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mutter/clutter/clutter/clutter-paint-volume.c
Jonas Dreßler cc912614c7 clutter/paint-volume: Union paint volumes correctly using Graphene 
Since commit d2f8a30625 we use Graphene to union paint volumes, it
turns out a quite severe issue snuck in during review of that MR though:
Unioned paint volumes (so paint volumes of any actors with children) now
have negative heights. Once projected to 2d coordinates they luckily are
correct again, which is why everything is still working.

The problem is that obvious once looking closer: For the y coordinates
of the unioned paint volume we confused the maximum and the minimum
points and simply used the wrong coordinates to create the unioned paint
volume.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1827>
2021-05-04 15:10:23 +00:00

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/*
* Clutter.
*
* An OpenGL based 'interactive canvas' library.
*
* Copyright (C) 2010 Intel Corporation.
*
* 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/>.
*
* Authors:
* Robert Bragg <robert@linux.intel.com>
* Emmanuele Bassi <ebassi@linux.intel.com>
*/
#include "clutter-build-config.h"
#include <string.h>
#include <glib-object.h>
#include <math.h>
#include "clutter-actor-private.h"
#include "clutter-paint-volume-private.h"
#include "clutter-private.h"
#include "clutter-stage-private.h"
#include "clutter-actor-box-private.h"
G_DEFINE_BOXED_TYPE (ClutterPaintVolume, clutter_paint_volume,
clutter_paint_volume_copy,
clutter_paint_volume_free);
/*<private>
* _clutter_paint_volume_new:
* @actor: a #ClutterActor
*
* Creates a new #ClutterPaintVolume for the given @actor.
*
* Return value: the newly allocated #ClutterPaintVolume. Use
* clutter_paint_volume_free() to free the resources it uses
*
* Since: 1.6
*/
ClutterPaintVolume *
_clutter_paint_volume_new (ClutterActor *actor)
{
ClutterPaintVolume *pv;
g_return_val_if_fail (actor != NULL, NULL);
pv = g_new0 (ClutterPaintVolume, 1);
pv->actor = actor;
memset (pv->vertices, 0, 8 * sizeof (graphene_point3d_t));
pv->is_static = FALSE;
pv->is_empty = TRUE;
pv->is_axis_aligned = TRUE;
pv->is_complete = TRUE;
pv->is_2d = TRUE;
return pv;
}
/* Since paint volumes are used so heavily in a typical paint
* traversal of a Clutter scene graph and since paint volumes often
* have a very short life cycle that maps well to stack allocation we
* allow initializing a static ClutterPaintVolume variable to avoid
* hammering the memory allocator.
*
* We were seeing slice allocation take about 1% cumulative CPU time
* for some very simple clutter tests which although it isn't a *lot*
* this is an easy way to basically drop that to 0%.
*
* The PaintVolume will be internally marked as static and
* clutter_paint_volume_free should still be used to "free" static
* volumes. This allows us to potentially store dynamically allocated
* data inside paint volumes in the future since we would be able to
* free it during _paint_volume_free().
*/
void
_clutter_paint_volume_init_static (ClutterPaintVolume *pv,
ClutterActor *actor)
{
pv->actor = actor;
memset (pv->vertices, 0, 8 * sizeof (graphene_point3d_t));
pv->is_static = TRUE;
pv->is_empty = TRUE;
pv->is_axis_aligned = TRUE;
pv->is_complete = TRUE;
pv->is_2d = TRUE;
}
void
_clutter_paint_volume_copy_static (const ClutterPaintVolume *src_pv,
ClutterPaintVolume *dst_pv)
{
g_return_if_fail (src_pv != NULL && dst_pv != NULL);
memcpy (dst_pv, src_pv, sizeof (ClutterPaintVolume));
dst_pv->is_static = TRUE;
}
/**
* clutter_paint_volume_copy:
* @pv: a #ClutterPaintVolume
*
* Copies @pv into a new #ClutterPaintVolume
*
* Return value: a newly allocated copy of a #ClutterPaintVolume
*
* Since: 1.6
*/
ClutterPaintVolume *
clutter_paint_volume_copy (const ClutterPaintVolume *pv)
{
ClutterPaintVolume *copy;
g_return_val_if_fail (pv != NULL, NULL);
copy = g_memdup2 (pv, sizeof (ClutterPaintVolume));
copy->is_static = FALSE;
return copy;
}
void
_clutter_paint_volume_set_from_volume (ClutterPaintVolume *pv,
const ClutterPaintVolume *src)
{
gboolean is_static = pv->is_static;
memcpy (pv, src, sizeof (ClutterPaintVolume));
pv->is_static = is_static;
}
/**
* clutter_paint_volume_free:
* @pv: a #ClutterPaintVolume
*
* Frees the resources allocated by @pv
*
* Since: 1.6
*/
void
clutter_paint_volume_free (ClutterPaintVolume *pv)
{
g_return_if_fail (pv != NULL);
if (G_LIKELY (pv->is_static))
return;
g_free (pv);
}
/**
* clutter_paint_volume_set_origin:
* @pv: a #ClutterPaintVolume
* @origin: a #graphene_point3d_t
*
* Sets the origin of the paint volume.
