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mutter-performance-source/src/wayland/meta-pointer-confinement-wayland.c

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/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
/*
* Copyright (C) 2015 Red Hat
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or (at your option) any later version.
*
* This program 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
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
* 02111-1307, USA.
*
* Written by:
* Jonas Ådahl <jadahl@gmail.com>
*/
#include "config.h"
#include "wayland/meta-pointer-confinement-wayland.h"
#include <glib-object.h>
#include <cairo.h>
#include "backends/meta-backend-private.h"
#include "core/meta-border.h"
#include "wayland/meta-wayland-seat.h"
#include "wayland/meta-wayland-pointer.h"
#include "wayland/meta-wayland-pointer-constraints.h"
#include "wayland/meta-wayland-surface.h"
#include "backends/meta-pointer-constraint.h"
#include "compositor/meta-surface-actor-wayland.h"
struct _MetaPointerConfinementWayland
{
MetaPointerConstraint parent;
MetaWaylandPointerConstraint *constraint;
};
typedef struct _MetaBox
{
int x1;
int y1;
int x2;
int y2;
} MetaBox;
G_DEFINE_TYPE (MetaPointerConfinementWayland, meta_pointer_confinement_wayland,
META_TYPE_POINTER_CONSTRAINT);
static MetaBorder *
add_border (GArray *borders,
float x1, float y1,
float x2, float y2,
MetaBorderMotionDirection blocking_directions)
{
MetaBorder border;
border = (MetaBorder) {
.line = (MetaLine2) {
.a = (MetaVector2) {
.x = x1,
.y = y1,
},
.b = (MetaVector2) {
.x = x2,
.y = y2,
},
},
.blocking_directions = blocking_directions,
};
g_array_append_val (borders, border);
return &g_array_index (borders, MetaBorder, borders->len - 1);
}
static gint
compare_lines_x (gconstpointer a, gconstpointer b)
{
const MetaBorder *border_a = a;
const MetaBorder *border_b = b;
if (border_a->line.a.x == border_b->line.a.x)
return border_a->line.b.x < border_b->line.b.x;
else
return border_a->line.a.x > border_b->line.a.x;
}
static void
add_non_overlapping_edges (MetaBox *boxes,
unsigned int band_above_start,
unsigned int band_below_start,
unsigned int band_below_end,
GArray *borders)
{
unsigned int i;
GArray *band_merge;
MetaBorder *border;
MetaBorder *prev_border;
MetaBorder *new_border;
band_merge = g_array_new (FALSE, FALSE, sizeof *border);
/* Add bottom band of previous row, and top band of current row, and
* sort them so lower left x coordinate comes first. If there are two
* borders with the same left x coordinate, the wider one comes first.
*/
for (i = band_above_start; i < band_below_start; i++)
{
MetaBox *box = &boxes[i];
add_border (band_merge, box->x1, box->y2, box->x2, box->y2,
META_BORDER_MOTION_DIRECTION_POSITIVE_Y);
}
for (i = band_below_start; i < band_below_end; i++)
{
MetaBox *box= &boxes[i];
add_border (band_merge, box->x1, box->y1, box->x2, box->y1,
META_BORDER_MOTION_DIRECTION_NEGATIVE_Y);
}
g_array_sort (band_merge, compare_lines_x);
/* Combine the two combined bands so that any overlapping border is
* eliminated. */
prev_border = NULL;
for (i = 0; i < band_merge->len; i++)
{
border = &g_array_index (band_merge, MetaBorder, i);
g_assert (border->line.a.y == border->line.b.y);
g_assert (!prev_border ||
prev_border->line.a.y == border->line.a.y);
g_assert (!prev_border ||
(prev_border->line.a.x != border->line.a.x ||
prev_border->line.b.x != border->line.b.x));
g_assert (!prev_border ||
prev_border->line.a.x <= border->line.a.x);
if (prev_border &&
prev_border->line.a.x == border->line.a.x)
{
/*
* ------------ +
* ------- =
* [ ]-----
*/
prev_border->line.a.x = border->line.b.x;
}
else if (prev_border &&
prev_border->line.b.x == border->line.b.x)
{
/*
* ------------ +
* ------ =
* ------[ ]
*/
prev_border->line.b.x = border->line.a.x;
}
else if (prev_border &&
prev_border->line.b.x == border->line.a.x)
{
/*
* -------- +
* ------ =
* --------------
*/
prev_border->line.b.x = border->line.b.x;
}
else if (prev_border &&
prev_border->line.b.x >= border->line.a.x)
{
/*
* --------------- +
* ------ =
* -----[ ]----
*/
new_border = add_border (borders,
border->line.b.x,
border->line.b.y,
prev_border->line.b.x,
prev_border->line.b.y,
prev_border->blocking_directions);
prev_border->line.b.x = border->line.a.x;
prev_border = new_border;
}
else
{
g_assert (!prev_border ||
prev_border->line.b.x < border->line.a.x);
/*
* First border or non-overlapping.
