/*

Simple DirectMedia Layer

Copyright (C) 1997-2011 Sam Lantinga <slouken@libsdl.org>

This software is provided 'as-is', without any express or implied

warranty. In no event will the authors be held liable for any damages

arising from the use of this software.

Permission is granted to anyone to use this software for any purpose,

including commercial applications, and to alter it and redistribute it

freely, subject to the following restrictions:

1. The origin of this software must not be misrepresented; you must not

claim that you wrote the original software. If you use this software

in a product, an acknowledgment in the product documentation would be

appreciated but is not required.

3. This notice may not be removed or altered from any source distribution.

*/

#include "SDL_config.h"

/* General mouse handling code for SDL */

#include "SDL_events.h"

#include "SDL_events_c.h"

#include "SDL_gesture_c.h"

#include <memory.h>

#include <string.h>

#include <stdio.h>

#include <math.h>

//TODO: Replace with malloc

#define MAXPATHSIZE 1024

#define DOLLARNPOINTS 64

#define DOLLARSIZE 256

#define ENABLE_DOLLAR

typedef struct {

} SDL_FloatPoint;

typedef struct {

float length;

int numPoints;

SDL_FloatPoint p[MAXPATHSIZE];

} SDL_DollarPath;

typedef struct {

SDL_FloatPoint path[DOLLARNPOINTS];

unsigned long hash;

} SDL_DollarTemplate;

typedef struct {

SDL_GestureID id;

SDL_FloatPoint res;

SDL_FloatPoint centroid;

SDL_DollarPath dollarPath;

Uint16 numDownFingers;

int numDollarTemplates;

SDL_DollarTemplate *dollarTemplate;

} SDL_GestureTouch;

SDL_GestureTouch *SDL_gestureTouch;

int SDL_numGestureTouches = 0;

SDL_bool recordAll;

#if 0

static void PrintPath(SDL_FloatPoint *path)

{

int i;

printf("Path:");

for(i=0;i<DOLLARNPOINTS;i++) {

printf(" (%f,%f)",path[i].x,path[i].y);

}

printf("\n");

}

#endif

int SDL_RecordGesture(SDL_TouchID touchId)

{

int i;

if(touchId < 0) recordAll = SDL_TRUE;

for(i = 0;i < SDL_numGestureTouches; i++) {

if((touchId < 0) || (SDL_gestureTouch[i].id == touchId)) {

SDL_gestureTouch[i].recording = SDL_TRUE;

if(touchId >= 0)

return 1;

}

}

return (touchId < 0);

}

unsigned long SDL_HashDollar(SDL_FloatPoint* points)

{

unsigned long hash = 5381;

int i;

for(i = 0;i < DOLLARNPOINTS; i++) {

hash = ((hash<<5) + hash) + (unsigned long)points[i].x;

hash = ((hash<<5) + hash) + (unsigned long)points[i].y;

}

return hash;

}

static int SaveTemplate(SDL_DollarTemplate *templ, SDL_RWops * src)

{

if(src == NULL) return 0;

//No Longer storing the Hash, rehash on load

//if(SDL_RWops.write(src,&(templ->hash),sizeof(templ->hash),1) != 1) return 0;

if(SDL_RWwrite(src,templ->path,

sizeof(templ->path[0]),DOLLARNPOINTS) != DOLLARNPOINTS)

return 0;

return 1;

}

int SDL_SaveAllDollarTemplates(SDL_RWops *src)

{

int i,j,rtrn = 0;

for(i = 0; i < SDL_numGestureTouches; i++) {

SDL_GestureTouch* touch = &SDL_gestureTouch[i];

for(j = 0;j < touch->numDollarTemplates; j++) {

rtrn += SaveTemplate(&touch->dollarTemplate[i],src);

}

}

int SDL_SaveDollarTemplate(SDL_GestureID gestureId, SDL_RWops *src)

{

int i,j;

for(i = 0; i < SDL_numGestureTouches; i++) {

SDL_GestureTouch* touch = &SDL_gestureTouch[i];

for(j = 0;j < touch->numDollarTemplates; j++) {

if(touch->dollarTemplate[i].hash == gestureId) {

return SaveTemplate(&touch->dollarTemplate[i],src);

}

}

SDL_SetError("Unknown gestureId");

return -1;

}

//path is an already sampled set of points

//Returns the index of the gesture on success, or -1

static int SDL_AddDollarGesture(SDL_GestureTouch* inTouch,SDL_FloatPoint* path)

{

SDL_DollarTemplate* dollarTemplate;