*
* The origin is defined as the X, Y and Z coordinates of the top-left
* corner of an actor's paint volume, in actor coordinates.
*
* The default is origin is assumed at: (0, 0, 0)
*
* Since: 1.6
*/
void
clutter_paint_volume_set_origin (ClutterPaintVolume *pv,
const graphene_point3d_t *origin)
{
static const int key_vertices[4] = { 0, 1, 3, 4 };
float dx, dy, dz;
int i;
g_return_if_fail (pv != NULL);
dx = origin->x - pv->vertices[0].x;
dy = origin->y - pv->vertices[0].y;
dz = origin->z - pv->vertices[0].z;
/* If we change the origin then all the key vertices of the paint
* volume need to be shifted too... */
for (i = 0; i < 4; i++)
{
pv->vertices[key_vertices[i]].x += dx;
pv->vertices[key_vertices[i]].y += dy;
pv->vertices[key_vertices[i]].z += dz;
}
pv->is_complete = FALSE;
}
/**
* clutter_paint_volume_get_origin:
* @pv: a #ClutterPaintVolume
* @vertex: (out): the return location for a #graphene_point3d_t
*
* Retrieves the origin of the #ClutterPaintVolume.
*
* Since: 1.6
*/
void
clutter_paint_volume_get_origin (const ClutterPaintVolume *pv,
graphene_point3d_t *vertex)
{
g_return_if_fail (pv != NULL);
g_return_if_fail (vertex != NULL);
*vertex = pv->vertices[0];
}
static void
_clutter_paint_volume_update_is_empty (ClutterPaintVolume *pv)
{
if (pv->vertices[0].x == pv->vertices[1].x &&
pv->vertices[0].y == pv->vertices[3].y &&
pv->vertices[0].z == pv->vertices[4].z)
pv->is_empty = TRUE;
else
pv->is_empty = FALSE;
}
/**
* clutter_paint_volume_set_width:
* @pv: a #ClutterPaintVolume
* @width: the width of the paint volume, in pixels
*
* Sets the width of the paint volume. The width is measured along
* the x axis in the actor coordinates that @pv is associated with.
*
* Since: 1.6
*/
void
clutter_paint_volume_set_width (ClutterPaintVolume *pv,
gfloat width)
{
gfloat right_xpos;
g_return_if_fail (pv != NULL);
g_return_if_fail (width >= 0.0f);
/* If the volume is currently empty then only the origin is
* currently valid */
if (pv->is_empty)
pv->vertices[1] = pv->vertices[3] = pv->vertices[4] = pv->vertices[0];
if (!pv->is_axis_aligned)
_clutter_paint_volume_axis_align (pv);
right_xpos = pv->vertices[0].x + width;
/* Move the right vertices of the paint box relative to the
* origin... */
pv->vertices[1].x = right_xpos;
/* pv->vertices[2].x = right_xpos; NB: updated lazily */
/* pv->vertices[5].x = right_xpos; NB: updated lazily */
/* pv->vertices[6].x = right_xpos; NB: updated lazily */
pv->is_complete = FALSE;
_clutter_paint_volume_update_is_empty (pv);
}
/**
* clutter_paint_volume_get_width:
* @pv: a #ClutterPaintVolume
*
* Retrieves the width of the volume's, axis aligned, bounding box.
*
* In other words; this takes into account what actor's coordinate
* space @pv belongs too and conceptually fits an axis aligned box
* around the volume. It returns the size of that bounding box as
* measured along the x-axis.
