compositor: use floats in computing bounding box

In surface_compute_bbox(), call surface_to_global_float() instead of
weston_surface_to_global(). This avoids the recursion:

weston_surface_update_transform()
  weston_surface_update_transform_enable()
    surface_compute_bbox()
       weston_surface_to_global()
         weston_surface_update_transform()

which might be non-obvious when reading the code.

Computing the min and max coordinates in floats, we can have a tight
rounding margin by using floor() and ceil().

Signed-off-by: Pekka Paalanen <ppaalanen@gmail.com>
Pekka Paalanen 13 years ago
parent ece8a016aa
commit 219b982ed0
  1. 17
      src/compositor.c

@ -277,18 +277,20 @@ surface_compute_bbox(struct weston_surface *surface, int32_t sx, int32_t sy,
int32_t width, int32_t height,
pixman_region32_t *bbox)
{
int min_x = INT_MAX, min_y = INT_MAX, max_x = INT_MIN, max_y = INT_MIN;
GLfloat min_x = HUGE_VALF, min_y = HUGE_VALF;
GLfloat max_x = -HUGE_VALF, max_y = -HUGE_VALF;
int32_t s[4][2] = {
{ sx, sy },
{ sx, sy + height },
{ sx + width, sy },
{ sx + width, sy + height }
};
GLfloat int_x, int_y;
int i;
for (i = 0; i < 4; ++i) {
int32_t x, y;
weston_surface_to_global(surface, s[i][0], s[i][1], &x, &y);
GLfloat x, y;
surface_to_global_float(surface, s[i][0], s[i][1], &x, &y);
if (x < min_x)
min_x = x;
if (x > max_x)
@ -299,11 +301,10 @@ surface_compute_bbox(struct weston_surface *surface, int32_t sx, int32_t sy,
max_y = y;
}
/* weston_surface_to_global rounds with floor(), add the
* minimum required safety margin.
*/
pixman_region32_init_rect(bbox, min_x, min_y,
max_x - min_x + 1, max_y - min_y + 1);
int_x = floorf(min_x);
int_y = floorf(min_y);
pixman_region32_init_rect(bbox, int_x, int_y,
ceilf(max_x) - int_x, ceilf(max_y) - int_y);
}
static void

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