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Moved Multi finger gesture recognition into the library.

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jimtla committed Jul 7, 2010
1 parent a5958fa commit ed49e7a6f97a3937a93cc799c4cdec7ad6dbd960
@@ -86,13 +86,17 @@ typedef enum
SDL_JOYBUTTONDOWN, /**< Joystick button pressed */
SDL_JOYBUTTONUP, /**< Joystick button released */

/*Touch events - is 0x700 the correct place?*/
/*Touch events*/
SDL_FINGERDOWN = 0x700,
SDL_FINGERUP,
SDL_FINGERMOTION,
SDL_TOUCHBUTTONDOWN,
SDL_TOUCHBUTTONUP,

/*Gesture events*/
SDL_DOLLARGESTURE = 0x800,
SDL_MULTIGESTURE,

/* Obsolete events */
SDL_EVENT_COMPAT1 = 0x7000, /**< SDL 1.2 events for compatibility */
SDL_EVENT_COMPAT2,
@@ -331,6 +335,28 @@ typedef struct SDL_TouchButtonEvent
} SDL_TouchButtonEvent;



/**
* \brief Multiple Finger Gesture Event
*/
typedef struct SDL_MultiGestureEvent
{
Uint32 type; /**< ::SDL_MULTIGESTURE */
Uint32 windowID; /**< The window with mouse focus, if any */
Uint8 touchId; /**< The touch device index */
Uint8 padding1;
Uint8 padding2;
Uint8 padding3;
float dTheta;
float dDist;
float x; //currently 0...1. Change to screen coords?
float y;

} SDL_MultiGestureEvent;




/**
* \brief The "quit requested" event
*/
@@ -416,6 +442,7 @@ typedef union SDL_Event
SDL_ProximityEvent proximity; /**< Proximity In or Out event */
SDL_TouchFingerEvent tfinger; /**< Touch finger event data */
SDL_TouchButtonEvent tbutton; /**< Touch button event data */
SDL_MultiGestureEvent mgesture; /**< Multi Finger Gesture data*/

/** Temporarily here for backwards compatibility */
/*@{*/
@@ -493,6 +493,10 @@ SDL_PushEvent(SDL_Event * event)
if (SDL_PeepEvents(event, 1, SDL_ADDEVENT, 0, 0) <= 0) {
return -1;
}

SDL_GestureProcessEvent(event);


return 1;
}

@@ -28,7 +28,7 @@
#include "SDL_keyboard_c.h"
#include "SDL_touch_c.h"
#include "SDL_windowevents_c.h"

#include "SDL_gesture_c.h"
/* Start and stop the event processing loop */
extern int SDL_StartEventLoop(Uint32 flags);
extern void SDL_StopEventLoop(void);
@@ -0,0 +1,189 @@
/*
SDL - Simple DirectMedia Layer
Copyright (C) 1997-2010 Sam Lantinga
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 2.1 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, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
Sam Lantinga
slouken@libsdl.org
*/
#include "SDL_config.h"

/* General mouse handling code for SDL */

#include "SDL_events.h"
#include "SDL_events_c.h"
#include "SDL_gesture_c.h"

//TODO: Replace with malloc
#define MAXFINGERS 3
#define MAXTOUCHES 2

typedef struct {
float x,y;
} Point;


typedef struct {
Point p;
float pressure;
int id;
} Finger;

typedef struct {
Finger f;
Point cv;
float dtheta,dDist;
} TouchPoint;


typedef struct {
int id;
Point res;
Point centroid;
TouchPoint gestureLast[MAXFINGERS];
int numDownFingers;
} GestureTouch;

GestureTouch gestureTouch[MAXTOUCHES];
int numGestureTouches = 0;
int SDL_GestureAddTouch(SDL_Touch* touch) {
if(numGestureTouches >= MAXTOUCHES) return -1;

gestureTouch[numGestureTouches].res.x = touch->xres;
gestureTouch[numGestureTouches].res.y = touch->yres;
gestureTouch[numGestureTouches].numDownFingers = 0;

gestureTouch[numGestureTouches].res.x = touch->xres;
gestureTouch[numGestureTouches].id = touch->id;

numGestureTouches++;
return 0;
}

GestureTouch * SDL_GetGestureTouch(int id) {
int i;
for(i = 0;i < numGestureTouches; i++) {
//printf("%i ?= %i\n",gestureTouch[i].id,id);
if(gestureTouch[i].id == id) return &gestureTouch[i];
}
return NULL;
}

int SDL_SendGestureMulti(GestureTouch* touch,float dTheta,float dDist) {
SDL_Event event;
event.mgesture.type = SDL_MULTIGESTURE;
event.mgesture.touchId = touch->id;
event.mgesture.x = touch->centroid.x;
event.mgesture.y = touch->centroid.y;
event.mgesture.dTheta = dTheta;
event.mgesture.dDist = dDist;
return SDL_PushEvent(&event) > 0;
}

void SDL_GestureProcessEvent(SDL_Event* event)
{
if(event->type == SDL_FINGERMOTION ||
event->type == SDL_FINGERDOWN ||
event->type == SDL_FINGERUP) {
GestureTouch* inTouch = SDL_GetGestureTouch(event->tfinger.touchId);