SDL_DollarTemplate *templ;

int i = 0;

if(inTouch == NULL) {

if(SDL_numGestureTouches == 0) return -1;

for(i = 0;i < SDL_numGestureTouches; i++) {

inTouch = &SDL_gestureTouch[i];

dollarTemplate =

(SDL_DollarTemplate *)SDL_realloc(inTouch->dollarTemplate,

(inTouch->numDollarTemplates + 1) *

sizeof(SDL_DollarTemplate));

if(!dollarTemplate) {

SDL_OutOfMemory();

return -1;

}

inTouch->dollarTemplate = dollarTemplate;

templ =

&inTouch->dollarTemplate[inTouch->numDollarTemplates];

SDL_memcpy(templ->path,path,DOLLARNPOINTS*sizeof(SDL_FloatPoint));

templ->hash = SDL_HashDollar(templ->path);

inTouch->numDollarTemplates++;

}

return inTouch->numDollarTemplates - 1;

} else {

SDL_DollarTemplate* dollarTemplate =

( SDL_DollarTemplate *)SDL_realloc(inTouch->dollarTemplate,

(inTouch->numDollarTemplates + 1) *

sizeof(SDL_DollarTemplate));

if(!dollarTemplate) {

SDL_OutOfMemory();

return -1;

}

inTouch->dollarTemplate = dollarTemplate;

templ =

&inTouch->dollarTemplate[inTouch->numDollarTemplates];

SDL_memcpy(templ->path,path,DOLLARNPOINTS*sizeof(SDL_FloatPoint));

templ->hash = SDL_HashDollar(templ->path);

inTouch->numDollarTemplates++;

return inTouch->numDollarTemplates - 1;

}

int SDL_LoadDollarTemplates(SDL_TouchID touchId, SDL_RWops *src)

{

int i,loaded = 0;

SDL_GestureTouch *touch = NULL;

if(src == NULL) return 0;

if(touchId >= 0) {

for(i = 0;i < SDL_numGestureTouches; i++)

if(SDL_gestureTouch[i].id == touchId)

touch = &SDL_gestureTouch[i];

if(touch == NULL) return -1;

}

while(1) {

SDL_DollarTemplate templ;

if(SDL_RWread(src,templ.path,sizeof(templ.path[0]),DOLLARNPOINTS) <

DOLLARNPOINTS) break;

if(touchId >= 0) {

//printf("Adding loaded gesture to 1 touch\n");

if(SDL_AddDollarGesture(touch,templ.path)) loaded++;

}

else {

//printf("Adding to: %i touches\n",SDL_numGestureTouches);

for(i = 0;i < SDL_numGestureTouches; i++) {

touch = &SDL_gestureTouch[i];

//printf("Adding loaded gesture to + touches\n");

//TODO: What if this fails?

SDL_AddDollarGesture(touch,templ.path);

}

loaded++;

}

}

}

float dollarDifference(SDL_FloatPoint* points,SDL_FloatPoint* templ,float ang)

{

// SDL_FloatPoint p[DOLLARNPOINTS];

float dist = 0;

SDL_FloatPoint p;

int i;

for(i = 0; i < DOLLARNPOINTS; i++) {

p.x = (float)(points[i].x * SDL_cos(ang) - points[i].y * SDL_sin(ang));

p.y = (float)(points[i].x * SDL_sin(ang) + points[i].y * SDL_cos(ang));

dist += (float)(SDL_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(SDL_FloatPoint* points,SDL_FloatPoint* templ)

{

//------------BEGIN DOLLAR BLACKBOX----------------//

//-TRANSLATED DIRECTLY FROM PSUDEO-CODE AVAILABLE AT-//

//-"http://depts.washington.edu/aimgroup/proj/dollar/"-//

double ta = -M_PI/4;

double tb = M_PI/4;

double dt = M_PI/90;

float x1 = (float)(PHI*ta + (1-PHI)*tb);

float f1 = dollarDifference(points,templ,x1);

float x2 = (float)((1-PHI)*ta + PHI*tb);

float f2 = dollarDifference(points,templ,x2);

while(SDL_fabs(ta-tb) > dt) {

if(f1 < f2) {

tb = x2;

x2 = x1;

f2 = f1;

x1 = (float)(PHI*ta + (1-PHI)*tb);

f1 = dollarDifference(points,templ,x1);

}

else {

ta = x1;

x1 = x2;

f1 = f2;

x2 = (float)((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);

}

//DollarPath contains raw points, plus (possibly) the calculated length

int dollarNormalize(const SDL_DollarPath *path,SDL_FloatPoint *points)

{

int i;

float interval;

float dist;

int numPoints = 0;

SDL_FloatPoint centroid;

float xmin,xmax,ymin,ymax;

float ang;

float w,h;

float length = path->length;

