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author | Matthias Clasen <mclasen@redhat.com> | 2020-09-01 08:36:45 -0400 |
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committer | Matthias Clasen <mclasen@redhat.com> | 2020-09-01 09:18:38 -0400 |
commit | 99a7a2188aaa0dddbaa968f0f80997d8906bef68 (patch) | |
tree | 8ea20cfc2c04ac95926ca4ff1f39918877212a1c /gsk/gsktransform.c | |
parent | 9377ce984d55a68623c7b9d50f138fb8ebdb039b (diff) | |
download | gtk+-99a7a2188aaa0dddbaa968f0f80997d8906bef68.tar.gz |
gsk: Add some private transform apis
Some of the graphene_matrix_transform apis don't work
correctly with projective matrices, so add our own
variants.
Diffstat (limited to 'gsk/gsktransform.c')
-rw-r--r-- | gsk/gsktransform.c | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/gsk/gsktransform.c b/gsk/gsktransform.c index a1b65ff13f..feaec99187 100644 --- a/gsk/gsktransform.c +++ b/gsk/gsktransform.c @@ -2165,3 +2165,80 @@ gsk_transform_parse (const char *string, return result; } + +/* Some of the graphene_matrix_transform apis yield unexpected + * results with projective matrices, since they silently drop + * the w component, so we provide working alternatives here. + */ +void +gsk_matrix_transform_point (const graphene_matrix_t *m, + const graphene_point_t *p, + graphene_point_t *res) +{ + graphene_vec4_t vec4; + float w; + + graphene_vec4_init (&vec4, p->x, p->y, 0.0f, 1.0f); + graphene_matrix_transform_vec4 (m, &vec4, &vec4); + + w = graphene_vec4_get_w (&vec4); + res->x = graphene_vec4_get_x (&vec4) / w; + res->y = graphene_vec4_get_y (&vec4) / w; +} + +void +gsk_matrix_transform_point3d (const graphene_matrix_t *m, + const graphene_point3d_t *p, + graphene_point3d_t *res) +{ + graphene_vec4_t vec4; + float w; + + graphene_vec4_init (&vec4, p->x, p->y, 0.0f, 1.0f); + graphene_matrix_transform_vec4 (m, &vec4, &vec4); + + w = graphene_vec4_get_w (&vec4); + res->x = graphene_vec4_get_x (&vec4) / w; + res->y = graphene_vec4_get_y (&vec4) / w; + res->z = graphene_vec4_get_z (&vec4) / w; +} + +void +gsk_matrix_transform_bounds (const graphene_matrix_t *m, + const graphene_rect_t *r, + graphene_rect_t *res) +{ + graphene_point_t ret[4]; + float min_x, min_y; + float max_x, max_y; + graphene_rect_t rr; + + graphene_rect_normalize_r (r, &rr); + +#define TRANSFORM_POINT(matrix, rect, corner, out_p) do {\ + graphene_vec4_t __s; \ + graphene_point_t __p; \ + float w; \ + graphene_rect_get_ ## corner (rect, &__p); \ + graphene_vec4_init (&__s, __p.x, __p.y, 0.f, 1.f); \ + graphene_matrix_transform_vec4 (matrix, &__s, &__s); \ + w = graphene_vec4_get_w (&__s); \ + out_p.x = graphene_vec4_get_x (&__s) / w; \ + out_p.y = graphene_vec4_get_y (&__s) / w; } while (0) + + TRANSFORM_POINT (m, &rr, top_left, ret[0]); + TRANSFORM_POINT (m, &rr, top_right, ret[1]); + TRANSFORM_POINT (m, &rr, bottom_right, ret[2]); + TRANSFORM_POINT (m, &rr, bottom_left, ret[3]); + +#undef TRANSFORM_POINT + + /* FIXME: graphene doesn't export a fast way to do this */ + min_x = MIN (MIN (ret[0].x, ret[1].x), MIN (ret[2].x, ret[3].x)); + min_y = MIN (MIN (ret[0].y, ret[1].y), MIN (ret[2].y, ret[3].y)); + + max_x = MAX (MAX (ret[0].x, ret[1].x), MAX (ret[2].x, ret[3].x)); + max_y = MAX (MAX (ret[0].y, ret[1].y), MAX (ret[2].y, ret[3].y)); + + graphene_rect_init (res, min_x, min_y, max_x - min_x, max_y - min_y); +} |