brl/mutter
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

MetaWindowGroup: Handle painting inside a ClutterClone

Browse Source 
Look at the current COGL model-view matrix and use that to find
out any offset we are painting at as a result of being inside
a ClutterClone.

https://bugzilla.gnome.org/show_bug.cgi?id=681953
This commit is contained in:
Owen W. Taylor 2012-08-15 19:03:39 -04:00
parent 0ab572d511
commit c27b4b7cfc
1 changed files with 142 additions and 29 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

171
src/compositor/meta-window-group.c
View File

@ -26,9 +26,28 @@ struct _MetaWindowGroup
G_DEFINE_TYPE (MetaWindowGroup, meta_window_group, CLUTTER_TYPE_GROUP);
/* We want to find out if the window is "close enough" to
* 1:1 transform. We do that by converting the transformed coordinates
* to 24.8 fixed-point before checking if they look right.
/* This file uses pixel-aligned region computation to determine what
* can be clipped out. This only really works if everything is aligned
* to the pixel grid - not scaled or rotated and at integer offsets.
*
* (This could be relaxed - if we turned off filtering for unscaled
* windows then windows would be, by definition aligned to the pixel
* grid. And for rectangular windows without a shape, the outline that
* we draw for an unrotated window is always a rectangle because we
* don't use antialasing for the window boundary - with or without
* filtering, with or without a scale. But figuring out exactly
* what pixels will be drawn by the graphics system in these cases
* gets tricky, so we just go for the easiest part - no scale,
* and at integer offsets.)
*
* The way we check for pixel-aligned is by looking at the
* transformation into screen space of the allocation box of an actor
* and and checking if the corners are "close enough" to integral
* pixel values.
*/
/* The definition of "close enough" to integral pixel values is
* equality when we convert to 24.8 fixed-point.
*/
static inline int
round_to_fixed (float x)
@ -36,41 +55,24 @@ round_to_fixed (float x)
return roundf (x * 256);
}
/* We can only (easily) apply our logic for figuring out what a window
* obscures if is not transformed. This function does that check and
* as a side effect gets the position of the upper-left corner of the
* actors.
*
* (We actually could handle scaled and non-integrally positioned actors
* too as long as they weren't shaped - no filtering is done at the
* edges so a rectangle stays a rectangle. But the gain from that is
* small, especally since most of our windows are shaped. The simple
* case we handle here is the case that matters when the user is just
* using the desktop normally.)
*
* If we assume that the window group is untransformed (it better not
* be!) then we could also make this determination by checking directly
* if the actor itself is rotated, scaled, or at a non-integral position.
* However, the criterion for "close enough" in that case get trickier,
* since, for example, the allowed rotation depends on the size of
* actor. The approach we take here is to just require everything
* to be within 1/256th of a pixel.
/* This helper function checks if (according to our fixed point precision)
* the vertices @verts form a box of width @widthf and height @heightf
* located at integral coordinates. These coordinates are returned
* in @x_origin and @y_origin.
*/
static gboolean
actor_is_untransformed (ClutterActor *actor,
int *x_origin,
int *y_origin)
vertices_are_untransformed (ClutterVertex *verts,
float widthf,
float heightf,
int *x_origin,
int *y_origin)
{
gfloat widthf, heightf;
int width, height;
ClutterVertex verts[4];
int v0x, v0y, v1x, v1y, v2x, v2y, v3x, v3y;
int x, y;
clutter_actor_get_size (actor, &widthf, &heightf);
width = round_to_fixed (widthf); height = round_to_fixed (heightf);
clutter_actor_get_abs_allocation_vertices (actor, verts);
v0x = round_to_fixed (verts[0].x); v0y = round_to_fixed (verts[0].y);
v1x = round_to_fixed (verts[1].x); v1y = round_to_fixed (verts[1].y);
v2x = round_to_fixed (verts[2].x); v2y = round_to_fixed (verts[2].y);
@ -101,6 +103,81 @@ actor_is_untransformed (ClutterActor *actor,
return TRUE;
}
/* Check if an actor is "untransformed" - which actually means transformed by
* at most a integer-translation. The integer translation, if any, is returned.
*/
static gboolean
