I've been curious about the GSEvent struct for a while, and was suspecting there was a way to access more than 2 of the multi-touch points of gestures... And I was right.
After some disassembling in the GraphicsServices framework, I managed to reverse enough of the GSEvent struct to get the needed info. Here is what I got so far:

Code:

struct GSPathPoint {
	char unk0;
	char unk1;
	short int status;
	int unk2;
	float x;
	float y;
};

typedef struct {
	int unk0;
	int unk1;
	int type;
	int subtype;
	float unk2;
	float unk3;
	float x;
	float y;
	int timestamp1;
	int timestamp2;
	int unk4;
	int modifierFlags;
	int unk5;
	int unk6;
	int mouseEvent;
	short int dx;
	short int fingerCount;
	int unk7;
	int unk8;
	char unk9;
	char numPoints;
	short int unk10;
	struct GSPathPoint points[numPoints];
} GSEvent;

The GSPathPoint struct that appeared inside the GSEvent struct probably has something to do/is a CGPath, but I've got enough of it to get things to work, so no more reversing for now...
After you get the event pointer in a view, you can access the good stuff like this:
event->mouseEvent - type of the event, one of :

• 1 - MouseDown
• 2 - MouseDragged
• 5 - something like a MouseUp, but not sure
• 6 - MouseUp

event->fingerCount - number of fingers touching the screen.

event->numPoints - number of points in the points array. Can be > than fingerCount after a MouseUp.

event->points[0..numPoints] contains the info on every point.

event->points[0..numPoints].status = 3 when the mouse is down, I think there is a flag for moved too.


This is good news for the games/emulators authors, as now you can have up to 5 buttons on screen working independently.
If someone can figure out the unk's, I would love to hear from you...

PS: This also means multi-touch support in the next version of iPhysics, and just a little more time until iPinball comes out...

Great work man!

Originally Posted by nop144666

PS: This also means multi-touch support in the next version of iPhysics, and just a little more time until iPinball comes out...

Holy crap, you don't know how many times I have tried to use multitouch in iPhysics without it being there. Add that one feature, and iPhysics becomes hands down the best iPhone app.

have you done any testing to verify this works? and can track more than 2 inputs simultaneously ?
say 3 fingers all moving at the same time?

Originally Posted by drunknbass

have you done any testing to verify this works? and can track more than 2 inputs simultaneously ?
say 3 fingers all moving at the same time?

Yup, lot's of testing, and it's integrated in iPhysics now... Up to 5 fingers, with full tracking...

Awesome. Waiting for the new version of iPhysics!

can you post a code sample... id like to see

Now that is hardcore. iPhysics rocks, the best mind stimulation ever.

maybe i dont get it because im new to iphysics, but how exactly do i manage to move more then one field simultanously? When i draw something and then touch it i can move it, but when i touch the screen in another place at the same time to draw something other or move another object it just doesnt react.

Does this only works with special levels or what else am i doing wrong?

Originally Posted by drunknbass

can you post a code sample... id like to see

I can't post the code from iPhysics, as it's quite tied up with the rest of the code, but here goes my testing code.

EDApplication.h:

Code:

#import <Foundation/Foundation.h>
#import <UIKit/UIKit.h>

struct GSPathPoint {
	char unk0;
	char unk1;
	short int status;
	int unk2;
	float x;
	float y;
};

typedef struct {
	int unk0;
	int unk1;
	int type;
	int subtype;
	float unk2;
	float unk3;
	float x;
	float y;
	int timestamp1;
	int timestamp2;
	int unk4;
	int modifierFlags;
	int unk5;
	int unk6;
	int mouseEvent;
	short int dx;
	short int fingerCount;
	int unk7;
	int unk8;
	char unk9;
	char numPoints;
	short int unk10;
	struct GSPathPoint points[10];
} GSEvent;

@interface EDView : UIView {
	CGPoint fingers[5];
	int numFingers;
}
- (void)dumpEvent:(GSEvent*)event;
@end

@interface EDApplication : UIApplication {
	EDView *vw;
}
@end

EDApplication.m:

Code:

#import "EDApplication.h"
#include <stdlib.h>
#include <math.h>

@implementation EDApplication
- (void) applicationDidFinishLaunching: (id) unused {
	[UIHardware _setStatusBarHeight:0.0f];
	[self setStatusBarMode:2 orientation:0 duration:0.0f fenceID:0];

	UIWindow *window;
	struct CGRect rect = [UIHardware fullScreenApplicationContentRect];

	window = [[UIWindow alloc] initWithContentRect: rect];
	
	vw = [[EDView alloc] initWithFrame: rect];