*
* ----- +
* ----- =
* ----- -----
*/
g_array_append_val (borders, *border);
prev_border = &g_array_index (borders, MetaBorder, borders->len - 1);
}
}
g_array_free (band_merge, FALSE);
}
static void
add_band_bottom_edges (MetaBox *boxes,
int band_start,
int band_end,
GArray *borders)
{
int i;
for (i = band_start; i < band_end; i++)
{
add_border (borders,
boxes[i].x1, boxes[i].y2,
boxes[i].x2, boxes[i].y2,
META_BORDER_MOTION_DIRECTION_POSITIVE_Y);
}
}
static void
region_to_outline (cairo_region_t *region,
GArray *borders)
{
MetaBox *boxes;
int num_boxes;
int i;
int top_most, bottom_most;
int current_roof;
int prev_top;
int band_start, prev_band_start;
/*
* Remove any overlapping lines from the set of rectangles. Note that
* pixman regions are grouped as rows of rectangles, where rectangles
* in one row never touch or overlap and are all of the same height.
*
* -------- --- -------- ---
* | | | | | | | |
* ----------====---- --- ----------- ----- ---
* | | => | |
* ----==========--------- ----- ----------
* | | | |
* ------------------- -------------------
*
*/
num_boxes = cairo_region_num_rectangles (region);
boxes = g_new (MetaBox, num_boxes);
for (i = 0; i < num_boxes; i++)
{
cairo_rectangle_int_t rect;
cairo_region_get_rectangle (region, i, &rect);
boxes[i] = (MetaBox) {
.x1 = rect.x,
.y1 = rect.y,
.x2 = rect.x + rect.width,
.y2 = rect.y + rect.height,
};
}
prev_top = 0;
top_most = boxes[0].y1;
current_roof = top_most;
bottom_most = boxes[num_boxes - 1].y2;
band_start = 0;
prev_band_start = 0;
for (i = 0; i < num_boxes; i++)
{
/* Detect if there is a vertical empty space, and add the lower
* level of the previous band if so was the case. */
if (i > 0 &&
boxes[i].y1 != prev_top &&
boxes[i].y1 != boxes[i - 1].y2)
{
current_roof = boxes[i].y1;
add_band_bottom_edges (boxes,
band_start,
i,
borders);
}
/* Special case adding the last band, since it won't be handled
* by the band change detection below. */
if (boxes[i].y1 != current_roof && i == num_boxes - 1)
{
if (boxes[i].y1 != prev_top)
{
/* The last band is a single box, so we don't
* have a prev_band_start to tell us when the
* previous band started. */
add_non_overlapping_edges (boxes,
band_start,
i,
i + 1,
borders);
}
else
{
add_non_overlapping_edges (boxes,
prev_band_start,
band_start,
i + 1,
borders);
}
}
/* Detect when passing a band and combine the top border of the
* just passed band with the bottom band of the previous band.
