gtk/gsk/gskroundedrect.c

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/* GSK - The GTK Scene Kit
*
* Copyright 2016 Endless
*
* This library 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 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that 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 library. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* SECTION:GskRoundedRect
* @Title: GskRoundedRect
* @Short_description: A rounded rectangle
*
* #GskRoundedRect defines a rectangle with rounded corners, as is commonly
* used in drawing.
*
* Operations on a #GskRoundedRect will normalize the rectangle, to
* ensure that the bounds are normalized and that the corner sizes don't exceed
* the size of the rectangle. The algorithm used for normalizing corner sizes
* is described in [the CSS specification](https://drafts.csswg.org/css-backgrounds-3/#border-radius).
*/
#include "config.h"
#include "gskroundedrect.h"
#include "gskroundedrectprivate.h"
#include "gskdebugprivate.h"
#include <math.h>
static void
gsk_rounded_rect_normalize_in_place (GskRoundedRect *self)
{
float factor = 1.0;
float corners;
guint i;
graphene_rect_normalize (&self->bounds);
for (i = 0; i < 4; i++)
{
self->corner[i].width = MAX (self->corner[i].width, 0);
self->corner[i].height = MAX (self->corner[i].height, 0);
}
/* clamp border radius, following CSS specs */
corners = self->corner[GSK_CORNER_TOP_LEFT].width + self->corner[GSK_CORNER_TOP_RIGHT].width;
if (corners > self->bounds.size.width)
factor = MIN (factor, self->bounds.size.width / corners);
corners = self->corner[GSK_CORNER_TOP_RIGHT].height + self->corner[GSK_CORNER_BOTTOM_RIGHT].height;
if (corners > self->bounds.size.height)
factor = MIN (factor, self->bounds.size.height / corners);
corners = self->corner[GSK_CORNER_BOTTOM_RIGHT].width + self->corner[GSK_CORNER_BOTTOM_LEFT].width;
if (corners > self->bounds.size.width)
factor = MIN (factor, self->bounds.size.width / corners);
corners = self->corner[GSK_CORNER_TOP_LEFT].height + self->corner[GSK_CORNER_BOTTOM_LEFT].height;
if (corners > self->bounds.size.height)
factor = MIN (factor, self->bounds.size.height / corners);
for (i = 0; i < 4; i++)
graphene_size_scale (&self->corner[i], factor, &self->corner[i]);
}
/**
* gsk_rounded_rect_init:
* @self: The #GskRoundedRect to initialize
* @bounds: a #graphene_rect_t describing the bounds
* @top_left: the rounding radius of the top left corner
* @top_right: the rounding radius of the top right corner
* @bottom_right: the rounding radius of the bottom right corner
* @bottom_left: the rounding radius of the bottom left corner
*
* Initializes the given #GskRoundedRect with the given values.
*
* This function will implicitly normalize the #GskRoundedRect
* before returning.
*
* Returns: (transfer none): the initialized rectangle
*/
GskRoundedRect *
gsk_rounded_rect_init (GskRoundedRect *self,
const graphene_rect_t *bounds,
const graphene_size_t *top_left,
const graphene_size_t *top_right,
const graphene_size_t *bottom_right,
const graphene_size_t *bottom_left)
{
graphene_rect_init_from_rect (&self->bounds, bounds);
graphene_size_init_from_size (&self->corner[GSK_CORNER_TOP_LEFT], top_left);
graphene_size_init_from_size (&self->corner[GSK_CORNER_TOP_RIGHT], top_right);
graphene_size_init_from_size (&self->corner[GSK_CORNER_BOTTOM_RIGHT], bottom_right);
graphene_size_init_from_size (&self->corner[GSK_CORNER_BOTTOM_LEFT], bottom_left);
gsk_rounded_rect_normalize_in_place (self);
return self;
}
/**
* gsk_rounded_rect_init_copy:
* @self: a #GskRoundedRect
* @src: a #GskRoundedRect
*
* Initializes @self using the given @src rectangle.