*
* If, for example, clutter_actor_get_transformed_paint_volume()
* is used to transform a 2D child actor that is 100px wide, 100px
* high and 0px deep into container coordinates then the width might
* not simply be 100px if the child actor has a 3D rotation applied to
* it.
*
* Remember: if clutter_actor_get_transformed_paint_volume() is
* used then a transformed child volume will be defined relative to the
* ancestor container actor and so a 2D child actor can have a 3D
* bounding volume.
*
* There are no accuracy guarantees for the reported width,
* except that it must always be greater than, or equal to, the
* actor's width. This is because actors may report simple, loose
* fitting paint volumes for efficiency.
* Return value: the width, in units of @pv's local coordinate system.
*
* Since: 1.6
*/
gfloat
clutter_paint_volume_get_width (const ClutterPaintVolume *pv)
{
g_return_val_if_fail (pv != NULL, 0.0);
if (pv->is_empty)
return 0;
else if (!pv->is_axis_aligned)
{
ClutterPaintVolume tmp;
float width;
_clutter_paint_volume_copy_static (pv, &tmp);
_clutter_paint_volume_axis_align (&tmp);
width = tmp.vertices[1].x - tmp.vertices[0].x;
clutter_paint_volume_free (&tmp);
return width;
}
else
return pv->vertices[1].x - pv->vertices[0].x;
}
/**
* clutter_paint_volume_set_height:
* @pv: a #ClutterPaintVolume
* @height: the height of the paint volume, in pixels
*
* Sets the height of the paint volume. The height is measured along
* the y axis in the actor coordinates that @pv is associated with.
*
* Since: 1.6
*/
void
clutter_paint_volume_set_height (ClutterPaintVolume *pv,
gfloat height)
{
gfloat height_ypos;
g_return_if_fail (pv != NULL);
g_return_if_fail (height >= 0.0f);
/* If the volume is currently empty then only the origin is
* currently valid */
if (pv->is_empty)
pv->vertices[1] = pv->vertices[3] = pv->vertices[4] = pv->vertices[0];
if (!pv->is_axis_aligned)
_clutter_paint_volume_axis_align (pv);
height_ypos = pv->vertices[0].y + height;
/* Move the bottom vertices of the paint box relative to the
* origin... */
/* pv->vertices[2].y = height_ypos; NB: updated lazily */
pv->vertices[3].y = height_ypos;
/* pv->vertices[6].y = height_ypos; NB: updated lazily */
/* pv->vertices[7].y = height_ypos; NB: updated lazily */
pv->is_complete = FALSE;
_clutter_paint_volume_update_is_empty (pv);
}
/**
* clutter_paint_volume_get_height:
* @pv: a #ClutterPaintVolume
*
* Retrieves the height of the volume's, axis aligned, bounding box.
*
* In other words; this takes into account what actor's coordinate
* space @pv belongs too and conceptually fits an axis aligned box
* around the volume. It returns the size of that bounding box as
* measured along the y-axis.
*
* If, for example, clutter_actor_get_transformed_paint_volume()
* is used to transform a 2D child actor that is 100px wide, 100px
* high and 0px deep into container coordinates then the height might
* not simply be 100px if the child actor has a 3D rotation applied to
* it.
*
* Remember: if clutter_actor_get_transformed_paint_volume() is
* used then a transformed child volume will be defined relative to the
* ancestor container actor and so a 2D child actor
* can have a 3D bounding volume.
*
* There are no accuracy guarantees for the reported height,
* except that it must always be greater than, or equal to, the actor's
* height. This is because actors may report simple, loose fitting paint
* volumes for efficiency.
*
* Return value: the height, in units of @pv's local coordinate system.
*
* Since: 1.6
*/
gfloat
clutter_paint_volume_get_height (const ClutterPaintVolume *pv)
{
g_return_val_if_fail (pv != NULL, 0.0);
if (pv->is_empty)
return 0;
else if (!pv->is_axis_aligned)
{
ClutterPaintVolume tmp;
float height;
_clutter_paint_volume_copy_static (pv, &tmp);
_clutter_paint_volume_axis_align (&tmp);
height = tmp.vertices[3].y - tmp.vertices[0].y;
clutter_paint_volume_free (&tmp);
return height;
}
else
return pv->vertices[3].y - pv->vertices[0].y;
}
/**
* clutter_paint_volume_set_depth:
* @pv: a #ClutterPaintVolume
* @depth: the depth of the paint volume, in pixels
*
* Sets the depth of the paint volume. The depth is measured along
* the z axis in the actor coordinates that @pv is associated with.
