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>
diff --git a/src/compositor.c b/src/compositor.c
index f631e23..0c62fb0 100644
--- a/src/compositor.c
+++ b/src/compositor.c
@@ -277,18 +277,20 @@
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 @@
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