*
* This function will not normalize the #GskRoundedRect, so
* make sure the source is normalized.
*
* Returns: (transfer none): the initialized rectangle
*/
GskRoundedRect *
gsk_rounded_rect_init_copy (GskRoundedRect *self,
const GskRoundedRect *src)
{
*self = *src;
return self;
}
/**
* gsk_rounded_rect_init_from_rect:
* @self: a #GskRoundedRect
* @bounds: a #graphene_rect_t
* @radius: the border radius
*
* Initializes @self to the given @bounds and sets the radius of all
* four corners to @radius.
*
* Returns: (transfer none): the initialized rectangle
**/
GskRoundedRect *
gsk_rounded_rect_init_from_rect (GskRoundedRect *self,
const graphene_rect_t *bounds,
float radius)
{
graphene_size_t corner = GRAPHENE_SIZE_INIT(radius, radius);
return gsk_rounded_rect_init (self, bounds, &corner, &corner, &corner, &corner);
}
/**
* gsk_rounded_rect_normalize:
* @self: a #GskRoundedRect
*
* Normalizes the passed rectangle.
*
* this function will ensure that the bounds of the rectanlge are normalized
* and ensure that the corner values are positive and the corners do not overlap.
*
* Returns: (transfer none): the normalized rectangle
*/
GskRoundedRect *
gsk_rounded_rect_normalize (GskRoundedRect *self)
{
gsk_rounded_rect_normalize_in_place (self);
return self;
}
/**
* gsk_rounded_rect_offset:
* @self: a #GskRoundedRect
* @dx: the horizontal offset
* @dy: the vertical offset
*
* Offsets the bound's origin by @dx and @dy.
*
* The size and corners of the rectangle are unchanged.
*
* Returns: (transfer none): the offset rectangle
*/
GskRoundedRect *
gsk_rounded_rect_offset (GskRoundedRect *self,
float dx,
float dy)
{
gsk_rounded_rect_normalize (self);
self->bounds.origin.x += dx;
self->bounds.origin.y += dy;
return self;
}
static void
border_radius_shrink (graphene_size_t *corner,
double width,
double height)
{
if (corner->width > 0)
corner->width -= width;
if (corner->height > 0)
corner->height -= height;
if (corner->width <= 0 || corner->height <= 0)
{
corner->width = 0;
corner->height = 0;
}
}
/**
* gsk_rounded_rect_shrink:
* @self: The #GskRoundedRect to shrink or grow
* @top: How far to move the top side downwards
* @right: How far to move the right side to the left
* @bottom: How far to move the bottom side upwards
* @left: How far to move the left side to the right
*
* Shrinks (or grows) the given rectangle by moving the 4 sides
* according to the offsets given. The corner radii will be changed
* in a way that tries to keep the center of the corner circle intact.
* This emulates CSS behavior.
*
* This function also works for growing rectangles if you pass
* negative values for the @top, @right, @bottom or @left.
*
* Returns: (transfer none): the resized #GskRoundedRect
**/
GskRoundedRect *
gsk_rounded_rect_shrink (GskRoundedRect *self,
float top,
float right,
float bottom,
float left)
{
if (self->bounds.size.width - left - right < 0)
{
self->bounds.origin.x += left * self->bounds.size.width / (left + right);
self->bounds.size.width = 0;
}
else
{
self->bounds.origin.x += left;
self->bounds.size.width -= left + right;
}
if (self->bounds.size.height - bottom - top < 0)
{
self->bounds.origin.y += top * self->bounds.size.height / (top + bottom);
self->bounds.size.height = 0;
}
else
{
self->bounds.origin.y += top;
self->bounds.size.height -= top + bottom;
}
border_radius_shrink (&self->corner[GSK_CORNER_TOP_LEFT], left, top);
border_radius_shrink (&self->corner[GSK_CORNER_TOP_RIGHT], right, top);
border_radius_shrink (&self->corner[GSK_CORNER_BOTTOM_RIGHT], right, bottom);
border_radius_shrink (&self->corner[GSK_CORNER_BOTTOM_LEFT], left, bottom);
return self;
}
/* XXX: Find a better name */
gboolean
gsk_rounded_rect_is_circular (const GskRoundedRect *self)
{
guint i;
for (i = 0; i < 4; i++)
{
if (self->corner[i].width != self->corner[i].height)
return FALSE;
}
return TRUE;
}
/**
* gsk_rounded_rect_is_rectilinear:
* @self: the #GskRoundedRect to check
*
* Checks if all corners of @self are right angles and the
* rectangle covers all of its bounds.