*
* Since: 1.6
*/
void
clutter_paint_volume_set_depth (ClutterPaintVolume *pv,
gfloat depth)
{
gfloat depth_zpos;
g_return_if_fail (pv != NULL);
g_return_if_fail (depth >= 0.0f);
/* If the volume is currently empty then only the origin is
* currently valid */
if (pv->is_empty)
pv->vertices[1] = pv->vertices[3] = pv->vertices[4] = pv->vertices[0];
if (!pv->is_axis_aligned)
_clutter_paint_volume_axis_align (pv);
depth_zpos = pv->vertices[0].z + depth;
/* Move the back vertices of the paint box relative to the
* origin... */
pv->vertices[4].z = depth_zpos;
/* pv->vertices[5].z = depth_zpos; NB: updated lazily */
/* pv->vertices[6].z = depth_zpos; NB: updated lazily */
/* pv->vertices[7].z = depth_zpos; NB: updated lazily */
pv->is_complete = FALSE;
pv->is_2d = depth ? FALSE : TRUE;
_clutter_paint_volume_update_is_empty (pv);
}
/**
* clutter_paint_volume_get_depth:
* @pv: a #ClutterPaintVolume
*
* Retrieves the depth of the volume's, axis aligned, bounding box.
*
* In other words; this takes into account what actor's coordinate
* space @pv belongs too and conceptually fits an axis aligned box
* around the volume. It returns the size of that bounding box as
* measured along the z-axis.
*
* If, for example, clutter_actor_get_transformed_paint_volume()
* is used to transform a 2D child actor that is 100px wide, 100px
* high and 0px deep into container coordinates then the depth might
* not simply be 0px if the child actor has a 3D rotation applied to
* it.
*
* Remember: if clutter_actor_get_transformed_paint_volume() is
* used then the transformed volume will be defined relative to the
* container actor and in container coordinates a 2D child actor
* can have a 3D bounding volume.
*
* There are no accuracy guarantees for the reported depth,
* except that it must always be greater than, or equal to, the actor's
* depth. This is because actors may report simple, loose fitting paint
* volumes for efficiency.
*
* Return value: the depth, in units of @pv's local coordinate system.
*
* Since: 1.6
*/
gfloat
clutter_paint_volume_get_depth (const ClutterPaintVolume *pv)
{
g_return_val_if_fail (pv != NULL, 0.0);
if (pv->is_empty)
return 0;
else if (!pv->is_axis_aligned)
{
ClutterPaintVolume tmp;
float depth;
_clutter_paint_volume_copy_static (pv, &tmp);
_clutter_paint_volume_axis_align (&tmp);
depth = tmp.vertices[4].z - tmp.vertices[0].z;
clutter_paint_volume_free (&tmp);
return depth;
}
else
return pv->vertices[4].z - pv->vertices[0].z;
}
/**
* clutter_paint_volume_union:
* @pv: The first #ClutterPaintVolume and destination for resulting
* union
* @another_pv: A second #ClutterPaintVolume to union with @pv
*
* Updates the geometry of @pv to encompass @pv and @another_pv.
*
* There are no guarantees about how precisely the two volumes
* will be unioned.
*
* Since: 1.6
*/
void
clutter_paint_volume_union (ClutterPaintVolume *pv,
const ClutterPaintVolume *another_pv)
{
ClutterPaintVolume aligned_pv;
graphene_point3d_t min;
graphene_point3d_t max;
graphene_box_t another_box;
graphene_box_t union_box;
graphene_box_t box;
g_return_if_fail (pv != NULL);
g_return_if_fail (another_pv != NULL);
/* Both volumes have to belong to the same local coordinate space */
g_return_if_fail (pv->actor == another_pv->actor);
/* We special case empty volumes because otherwise we'd end up
* calculating a bounding box that would enclose the origin of
* the empty volume which isn't desired.
