gimp/app/display/gimpdisplayshell-coords.c

514 lines
17 KiB
C

/* GIMP - The GNU Image Manipulation Program
* Copyright (C) 1995 Spencer Kimball and Peter Mattis
*
* 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 3 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, see <http://www.gnu.org/licenses/>.
*/
#include "config.h"
#include <gtk/gtk.h>
#include "libgimpmath/gimpmath.h"
#include "display-types.h"
#include "gimpdisplayshell.h"
#include "gimpdisplayshell-coords.h"
#include "core/gimpcoords-interpolate.h"
/* Velocity unit is screen pixels per millisecond we pass to tools as 1. */
#define VELOCITY_UNIT 3.0
#define EVENT_FILL_PRECISION 6.0
static void gimp_display_shell_interpolate_stroke (GimpDisplayShell *shell,
GimpCoords *coords);
/* public functions */
gboolean
gimp_display_shell_get_event_coords (GimpDisplayShell *shell,
GdkEvent *event,
GdkDevice *device,
GimpCoords *coords)
{
if (gdk_event_get_axis (event, GDK_AXIS_X, &coords->x))
{
gdk_event_get_axis (event, GDK_AXIS_Y, &coords->y);
/* CLAMP() the return value of each *_get_axis() call to be safe
* against buggy XInput drivers. Provide default values if the
* requested axis does not exist.
*/
if (gdk_event_get_axis (event, GDK_AXIS_PRESSURE, &coords->pressure))
coords->pressure = CLAMP (coords->pressure, GIMP_COORDS_MIN_PRESSURE,
GIMP_COORDS_MAX_PRESSURE);
else
coords->pressure = GIMP_COORDS_DEFAULT_PRESSURE;
if (gdk_event_get_axis (event, GDK_AXIS_XTILT, &coords->xtilt))
coords->xtilt = CLAMP (coords->xtilt, GIMP_COORDS_MIN_TILT,
GIMP_COORDS_MAX_TILT);
else
coords->xtilt = GIMP_COORDS_DEFAULT_TILT;
if (gdk_event_get_axis (event, GDK_AXIS_YTILT, &coords->ytilt))
coords->ytilt = CLAMP (coords->ytilt, GIMP_COORDS_MIN_TILT,
GIMP_COORDS_MAX_TILT);
else
coords->ytilt = GIMP_COORDS_DEFAULT_TILT;
if (gdk_event_get_axis (event, GDK_AXIS_WHEEL, &coords->wheel))
coords->wheel = CLAMP (coords->wheel, GIMP_COORDS_MIN_WHEEL,
GIMP_COORDS_MAX_WHEEL);
else
coords->wheel = GIMP_COORDS_DEFAULT_WHEEL;
return TRUE;
}
gimp_display_shell_get_device_coords (shell, device, coords);
return FALSE;
}
void
gimp_display_shell_get_device_coords (GimpDisplayShell *shell,
GdkDevice *device,
GimpCoords *coords)
{
gdouble axes[GDK_AXIS_LAST];
gdk_device_get_state (device, gtk_widget_get_window (shell->canvas),
axes, NULL);
gdk_device_get_axis (device, axes, GDK_AXIS_X, &coords->x);
gdk_device_get_axis (device, axes, GDK_AXIS_Y, &coords->y);
/* CLAMP() the return value of each *_get_axis() call to be safe
* against buggy XInput drivers. Provide default values if the
* requested axis does not exist.