*
* This information can be used to decide if gsk_clip_node_new()
* or gsk_rounded_clip_node_new() should be called.
*
* Returns: %TRUE if the rectangle is rectilinear
**/
gboolean
gsk_rounded_rect_is_rectilinear (const GskRoundedRect *self)
{
guint i;
for (i = 0; i < 4; i++)
{
if (self->corner[i].width > 0 ||
self->corner[i].height > 0)
return FALSE;
}
return TRUE;
}
static gboolean
ellipsis_contains_point (const graphene_size_t *ellipsis,
const graphene_point_t *point)
{
return (point->x * point->x) / (ellipsis->width * ellipsis->width)
+ (point->y * point->y) / (ellipsis->height * ellipsis->height) <= 1;
}
/**
* gsk_rounded_rect_contains_point:
* @self: a #GskRoundedRect
* @point: the point to check
*
* Checks if the given @point is inside the rounded rectangle. This function
* returns %FALSE if the point is in the rounded corner areas.
*
* Returns: %TRUE if the @point is inside the rounded rectangle
**/
gboolean
gsk_rounded_rect_contains_point (const GskRoundedRect *self,
const graphene_point_t *point)
{
if (!graphene_rect_contains_point (&self->bounds, point))
return FALSE;
if (self->bounds.origin.x + self->corner[GSK_CORNER_TOP_LEFT].width > point->x &&
self->bounds.origin.y + self->corner[GSK_CORNER_TOP_LEFT].height > point->y &&
!ellipsis_contains_point (&self->corner[GSK_CORNER_TOP_LEFT],
&GRAPHENE_POINT_INIT (
self->bounds.origin.x + self->corner[GSK_CORNER_TOP_LEFT].width - point->x,
self->bounds.origin.y + self->corner[GSK_CORNER_TOP_LEFT].height- point->y
)))
return FALSE;
if (self->bounds.origin.x + self->bounds.size.width - self->corner[GSK_CORNER_TOP_RIGHT].width < point->x &&
self->bounds.origin.y + self->corner[GSK_CORNER_TOP_RIGHT].height > point->y &&
!ellipsis_contains_point (&self->corner[GSK_CORNER_TOP_RIGHT],
&GRAPHENE_POINT_INIT (
self->bounds.origin.x + self->bounds.size.width - self->corner[GSK_CORNER_TOP_RIGHT].width - point->x,
self->bounds.origin.y + self->corner[GSK_CORNER_TOP_RIGHT].height- point->y
)))
return FALSE;
if (self->bounds.origin.x + self->corner[GSK_CORNER_BOTTOM_LEFT].width > point->x &&
self->bounds.origin.y + self->bounds.size.height - self->corner[GSK_CORNER_BOTTOM_LEFT].height < point->y &&
!ellipsis_contains_point (&self->corner[GSK_CORNER_BOTTOM_LEFT],
&GRAPHENE_POINT_INIT (
self->bounds.origin.x + self->corner[GSK_CORNER_BOTTOM_LEFT].width - point->x,
self->bounds.origin.y + self->bounds.size.height - self->corner[GSK_CORNER_BOTTOM_LEFT].height- point->y
)))
return FALSE;
if (self->bounds.origin.x + self->bounds.size.width - self->corner[GSK_CORNER_BOTTOM_RIGHT].width < point->x &&
self->bounds.origin.y + self->bounds.size.height - self->corner[GSK_CORNER_BOTTOM_RIGHT].height < point->y &&
!ellipsis_contains_point (&self->corner[GSK_CORNER_BOTTOM_RIGHT],
&GRAPHENE_POINT_INIT (
self->bounds.origin.x + self->bounds.size.width - self->corner[GSK_CORNER_BOTTOM_RIGHT].width - point->x,
self->bounds.origin.y + self->bounds.size.height - self->corner[GSK_CORNER_BOTTOM_RIGHT].height- point->y
)))
return FALSE;
return TRUE;
}
/**
* gsk_rounded_rect_contains_rect:
* @self: a #GskRoundedRect
* @rect: the rectangle to check
*
* Checks if the given @rect is contained inside the rounded rectangle.