*/
if (another_pv->is_empty)
return;
if (pv->is_empty)
{
_clutter_paint_volume_set_from_volume (pv, another_pv);
goto done;
}
if (!pv->is_axis_aligned)
_clutter_paint_volume_axis_align (pv);
_clutter_paint_volume_complete (pv);
if (!another_pv->is_axis_aligned || !another_pv->is_complete)
{
_clutter_paint_volume_copy_static (another_pv, &aligned_pv);
_clutter_paint_volume_axis_align (&aligned_pv);
_clutter_paint_volume_complete (&aligned_pv);
another_pv = &aligned_pv;
}
if (G_LIKELY (pv->is_2d))
graphene_box_init_from_points (&box, 4, pv->vertices);
else
graphene_box_init_from_points (&box, 8, pv->vertices);
if (G_LIKELY (another_pv->is_2d))
graphene_box_init_from_points (&another_box, 4, another_pv->vertices);
else
graphene_box_init_from_points (&another_box, 8, another_pv->vertices);
graphene_box_union (&box, &another_box, &union_box);
graphene_box_get_min (&union_box, &min);
graphene_box_get_max (&union_box, &max);
graphene_point3d_init (&pv->vertices[0], min.x, min.y, min.z);
graphene_point3d_init (&pv->vertices[1], max.x, min.y, min.z);
graphene_point3d_init (&pv->vertices[3], min.x, max.y, min.z);
graphene_point3d_init (&pv->vertices[4], min.x, min.y, max.z);
if (pv->vertices[4].z == pv->vertices[0].z)
pv->is_2d = TRUE;
else
pv->is_2d = FALSE;
done:
pv->is_empty = FALSE;
pv->is_complete = FALSE;
}
/**
* clutter_paint_volume_union_box:
* @pv: a #ClutterPaintVolume
* @box: a #ClutterActorBox to union to @pv
*
* Unions the 2D region represented by @box to a #ClutterPaintVolume.
*
* This function is similar to clutter_paint_volume_union(), but it is
* specific for 2D regions.
*
* Since: 1.10
*/
void
clutter_paint_volume_union_box (ClutterPaintVolume *pv,
const ClutterActorBox *box)
{
ClutterPaintVolume volume;
graphene_point3d_t origin;
g_return_if_fail (pv != NULL);
g_return_if_fail (box != NULL);
_clutter_paint_volume_init_static (&volume, pv->actor);
origin.x = box->x1;
origin.y = box->y1;
origin.z = 0.f;
clutter_paint_volume_set_origin (&volume, &origin);
clutter_paint_volume_set_width (&volume, box->x2 - box->x1);
clutter_paint_volume_set_height (&volume, box->y2 - box->y1);
clutter_paint_volume_union (pv, &volume);
clutter_paint_volume_free (&volume);
}
/* The paint_volume setters only update vertices 0, 1, 3 and
* 4 since the others can be drived from them.
*
* This will set pv->completed = TRUE;
*/
void
_clutter_paint_volume_complete (ClutterPaintVolume *pv)
{
float dx_l2r, dy_l2r, dz_l2r;
float dx_t2b, dy_t2b, dz_t2b;
if (pv->is_empty)
return;
if (pv->is_complete)
return;
/* Find the vector that takes us from any vertex on the left face to
* the corresponding vertex on the right face. */
dx_l2r = pv->vertices[1].x - pv->vertices[0].x;
dy_l2r = pv->vertices[1].y - pv->vertices[0].y;
dz_l2r = pv->vertices[1].z - pv->vertices[0].z;
/* Find the vector that takes us from any vertex on the top face to
* the corresponding vertex on the bottom face. */
dx_t2b = pv->vertices[3].x - pv->vertices[0].x;
dy_t2b = pv->vertices[3].y - pv->vertices[0].y;
dz_t2b = pv->vertices[3].z - pv->vertices[0].z;
/* front-bottom-right */
pv->vertices[2].x = pv->vertices[3].x + dx_l2r;
pv->vertices[2].y = pv->vertices[3].y + dy_l2r;
pv->vertices[2].z = pv->vertices[3].z + dz_l2r;
if (G_UNLIKELY (!pv->is_2d))
{
/* back-top-right */
pv->vertices[5].x = pv->vertices[4].x + dx_l2r;
pv->vertices[5].y = pv->vertices[4].y + dy_l2r;
pv->vertices[5].z = pv->vertices[4].z + dz_l2r;
/* back-bottom-right */
pv->vertices[6].x = pv->vertices[5].x + dx_t2b;
pv->vertices[6].y = pv->vertices[5].y + dy_t2b;
pv->vertices[6].z = pv->vertices[5].z + dz_t2b;
/* back-bottom-left */
pv->vertices[7].x = pv->vertices[4].x + dx_t2b;
pv->vertices[7].y = pv->vertices[4].y + dy_t2b;
pv->vertices[7].z = pv->vertices[4].z + dz_t2b;
}
pv->is_complete = TRUE;
}
/*<private>
* _clutter_paint_volume_get_box:
* @pv: a #ClutterPaintVolume
* @box: a pixel aligned #ClutterActorBox
*
* Transforms a 3D paint volume into a 2D bounding box in the
* same coordinate space as the 3D paint volume.
