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st-theme-node: Add support for inset box-shadows

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Implement inset box-shadows as in the CSS3 draft[0]. As the shadow
should appear beneath the node's border, we pick the slow cairo based
rendering path (though a cogl based path could be added in case the
node has a solid background with no borders).

[0] http://www.w3.org/TR/css3-background/#box-shadow

https://bugzilla.gnome.org/show_bug.cgi?id=642334
This commit is contained in:
Florian Müllner 2011-02-14 02:34:00 +01:00
parent 2b90be77b3
commit a3a6650e66
3 changed files with 255 additions and 46 deletions
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44
src/st/st-private.c
View File

@ -636,6 +636,23 @@ _st_create_shadow_material_from_actor (StShadow *shadow_spec,
return shadow_material;
}
/**
* _st_create_shadow_cairo_pattern:
* @shadow_spec: the definition of the shadow
* @src_pattern: surface pattern for which we create the shadow
* (must be a surface pattern)
*
* This is a utility function for creating shadows used by
* st-theme-node.c; it's in this file to share the gaussian
* blur implementation. The usage of this function is quite different
* depending on whether shadow_spec->inset is %TRUE or not. If
* shadow_spec->inset is %TRUE, the caller should pass in a @src_pattern
* which is the <i>inverse</i> of what they want shadowed, and must take
* care of the spread and offset from the shadow spec themselves. If
* shadow_spec->inset is %FALSE then the caller should pass in what they
* want shadowed directly, and this function takes care of the spread and
* the offset.
*/
cairo_pattern_t *
_st_create_shadow_cairo_pattern (StShadow *shadow_spec,
cairo_pattern_t *src_pattern)
@ -649,6 +666,7 @@ _st_create_shadow_cairo_pattern (StShadow *shadow_spec,
gint width_in, height_in, rowstride_in;
gint width_out, height_out, rowstride_out;
cairo_matrix_t shadow_matrix;
int i, j;
g_return_val_if_fail (shadow_spec != NULL, NULL);
g_return_val_if_fail (src_pattern != NULL, NULL);
@ -684,6 +702,17 @@ _st_create_shadow_cairo_pattern (StShadow *shadow_spec,
&width_out, &height_out, &rowstride_out);
cairo_surface_destroy (surface_in);
/* Invert pixels for inset shadows */
if (shadow_spec->inset)
{
for (j = 0; j < height_out; j++)
{
guchar *p = pixels_out + rowstride_out * j;
for (i = 0; i < width_out; i++, p++)
*p = ~*p;
}
}
surface_out = cairo_image_surface_create_for_data (pixels_out,
CAIRO_FORMAT_A8,
width_out,
@ -695,6 +724,21 @@ _st_create_shadow_cairo_pattern (StShadow *shadow_spec,
cairo_pattern_get_matrix (src_pattern, &shadow_matrix);
if (shadow_spec->inset)
{
/* For inset shadows, offsets and spread radius have already been
* applied to the original pattern, so all left to do is shift the
* blurred image left, so that it aligns centered under the
* unblurred one
*/
cairo_matrix_translate (&shadow_matrix,
(width_out - width_in) / 2.0,
(height_out - height_in) / 2.0);
cairo_pattern_set_matrix (dst_pattern, &shadow_matrix);
return dst_pattern;
}
/* Read all the code from the cairo_pattern_set_matrix call
* at the end of this function to here from bottom to top,
* because each new affine transformation is applied in