* This function returns %FALSE if @rect extends into one of the rounded
* corner areas.
*
* Returns: %TRUE if the @rect is fully contained inside the rounded rectangle
**/
gboolean
gsk_rounded_rect_contains_rect (const GskRoundedRect *self,
const graphene_rect_t *rect)
{
if (!graphene_rect_contains_rect (&self->bounds, rect))
return FALSE;
if (!gsk_rounded_rect_contains_point (self, &rect->origin) ||
!gsk_rounded_rect_contains_point (self, &GRAPHENE_POINT_INIT (rect->origin.x + rect->size.width, rect->origin.y)) ||
!gsk_rounded_rect_contains_point (self, &GRAPHENE_POINT_INIT (rect->origin.x, rect->origin.y + rect->size.height)) ||
!gsk_rounded_rect_contains_point (self, &GRAPHENE_POINT_INIT (rect->origin.x + rect->size.width, rect->origin.y + rect->size.height)))
return FALSE;
return TRUE;
}
/**
* gsk_rounded_rect_intersects_rect:
* @self: a #GskRoundedRect
* @rect: the rectangle to check
*
* Checks if part of the given @rect is contained inside the rounded rectangle.
* This function returns %FALSE if @rect only extends into one of the rounded
* corner areas but not into the rounded rectangle itself.
*
* Returns: %TRUE if the @rect intersects with the rounded rectangle
**/
gboolean
gsk_rounded_rect_intersects_rect (const GskRoundedRect *self,
const graphene_rect_t *rect)
{
if (!graphene_rect_intersection (&self->bounds, rect, NULL))
return FALSE;
if (!gsk_rounded_rect_contains_point (self, &rect->origin) &&
!gsk_rounded_rect_contains_point (self, &GRAPHENE_POINT_INIT (rect->origin.x + rect->size.width, rect->origin.y)) &&
!gsk_rounded_rect_contains_point (self, &GRAPHENE_POINT_INIT (rect->origin.x, rect->origin.y + rect->size.height)) &&
!gsk_rounded_rect_contains_point (self, &GRAPHENE_POINT_INIT (rect->origin.x + rect->size.width, rect->origin.y + rect->size.height)))
return FALSE;
return TRUE;
}
static void
append_arc (cairo_t *cr, double angle1, double angle2, gboolean negative)
{
if (negative)
cairo_arc_negative (cr, 0.0, 0.0, 1.0, angle1, angle2);
else
cairo_arc (cr, 0.0, 0.0, 1.0, angle1, angle2);
}
static void
_cairo_ellipsis (cairo_t *cr,
double xc, double yc,
double xradius, double yradius,
double angle1, double angle2)
{
cairo_matrix_t save;
if (xradius <= 0.0 || yradius <= 0.0)
{
cairo_line_to (cr, xc, yc);
return;
}
cairo_get_matrix (cr, &save);
cairo_translate (cr, xc, yc);
cairo_scale (cr, xradius, yradius);
append_arc (cr, angle1, angle2, FALSE);
cairo_set_matrix (cr, &save);
}
void
gsk_rounded_rect_path (const GskRoundedRect *self,
cairo_t *cr)
{
cairo_new_sub_path (cr);
_cairo_ellipsis (cr,
self->bounds.origin.x + self->corner[GSK_CORNER_TOP_LEFT].width,
self->bounds.origin.y + self->corner[GSK_CORNER_TOP_LEFT].height,
