PIKApp/app/display/pikamotionbuffer.c

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2023-09-26 00:35:21 +02:00
/* PIKA - Photo and Image Kooker Application
* a rebranding of The GNU Image Manipulation Program (created with heckimp)
* A derived work which may be trivial. However, any changes may be (C)2023 by Aldercone Studio
*
* Original copyright, applying to most contents (license remains unchanged):
* 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 <https://www.gnu.org/licenses/>.
*/
#include "config.h"
#include <string.h>
#include <gegl.h>
#include <gtk/gtk.h>
#include "libpikamath/pikamath.h"
#include "display-types.h"
#include "core/pikacoords.h"
#include "core/pikacoords-interpolate.h"
#include "core/pikamarshal.h"
#include "pikamotionbuffer.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
#define DIRECTION_RADIUS (1.0 / MAX (scale_x, scale_y))
#define SMOOTH_FACTOR 0.3
enum
{
PROP_0
};
enum
{
STROKE,
HOVER,
LAST_SIGNAL
};
/* local function prototypes */
static void pika_motion_buffer_dispose (GObject *object);
static void pika_motion_buffer_finalize (GObject *object);
static void pika_motion_buffer_set_property (GObject *object,
guint property_id,
const GValue *value,
GParamSpec *pspec);
static void pika_motion_buffer_get_property (GObject *object,
guint property_id,
GValue *value,
GParamSpec *pspec);
static void pika_motion_buffer_push_event_history (PikaMotionBuffer *buffer,
const PikaCoords *coords);
static void pika_motion_buffer_pop_event_queue (PikaMotionBuffer *buffer,
PikaCoords *coords);
static void pika_motion_buffer_interpolate_stroke (PikaMotionBuffer *buffer,
PikaCoords *coords);
static gboolean pika_motion_buffer_event_queue_timeout (PikaMotionBuffer *buffer);
G_DEFINE_TYPE (PikaMotionBuffer, pika_motion_buffer, PIKA_TYPE_OBJECT)
#define parent_class pika_motion_buffer_parent_class
static guint motion_buffer_signals[LAST_SIGNAL] = { 0 };
static void
pika_motion_buffer_class_init (PikaMotionBufferClass *klass)
{
GObjectClass *object_class = G_OBJECT_CLASS (klass);
motion_buffer_signals[STROKE] =
g_signal_new ("stroke",
G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_FIRST,
G_STRUCT_OFFSET (PikaMotionBufferClass, stroke),
NULL, NULL,
pika_marshal_VOID__POINTER_UINT_FLAGS,
G_TYPE_NONE, 3,
G_TYPE_POINTER,
G_TYPE_UINT,
GDK_TYPE_MODIFIER_TYPE);
motion_buffer_signals[HOVER] =
g_signal_new ("hover",
G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_FIRST,
G_STRUCT_OFFSET (PikaMotionBufferClass, hover),
NULL, NULL,
pika_marshal_VOID__POINTER_FLAGS_BOOLEAN,
G_TYPE_NONE, 3,
G_TYPE_POINTER,
GDK_TYPE_MODIFIER_TYPE,
G_TYPE_BOOLEAN);
object_class->dispose = pika_motion_buffer_dispose;
object_class->finalize = pika_motion_buffer_finalize;
object_class->set_property = pika_motion_buffer_set_property;
object_class->get_property = pika_motion_buffer_get_property;
}
static void
pika_motion_buffer_init (PikaMotionBuffer *buffer)
{
buffer->event_history = g_array_new (FALSE, FALSE, sizeof (PikaCoords));
buffer->event_queue = g_array_new (FALSE, FALSE, sizeof (PikaCoords));
}
static void
pika_motion_buffer_dispose (GObject *object)
{
PikaMotionBuffer *buffer = PIKA_MOTION_BUFFER (object);
if (buffer->event_delay_timeout)
{
g_source_remove (buffer->event_delay_timeout);
buffer->event_delay_timeout = 0;
}
G_OBJECT_CLASS (parent_class)->dispose (object);
}
static void
pika_motion_buffer_finalize (GObject *object)
{
PikaMotionBuffer *buffer = PIKA_MOTION_BUFFER (object);
if (buffer->event_history)
{
g_array_free (buffer->event_history, TRUE);
buffer->event_history = NULL;
}
if (buffer->event_queue)
{
g_array_free (buffer->event_queue, TRUE);
buffer->event_queue = NULL;
}
G_OBJECT_CLASS (parent_class)->finalize (object);
}
static void
pika_motion_buffer_set_property (GObject *object,
guint property_id,
const GValue *value,
GParamSpec *pspec)
{
switch (property_id)
{
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
break;
}
}
static void
pika_motion_buffer_get_property (GObject *object,
guint property_id,
GValue *value,
GParamSpec *pspec)
{
switch (property_id)
{
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
break;
}
}
/* public functions */
PikaMotionBuffer *
pika_motion_buffer_new (void)
{
return g_object_new (PIKA_TYPE_MOTION_BUFFER,
NULL);
}
void
pika_motion_buffer_begin_stroke (PikaMotionBuffer *buffer,
guint32 time,
PikaCoords *last_motion)
{
g_return_if_fail (PIKA_IS_MOTION_BUFFER (buffer));
g_return_if_fail (last_motion != NULL);
buffer->last_read_motion_time = time;
*last_motion = buffer->last_coords;
}
void
pika_motion_buffer_end_stroke (PikaMotionBuffer *buffer)
{
g_return_if_fail (PIKA_IS_MOTION_BUFFER (buffer));
if (buffer->event_delay_timeout)
{
g_source_remove (buffer->event_delay_timeout);
buffer->event_delay_timeout = 0;
}
pika_motion_buffer_event_queue_timeout (buffer);
}
/**
* pika_motion_buffer_motion_event:
* @buffer:
* @coords:
* @time:
* @event_fill:
*
* 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 PikaCoords because its a
* sideproduct of velocity calculation and is currently calculated in
* each tool. If they were to use this distance, more resources on
* recalculating the same value would be saved.
