goto done;
+ ++j;
+ }
+
+ ret = TRUE;
+
+done:
+ HeapFree(GetProcessHeap(), 0, intersections.intersections);
+ return ret;
}
static HRESULT d2d_path_geometry_triangulate(struct d2d_geometry *geometry)
--
2.1.4
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