//Shouldn't be possible
if(inTouch == NULL) return;


float x = ((float)event->tfinger.x)/inTouch->res.x;
float y = ((float)event->tfinger.y)/inTouch->res.y;
int j,empty = -1;

for(j = 0;j<inTouch->numDownFingers;j++) {
if(inTouch->gestureLast[j].f.id != event->tfinger.fingerId) continue;

if(event->type == SDL_FINGERUP) {
inTouch->numDownFingers--;
inTouch->gestureLast[j] = inTouch->gestureLast[inTouch->numDownFingers];
break;
}
else {
float dx = x - inTouch->gestureLast[j].f.p.x;
float dy = y - inTouch->gestureLast[j].f.p.y;
inTouch->centroid.x += dx/inTouch->numDownFingers;
inTouch->centroid.y += dy/inTouch->numDownFingers;
if(inTouch->numDownFingers > 1) {
Point lv; //Vector from centroid to last x,y position
Point v; //Vector from centroid to current x,y position
lv = inTouch->gestureLast[j].cv;
float lDist = sqrt(lv.x*lv.x + lv.y*lv.y);
//printf("lDist = %f\n",lDist);
v.x = x - inTouch->centroid.x;
v.y = y - inTouch->centroid.y;
inTouch->gestureLast[j].cv = v;
float Dist = sqrt(v.x*v.x+v.y*v.y);
// cos(dTheta) = (v . lv)/(|v| * |lv|)

//Normalize Vectors to simplify angle calculation
lv.x/=lDist;
lv.y/=lDist;
v.x/=Dist;
v.y/=Dist;
float dtheta = atan2(lv.x*v.y - lv.y*v.x,lv.x*v.x + lv.y*v.y);

float dDist = (Dist - lDist);
if(lDist == 0) {dDist = 0;dtheta = 0;} //To avoid impossible values
inTouch->gestureLast[j].dDist = dDist;
inTouch->gestureLast[j].dtheta = dtheta;

//printf("dDist = %f, dTheta = %f\n",dDist,dtheta);
//gdtheta = gdtheta*.9 + dtheta*.1;
//gdDist = gdDist*.9 + dDist*.1
//knob.r += dDist/numDownFingers;
//knob.ang += dtheta;
//printf("thetaSum = %f, distSum = %f\n",gdtheta,gdDist);
//printf("id: %i dTheta = %f, dDist = %f\n",j,dtheta,dDist);
SDL_SendGestureMulti(inTouch,dtheta,dDist);
}
else {
inTouch->gestureLast[j].dDist = 0;
inTouch->gestureLast[j].dtheta = 0;
inTouch->gestureLast[j].cv.x = 0;
inTouch->gestureLast[j].cv.y = 0;
}
inTouch->gestureLast[j].f.p.x = x;
inTouch->gestureLast[j].f.p.y = y;
break;
//pressure?
}
}

if(j == inTouch->numDownFingers) {
//printf("Finger Down!!!\n");
inTouch->numDownFingers++;
inTouch->centroid.x = (inTouch->centroid.x*(inTouch->numDownFingers - 1)+
x)/inTouch->numDownFingers;
inTouch->centroid.y = (inTouch->centroid.y*(inTouch->numDownFingers - 1)+
y)/inTouch->numDownFingers;

inTouch->gestureLast[j].f.id = event->tfinger.fingerId;
inTouch->gestureLast[j].f.p.x = x;
inTouch->gestureLast[j].f.p.y = y;
inTouch->gestureLast[j].cv.x = 0;
inTouch->gestureLast[j].cv.y = 0;
}
}
}

/* vi: set ts=4 sw=4 expandtab: */

@@ -0,0 +1,32 @@
/*
SDL - Simple DirectMedia Layer
Copyright (C) 1997-2010 Sam Lantinga
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 2.1 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, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
Sam Lantinga
slouken@libsdl.org
*/
#include "SDL_config.h"

#ifndef _SDL_gesture_c_h
#define _SDL_gesture_c_h

extern void SDL_GestureProcessEvent(SDL_Event* event);


#endif /* _SDL_gesture_c_h */

/* vi: set ts=4 sw=4 expandtab: */
@@ -140,6 +140,9 @@ SDL_AddTouch(const SDL_Touch * touch, char *name)
SDL_touchPads[index]->relative_mode = SDL_FALSE;
SDL_touchPads[index]->flush_motion = SDL_FALSE;

//Do I want this here? Probably
SDL_GestureAddTouch(SDL_touchPads[index]);

return index;
}

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