compositor: rewrite draw and input coordinate transformations
For unifying the coordinate system handling, introduce functions for
converting explicitly between the global and the surface local
coordinate systems.
Use these functions in the input path, replacing
weston_surface_transform().
In the draw path, rewrite transform_vertex() to take in surface local
coordinates.
As shell now uses the new functions, the rotation origin is properly
placed in the middle of the surface.
Signed-off-by: Pekka Paalanen <ppaalanen@gmail.com>
diff --git a/src/compositor.c b/src/compositor.c
index 3330ffb..cc77747 100644
--- a/src/compositor.c
+++ b/src/compositor.c
@@ -259,6 +259,65 @@
}
WL_EXPORT void
+weston_surface_to_global(struct weston_surface *surface,
+ int32_t sx, int32_t sy, int32_t *x, int32_t *y)
+{
+ weston_surface_update_transform(surface);
+
+ if (surface->transform.enabled) {
+ struct weston_vector v = { { sx, sy, 0.0f, 1.0f } };
+
+ v.f[0] += surface->x;
+ v.f[1] += surface->y;
+
+ weston_matrix_transform(&surface->transform.matrix, &v);
+
+ if (fabsf(v.f[3]) < 1e-6) {
+ fprintf(stderr, "warning: numerical instability in "
+ "weston_surface_to_global(), divisor = %g\n",
+ v.f[3]);
+ *x = 0;
+ *y = 0;
+ return;
+ }
+
+ *x = floorf(v.f[0] / v.f[3]);
+ *y = floorf(v.f[1] / v.f[3]);
+ } else {
+ *x = sx + surface->x;
+ *y = sy + surface->y;
+ }
+}
+
+WL_EXPORT void
+weston_surface_from_global(struct weston_surface *surface,
+ int32_t x, int32_t y, int32_t *sx, int32_t *sy)
+{
+ weston_surface_update_transform(surface);
+
+ if (surface->transform.enabled) {
+ struct weston_vector v = { { x, y, 0.0f, 1.0f } };
+
+ weston_matrix_transform(&surface->transform.inverse, &v);
+
+ if (fabsf(v.f[3]) < 1e-6) {
+ fprintf(stderr, "warning: numerical instability in "
+ "weston_surface_from_global(), divisor = %g\n",
+ v.f[3]);
+ *sx = 0;
+ *sy = 0;
+ return;
+ }
+
+ *sx = floorf(v.f[0] / v.f[3] - surface->x);
+ *sy = floorf(v.f[1] / v.f[3] - surface->y);
+ } else {
+ *sx = x - surface->x;
+ *sy = y - surface->y;
+ }
+}
+
+WL_EXPORT void
weston_surface_damage_rectangle(struct weston_surface *surface,
int32_t x, int32_t y,
int32_t width, int32_t height)
@@ -337,23 +396,6 @@
pixman_region32_init(&surface->opaque);
}
-static void
-weston_surface_transform(struct weston_surface *surface,
- int32_t x, int32_t y, int32_t *sx, int32_t *sy)
-{
- weston_surface_update_transform(surface);
-
- if (surface->transform.enabled) {
- struct weston_vector v = { { x, y, 0.0f, 1.0f } };
- weston_matrix_transform(&surface->transform.inverse, &v);
- x = floorf(v.f[0] / v.f[3]);
- y = floorf(v.f[1] / v.f[3]);
- }
-
- *sx = x - surface->x;
- *sy = y - surface->y;
-}
-
WL_EXPORT uint32_t
weston_compositor_get_time(void)
{
@@ -385,8 +427,8 @@
focus = (struct weston_surface *) device->grab->focus;
if (focus)
- weston_surface_transform(focus, device->x, device->y,
- &device->grab->x, &device->grab->y);
+ weston_surface_from_global(focus, device->x, device->y,
+ &device->grab->x, &device->grab->y);
}
WL_EXPORT void
@@ -536,23 +578,27 @@
static void
transform_vertex(struct weston_surface *surface,
- GLfloat x, GLfloat y, GLfloat u, GLfloat v, GLfloat *r)
+ GLfloat sx, GLfloat sy,
+ GLfloat tex_x, GLfloat tex_y, GLfloat *r)
{
- struct weston_vector t;
+ /* surface->transform.enabled must always be 1 here. */
- t.f[0] = x;
- t.f[1] = y;
- t.f[2] = 0.0;
- t.f[3] = 1.0;
+ struct weston_vector v = { { sx, sy, 0.0f, 1.0f } };
- weston_matrix_transform(&surface->transform.matrix, &t);
+ v.f[0] += surface->x;
+ v.f[1] += surface->y;
- /* XXX: assumes last row of matrix is [0 0 * 1] */
+ weston_matrix_transform(&surface->transform.matrix, &v);
- r[ 0] = t.f[0];
- r[ 1] = t.f[1];
- r[ 2] = u;
- r[ 3] = v;
+ if (fabsf(v.f[3]) < 1e-6) {
+ fprintf(stderr, "warning: numerical instability in "
+ "transform_vertex(), divisor = %g\n", v.f[3]);
+ }
+
+ r[ 0] = v.f[0] / v.f[3];
+ r[ 1] = v.f[1] / v.f[3];
+ r[ 2] = tex_x;
+ r[ 3] = tex_y;
}
static int
@@ -565,11 +611,10 @@
v = wl_array_add(&ec->vertices, 16 * sizeof *v);
p = wl_array_add(&ec->indices, 6 * sizeof *p);
- transform_vertex(es, es->x, es->y, 0.0, 0.0, &v[0]);
- transform_vertex(es, es->x, es->y + es->height, 0.0, 1.0, &v[4]);
- transform_vertex(es, es->x + es->width, es->y, 1.0, 0.0, &v[8]);
- transform_vertex(es, es->x + es->width, es->y + es->height,
- 1.0, 1.0, &v[12]);
+ transform_vertex(es, 0, 0, 0.0, 0.0, &v[0]);
+ transform_vertex(es, 0, es->height, 0.0, 1.0, &v[4]);
+ transform_vertex(es, es->width, 0, 1.0, 0.0, &v[8]);
+ transform_vertex(es, es->width, es->height, 1.0, 1.0, &v[12]);
p[0] = 0;
p[1] = 1;
@@ -1096,7 +1141,7 @@
wl_list_for_each(surface, &compositor->surface_list, link) {
if (surface->surface.resource.client == NULL)
continue;
- weston_surface_transform(surface, x, y, sx, sy);
+ weston_surface_from_global(surface, x, y, sx, sy);
if (0 <= *sx && *sx < surface->width &&
0 <= *sy && *sy < surface->height)
return surface;
@@ -1484,7 +1529,7 @@
touch_set_focus(wd, &es->surface, time);
} else if (wd->touch_focus) {
es = (struct weston_surface *) wd->touch_focus;
- weston_surface_transform(es, x, y, &sx, &sy);
+ weston_surface_from_global(es, x, y, &sx, &sy);
}
if (wd->touch_focus_resource && wd->touch_focus)
@@ -1498,7 +1543,7 @@
if (!es)
break;
- weston_surface_transform(es, x, y, &sx, &sy);
+ weston_surface_from_global(es, x, y, &sx, &sy);
if (wd->touch_focus_resource)
wl_resource_post_event(wd->touch_focus_resource,
touch_type, time,