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#include "backingstore.h"
struct BackingStore
{
GdkPixmap *pixmap;
GdkRegion *update_region;
int width;
int height;
};
BackingStore *
backing_store_new (GdkWindow *window,
int width,
int height)
{
BackingStore *store = g_new0 (BackingStore, 1);
GdkRectangle rect = { 0, 0, width, height };
store->pixmap = gdk_pixmap_new (window, width, height, -1);
store->update_region = gdk_region_rectangle (&rect);
store->width = width;
store->height = height;
return store;
}
void
backing_store_free (BackingStore *store)
{
g_object_unref (store->pixmap);
gdk_region_destroy (store->update_region);
g_free (store);
}
void
backing_store_scroll (BackingStore *store,
int dx,
int dy)
{
GdkGC *gc = gdk_gc_new (store->pixmap);
GdkRectangle rect;
gdk_draw_drawable (store->pixmap, gc, store->pixmap,
0, 0, dx, dy,
store->width, store->height);
gdk_region_offset (store->update_region, dx, dy);
/* Invalidate vertically */
rect.x = 0;
rect.width = store->width;
if (dy > 0)
{
rect.y = 0;
rect.height = dy;
}
else
{
rect.y = store->height + dy;
rect.height = -dy;
}
gdk_region_union_with_rect (store->update_region, &rect);
/* Invalidate horizontally */
rect.y = 0;
rect.height = store->height;
if (dx > 0)
{
rect.x = 0;
rect.width = dx;
}
else
{
rect.x = store->width + dx;
rect.width = -dx;
}
gdk_region_union_with_rect (store->update_region, &rect);
}
#if 0
static void
print_region (const char *header, GdkRegion *region)
{
GdkRectangle *rects;
int n_rects;
int i;
g_print ("%s\n", header);
gdk_region_get_rectangles (region, &rects, &n_rects);
for (i = 0; i < n_rects; ++i)
{
GdkRectangle *rect = &(rects[i]);
g_print (" %d %d %d %d\n",
rect->x, rect->y, rect->width, rect->height);
}
g_free (rects);
}
#endif
void
backing_store_invalidate_rect (BackingStore *store,
GdkRectangle *rect)
{
g_return_if_fail (store != NULL);
g_return_if_fail (rect != NULL);
gdk_region_union_with_rect (store->update_region, rect);
}
void
backing_store_invalidate_region (BackingStore *store,
GdkRegion *region)
{
g_return_if_fail (store != NULL);
g_return_if_fail (region != NULL);
gdk_region_union (store->update_region, region);
}
void
backing_store_invalidate_all (BackingStore *store)
{
GdkRectangle rect;
g_return_if_fail (store != NULL);
gdk_region_destroy (store->update_region);
rect.x = 0;
rect.y = 0;
rect.width = store->width;
rect.height = store->height;
store->update_region = gdk_region_rectangle (&rect);
}
static void
simple_draw_drawable (GdkDrawable *dst,
GdkDrawable *src,
int src_x,
int src_y,
int dst_x,
int dst_y,
int width,
int height)
{
GdkGC *gc = gdk_gc_new (dst);
gdk_draw_drawable (dst, gc, src, src_x, src_y, dst_x, dst_y, width, height);
g_object_unref (gc);
}
void
backing_store_resize (BackingStore *store,
int width,
int height)
{
GdkPixmap *pixmap;
GdkRegion *old, *invalid;
GdkRectangle r;
width = MAX (width, 1);
height = MAX (height, 1);
pixmap = gdk_pixmap_new (store->pixmap, width, height, -1);
/* Unfortunately we don't know in which direction we were resized,
* so we just assume we were dragged from the south-east corner.
*
* Although, maybe we could get the root coordinates of the input-window?
* That might just work, actually. We need to make sure metacity uses
* static gravity for the window before this will be useful.
*/
simple_draw_drawable (pixmap, store->pixmap, 0, 0, 0, 0, -1, -1);
g_object_unref (store->pixmap);
store->pixmap = pixmap;
r.x = r.y = 0;
r.height = store->height;
r.width = store->width;
old = gdk_region_rectangle (&r);
store->width = width;
store->height = height;
r.height = store->height;
r.width = store->width;
invalid = gdk_region_rectangle (&r);
gdk_region_subtract (invalid, old);
backing_store_invalidate_region (store, invalid);
gdk_region_destroy (old);
gdk_region_destroy (invalid);
}
static void
cclip_to_region (cairo_t *cr, GdkRegion *region)
{
int n_rects;
GdkRectangle *rects;
gdk_region_get_rectangles (region, &rects, &n_rects);
cairo_new_path (cr);
while (n_rects--)
{
GdkRectangle *rect = &(rects[n_rects]);
cairo_rectangle (cr, rect->x, rect->y, rect->width, rect->height);
}
cairo_clip (cr);
g_free (rects);
}
void
backing_store_draw (BackingStore *store,
GdkDrawable *dest,
GdkRegion *clip,
int dest_x,
int dest_y)
{
GdkGC *gc = gdk_gc_new (dest);
gdk_gc_set_clip_region (gc, clip);
gdk_draw_drawable (dest, gc, store->pixmap,
0, 0, dest_x, dest_y, store->width, store->height);
g_object_unref (gc);
}
void
backing_store_process_updates (BackingStore *store,
BackingPaintFunc func,
gpointer data)
{
cairo_t *cr = gdk_cairo_create (store->pixmap);
GdkRegion *region = store->update_region;
store->update_region = gdk_region_new ();
cclip_to_region (cr, region);
cairo_set_source_rgb (cr, g_random_double(), 0, 0);
cairo_paint (cr);
func (cr, region, data);
gdk_region_destroy (region);
cairo_destroy (cr);
}
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