*/
if (gdk_device_get_axis (device, axes, GDK_AXIS_PRESSURE, &coords->pressure))
coords->pressure = CLAMP (coords->pressure, GIMP_COORDS_MIN_PRESSURE,
GIMP_COORDS_MAX_PRESSURE);
else
coords->pressure = GIMP_COORDS_DEFAULT_PRESSURE;
if (gdk_device_get_axis (device, axes, GDK_AXIS_XTILT, &coords->xtilt))
coords->xtilt = CLAMP (coords->xtilt, GIMP_COORDS_MIN_TILT,
GIMP_COORDS_MAX_TILT);
else
coords->xtilt = GIMP_COORDS_DEFAULT_TILT;
if (gdk_device_get_axis (device, axes, GDK_AXIS_YTILT, &coords->ytilt))
coords->ytilt = CLAMP (coords->ytilt, GIMP_COORDS_MIN_TILT,
GIMP_COORDS_MAX_TILT);
else
coords->ytilt = GIMP_COORDS_DEFAULT_TILT;
if (gdk_device_get_axis (device, axes, GDK_AXIS_WHEEL, &coords->wheel))
coords->wheel = CLAMP (coords->wheel, GIMP_COORDS_MIN_WHEEL,
GIMP_COORDS_MAX_WHEEL);
else
coords->wheel = GIMP_COORDS_DEFAULT_WHEEL;
}
void
gimp_display_shell_get_time_coords (GimpDisplayShell *shell,
GdkDevice *device,
GdkTimeCoord *event,
GimpCoords *coords)
{
gdk_device_get_axis (device, event->axes, GDK_AXIS_X, &coords->x);
gdk_device_get_axis (device, event->axes, GDK_AXIS_Y, &coords->y);
/* CLAMP() the return value of each *_get_axis() call to be safe
* against buggy XInput drivers. Provide default values if the
* requested axis does not exist.
*/
if (gdk_device_get_axis (device,
event->axes, GDK_AXIS_PRESSURE, &coords->pressure))
coords->pressure = CLAMP (coords->pressure, GIMP_COORDS_MIN_PRESSURE,
GIMP_COORDS_MAX_PRESSURE);
else
coords->pressure = GIMP_COORDS_DEFAULT_PRESSURE;
if (gdk_device_get_axis (device, event->axes, GDK_AXIS_XTILT, &coords->xtilt))
coords->xtilt = CLAMP (coords->xtilt, GIMP_COORDS_MIN_TILT,
GIMP_COORDS_MAX_TILT);
else
coords->xtilt = GIMP_COORDS_DEFAULT_TILT;
if (gdk_device_get_axis (device, event->axes, GDK_AXIS_YTILT, &coords->ytilt))
coords->ytilt = CLAMP (coords->ytilt, GIMP_COORDS_MIN_TILT,
GIMP_COORDS_MAX_TILT);
else
coords->ytilt = GIMP_COORDS_DEFAULT_TILT;
if (gdk_device_get_axis (device, event->axes, GDK_AXIS_WHEEL, &coords->wheel))
coords->wheel = CLAMP (coords->wheel, GIMP_COORDS_MIN_WHEEL,
GIMP_COORDS_MAX_WHEEL);
else
coords->wheel = GIMP_COORDS_DEFAULT_WHEEL;
}
gboolean
gimp_display_shell_get_event_state (GimpDisplayShell *shell,
GdkEvent *event,
GdkDevice *device,
GdkModifierType *state)
{
if (gdk_event_get_state (event, state))
return TRUE;
gimp_display_shell_get_device_state (shell, device, state);
return FALSE;
}
void
gimp_display_shell_get_device_state (GimpDisplayShell *shell,
GdkDevice *device,
GdkModifierType *state)
{
gdk_device_get_state (device, gtk_widget_get_window (shell->canvas),
NULL, state);
}
/**
* gimp_display_shell_eval_event:
* @shell:
* @coords:
* @inertia_factor:
* @time:
*
* This function evaluates the event to decide if the change is
* big enough to need handling and returns FALSE, if change is less
* than set filter level taking a whole lot of load off any draw tools
* that have no use for these events anyway. If the event is
* seen fit at first look, it is evaluated for speed and smoothed.
* Due to lousy time resolution of events pretty strong smoothing is
* applied to timestamps for sensible speed result. This function is
* also ideal for other event adjustment like pressure curve or
* calculating other derived dynamics factors like angular velocity
* calculation from tilt values, to allow for even more dynamic
* brushes. Calculated distance to last event is stored in GimpCoords
* because its a sideproduct of velocity calculation and is currently
* calculated in each tool. If they were to use this distance, more
* resouces on recalculating the same value would be saved.