//Calculate length if it hasn't already been done

if(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;

length += (float)(SDL_sqrt(dx*dx+dy*dy));

}

//Resample

interval = length/(DOLLARNPOINTS - 1);

dist = interval;

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 = (float)(SDL_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 < DOLLARNPOINTS-1) {

SDL_SetError("ERROR: NumPoints = %i\n",numPoints);

return 0;

}

//copy the last point

points[DOLLARNPOINTS-1] = path->p[path->numPoints-1];

numPoints = DOLLARNPOINTS;

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

xmin = centroid.x;

xmax = centroid.x;

ymin = centroid.y;

ymax = centroid.y;

ang = (float)(SDL_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 = (float)((px - centroid.x)*SDL_cos(ang) -

(py - centroid.y)*SDL_sin(ang) + centroid.x);

points[i].y = (float)((px - centroid.x)*SDL_sin(ang) +

(py - centroid.y)*SDL_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

w = xmax-xmin;

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;

}

float dollarRecognize(const SDL_DollarPath *path,int *bestTempl,SDL_GestureTouch* touch)

{

SDL_FloatPoint points[DOLLARNPOINTS];

int i;

float bestDiff = 10000;

dollarNormalize(path,points);

//PrintPath(points);

*bestTempl = -1;

for(i = 0;i < touch->numDollarTemplates;i++) {

float diff = bestDollarDifference(points,touch->dollarTemplate[i].path);

if(diff < bestDiff) {bestDiff = diff; *bestTempl = i;}

}

return bestDiff;

}

int SDL_GestureAddTouch(SDL_Touch* touch)

{

SDL_GestureTouch *gestureTouch = (SDL_GestureTouch *)SDL_realloc(SDL_gestureTouch,

(SDL_numGestureTouches + 1) *

sizeof(SDL_GestureTouch));

if(!gestureTouch) {

SDL_OutOfMemory();

return -1;

}

SDL_gestureTouch[SDL_numGestureTouches].res.x = touch->xres;

SDL_gestureTouch[SDL_numGestureTouches].res.y = touch->yres;

SDL_gestureTouch[SDL_numGestureTouches].numDownFingers = 0;

SDL_gestureTouch[SDL_numGestureTouches].res.x = touch->xres;

SDL_gestureTouch[SDL_numGestureTouches].id = touch->id;

SDL_numGestureTouches++;

return 0;

}

int SDL_GestureRemoveTouch(SDL_TouchID id)

{

int i;

for (i = 0; i < SDL_numGestureTouches; i++) {

if (SDL_gestureTouch[i].id == id) {

SDL_numGestureTouches--;

SDL_memcpy(&SDL_gestureTouch[i], &SDL_gestureTouch[SDL_numGestureTouches], sizeof(SDL_gestureTouch[i]));

return 1;

}

}

SDL_GestureTouch * SDL_GetGestureTouch(SDL_TouchID id)

{

int i;

for(i = 0;i < SDL_numGestureTouches; i++) {

//printf("%i ?= %i\n",SDL_gestureTouch[i].id,id);

if(SDL_gestureTouch[i].id == id) return &SDL_gestureTouch[i];

}

return NULL;

}

int SDL_SendGestureMulti(SDL_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;

event.mgesture.numFingers = touch->numDownFingers;

return SDL_PushEvent(&event) > 0;

}

int SDL_SendGestureDollar(SDL_GestureTouch* touch,

SDL_GestureID gestureId,float error)

{

SDL_Event event;

event.dgesture.type = SDL_DOLLARGESTURE;

event.dgesture.touchId = touch->id;

/*

event.mgesture.x = touch->centroid.x;

event.mgesture.y = touch->centroid.y;

*/

event.dgesture.gestureId = gestureId;

event.dgesture.error = error;

//A finger came up to trigger this event.

event.dgesture.numFingers = touch->numDownFingers + 1;

return SDL_PushEvent(&event) > 0;

}

int SDL_SendDollarRecord(SDL_GestureTouch* touch,SDL_GestureID gestureId)

{

SDL_Event event;

event.dgesture.type = SDL_DOLLARRECORD;

event.dgesture.touchId = touch->id;

event.dgesture.gestureId = gestureId;

return SDL_PushEvent(&event) > 0;

}

void SDL_GestureProcessEvent(SDL_Event* event)

{

float x,y;

SDL_FloatPoint path[DOLLARNPOINTS];

int index;

int i;

float pathDx, pathDy;

SDL_FloatPoint lastP;