*
* To get an actors "paint box" you should first project
* the paint volume into window coordinates before getting
* the 2D bounding box.
*
* The coordinates of the returned box are not clamped to
* integer pixel values; if you need them to be rounded to the
* nearest integer pixel values, you can use the
* clutter_actor_box_clamp_to_pixel() function.
*
* Since: 1.6
*/
void
_clutter_paint_volume_get_bounding_box (ClutterPaintVolume *pv,
ClutterActorBox *box)
{
gfloat x_min, y_min, x_max, y_max;
graphene_point3d_t *vertices;
int count;
gint i;
g_return_if_fail (pv != NULL);
g_return_if_fail (box != NULL);
if (pv->is_empty)
{
box->x1 = box->x2 = pv->vertices[0].x;
box->y1 = box->y2 = pv->vertices[0].y;
return;
}
/* Updates the vertices we calculate lazily
* (See ClutterPaintVolume typedef for more details) */
_clutter_paint_volume_complete (pv);
vertices = pv->vertices;
x_min = x_max = vertices[0].x;
y_min = y_max = vertices[0].y;
/* Most actors are 2D so we only have to look at the front 4
* vertices of the paint volume... */
if (G_LIKELY (pv->is_2d))
count = 4;
else
count = 8;
for (i = 1; i < count; i++)
{
if (vertices[i].x < x_min)
x_min = vertices[i].x;
else if (vertices[i].x > x_max)
x_max = vertices[i].x;
if (vertices[i].y < y_min)
y_min = vertices[i].y;
else if (vertices[i].y > y_max)
y_max = vertices[i].y;
}
box->x1 = x_min;
box->y1 = y_min;
box->x2 = x_max;
box->y2 = y_max;
}
void
_clutter_paint_volume_project (ClutterPaintVolume *pv,
const graphene_matrix_t *modelview,
const graphene_matrix_t *projection,
const float *viewport)
{
int transform_count;
if (pv->is_empty)
{
/* Just transform the origin... */
_clutter_util_fully_transform_vertices (modelview,
projection,
viewport,
pv->vertices,
pv->vertices,
1);
return;
}
/* All the vertices must be up to date, since after the projection
* it won't be trivial to derive the other vertices. */
_clutter_paint_volume_complete (pv);
/* Most actors are 2D so we only have to transform the front 4
* vertices of the paint volume... */
if (G_LIKELY (pv->is_2d))
transform_count = 4;
else
transform_count = 8;
_clutter_util_fully_transform_vertices (modelview,
projection,
viewport,
pv->vertices,
pv->vertices,
transform_count);
pv->is_axis_aligned = FALSE;
}
void
_clutter_paint_volume_transform (ClutterPaintVolume *pv,
const graphene_matrix_t *matrix)
{
int transform_count;
if (pv->is_empty)
{
gfloat w = 1;
/* Just transform the origin */
cogl_graphene_matrix_project_point (matrix,
&pv->vertices[0].x,
&pv->vertices[0].y,
&pv->vertices[0].z,
&w);
return;
}
/* All the vertices must be up to date, since after the transform
* it won't be trivial to derive the other vertices. */
_clutter_paint_volume_complete (pv);
/* Most actors are 2D so we only have to transform the front 4
* vertices of the paint volume... */
if (G_LIKELY (pv->is_2d))
transform_count = 4;
else
transform_count = 8;
cogl_graphene_matrix_transform_points (matrix,
3,
sizeof (graphene_point3d_t),
pv->vertices,
sizeof (graphene_point3d_t),
pv->vertices,
transform_count);
pv->is_axis_aligned = FALSE;
}
/* Given a paint volume that has been transformed by an arbitrary
* modelview and is no longer axis aligned, this derives a replacement
* that is axis aligned. */
void
_clutter_paint_volume_axis_align (ClutterPaintVolume *pv)