actor_is_untransformed (ClutterActor *actor,
int *x_origin,
int *y_origin)
{
gfloat widthf, heightf;
ClutterVertex verts[4];
clutter_actor_get_size (actor, &widthf, &heightf);
clutter_actor_get_abs_allocation_vertices (actor, verts);
return vertices_are_untransformed (verts, widthf, heightf, x_origin, y_origin);
}
/* Help macros to scale from OpenGL <-1,1> coordinates system to
* window coordinates ranging [0,window-size]. Borrowed from clutter-utils.c
*/
#define MTX_GL_SCALE_X(x,w,v1,v2) ((((((x) / (w)) + 1.0f) / 2.0f) * (v1)) + (v2))
#define MTX_GL_SCALE_Y(y,w,v1,v2) ((v1) - (((((y) / (w)) + 1.0f) / 2.0f) * (v1)) + (v2))
/* Check if we're painting the MetaWindowGroup "untransformed". This can
* differ from the result of actor_is_untransformed(window_group) if we're
* inside a clone paint. The integer translation, if any, is returned.
*/
static gboolean
painting_untransformed (MetaWindowGroup *window_group,
int *x_origin,
int *y_origin)
{
CoglMatrix modelview, projection, modelview_projection;
ClutterVertex vertices[4];
int width, height;
float viewport[4];
int i;
cogl_get_modelview_matrix (&modelview);
cogl_get_projection_matrix (&projection);
cogl_matrix_multiply (&modelview_projection,
&projection,
&modelview);
meta_screen_get_size (window_group->screen, &width, &height);
vertices[0].x = 0;
vertices[0].y = 0;
vertices[0].z = 0;
vertices[1].x = width;
vertices[1].y = 0;
vertices[1].z = 0;
vertices[2].x = 0;
vertices[2].y = height;
vertices[2].z = 0;
vertices[3].x = width;
vertices[3].y = height;
vertices[3].z = 0;
cogl_get_viewport (viewport);
for (i = 0; i < 4; i++)
{
float w = 1;
cogl_matrix_transform_point (&modelview_projection, &vertices[i].x, &vertices[i].y, &vertices[i].z, &w);
vertices[i].x = MTX_GL_SCALE_X (vertices[i].x, w,
viewport[2], viewport[0]);
vertices[i].y = MTX_GL_SCALE_Y (vertices[i].y, w,
viewport[3], viewport[1]);
}
return vertices_are_untransformed (vertices, width, height, x_origin, y_origin);
}
static void
meta_window_group_paint (ClutterActor *actor)
{
@ -109,10 +186,40 @@ meta_window_group_paint (ClutterActor *actor)
ClutterActor *stage;
cairo_rectangle_int_t visible_rect, unredirected_rect;
GList *children, *l;
<<<<<<< HEAD
gfloat group_x, group_y;
=======
int paint_x_origin, paint_y_origin;
int actor_x_origin, actor_y_origin;
int paint_x_offset, paint_y_offset;
>>>>>>> MetaWindowGroup: Handle painting inside a ClutterClone
MetaWindowGroup *window_group = META_WINDOW_GROUP (actor);
MetaCompScreen *info = meta_screen_get_compositor_data (window_group->screen);
/* Normally we expect an actor to be drawn at it's position on the screen.
* However, if we're inside the paint of a ClutterClone, that won't be the
* case and we need to compensate. We look at the position of the window
* group under the current model-view matrix and the position of the actor.
* If they are both simply integer translations, then we can compensate
* easily, otherwise we give up.
*
* Possible cleanup: work entirely in paint space - we can compute the
* combination of the model-view matrix with the local matrix for each child
* actor and get a total transformation for that actor for how we are
* painting currently, and never worry about how actors are positioned
* on the stage.
*/
if (!painting_untransformed (window_group, &paint_x_origin, &paint_y_origin) ||
!actor_is_untransformed (actor, &actor_x_origin, &actor_y_origin))
{
CLUTTER_ACTOR_CLASS (meta_window_group_parent_class)->paint (actor);
return;
}
paint_x_offset = paint_x_origin - actor_x_origin;
paint_y_offset = paint_y_origin - actor_y_origin;
if (info->unredirected_window != NULL)
{
meta_window_actor_get_shape_bounds (META_WINDOW_ACTOR (info->unredirected_window), &unredirected_rect);
@ -175,6 +282,9 @@ meta_window_group_paint (ClutterActor *actor)
if (!actor_is_untransformed (CLUTTER_ACTOR (window_actor), &x, &y))
continue;
x += paint_x_offset;
y += paint_y_offset;
/* Temporarily move to the coordinate system of the actor */
cairo_region_translate (visible_region, - x, - y);
@ -198,6 +308,9 @@ meta_window_group_paint (ClutterActor *actor)
if (!actor_is_untransformed (CLUTTER_ACTOR (background_actor), &x, &y))
continue;
x += paint_x_offset;
y += paint_y_offset;
cairo_region_translate (visible_region, - x, - y);
meta_background_actor_set_visible_region (background_actor, visible_region);
cairo_region_translate (visible_region, x, y);