SDL_FloatPoint lastCentroid;

float lDist;

float Dist;

float dtheta;

float dDist;

if(event->type == SDL_FINGERMOTION ||

event->type == SDL_FINGERDOWN ||

event->type == SDL_FINGERUP) {

SDL_GestureTouch* inTouch = SDL_GetGestureTouch(event->tfinger.touchId);

//Shouldn't be possible

if(inTouch == NULL) return;

//printf("@ (%i,%i) with res: (%i,%i)\n",(int)event->tfinger.x,

// (int)event->tfinger.y,

// (int)inTouch->res.x,(int)inTouch->res.y);

x = ((float)event->tfinger.x)/(float)inTouch->res.x;

y = ((float)event->tfinger.y)/(float)inTouch->res.y;

//Finger Up

if(event->type == SDL_FINGERUP) {

inTouch->numDownFingers--;

if(inTouch->recording) {

inTouch->recording = SDL_FALSE;

dollarNormalize(&inTouch->dollarPath,path);

//PrintPath(path);

if(recordAll) {

index = SDL_AddDollarGesture(NULL,path);

for(i = 0;i < SDL_numGestureTouches; i++)

SDL_gestureTouch[i].recording = SDL_FALSE;

}

else {

index = SDL_AddDollarGesture(inTouch,path);

}

if(index >= 0) {

SDL_SendDollarRecord(inTouch,inTouch->dollarTemplate[index].hash);

}

else {

SDL_SendDollarRecord(inTouch,-1);

}

}

else {

int bestTempl;

float error;

error = dollarRecognize(&inTouch->dollarPath,

&bestTempl,inTouch);

if(bestTempl >= 0){

//Send Event

unsigned long gestureId = inTouch->dollarTemplate[bestTempl].hash;

SDL_SendGestureDollar(inTouch,gestureId,error);

//printf ("%s\n",);("Dollar error: %f\n",error);

}

}

#endif

//inTouch->gestureLast[j] = inTouch->gestureLast[inTouch->numDownFingers];

if(inTouch->numDownFingers > 0) {

inTouch->centroid.x = (inTouch->centroid.x*(inTouch->numDownFingers+1)-

x)/inTouch->numDownFingers;

inTouch->centroid.y = (inTouch->centroid.y*(inTouch->numDownFingers+1)-

y)/inTouch->numDownFingers;

}

else if(event->type == SDL_FINGERMOTION) {

float dx = ((float)event->tfinger.dx)/(float)inTouch->res.x;

float dy = ((float)event->tfinger.dy)/(float)inTouch->res.y;

//printf("dx,dy: (%f,%f)\n",dx,dy);

SDL_DollarPath* path = &inTouch->dollarPath;

if(path->numPoints < MAXPATHSIZE) {

path->p[path->numPoints].x = inTouch->centroid.x;

path->p[path->numPoints].y = inTouch->centroid.y;

pathDx =

(path->p[path->numPoints].x-path->p[path->numPoints-1].x);

pathDy =

(path->p[path->numPoints].y-path->p[path->numPoints-1].y);

path->length += (float)SDL_sqrt(pathDx*pathDx + pathDy*pathDy);

path->numPoints++;

}

lastP.x = x - dx;

lastP.y = y - dy;

lastCentroid = inTouch->centroid;

inTouch->centroid.x += dx/inTouch->numDownFingers;

inTouch->centroid.y += dy/inTouch->numDownFingers;

//printf("Centrid : (%f,%f)\n",inTouch->centroid.x,inTouch->centroid.y);

if(inTouch->numDownFingers > 1) {

SDL_FloatPoint lv; //Vector from centroid to last x,y position

SDL_FloatPoint v; //Vector from centroid to current x,y position

//lv = inTouch->gestureLast[j].cv;

lv.x = lastP.x - lastCentroid.x;

lv.y = lastP.y - lastCentroid.y;

lDist = (float)SDL_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;

Dist = (float)SDL_sqrt(v.x*v.x+v.y*v.y);

// SDL_cos(dTheta) = (v . lv)/(|v| * |lv|)

//Normalize Vectors to simplify angle calculation

lv.x/=lDist;

lv.y/=lDist;

v.x/=Dist;

v.y/=Dist;

dtheta = (float)SDL_atan2(lv.x*v.y - lv.y*v.x,lv.x*v.x + lv.y*v.y);

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(event->type == SDL_FINGERDOWN) {

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;

//printf("Finger Down: (%f,%f). Centroid: (%f,%f\n",x,y,

// inTouch->centroid.x,inTouch->centroid.y);

#ifdef ENABLE_DOLLAR

inTouch->dollarPath.length = 0;

inTouch->dollarPath.p[0].x = x;

inTouch->dollarPath.p[0].y = y;

inTouch->dollarPath.numPoints = 1;

}

}