*/
if (boxes[i].y1 != top_most && boxes[i].y1 != prev_top)
{
/* Combine the two passed bands. */
if (prev_top != current_roof)
{
add_non_overlapping_edges (boxes,
prev_band_start,
band_start,
i,
borders);
}
prev_band_start = band_start;
band_start = i;
}
/* Add the top border if the box is part of the current roof. */
if (boxes[i].y1 == current_roof)
{
add_border (borders,
boxes[i].x1, boxes[i].y1,
boxes[i].x2, boxes[i].y1,
META_BORDER_MOTION_DIRECTION_NEGATIVE_Y);
}
/* Add the bottom border of the last band. */
if (boxes[i].y2 == bottom_most)
{
add_border (borders,
boxes[i].x1, boxes[i].y2,
boxes[i].x2, boxes[i].y2,
META_BORDER_MOTION_DIRECTION_POSITIVE_Y);
}
/* Always add the left border. */
add_border (borders,
boxes[i].x1, boxes[i].y1,
boxes[i].x1, boxes[i].y2,
META_BORDER_MOTION_DIRECTION_NEGATIVE_X);
/* Always add the right border. */
add_border (borders,
boxes[i].x2, boxes[i].y1,
boxes[i].x2, boxes[i].y2,
META_BORDER_MOTION_DIRECTION_POSITIVE_X);
prev_top = boxes[i].y1;
}
g_free (boxes);
}
static MetaBorder *
get_closest_border (GArray *borders,
MetaLine2 *motion,
uint32_t directions)
{
MetaBorder *border;
MetaVector2 intersection;
MetaVector2 delta;
float distance_2;
MetaBorder *closest_border = NULL;
float closest_distance_2 = DBL_MAX;
unsigned int i;
for (i = 0; i < borders->len; i++)
{
border = &g_array_index (borders, MetaBorder, i);
if (!meta_border_is_blocking_directions (border, directions))
continue;
if (!meta_line2_intersects_with (&border->line, motion, &intersection))
continue;
delta = meta_vector2_subtract (intersection, motion->a);
distance_2 = delta.x*delta.x + delta.y*delta.y;
if (distance_2 < closest_distance_2)
{
closest_border = border;
closest_distance_2 = distance_2;
}
}
return closest_border;
}
static void
clamp_to_border (MetaBorder *border,
MetaLine2 *motion,
uint32_t *motion_dir)
{
/*
* When clamping either rightward or downward motions, the motion needs to be
* clamped so that the destination coordinate does not end up on the border
* (see weston_pointer_clamp_event_to_region). Do this by clamping such
* motions to the border minus the smallest possible wl_fixed_t value.
*
* When clamping in either leftward or upward motion, the resulting coordinate
* needs to be clamped so that it is enough on the inside to avoid the
* inaccuracies of clutter's stage to actor transformation algorithm (the one
* used in clutter_actor_transform_stage_point) to make it end up outside the
* next motion. It also needs to be clamped so that to the wl_fixed_t
* coordinate may still be right on the border (i.e. at .0). Testing shows
* that the smallest wl_fixed_t value divided by 10 is small enough to make
* the wl_fixed_t coordinate .0 and large enough to avoid the inaccuracies of
* clutters transform algorithm.
