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Diffstat (limited to 'src/st/st-shadow.c')
| -rw-r--r-- | src/st/st-shadow.c | 304 |
1 files changed, 304 insertions, 0 deletions
diff --git a/src/st/st-shadow.c b/src/st/st-shadow.c new file mode 100644 index 0000000..070e7bf --- /dev/null +++ b/src/st/st-shadow.c @@ -0,0 +1,304 @@ +/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */ +/* + * st-shadow.c: Boxed type holding for -st-shadow attributes + * + * Copyright 2009, 2010 Florian Müllner + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU Lesser General Public License as + * published by the Free Software Foundation, either version 2.1 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope it will be useful, but WITHOUT ANY + * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS + * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for + * more details. + * + * You should have received a copy of the GNU Lesser General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include "config.h" + +#include "st-shadow.h" +#include "st-private.h" + +G_DEFINE_BOXED_TYPE (StShadow, st_shadow, st_shadow_ref, st_shadow_unref) +G_DEFINE_BOXED_TYPE (StShadowHelper, st_shadow_helper, st_shadow_helper_copy, st_shadow_helper_free) + +/** + * SECTION: st-shadow + * @short_description: Boxed type for -st-shadow attributes + * + * #StShadow is a boxed type for storing attributes of the -st-shadow + * property, modelled liberally after the CSS3 box-shadow property. + * See http://www.css3.info/preview/box-shadow/ + * + */ + +/** + * st_shadow_new: + * @color: shadow's color + * @xoffset: horizontal offset + * @yoffset: vertical offset + * @blur: blur radius + * @spread: spread radius + * @inset: whether the shadow should be inset + * + * Creates a new #StShadow + * + * Returns: the newly allocated shadow. Use st_shadow_free() when done + */ +StShadow * +st_shadow_new (ClutterColor *color, + gdouble xoffset, + gdouble yoffset, + gdouble blur, + gdouble spread, + gboolean inset) +{ + StShadow *shadow; + + shadow = g_slice_new (StShadow); + + shadow->color = *color; + shadow->xoffset = xoffset; + shadow->yoffset = yoffset; + shadow->blur = blur; + shadow->spread = spread; + shadow->inset = inset; + shadow->ref_count = 1; + + return shadow; +} + +/** + * st_shadow_ref: + * @shadow: a #StShadow + * + * Atomically increments the reference count of @shadow by one. + * + * Returns: the passed in #StShadow. + */ +StShadow * +st_shadow_ref (StShadow *shadow) +{ + g_return_val_if_fail (shadow != NULL, NULL); + g_return_val_if_fail (shadow->ref_count > 0, shadow); + + g_atomic_int_inc (&shadow->ref_count); + return shadow; +} + +/** + * st_shadow_unref: + * @shadow: a #StShadow + * + * Atomically decrements the reference count of @shadow by one. + * If the reference count drops to 0, all memory allocated by the + * #StShadow is released. + */ +void +st_shadow_unref (StShadow *shadow) +{ + g_return_if_fail (shadow != NULL); + g_return_if_fail (shadow->ref_count > 0); + + if (g_atomic_int_dec_and_test (&shadow->ref_count)) + g_slice_free (StShadow, shadow); +} + +/** + * st_shadow_equal: + * @shadow: a #StShadow + * @other: a different #StShadow + * + * Check if two shadow objects are identical. Note that two shadows may + * compare non-identically if they differ only by floating point rounding + * errors. + * + * Returns: %TRUE if the two shadows are identical + */ +gboolean +st_shadow_equal (StShadow *shadow, + StShadow *other) +{ + g_return_val_if_fail (shadow != NULL, FALSE); + g_return_val_if_fail (other != NULL, FALSE); + + /* We use strict equality to compare double quantities; this means + * that, for example, a shadow offset of 0.25in does not necessarily + * compare equal to a shadow offset of 18pt in this test. Assume + * that a few false negatives are mostly harmless. + */ + + return (clutter_color_equal (&shadow->color, &other->color) && + shadow->xoffset == other->xoffset && + shadow->yoffset == other->yoffset && + shadow->blur == other->blur && + shadow->spread == other->spread && + shadow->inset == other->inset); +} + +/** + * st_shadow_get_box: + * @shadow: a #StShadow + * @actor_box: the box allocated to a #ClutterAlctor + * @shadow_box: computed box occupied by @shadow + * + * Gets the box used to paint @shadow, which will be partly + * outside of @actor_box + */ +void +st_shadow_get_box (StShadow *shadow, + const ClutterActorBox *actor_box, + ClutterActorBox *shadow_box) +{ + g_return_if_fail (shadow != NULL); + g_return_if_fail (actor_box != NULL); + g_return_if_fail (shadow_box != NULL); + + /* Inset shadows are drawn below the border, so returning + * the original box is not actually correct; still, it's + * good enough for the purpose of determining additional space + * required outside the actor box. + */ + if (shadow->inset) + { + *shadow_box = *actor_box; + return; + } + + shadow_box->x1 = actor_box->x1 + shadow->xoffset + - shadow->blur - shadow->spread; + shadow_box->x2 = actor_box->x2 + shadow->xoffset + + shadow->blur + shadow->spread; + shadow_box->y1 = actor_box->y1 + shadow->yoffset + - shadow->blur - shadow->spread; + shadow_box->y2 = actor_box->y2 + shadow->yoffset + + shadow->blur + shadow->spread; +} + +/** + * SECTION: st-shadow-helper + * + * An helper for implementing a drop shadow on a actor. + * The actor is expected to recreate the helper whenever its contents + * or size change. Then, it would call st_shadow_helper_paint() inside + * its paint() virtual function. + */ + +struct _StShadowHelper { + StShadow *shadow; + CoglPipeline *pipeline; + + gfloat width; + gfloat height; +}; + +/** + * st_shadow_helper_new: + * @shadow: a #StShadow representing the shadow properties + * + * Builds a #StShadowHelper that will build a drop shadow + * using @source as the mask. + * + * Returns: (transfer full): a new #StShadowHelper + */ +StShadowHelper * +st_shadow_helper_new (StShadow *shadow) +{ + StShadowHelper *helper; + + helper = g_slice_new0 (StShadowHelper); + helper->shadow = st_shadow_ref (shadow); + + return helper; +} + +/** + * st_shadow_helper_update: + * @helper: a #StShadowHelper + * @source: a #ClutterActor + * + * Update @helper from @source. + */ +void +st_shadow_helper_update (StShadowHelper *helper, + ClutterActor *source) +{ + gfloat width, height; + + clutter_actor_get_size (source, &width, &height); + + if (helper->pipeline == NULL || + helper->width != width || + helper->height != height) + { + if (helper->pipeline) + cogl_object_unref (helper->pipeline); + + helper->pipeline = _st_create_shadow_pipeline_from_actor (helper->shadow, source); + helper->width = width; + helper->height = height; + } +} + +/** + * st_shadow_helper_copy: + * @helper: the #StShadowHelper to copy + * + * Returns: (transfer full): a copy of @helper + */ +StShadowHelper * +st_shadow_helper_copy (StShadowHelper *helper) +{ + StShadowHelper *copy; + + copy = g_slice_new (StShadowHelper); + *copy = *helper; + if (copy->pipeline) + cogl_object_ref (copy->pipeline); + st_shadow_ref (copy->shadow); + + return copy; +} + +/** + * st_shadow_helper_free: + * @helper: a #StShadowHelper + * + * Free resources associated with @helper. + */ +void +st_shadow_helper_free (StShadowHelper *helper) +{ + if (helper->pipeline) + cogl_object_unref (helper->pipeline); + st_shadow_unref (helper->shadow); + + g_slice_free (StShadowHelper, helper); +} + +/** + * st_shadow_helper_paint: + * @helper: a #StShadowHelper + * @framebuffer: a #CoglFramebuffer + * @actor_box: the bounding box of the shadow + * @paint_opacity: the opacity at which the shadow is painted + * + * Paints the shadow associated with @helper This must only + * be called from the implementation of ClutterActor::paint(). + */ +void +st_shadow_helper_paint (StShadowHelper *helper, + CoglFramebuffer *framebuffer, + ClutterActorBox *actor_box, + guint8 paint_opacity) +{ + _st_paint_shadow_with_opacity (helper->shadow, + framebuffer, + helper->pipeline, + actor_box, + paint_opacity); +} |