*
* Returns: %TRUE if the motion was significant enough to be
* processed, %FALSE otherwise.
**/
gboolean
pika_motion_buffer_motion_event (PikaMotionBuffer *buffer,
PikaCoords *coords,
guint32 time,
gboolean event_fill)
{
gdouble delta_time = 0.001;
gdouble delta_x = 0.0;
gdouble delta_y = 0.0;
gdouble distance = 1.0;
gdouble scale_x = coords->xscale;
gdouble scale_y = coords->yscale;
g_return_val_if_fail (PIKA_IS_MOTION_BUFFER (buffer), FALSE);
g_return_val_if_fail (coords != NULL, FALSE);
/* the last_read_motion_time most be set unconditionally, so set
* it early
*/
buffer->last_read_motion_time = time;
delta_time = (buffer->last_motion_delta_time * (1 - SMOOTH_FACTOR) +
(time - buffer->last_motion_time) * SMOOTH_FACTOR);
if (buffer->last_motion_time == 0)
{
/* First pair is invalid to do any velocity calculation, so we
* apply a constant value.
*/
coords->velocity = 1.0;
}
else
{
PikaCoords last_dir_event = buffer->last_coords;
gdouble filter;
gdouble dist;
gdouble delta_dir;
gdouble dir_delta_x = 0.0;
gdouble dir_delta_y = 0.0;
delta_x = last_dir_event.x - coords->x;
delta_y = last_dir_event.y - coords->y;
/* Events with distances less than the screen resolution are
* not worth handling.
*/
filter = MIN (1.0 / scale_x, 1.0 / scale_y) / 2.0;
if (fabs (delta_x) < filter &&
fabs (delta_y) < filter)
{
return FALSE;
}
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 = buffer->last_coords.velocity;
}
else
{
/* We need to calculate the velocity in screen coordinates
* for human interaction
*/
gdouble screen_distance = (distance * MIN (scale_x, scale_y));
/* Calculate raw valocity */
coords->velocity = ((screen_distance / delta_time) / VELOCITY_UNIT);
/* Adding velocity dependent smoothing, feels better in tools. */
coords->velocity = (buffer->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) > DIRECTION_RADIUS) &&
(fabs (delta_y) > DIRECTION_RADIUS)) ||
(buffer->event_history->len < 4))
{
dir_delta_x = delta_x;
dir_delta_y = delta_y;
}
else
{
gint x = CLAMP ((buffer->event_history->len - 1), 3, 15);
while (((fabs (dir_delta_x) < DIRECTION_RADIUS) ||
(fabs (dir_delta_y) < DIRECTION_RADIUS)) &&
(x >= 0))
{
last_dir_event = g_array_index (buffer->event_history,
PikaCoords, x);
dir_delta_x = last_dir_event.x - coords->x;
dir_delta_y = last_dir_event.y - coords->y;
x--;
}
}
if ((fabs (dir_delta_x) < DIRECTION_RADIUS) ||
(fabs (dir_delta_y) < DIRECTION_RADIUS))
{
coords->direction = buffer->last_coords.direction;
}
else
{
coords->direction = pika_coords_direction (&last_dir_event, coords);
}
coords->direction = coords->direction - floor (coords->direction);
delta_dir = coords->direction - buffer->last_coords.direction;
if (delta_dir < -0.5)
{
coords->direction = (0.5 * coords->direction +
0.5 * (buffer->last_coords.direction - 1.0));
}
else if (delta_dir > 0.5)
{
coords->direction = (0.5 * coords->direction +
0.5 * (buffer->last_coords.direction + 1.0));
}
else
{
coords->direction = (0.5 * coords->direction +
0.5 * buffer->last_coords.direction);
}
coords->direction = coords->direction - floor (coords->direction);
/* do event fill for devices that do not provide enough events */
if (distance >= EVENT_FILL_PRECISION &&
event_fill &&
buffer->event_history->len >= 2)
{
if (buffer->event_delay)
{
pika_motion_buffer_interpolate_stroke (buffer, coords);
}
else
{
buffer->event_delay = TRUE;
pika_motion_buffer_push_event_history (buffer, coords);
}
}
else
{
if (buffer->event_delay)
buffer->event_delay = FALSE;
pika_motion_buffer_push_event_history (buffer, coords);
}
#ifdef EVENT_VERBOSE
g_printerr ("DIST: %f, DT:%f, Vel:%f, Press:%f,smooth_dd:%f, POS: (%f, %f)\n",
distance,
delta_time,
buffer->last_coords.velocity,
coords->pressure,
distance - dist,
coords->x,
coords->y);
#endif
}
g_array_append_val (buffer->event_queue, *coords);