*/
if (meta_border_is_horizontal (border))
{
if (*motion_dir & META_BORDER_MOTION_DIRECTION_POSITIVE_Y)
motion->b.y = border->line.a.y - wl_fixed_to_double (1);
else
motion->b.y = border->line.a.y + wl_fixed_to_double (1) / 10;
*motion_dir &= ~(META_BORDER_MOTION_DIRECTION_POSITIVE_Y |
META_BORDER_MOTION_DIRECTION_NEGATIVE_Y);
}
else
{
if (*motion_dir & META_BORDER_MOTION_DIRECTION_POSITIVE_X)
motion->b.x = border->line.a.x - wl_fixed_to_double (1);
else
motion->b.x = border->line.a.x + wl_fixed_to_double (1) / 10;
*motion_dir &= ~(META_BORDER_MOTION_DIRECTION_POSITIVE_X |
META_BORDER_MOTION_DIRECTION_NEGATIVE_X);
}
}
static uint32_t
get_motion_directions (MetaLine2 *motion)
{
uint32_t directions = 0;
if (motion->a.x < motion->b.x)
directions |= META_BORDER_MOTION_DIRECTION_POSITIVE_X;
else if (motion->a.x > motion->b.x)
directions |= META_BORDER_MOTION_DIRECTION_NEGATIVE_X;
if (motion->a.y < motion->b.y)
directions |= META_BORDER_MOTION_DIRECTION_POSITIVE_Y;
else if (motion->a.y > motion->b.y)
directions |= META_BORDER_MOTION_DIRECTION_NEGATIVE_Y;
return directions;
}
static void
meta_pointer_confinement_wayland_constrain (MetaPointerConstraint *constraint,
ClutterInputDevice *device,
guint32 time,
float prev_x,
float prev_y,
float *x,
float *y)
{
MetaPointerConfinementWayland *self =
META_POINTER_CONFINEMENT_WAYLAND (constraint);
MetaWaylandSurface *surface;
cairo_region_t *region;
float sx, sy;
float prev_sx, prev_sy;
GArray *borders;
MetaLine2 motion;
MetaBorder *closest_border;
uint32_t directions;
surface = meta_wayland_pointer_constraint_get_surface (self->constraint);
meta_wayland_surface_get_relative_coordinates (surface, *x, *y, &sx, &sy);
meta_wayland_surface_get_relative_coordinates (surface, prev_x, prev_y,
&prev_sx, &prev_sy);
/* For motions in a positive direction on any axis, append the smallest
* possible value representable in a Wayland absolute coordinate. This is
* in order to avoid not clamping motion that as a floating point number
* won't be clamped, but will be rounded up to be outside of the range
* of wl_fixed_t. */
if (sx > prev_sx)
sx += (float)wl_fixed_to_double(1);
if (sy > prev_sy)
sy += (float)wl_fixed_to_double(1);
borders = g_array_new (FALSE, FALSE, sizeof (MetaBorder));
/*
* Generate borders given the confine region we are to use. The borders
* are defined to be the outer region of the allowed area. This means
* top/left borders are "within" the allowed area, while bottom/right
* borders are outside. This needs to be considered when clamping
* confined motion vectors.
*/
region =
meta_wayland_pointer_constraint_calculate_effective_region (self->constraint);
region_to_outline (region, borders);
cairo_region_destroy (region);
motion = (MetaLine2) {
.a = (MetaVector2) {
.x = prev_sx,
.y = prev_sy,
},
.b = (MetaVector2) {
.x = sx,
.y = sy,
},
};
directions = get_motion_directions (&motion);
while (directions)
{
closest_border = get_closest_border (borders,
&motion,
directions);
if (closest_border)
clamp_to_border (closest_border, &motion, &directions);
else
break;
}
meta_wayland_surface_get_absolute_coordinates (surface,
motion.b.x, motion.b.y,
x, y);
g_array_free (borders, FALSE);
}
static float
point_to_border_distance_2 (MetaBorder *border,
float x,
float y)
{
float orig_x, orig_y;
float dx, dy;
if (meta_border_is_horizontal (border))
{
if (x < border->line.a.x)
orig_x = border->line.a.x;
else if (x > border->line.b.x)
orig_x = border->line.b.x;
else
orig_x = x;
orig_y = border->line.a.y;
}
else
{
if (y < border->line.a.y)
orig_y = border->line.a.y;
else if (y > border->line.b.y)
orig_y = border->line.b.y;
else
orig_y = y;
