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Moved $1 Gestures into the SDL Library

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Jim Grandpre 2010-07-09 00:50:40 -07:00
parent 874300f89c
commit 746dc79478
4 changed files with 229 additions and 1 deletions
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213
src/events/SDL_gesture.c
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@ -30,6 +30,14 @@
//TODO: Replace with malloc
#define MAXFINGERS 3
#define MAXTOUCHES 2
#define MAXTEMPLATES 4
#define MAXPATHSIZE 1024
#define DOLLARNPOINTS 64
#define DOLLARSIZE 256
//PHI = ((sqrt(5)-1)/2)
#define PHI 0.618033989
typedef struct {
float x,y;
@ -42,10 +50,20 @@ typedef struct {
int id;
} Finger;
typedef struct {
float length;
int numPoints;
Point p[MAXPATHSIZE];
} DollarPath;
typedef struct {
Finger f;
Point cv;
float dtheta,dDist;
DollarPath dollarPath;
} TouchPoint;
@ -55,10 +73,160 @@ typedef struct {
Point centroid;
TouchPoint gestureLast[MAXFINGERS];
int numDownFingers;
int numDollarTemplates;
Point dollarTemplate[MAXTEMPLATES][DOLLARNPOINTS];
} GestureTouch;
GestureTouch gestureTouch[MAXTOUCHES];
int numGestureTouches = 0;
float dollarDifference(Point* points,Point* templ,float ang) {
// Point p[DOLLARNPOINTS];
float dist = 0;
Point p;
int i;
for(i = 0; i < DOLLARNPOINTS; i++) {
p.x = points[i].x * cos(ang) - points[i].y * sin(ang);
p.y = points[i].x * sin(ang) + points[i].y * cos(ang);
dist += sqrt((p.x-templ[i].x)*(p.x-templ[i].x)+
(p.y-templ[i].y)*(p.y-templ[i].y));
}
return dist/DOLLARNPOINTS;
}
float bestDollarDifference(Point* points,Point* templ) {
//------------BEGIN DOLLAR BLACKBOX----------------//
//-TRANSLATED DIRECTLY FROM PSUDEO-CODE AVAILABLE AT-//
//-"http://depts.washington.edu/aimgroup/proj/dollar/"-//
float ta = -M_PI/4;
float tb = M_PI/4;
float dt = M_PI/90;
float x1 = PHI*ta + (1-PHI)*tb;
float f1 = dollarDifference(points,templ,x1);
float x2 = (1-PHI)*ta + PHI*tb;
float f2 = dollarDifference(points,templ,x2);
while(abs(ta-tb) > dt) {
if(f1 < f2) {
tb = x2;
x2 = x1;
f2 = f1;
x1 = PHI*ta + (1-PHI)*tb;
f1 = dollarDifference(points,templ,x1);
}
else {
ta = x1;
x1 = x2;
f1 = f2;
x2 = (1-PHI)*ta + PHI*tb;
f2 = dollarDifference(points,templ,x2);
}
}
/*
if(f1 <= f2)
printf("Min angle (x1): %f\n",x1);
else if(f1 > f2)
printf("Min angle (x2): %f\n",x2);
*/
return SDL_min(f1,f2);
}
float dollarRecognize(DollarPath path,int *bestTempl,GestureTouch* touch) {
Point points[DOLLARNPOINTS];
int numPoints = dollarNormalize(path,points);
int i;
int bestDiff = 10000;
*bestTempl = -1;
for(i = 0;i < touch->numDollarTemplates;i++) {
int diff = bestDollarDifference(points,touch->dollarTemplate[i]);
if(diff < bestDiff) {bestDiff = diff; *bestTempl = i;}
}
return bestDiff;
}
//DollarPath contains raw points, plus (possibly) the calculated length
int dollarNormalize(DollarPath path,Point *points) {
int i;
//Calculate length if it hasn't already been done
if(path.length <= 0) {
for(i=1;i<path.numPoints;i++) {
float dx = path.p[i ].x -
path.p[i-1].x;
float dy = path.p[i ].y -
path.p[i-1].y;
path.length += sqrt(dx*dx+dy*dy);
}
}
//Resample
float interval = path.length/(DOLLARNPOINTS - 1);
float dist = 0;
int numPoints = 0;
Point centroid; centroid.x = 0;centroid.y = 0;
//printf("(%f,%f)\n",path.p[path.numPoints-1].x,path.p[path.numPoints-1].y);
for(i = 1;i < path.numPoints;i++) {
float d = sqrt((path.p[i-1].x-path.p[i].x)*(path.p[i-1].x-path.p[i].x)+
(path.p[i-1].y-path.p[i].y)*(path.p[i-1].y-path.p[i].y));
//printf("d = %f dist = %f/%f\n",d,dist,interval);
while(dist + d > interval) {
points[numPoints].x = path.p[i-1].x +