self->corner[GSK_CORNER_TOP_LEFT].width,
self->corner[GSK_CORNER_TOP_LEFT].height,
G_PI, 3 * G_PI_2);
_cairo_ellipsis (cr,
self->bounds.origin.x + self->bounds.size.width - self->corner[GSK_CORNER_TOP_RIGHT].width,
self->bounds.origin.y + self->corner[GSK_CORNER_TOP_RIGHT].height,
self->corner[GSK_CORNER_TOP_RIGHT].width,
self->corner[GSK_CORNER_TOP_RIGHT].height,
- G_PI_2, 0);
_cairo_ellipsis (cr,
self->bounds.origin.x + self->bounds.size.width - self->corner[GSK_CORNER_BOTTOM_RIGHT].width,
self->bounds.origin.y + self->bounds.size.height - self->corner[GSK_CORNER_BOTTOM_RIGHT].height,
self->corner[GSK_CORNER_BOTTOM_RIGHT].width,
self->corner[GSK_CORNER_BOTTOM_RIGHT].height,
0, G_PI_2);
_cairo_ellipsis (cr,
self->bounds.origin.x + self->corner[GSK_CORNER_BOTTOM_LEFT].width,
self->bounds.origin.y + self->bounds.size.height - self->corner[GSK_CORNER_BOTTOM_LEFT].height,
self->corner[GSK_CORNER_BOTTOM_LEFT].width,
self->corner[GSK_CORNER_BOTTOM_LEFT].height,
G_PI_2, G_PI);
cairo_close_path (cr);
}
/*< private >
* Converts to the format we use in our shaders:
* vec4 rect;
* vec4 corner_widths;
* vec4 corner_heights;
* rect is (x, y, width, height), the corners are the same
* order as in the rounded rect.
*
* This is so that shaders can use just the first vec4 for
* rectilinear rects, the 2nd vec4 for circular rects and
* only look at the last vec4 if they have to.
*/
void
gsk_rounded_rect_to_float (const GskRoundedRect *self,
float rect[12])
{
guint i;
rect[0] = self->bounds.origin.x;
rect[1] = self->bounds.origin.y;
rect[2] = self->bounds.size.width;
rect[3] = self->bounds.size.height;
for (i = 0; i < 4; i++)
{
rect[4 + i] = self->corner[i].width;
rect[8 + i] = self->corner[i].height;
}
}
gboolean
gsk_rounded_rect_equal (gconstpointer rect1,
gconstpointer rect2)
{
const GskRoundedRect *self1 = rect1;
const GskRoundedRect *self2 = rect2;
return graphene_rect_equal (&self1->bounds, &self2->bounds)
&& graphene_size_equal (&self1->corner[0], &self2->corner[0])
&& graphene_size_equal (&self1->corner[1], &self2->corner[1])
&& graphene_size_equal (&self1->corner[2], &self2->corner[2])
&& graphene_size_equal (&self1->corner[3], &self2->corner[3]);
}
char *
gsk_rounded_rect_to_string (const GskRoundedRect *self)
{
return g_strdup_printf ("GskRoundedRect %p: Bounds: (%f, %f, %f, %f)"
" Corners: (%f, %f) (%f, %f) (%f, %f) (%f, %f)",
self,
self->bounds.origin.x,
self->bounds.origin.y,
self->bounds.size.width,
self->bounds.size.height,
self->corner[0].width,
self->corner[0].height,
self->corner[1].width,
self->corner[1].height,
self->corner[2].width,
self->corner[2].height,
self->corner[3].width,
self->corner[3].height);
}