orig_x = border->line.a.x;
}
dx = fabsf (orig_x - x);
dy = fabsf (orig_y - y);
return dx*dx + dy*dy;
}
static void
warp_to_behind_border (MetaBorder *border,
float *sx,
float *sy)
{
switch (border->blocking_directions)
{
case META_BORDER_MOTION_DIRECTION_POSITIVE_X:
case META_BORDER_MOTION_DIRECTION_NEGATIVE_X:
if (border->blocking_directions == META_BORDER_MOTION_DIRECTION_POSITIVE_X)
*sx = border->line.a.x - wl_fixed_to_double (1);
else
*sx = border->line.a.x + wl_fixed_to_double (1);
if (*sy < border->line.a.y)
*sy = border->line.a.y + wl_fixed_to_double (1);
else if (*sy > border->line.b.y)
*sy = border->line.b.y - wl_fixed_to_double (1);
break;
case META_BORDER_MOTION_DIRECTION_POSITIVE_Y:
case META_BORDER_MOTION_DIRECTION_NEGATIVE_Y:
if (border->blocking_directions == META_BORDER_MOTION_DIRECTION_POSITIVE_Y)
*sy = border->line.a.y - wl_fixed_to_double (1);
else
*sy = border->line.a.y + wl_fixed_to_double (1);
if (*sx < border->line.a.x)
*sx = border->line.a.x + wl_fixed_to_double (1);
else if (*sx > (border->line.b.x))
*sx = border->line.b.x - wl_fixed_to_double (1);
break;
}
}
static void
meta_pointer_confinement_wayland_maybe_warp (MetaPointerConfinementWayland *self)
{
MetaWaylandSeat *seat;
MetaWaylandSurface *surface;
ClutterPoint point;
float sx;
float sy;
cairo_region_t *region;
seat = meta_wayland_pointer_constraint_get_seat (self->constraint);
surface = meta_wayland_pointer_constraint_get_surface (self->constraint);
clutter_input_device_get_coords (seat->pointer->device, NULL, &point);
meta_wayland_surface_get_relative_coordinates (surface,
point.x, point.y,
&sx, &sy);
region =
meta_wayland_pointer_constraint_calculate_effective_region (self->constraint);
if (!cairo_region_contains_point (region, (int)sx, (int)sy))
{
GArray *borders;
float closest_distance_2 = FLT_MAX;
MetaBorder *closest_border = NULL;
unsigned int i;
float x;
float y;
borders = g_array_new (FALSE, FALSE, sizeof (MetaBorder));
region_to_outline (region, borders);
for (i = 0; i < borders->len; i++)
{
MetaBorder *border = &g_array_index (borders, MetaBorder, i);
float distance_2;
distance_2 = point_to_border_distance_2 (border, sx, sy);
if (distance_2 < closest_distance_2)
{
closest_border = border;
closest_distance_2 = distance_2;
}
}
warp_to_behind_border (closest_border, &sx, &sy);
meta_wayland_surface_get_absolute_coordinates (surface, sx, sy, &x, &y);
meta_backend_warp_pointer (meta_get_backend (), (int)x, (int)y);
}
cairo_region_destroy (region);
}
static void
surface_actor_painting (MetaSurfaceActorWayland *surface_actor,
MetaPointerConfinementWayland *self)
{
meta_pointer_confinement_wayland_maybe_warp (self);
}
MetaPointerConstraint *
meta_pointer_confinement_wayland_new (MetaWaylandPointerConstraint *constraint)
{
GObject *object;
MetaPointerConfinementWayland *confinement;
MetaWaylandSurface *surface;
object = g_object_new (META_TYPE_POINTER_CONFINEMENT_WAYLAND, NULL);
confinement = META_POINTER_CONFINEMENT_WAYLAND (object);
confinement->constraint = constraint;
surface = meta_wayland_pointer_constraint_get_surface (constraint);
g_signal_connect_object (surface->surface_actor,
"painting",
G_CALLBACK (surface_actor_painting),
confinement,
0);
return META_POINTER_CONSTRAINT (confinement);
}
static void
meta_pointer_confinement_wayland_init (MetaPointerConfinementWayland *confinement_wayland)
{
}
static void
meta_pointer_confinement_wayland_class_init (MetaPointerConfinementWaylandClass *klass)
{
MetaPointerConstraintClass *pointer_constraint_class =
META_POINTER_CONSTRAINT_CLASS (klass);
pointer_constraint_class->constrain = meta_pointer_confinement_wayland_constrain;
}