261
src/st/st-theme-node-drawing.c
View File

@ -602,6 +602,89 @@ create_cairo_pattern_of_background_image (StThemeNode *node,
return pattern;
}
/* fill_exterior = TRUE means that pattern is a surface pattern and
* we should extend the pattern with a solid fill from its edges.
* This is a bit of a hack; the alternative would be to make the
* surface of the surface pattern 1 pixel bigger and use CAIRO_EXTEND_PAD.
*/
static void
paint_shadow_pattern_to_cairo_context (StShadow *shadow_spec,
cairo_pattern_t *pattern,
gboolean fill_exterior,
cairo_t *cr,
cairo_path_t *interior_path,
cairo_path_t *outline_path)
{
/* If there are borders, clip the shadow to the interior
* of the borders; if there is a visible outline, clip the shadow to
* that outline
*/
cairo_path_t *path = (interior_path != NULL) ? interior_path : outline_path;
double x1, x2, y1, y2;
/* fill_exterior only makes sense if we're clipping the shadow - filling
* to the edges of the surface would be silly */
g_assert (!(fill_exterior && path == NULL));
cairo_save (cr);
if (path != NULL)
{
cairo_append_path (cr, path);
/* There's no way to invert a path in cairo, so we need bounds for
* the area we are drawing in order to create the "exterior" region.
* Pixel align to hit fast paths.
*/
if (fill_exterior)
{
cairo_path_extents (cr, &x1, &y1, &x2, &y2);
x1 = floor (x1);
y1 = floor (y1);
x2 = ceil (x2);
y2 = ceil (y2);
}
cairo_clip (cr);
}
cairo_set_source_rgba (cr,
shadow_spec->color.red / 255.0,
shadow_spec->color.green / 255.0,
shadow_spec->color.blue / 255.0,
shadow_spec->color.alpha / 255.0);
if (fill_exterior)
{
cairo_surface_t *surface;
int width, height;
cairo_matrix_t matrix;
cairo_save (cr);
/* Start with a rectangle enclosing the bounds of the clipped
* region */
cairo_rectangle (cr, x1, y1, x2 - x1, y2 - y1);
/* Then subtract out the bounds of the surface in the surface
* pattern; we transform the context by the inverse of the
* pattern matrix to get to surface coordinates */
cairo_pattern_get_surface (pattern, &surface);
width = cairo_image_surface_get_width (surface);
height = cairo_image_surface_get_height (surface);
cairo_pattern_get_matrix (pattern, &matrix);
cairo_matrix_invert (&matrix);
cairo_transform (cr, &matrix);
cairo_rectangle (cr, 0, height, width, - height);
cairo_fill (cr);
cairo_restore (cr);
}
cairo_mask (cr, pattern);
cairo_restore (cr);
}
static void
paint_background_image_shadow_to_cairo_context (StThemeNode *node,
StShadow *shadow_spec,
@ -661,52 +744,128 @@ paint_background_image_shadow_to_cairo_context (StThemeNode *node,
pattern);
}
/* Stamp the shadow pattern out in the appropriate color
* in a new layer
*/
cairo_push_group (cr);
cairo_set_operator (cr, CAIRO_OPERATOR_CLEAR);
cairo_paint (cr);
cairo_set_operator (cr, CAIRO_OPERATOR_SOURCE);
cairo_set_source_rgba (cr,
shadow_spec->color.red / 255.0,
shadow_spec->color.green / 255.0,
shadow_spec->color.blue / 255.0,
shadow_spec->color.alpha / 255.0);
cairo_paint (cr);
cairo_set_operator (cr, CAIRO_OPERATOR_DEST_IN);
cairo_set_source (cr, shadow_pattern);
cairo_paint (cr);
paint_shadow_pattern_to_cairo_context (shadow_spec,
shadow_pattern, FALSE,
cr,
interior_path,
outline_path);
cairo_pattern_destroy (shadow_pattern);
cairo_pop_group_to_source (cr);
/* mask and merge the shadow
*/
cairo_set_operator (cr, CAIRO_OPERATOR_OVER);