{
int count;
int i;
graphene_point3d_t origin;
float max_x;
float max_y;
float max_z;
g_return_if_fail (pv != NULL);
if (pv->is_empty)
return;
if (G_LIKELY (pv->is_axis_aligned))
return;
if (G_LIKELY (pv->vertices[0].x == pv->vertices[1].x &&
pv->vertices[0].y == pv->vertices[3].y &&
pv->vertices[0].z == pv->vertices[4].z))
{
pv->is_axis_aligned = TRUE;
return;
}
if (!pv->is_complete)
_clutter_paint_volume_complete (pv);
origin = pv->vertices[0];
max_x = pv->vertices[0].x;
max_y = pv->vertices[0].y;
max_z = pv->vertices[0].z;
count = pv->is_2d ? 4 : 8;
for (i = 1; i < count; i++)
{
if (pv->vertices[i].x < origin.x)
origin.x = pv->vertices[i].x;
else if (pv->vertices[i].x > max_x)
max_x = pv->vertices[i].x;
if (pv->vertices[i].y < origin.y)
origin.y = pv->vertices[i].y;
else if (pv->vertices[i].y > max_y)
max_y = pv->vertices[i].y;
if (pv->vertices[i].z < origin.z)
origin.z = pv->vertices[i].z;
else if (pv->vertices[i].z > max_z)
max_z = pv->vertices[i].z;
}
pv->vertices[0] = origin;
pv->vertices[1].x = max_x;
pv->vertices[1].y = origin.y;
pv->vertices[1].z = origin.z;
pv->vertices[3].x = origin.x;
pv->vertices[3].y = max_y;
pv->vertices[3].z = origin.z;
pv->vertices[4].x = origin.x;
pv->vertices[4].y = origin.y;
pv->vertices[4].z = max_z;
pv->is_complete = FALSE;
pv->is_axis_aligned = TRUE;
if (pv->vertices[4].z == pv->vertices[0].z)
pv->is_2d = TRUE;
else
pv->is_2d = FALSE;
}
/*<private>
* _clutter_actor_set_default_paint_volume:
* @self: a #ClutterActor
* @check_gtype: if not %G_TYPE_INVALID, match the type of @self against
* this type
* @volume: the #ClutterPaintVolume to set
*
* Sets the default paint volume for @self.
*
* This function should be called by #ClutterActor sub-classes that follow
* the default assumption that their paint volume is defined by their
* allocation.
*
* If @check_gtype is not %G_TYPE_INVALID, this function will check the
* type of @self and only compute the paint volume if the type matches;
* this can be used to avoid computing the paint volume for sub-classes
* of an actor class
*
* Return value: %TRUE if the paint volume was set, and %FALSE otherwise
*/
gboolean
_clutter_actor_set_default_paint_volume (ClutterActor *self,
GType check_gtype,
ClutterPaintVolume *volume)
{
ClutterActorBox box;
if (check_gtype != G_TYPE_INVALID)
{
if (G_OBJECT_TYPE (self) != check_gtype)
return FALSE;
}
/* calling clutter_actor_get_allocation_* can potentially be very
* expensive, as it can result in a synchronous full stage relayout
* and redraw
*/
if (!clutter_actor_has_allocation (self))
return FALSE;
clutter_actor_get_allocation_box (self, &box);
/* we only set the width and height, as the paint volume is defined
* to be relative to the actor's modelview, which means that the
* allocation's origin has already been applied
*/
clutter_paint_volume_set_width (volume, box.x2 - box.x1);
clutter_paint_volume_set_height (volume, box.y2 - box.y1);
return TRUE;
}
/**
* clutter_paint_volume_set_from_allocation:
* @pv: a #ClutterPaintVolume
* @actor: a #ClutterActor
*
* Sets the #ClutterPaintVolume from the allocation of @actor.
*
* This function should be used when overriding the
* #ClutterActorClass.get_paint_volume() by #ClutterActor sub-classes
* that do not paint outside their allocation.