*
* Return value:
**/
gboolean
gimp_display_shell_eval_event (GimpDisplayShell *shell,
GimpCoords *coords,
gdouble inertia_factor,
guint32 time)
{
gdouble delta_time = 0.001;
gdouble delta_x = 0.0;
gdouble delta_y = 0.0;
gdouble dir_delta_x = 0.0;
gdouble dir_delta_y = 0.0;
gdouble distance = 1.0;
gboolean event_fill = (inertia_factor > 0);
/* Smoothing causes problems with cursor tracking
* when zoomed above screen resolution so we need to supress it.
*/
if (shell->scale_x > 1.0 || shell->scale_y > 1.0)
{
inertia_factor = 0.0;
}
if (shell->last_motion_time == 0)
{
/* First pair is invalid to do any velocity calculation,
* so we apply a constant value.
*/
coords->velocity = 1.0;
}
else
{
gdouble filter;
gdouble dist;
gdouble delta_dir;
delta_x = shell->last_coords.x - coords->x;
delta_y = shell->last_coords.y - coords->y;
#define SMOOTH_FACTOR 0.3
/* Events with distances less than the screen resolution are not
* worth handling.
*/
filter = MIN (1 / shell->scale_x, 1 / shell->scale_y) / 2.0;
if (fabs (delta_x) < filter && fabs (delta_y) < filter)
return FALSE;
delta_time = (shell->last_motion_delta_time * (1 - SMOOTH_FACTOR)
+ (time - shell->last_motion_time) * SMOOTH_FACTOR);
distance = dist = sqrt (SQR (delta_x) + SQR (delta_y));
/* If even smoothed time resolution does not allow to guess for speed,
* use last velocity.
*/
if (delta_time == 0)
{
coords->velocity = shell->last_coords.velocity;
}
else
{
/* We need to calculate the velocity in screen coordinates
* for human interaction
*/
gdouble screen_distance = (distance *
MIN (shell->scale_x, shell->scale_y));
/* Calculate raw valocity */
coords->velocity = ((screen_distance / delta_time) / VELOCITY_UNIT);
/* Adding velocity dependent smoothing, feels better in tools. */
coords->velocity = (shell->last_coords.velocity *
(1 - MIN (SMOOTH_FACTOR, coords->velocity)) +
coords->velocity *
MIN (SMOOTH_FACTOR, coords->velocity));
/* Speed needs upper limit */
coords->velocity = MIN (coords->velocity, 1.0);
}
if ((fabs (delta_x) > 1.5) && (fabs (delta_y) > 1.5))
{
dir_delta_x = delta_x;
dir_delta_y = delta_y;
}
else
{
gint x = 3;
while (((fabs (dir_delta_x) < 1.5) ||
(fabs (dir_delta_y) < 1.5)) && (x >= 0))
{
const GimpCoords old_event = g_array_index (shell->event_history,
GimpCoords, x);
dir_delta_x = old_event.x - coords->x;
dir_delta_y = old_event.y - coords->y;
x--;
}
}
if (dir_delta_x == 0.0)
{
if (dir_delta_y >= 0.0)
coords->direction = 0.5;
else if (dir_delta_y < 0.0)
coords->direction = 0.0;
else coords->direction = shell->last_coords.direction;
}
else
{
coords->direction = atan ((- 1.0 * dir_delta_y) /
dir_delta_x) / (2 * G_PI);
if (dir_delta_x > 0.0)
coords->direction = coords->direction + 0.5;
}
coords->direction = coords->direction - floor (coords->direction);
delta_dir = coords->direction - shell->last_coords.direction;
if ((fabs (delta_dir) > 0.5) && (delta_dir < 0.0))
{
coords->direction = (0.5 * coords->direction +
0.5 * (shell->last_coords.direction - 1.0));
}
else if ((fabs (delta_dir) > 0.5) && (delta_dir > 0.0))
{
coords->direction = (0.5 * coords->direction +
0.5 * (shell->last_coords.direction + 1.0));
}
else
{
coords->direction = (0.5 * coords->direction +
0.5 * shell->last_coords.direction);
}
coords->direction = coords->direction - floor (coords->direction);
/* High speed -> less smooth*/
inertia_factor *= (1 - coords->velocity);
if (inertia_factor > 0 && distance > 0)
{