cairo_save (cr);
if (interior_path != NULL)
{
/* If there are borders, clip the shadow to the interior
* of the borders
*/
cairo_append_path (cr, interior_path);
cairo_clip (cr);
}
else if (outline_path != NULL)
{
/* If there is a visible outline, clip the shadow to
* that outline
*/
cairo_append_path (cr, outline_path);
cairo_clip (cr);
}
cairo_paint (cr);
cairo_restore (cr);
/* gets the extents of a cairo_path_t; slightly inefficient, but much simpler than
* computing from the raw path data */
static void
path_extents (cairo_path_t *path,
double *x1,
double *y1,
double *x2,
double *y2)
{
cairo_surface_t *dummy = cairo_image_surface_create (CAIRO_FORMAT_A8, 1, 1);
cairo_t *cr = cairo_create (dummy);
cairo_append_path (cr, path);
cairo_path_extents (cr, x1, y1, x2, y2);
cairo_destroy (cr);
cairo_surface_destroy (dummy);
}
static void
paint_inset_box_shadow_to_cairo_context (StThemeNode *node,
StShadow *shadow_spec,
cairo_t *cr,
cairo_path_t *shadow_outline)
{
cairo_surface_t *shadow_surface;
cairo_pattern_t *shadow_pattern;
double extents_x1, extents_y1, extents_x2, extents_y2;
double shrunk_extents_x1, shrunk_extents_y1, shrunk_extents_x2, shrunk_extents_y2;
gboolean fill_exterior;
g_assert (shadow_spec != NULL);
g_assert (shadow_outline != NULL);
/* Create the pattern used to create the inset shadow; as the shadow
* should be drawn as if everything outside the outline was opaque,
* we use a temporary surface to draw the background as a solid shape,
* which is inverted when creating the shadow pattern.
*/
/* First we need to find the size of the temporary surface
*/
path_extents (shadow_outline,
&extents_x1, &extents_y1, &extents_x2, &extents_y2);
/* Shrink the extents by the spread, and offset */
shrunk_extents_x1 = extents_x1 + shadow_spec->xoffset + shadow_spec->spread;
shrunk_extents_y1 = extents_y1 + shadow_spec->yoffset + shadow_spec->spread;
shrunk_extents_x2 = extents_x2 + shadow_spec->xoffset - shadow_spec->spread;
shrunk_extents_y2 = extents_y2 + shadow_spec->yoffset - shadow_spec->spread;
if (shrunk_extents_x1 >= shrunk_extents_x2 || shrunk_extents_y1 >= shrunk_extents_x2)
{
/* Shadow occupies entire area within border */
shadow_pattern = cairo_pattern_create_rgb (0., 0., 0.);
fill_exterior = FALSE;
}
else
{
/* Bounds of temporary surface */
int surface_x = floor (shrunk_extents_x1);
int surface_y = floor (shrunk_extents_y1);
int surface_width = ceil (shrunk_extents_x2) - surface_x;
int surface_height = ceil (shrunk_extents_y2) - surface_y;
/* Center of the original path */
double x_center = (extents_x1 + extents_x2) / 2;
double y_center = (extents_y1 + extents_y2) / 2;
cairo_pattern_t *pattern;
cairo_t *temp_cr;
cairo_matrix_t matrix;
shadow_surface = cairo_image_surface_create (CAIRO_FORMAT_A8, surface_width, surface_height);
temp_cr = cairo_create (shadow_surface);
/* Match the coordinates in the temporary context to the parent context */
cairo_translate (temp_cr, - surface_x, - surface_y);
/* Shadow offset */
cairo_translate (temp_cr, shadow_spec->xoffset, shadow_spec->yoffset);
/* Scale the path around the center to match the shrunk bounds */
cairo_translate (temp_cr, x_center, y_center);
cairo_scale (temp_cr,
(shrunk_extents_x2 - shrunk_extents_x1) / (extents_x2 - extents_x1),
(shrunk_extents_y2 - shrunk_extents_y1) / (extents_y2 - extents_y1));