*
* A typical example is:
*
* |[
* static gboolean
* my_actor_get_paint_volume (ClutterActor *self,
* ClutterPaintVolume *volume)
* {
* return clutter_paint_volume_set_from_allocation (volume, self);
* }
* ]|
*
* Return value: %TRUE if the paint volume was successfully set, and %FALSE
* otherwise
*
* Since: 1.6
*/
gboolean
clutter_paint_volume_set_from_allocation (ClutterPaintVolume *pv,
ClutterActor *actor)
{
g_return_val_if_fail (pv != NULL, FALSE);
g_return_val_if_fail (CLUTTER_IS_ACTOR (actor), FALSE);
return _clutter_actor_set_default_paint_volume (actor, G_TYPE_INVALID, pv);
}
/* Currently paint volumes are defined relative to a given actor, but
* in some cases it is desirable to be able to change the actor that
* a volume relates too (For instance for ClutterClone actors where we
* need to masquerade the source actors volume as the volume for the
* clone). */
void
_clutter_paint_volume_set_reference_actor (ClutterPaintVolume *pv,
ClutterActor *actor)
{
g_return_if_fail (pv != NULL);
pv->actor = actor;
}
ClutterCullResult
_clutter_paint_volume_cull (ClutterPaintVolume *pv,
const graphene_frustum_t *frustum)
{
int vertex_count;
graphene_box_t box;
if (pv->is_empty)
return CLUTTER_CULL_RESULT_OUT;
/* We expect the volume to already be transformed into eye coordinates
*/
g_return_val_if_fail (pv->is_complete == TRUE, CLUTTER_CULL_RESULT_IN);
g_return_val_if_fail (pv->actor == NULL, CLUTTER_CULL_RESULT_IN);
/* Most actors are 2D so we only have to transform the front 4
* vertices of the paint volume... */
if (G_LIKELY (pv->is_2d))
vertex_count = 4;
else
vertex_count = 8;
graphene_box_init_from_points (&box, vertex_count, pv->vertices);
if (graphene_frustum_intersects_box (frustum, &box))
return CLUTTER_CULL_RESULT_IN;
else
return CLUTTER_CULL_RESULT_OUT;
}
void
_clutter_paint_volume_get_stage_paint_box (ClutterPaintVolume *pv,
ClutterStage *stage,
ClutterActorBox *box)
{
ClutterPaintVolume projected_pv;
graphene_matrix_t modelview;
graphene_matrix_t projection;
float viewport[4];
_clutter_paint_volume_copy_static (pv, &projected_pv);
graphene_matrix_init_identity (&modelview);
/* If the paint volume isn't already in eye coordinates... */
if (pv->actor)
_clutter_actor_apply_relative_transformation_matrix (pv->actor, NULL,
&modelview);
_clutter_stage_get_projection_matrix (stage, &projection);
_clutter_stage_get_viewport (stage,
&viewport[0],
&viewport[1],
&viewport[2],
&viewport[3]);
_clutter_paint_volume_project (&projected_pv,
&modelview,
&projection,
viewport);
_clutter_paint_volume_get_bounding_box (&projected_pv, box);
if (pv->is_2d && pv->actor &&
clutter_actor_get_z_position (pv->actor) == 0)
{
/* If the volume/actor are perfectly 2D, take the bounding box as
* good. We won't need to add any extra room for sub-pixel positioning
* in this case.
*/
clutter_paint_volume_free (&projected_pv);
box->x1 = CLUTTER_NEARBYINT (box->x1);
box->y1 = CLUTTER_NEARBYINT (box->y1);
box->x2 = CLUTTER_NEARBYINT (box->x2);
box->y2 = CLUTTER_NEARBYINT (box->y2);
return;
}
_clutter_actor_box_enlarge_for_effects (box);
clutter_paint_volume_free (&projected_pv);
}
void
_clutter_paint_volume_transform_relative (ClutterPaintVolume *pv,
ClutterActor *relative_to_ancestor)
{
graphene_matrix_t matrix;
ClutterActor *actor;
actor = pv->actor;
g_return_if_fail (actor != NULL);
_clutter_paint_volume_set_reference_actor (pv, relative_to_ancestor);
graphene_matrix_init_identity (&matrix);
_clutter_actor_apply_relative_transformation_matrix (actor,
relative_to_ancestor,
&matrix);
_clutter_paint_volume_transform (pv, &matrix);
}
void
clutter_paint_volume_to_box (ClutterPaintVolume *pv,
graphene_box_t *box)
{
int vertex_count;
if (pv->is_empty)
{
graphene_box_init_from_box (box, graphene_box_empty ());
return;
}
_clutter_paint_volume_complete (pv);
if (G_LIKELY (pv->is_2d))
vertex_count = 4;
else
vertex_count = 8;
graphene_box_init_from_points (box, vertex_count, pv->vertices);
}
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