((interval-dist)/d)*(path.p[i].x-path.p[i-1].x);
points[numPoints].y = path.p[i-1].y +
((interval-dist)/d)*(path.p[i].y-path.p[i-1].y);
centroid.x += points[numPoints].x;
centroid.y += points[numPoints].y;
numPoints++;
dist -= interval;
}
dist += d;
}
if(numPoints < 1) return 0;
centroid.x /= numPoints;
centroid.y /= numPoints;
//printf("Centroid (%f,%f)",centroid.x,centroid.y);
//Rotate Points so point 0 is left of centroid and solve for the bounding box
float xmin,xmax,ymin,ymax;
xmin = centroid.x;
xmax = centroid.x;
ymin = centroid.y;
ymax = centroid.y;
float ang = atan2(centroid.y - points[0].y,
centroid.x - points[0].x);
for(i = 0;i<numPoints;i++) {
float px = points[i].x;
float py = points[i].y;
points[i].x = (px - centroid.x)*cos(ang) -
(py - centroid.y)*sin(ang) + centroid.x;
points[i].y = (px - centroid.x)*sin(ang) +
(py - centroid.y)*cos(ang) + centroid.y;
if(points[i].x < xmin) xmin = points[i].x;
if(points[i].x > xmax) xmax = points[i].x;
if(points[i].y < ymin) ymin = points[i].y;
if(points[i].y > ymax) ymax = points[i].y;
}
//Scale points to DOLLARSIZE, and translate to the origin
float w = xmax-xmin;
float h = ymax-ymin;
for(i=0;i<numPoints;i++) {
points[i].x = (points[i].x - centroid.x)*DOLLARSIZE/w;
points[i].y = (points[i].y - centroid.y)*DOLLARSIZE/h;
}
return numPoints;
}
int SDL_GestureAddTouch(SDL_Touch* touch) {
if(numGestureTouches >= MAXTOUCHES) return -1;
@ -69,6 +237,8 @@ int SDL_GestureAddTouch(SDL_Touch* touch) {
gestureTouch[numGestureTouches].res.x = touch->xres;
gestureTouch[numGestureTouches].id = touch->id;
gestureTouch[numGestureTouches].numDollarTemplates = 0;
numGestureTouches++;
return 0;
}
@ -93,6 +263,20 @@ int SDL_SendGestureMulti(GestureTouch* touch,float dTheta,float dDist) {
return SDL_PushEvent(&event) > 0;
}
int SDL_SendGestureDollar(GestureTouch* touch,int gestureId,float error) {
SDL_Event event;
event.dgesture.type = SDL_DOLLARGESTURE;
event.dgesture.touchId = touch->id;
/*
//TODO: Add this to give location of gesture?
event.mgesture.x = touch->centroid.x;
event.mgesture.y = touch->centroid.y;
*/
event.dgesture.gestureId = gestureId;
event.dgesture.error = error;
return SDL_PushEvent(&event) > 0;
}
void SDL_GestureProcessEvent(SDL_Event* event)
{
if(event->type == SDL_FINGERMOTION ||
@ -100,7 +284,6 @@ void SDL_GestureProcessEvent(SDL_Event* event)
event->type == SDL_FINGERUP) {
GestureTouch* inTouch = SDL_GetGestureTouch(event->tfinger.touchId);
//Shouldn't be possible
if(inTouch == NULL) return;
@ -114,12 +297,35 @@ void SDL_GestureProcessEvent(SDL_Event* event)
if(event->type == SDL_FINGERUP) {
inTouch->numDownFingers--;
int bestTempl;
float error;
error = dollarRecognize(inTouch->gestureLast[j].dollarPath,
&bestTempl,inTouch);
if(bestTempl >= 0){
//Send Event
int gestureId = 0; //?
SDL_SendGestureDollar(inTouch->id,gestureId,error);
printf("Dollar error: %f\n",error);
}
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;
DollarPath* path = &inTouch->gestureLast[j].dollarPath;
if(path->numPoints < MAXPATHSIZE) {
path->p[path->numPoints].x = x;
path->p[path->numPoints].y = y;
path->length += sqrt(dx*dx + dy*dy);
path->numPoints++;
}
inTouch->centroid.x += dx/inTouch->numDownFingers;
inTouch->centroid.y += dy/inTouch->numDownFingers;
if(inTouch->numDownFingers > 1) {
@ -181,6 +387,11 @@ void SDL_GestureProcessEvent(SDL_Event* event)
inTouch->gestureLast[j].f.p.y = y;
inTouch->gestureLast[j].cv.x = 0;
inTouch->gestureLast[j].cv.y = 0;
inTouch->gestureLast[j].dollarPath.length = 0;
inTouch->gestureLast[j].dollarPath.p[0].x = x;
inTouch->gestureLast[j].dollarPath.p[0].y = y;
inTouch->gestureLast[j].dollarPath.numPoints = 1;
}
}
}