buffer->last_coords = *coords;
buffer->last_motion_time = time;
buffer->last_motion_delta_time = delta_time;
buffer->last_motion_delta_x = delta_x;
buffer->last_motion_delta_y = delta_y;
buffer->last_motion_distance = distance;
return TRUE;
}
guint32
pika_motion_buffer_get_last_motion_time (PikaMotionBuffer *buffer)
{
g_return_val_if_fail (PIKA_IS_MOTION_BUFFER (buffer), 0);
return buffer->last_read_motion_time;
}
void
pika_motion_buffer_request_stroke (PikaMotionBuffer *buffer,
GdkModifierType state,
guint32 time)
{
GdkModifierType event_state;
gint keep = 0;
g_return_if_fail (PIKA_IS_MOTION_BUFFER (buffer));
if (buffer->event_delay)
{
/* If we are in delay we use LAST state, not current */
event_state = buffer->last_active_state;
keep = 1; /* Holding one event in buf */
}
else
{
/* Save the state */
event_state = state;
}
if (buffer->event_delay_timeout)
{
g_source_remove (buffer->event_delay_timeout);
buffer->event_delay_timeout = 0;
}
buffer->last_active_state = state;
while (buffer->event_queue->len > keep)
{
PikaCoords buf_coords;
pika_motion_buffer_pop_event_queue (buffer, &buf_coords);
g_signal_emit (buffer, motion_buffer_signals[STROKE], 0,
&buf_coords, time, event_state);
}
if (buffer->event_delay)
{
buffer->event_delay_timeout =
g_timeout_add (50,
(GSourceFunc) pika_motion_buffer_event_queue_timeout,
buffer);
}
}
void
pika_motion_buffer_request_hover (PikaMotionBuffer *buffer,
GdkModifierType state,
gboolean proximity)
{
g_return_if_fail (PIKA_IS_MOTION_BUFFER (buffer));
if (buffer->event_queue->len > 0)
{
PikaCoords buf_coords = g_array_index (buffer->event_queue,
PikaCoords,
buffer->event_queue->len - 1);
g_signal_emit (buffer, motion_buffer_signals[HOVER], 0,
&buf_coords, state, proximity);
g_array_set_size (buffer->event_queue, 0);
}
}
/* private functions */
static void
pika_motion_buffer_push_event_history (PikaMotionBuffer *buffer,
const PikaCoords *coords)
{
if (buffer->event_history->len == 4)
g_array_remove_index (buffer->event_history, 0);
g_array_append_val (buffer->event_history, *coords);
}
static void
pika_motion_buffer_pop_event_queue (PikaMotionBuffer *buffer,
PikaCoords *coords)
{
*coords = g_array_index (buffer->event_queue, PikaCoords, 0);
g_array_remove_index (buffer->event_queue, 0);
}
static void
pika_motion_buffer_interpolate_stroke (PikaMotionBuffer *buffer,
PikaCoords *coords)
{
PikaCoords catmull[4];
GArray *ret_coords;
gint i = buffer->event_history->len - 1;
/* Note that there must be exactly one event in buffer or bad things
* can happen. This must never get called under other circumstances.
*/
ret_coords = g_array_new (FALSE, FALSE, sizeof (PikaCoords));
catmull[0] = g_array_index (buffer->event_history, PikaCoords, i - 1);
catmull[1] = g_array_index (buffer->event_history, PikaCoords, i);
catmull[2] = g_array_index (buffer->event_queue, PikaCoords, 0);
catmull[3] = *coords;
pika_coords_interpolate_catmull (catmull, EVENT_FILL_PRECISION / 2,
ret_coords, NULL);
/* Push the last actual event in history */
pika_motion_buffer_push_event_history (buffer,
&g_array_index (buffer->event_queue,
PikaCoords, 0));
g_array_set_size (buffer->event_queue, 0);
g_array_append_vals (buffer->event_queue,
&g_array_index (ret_coords, PikaCoords, 0),
ret_coords->len);
g_array_free (ret_coords, TRUE);
}
static gboolean
pika_motion_buffer_event_queue_timeout (PikaMotionBuffer *buffer)
{
buffer->event_delay = FALSE;
buffer->event_delay_timeout = 0;
if (buffer->event_queue->len > 0)
{
PikaCoords last_coords = g_array_index (buffer->event_queue,
PikaCoords,
buffer->event_queue->len - 1);
pika_motion_buffer_push_event_history (buffer, &last_coords);
pika_motion_buffer_request_stroke (buffer,
buffer->last_active_state,
buffer->last_read_motion_time);
}
return FALSE;
}