/* Apply smoothing to X and Y. */
/* This tells how far from the pointer can stray from the line */
gdouble max_deviation = SQR (20 * inertia_factor);
gdouble cur_deviation = max_deviation;
gdouble sin_avg;
gdouble sin_old;
gdouble sin_new;
gdouble cos_avg;
gdouble cos_old;
gdouble cos_new;
gdouble new_x;
gdouble new_y;
sin_new = delta_x / distance;
sin_old = shell->last_motion_delta_x / shell->last_motion_distance;
sin_avg = sin (asin (sin_old) * inertia_factor +
asin (sin_new) * (1 - inertia_factor));
cos_new = delta_y / distance;
cos_old = shell->last_motion_delta_y / shell->last_motion_distance;
cos_avg = cos (acos (cos_old) * inertia_factor +
acos (cos_new) * (1 - inertia_factor));
delta_x = sin_avg * distance;
delta_y = cos_avg * distance;
new_x = (shell->last_coords.x - delta_x) * 0.5 + coords->x * 0.5;
new_y = (shell->last_coords.y - delta_y) * 0.5 + coords->y * 0.5;
cur_deviation = SQR (coords->x - new_x) + SQR (coords->y - new_y);
while (cur_deviation >= max_deviation)
{
new_x = new_x * 0.8 + coords->x * 0.2;
new_y = new_y * 0.8 + coords->y * 0.2;
cur_deviation = (SQR (coords->x - new_x) +
SQR (coords->y - new_y));
}
coords->x = new_x;
coords->y = new_y;
delta_x = shell->last_coords.x - coords->x;
delta_y = shell->last_coords.y - coords->y;
/* Recalculate distance */
distance = sqrt (SQR (delta_x) + SQR (delta_y));
}
/* do event fill for devices that do not provide enough events*/
if (distance >= EVENT_FILL_PRECISION &&
event_fill &&
shell->event_history->len >= 2)
{
if (shell->event_delay)
{
gimp_display_shell_interpolate_stroke (shell,
coords);
}
else
{
shell->event_delay = TRUE;
}
}
else
{
if (shell->event_delay)
{
shell->event_delay = FALSE;
}
gimp_display_shell_push_event_history (shell, coords);
}
#ifdef VERBOSE
g_printerr ("DIST: %f, DT:%f, Vel:%f, Press:%f,smooth_dd:%f, sf %f\n",
distance,
delta_time,
shell->last_coords.velocity,
coords->pressure,
distance - dist,
inertia_factor);
#endif
}
g_array_append_val (shell->event_queue, *coords);
shell->last_coords = *coords;
shell->last_motion_time = time;
shell->last_motion_delta_time = delta_time;
shell->last_motion_delta_x = delta_x;
shell->last_motion_delta_y = delta_y;
shell->last_motion_distance = distance;
return TRUE;
}
/* Helper function fo managing event history */
void
gimp_display_shell_push_event_history (GimpDisplayShell *shell,
GimpCoords *coords)
{
if (shell->event_history->len == 4)
g_array_remove_index (shell->event_history, 0);
g_array_append_val (shell->event_history, *coords);
}
static void
gimp_display_shell_interpolate_stroke (GimpDisplayShell *shell,
GimpCoords *coords)
{
GArray *ret_coords;
gint i = shell->event_history->len - 1;
/* Note that there must be exactly one event in buffer or bad things
* can happen. This should never get called under other circumstances.
*/
ret_coords = g_array_new (FALSE, FALSE, sizeof (GimpCoords));
gimp_coords_interpolate_catmull (g_array_index (shell->event_history,
GimpCoords, i - 1),
g_array_index (shell->event_history,
GimpCoords, i),
g_array_index (shell->event_queue,
GimpCoords, 0),
*coords,
EVENT_FILL_PRECISION / 2,
&ret_coords,
NULL);
/* Push the last actual event in history */
gimp_display_shell_push_event_history (shell,
&g_array_index (shell->event_queue,
GimpCoords, 0));
g_array_set_size (shell->event_queue, 0);
g_array_append_vals (shell->event_queue,
&g_array_index (ret_coords, GimpCoords, 0),
ret_coords->len);
g_array_free (ret_coords, TRUE);
}