Commit bbf5fe17 authored by Benjamin Otte's avatar Benjamin Otte

background: Implement all options of background-repeat

parent af8c7ebe
......@@ -21,12 +21,21 @@
* Boston, MA 02111-1307, USA.
*/
#include "config.h"
#include "gtkcsstypesprivate.h"
#include "gtkthemingbackgroundprivate.h"
#include "gtkthemingengineprivate.h"
#include <math.h>
#include <gdk/gdk.h>
/* this is in case round() is not provided by the compiler,
* such as in the case of C89 compilers, like MSVC
*/
#include "fallback-c89.c"
static void
_gtk_theming_background_apply_window_background (GtkThemingBackground *bg,
cairo_t *cr)
......@@ -116,21 +125,121 @@ _gtk_theming_background_paint (GtkThemingBackground *bg,
if (bg->image)
{
GtkCssBackgroundRepeat repeat;
GtkCssBackgroundRepeat hrepeat, vrepeat;
double image_width, image_height;
double width, height;
gtk_theming_engine_get (bg->engine, bg->flags,
"background-repeat", &repeat,
"background-repeat", &hrepeat,
NULL);
vrepeat = GTK_CSS_BACKGROUND_VERTICAL (hrepeat);
hrepeat = GTK_CSS_BACKGROUND_HORIZONTAL (hrepeat);
width = bg->image_rect.width;
height = bg->image_rect.height;
_gtk_css_image_get_concrete_size (bg->image,
0, 0, /* XXX: needs background-size support */
bg->image_rect.width, bg->image_rect.height,
width, height,
&image_width, &image_height);
/* optimization */
if (image_width == width)
hrepeat = GTK_CSS_BACKGROUND_NO_REPEAT;
if (image_height == height)
vrepeat = GTK_CSS_BACKGROUND_NO_REPEAT;
cairo_translate (cr, bg->image_rect.x, bg->image_rect.y);
/* XXX: repeat flags */
_gtk_css_image_draw (bg->image, cr, image_width, image_height);
if (hrepeat == GTK_CSS_BACKGROUND_NO_REPEAT && vrepeat == GTK_CSS_BACKGROUND_NO_REPEAT)
{
/* shortcut for normal case */
_gtk_css_image_draw (bg->image, cr, image_width, image_height);
}
else
{
int surface_width, surface_height;
cairo_surface_t *surface;
cairo_t *cr2;
/* If ‘background-repeat’ is ‘round’ for one (or both) dimensions,
* there is a second step. The UA must scale the image in that
* dimension (or both dimensions) so that it fits a whole number of
* times in the background positioning area. In the case of the width
* (height is analogous):
*
* If X ≠ 0 is the width of the image after step one and W is the width
* of the background positioning area, then the rounded width
* X' = W / round(W / X) where round() is a function that returns the
* nearest natural number (integer greater than zero).
*
* If ‘background-repeat’ is ‘round’ for one dimension only and if
* ‘background-size’ is ‘auto’ for the other dimension, then there is
* a third step: that other dimension is scaled so that the original
* aspect ratio is restored.
*/
if (hrepeat == GTK_CSS_BACKGROUND_ROUND)
{
double n = round (width / image_width);
n = MAX (1, n);
if (vrepeat != GTK_CSS_BACKGROUND_ROUND
/* && vsize == auto (it is by default) */)
image_height *= width / (image_width * n);
image_width = width / n;
}
if (vrepeat == GTK_CSS_BACKGROUND_ROUND)
{
double n = round (height / image_height);
n = MAX (1, n);
if (hrepeat != GTK_CSS_BACKGROUND_ROUND
/* && hsize == auto (it is by default) */)
image_width *= height / (image_height * n);
image_height = height / n;
}
/* if hrepeat or vrepeat is 'space', we create a somewhat larger surface
* to store the extra space. */
if (hrepeat == GTK_CSS_BACKGROUND_SPACE)
{
double n = floor (width / image_width);
surface_width = n ? round (width / n) : 0;
}
else
surface_width = round (image_width);
if (vrepeat == GTK_CSS_BACKGROUND_SPACE)
{
double n = floor (height / image_height);
surface_height = n ? round (height / n) : 0;
}
else
surface_height = round (image_height);
surface = cairo_surface_create_similar (cairo_get_target (cr),
CAIRO_CONTENT_COLOR_ALPHA,
surface_width, surface_height);
cr2 = cairo_create (surface);
cairo_translate (cr2,
0.5 * (surface_width - image_width),
0.5 * (surface_height - image_height));
_gtk_css_image_draw (bg->image, cr2, image_width, image_height);
cairo_destroy (cr2);
cairo_set_source_surface (cr, surface,
/* background-position goes here */
0, 0);
cairo_pattern_set_extend (cairo_get_source (cr), CAIRO_EXTEND_REPEAT);
cairo_surface_destroy (surface);
cairo_rectangle (cr,
0, 0,
hrepeat == GTK_CSS_BACKGROUND_NO_REPEAT ? image_width : width,
vrepeat == GTK_CSS_BACKGROUND_NO_REPEAT ? image_height : height);
cairo_fill (cr);
}
}
cairo_restore (cr);
......
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