cairo_translate (temp_cr, - x_center, - y_center);
cairo_append_path (temp_cr, shadow_outline);
cairo_fill (temp_cr);
cairo_destroy (temp_cr);
pattern = cairo_pattern_create_for_surface (shadow_surface);
cairo_surface_destroy (shadow_surface);
/* The pattern needs to be offset back to coordinates in the parent context */
cairo_matrix_init_translate (&matrix, - surface_x, - surface_y);
cairo_pattern_set_matrix (pattern, &matrix);
shadow_pattern = _st_create_shadow_cairo_pattern (shadow_spec, pattern);
fill_exterior = TRUE;
cairo_pattern_destroy (pattern);
}
paint_shadow_pattern_to_cairo_context (shadow_spec,
shadow_pattern, fill_exterior,
cr,
shadow_outline,
NULL);
cairo_pattern_destroy (shadow_pattern);
}
/* In order for borders to be smoothly blended with non-solid backgrounds,
@ -722,6 +881,7 @@ st_theme_node_prerender_background (StThemeNode *node)
cairo_t *cr;
cairo_surface_t *surface;
StShadow *shadow_spec;
StShadow *box_shadow_spec;
cairo_pattern_t *pattern = NULL;
cairo_path_t *outline_path = NULL;
gboolean draw_solid_background = TRUE;
@ -740,6 +900,7 @@ st_theme_node_prerender_background (StThemeNode *node)
border_image = st_theme_node_get_border_image (node);
shadow_spec = st_theme_node_get_background_image_shadow (node);
box_shadow_spec = st_theme_node_get_box_shadow (node);
actor_box.x1 = 0;
actor_box.x2 = node->alloc_width;
@ -1019,6 +1180,15 @@ st_theme_node_prerender_background (StThemeNode *node)
cairo_pattern_destroy (pattern);
}
if (box_shadow_spec && box_shadow_spec->inset)
{
paint_inset_box_shadow_to_cairo_context (node,
box_shadow_spec,
cr,
interior_path ? interior_path
: outline_path);
}
if (outline_path != NULL)
cairo_path_destroy (outline_path);
@ -1107,6 +1277,7 @@ st_theme_node_render_resources (StThemeNode *node,
StBorderImage *border_image;
gboolean has_border;
gboolean has_border_radius;
gboolean has_inset_box_shadow;
StShadow *box_shadow_spec;
StShadow *background_image_shadow_spec;
const char *background_image;
@ -1126,6 +1297,7 @@ st_theme_node_render_resources (StThemeNode *node,
_st_theme_node_ensure_geometry (node);
box_shadow_spec = st_theme_node_get_box_shadow (node);
has_inset_box_shadow = box_shadow_spec && box_shadow_spec->inset;
if (node->border_width[ST_SIDE_TOP] > 0 ||
node->border_width[ST_SIDE_LEFT] > 0 ||
@ -1170,6 +1342,7 @@ st_theme_node_render_resources (StThemeNode *node,
* then we could use cogl for that case.
*/
if ((node->background_gradient_type != ST_GRADIENT_NONE)
|| (has_inset_box_shadow && (has_border || node->background_color.alpha > 0))
|| (background_image && (has_border || has_border_radius)))
node->prerendered_texture = st_theme_node_prerender_background (node);
@ -1178,7 +1351,7 @@ st_theme_node_render_resources (StThemeNode *node,
else
node->prerendered_material = COGL_INVALID_HANDLE;
if (box_shadow_spec)
if (box_shadow_spec && !has_inset_box_shadow)
{
if (node->border_slices_texture != COGL_INVALID_HANDLE)
node->box_shadow_material = _st_create_shadow_material (box_shadow_spec,

8
src/st/st-theme-node.c
View File

@ -2886,14 +2886,6 @@ st_theme_node_get_box_shadow (StThemeNode *node)
FALSE,
&shadow))
{
if (shadow->inset)
{
g_warning ("Inset shadows are not implemented for the box-shadow "
"property");
st_shadow_unref (shadow);
shadow = NULL;
}
node->box_shadow = shadow;
return node->box_shadow;