	[window orderFront: self];
	[window makeKey: self];
	[window _setHidden: NO];

	[window setContentView: vw];
}
@end

#define DUMP_LINES 10

@implementation EDView
- (void)dumpEvent:(GSEvent*)event {
/* Test 1: Dump raw data
	char tmp[256];
	int l, i;
	char *bytes = (char *)event;
	for (l = 0; l < DUMP_LINES; l++) {
		tmp[0] = 0;
		for (i = 0; i < 8; i++) {
			sprintf(tmp, "%s %02X", tmp, *(bytes++));
		}
		sprintf(tmp, "%s -", tmp);
		for (i = 0; i < 8; i++) {
			sprintf(tmp, "%s %02X", tmp, *(bytes++));
		}
		NSLog(@"%s", tmp);
	}
*/
/* Test 2: Simple events
	NSLog(@"MouseEvent: %d, fingerCount: %hd, numPoints: %hhd, pos: %f, %f", event->mouseEvent, event->fingerCount, event->numPoints, event->x, event->y);
	int i;
	for (i = 0; i < event->numPoints; i++) {
		NSLog(@"  Point %d: %f, %f", i + 1, event->points[i].x, event->points[i].y);
	}
*/
/* Test 3: Multi-mouse tracking
	int i, j;
	
	bool oks[5] = {false, false, false, false, false};
	
	for (i = 0; i < event->fingerCount; i++) {
		bool found = false;
		for (j = 0; j < numFingers; j++) {
			int dist = ABS(event->points[i].x - fingers[j].x) + ABS(event->points[i].y - fingers[j].y);
			if (dist < 20) {
				found = true;
				oks[j] = true;
				if (dist > 2) {
					fingers[j].x = event->points[i].x;
					fingers[j].y = event->points[i].y;
					// MOUSEMOVE
					NSLog(@"MouseMove: %d, pos: %f, %f", j, fingers[j].x, fingers[j].y);
				}
				break;
			}
		}
		if (!found) {
			fingers[numFingers].x = event->points[i].x;
			fingers[numFingers].y = event->points[i].y;
			oks[numFingers] = true;
			numFingers++;
			// MOUSEDOWN
			NSLog(@"MouseDown: %d, pos: %f, %f", numFingers, fingers[numFingers-1].x, fingers[numFingers-1].y);
		}
	}
	for (j = 0; j < numFingers; j++) {
		if (!oks[j]) {
			// MOUSEUP
			NSLog(@"MouseUp: %d, pos: %f, %f", j + 1, fingers[j].x, fingers[j].y);
			numFingers--;
			fingers[j].x = fingers[numFingers].x;
			fingers[j].y = fingers[numFingers].y;
			oks[j] = oks[numFingers];
			j--;
		}
	}
*/
}

- (id)initWithFrame:(struct CGRect)frame {
	[super initWithFrame: frame];
	numFingers = 0;
	[super setTapDelegate: self];
	[super setGestureDelegate: self];
	return self;
}

- (void)gestureChanged:(GSEvent*)event {
	NSLog(@"gestureChanged:");
	[self dumpEvent: event];
}

- (void)gestureEnded:(GSEvent*)event {
	NSLog(@"gestureEnded:");
	[self dumpEvent: event];
}

- (void)gestureStarted:(GSEvent*)event {
	NSLog(@"gestureStarted:");
	[self dumpEvent: event];
}

- (void)mouseDown:(GSEvent*)event {
	NSLog(@"mouseDown:");
	[self dumpEvent: event];
}

- (void)mouseDragged:(GSEvent*)event {
	NSLog(@"mouseDragged:");
	[self dumpEvent: event];
}

- (void)mouseEntered:(GSEvent*)event {		
	NSLog(@"mouseEntered:");
	[self dumpEvent: event];
}

- (void)mouseExited:(GSEvent*)event {		
	NSLog(@"mouseExited:");
	[self dumpEvent: event];
}

- (void)mouseMoved:(GSEvent*)event {
	NSLog(@"mouseMoved:");
	[self dumpEvent: event];
}

- (void)mouseUp:(GSEvent*)event {
	NSLog(@"mouseUp:");
	[self dumpEvent: event];
}

- (void)view:(UIView *)view handleTapWithCount:(int)count event:(GSEvent *)event {
	NSLog(@"handleTapWithCount: %d", count);
	[self dumpEvent: event];
}
			
- (double)viewTouchPauseThreshold:(UIView *)view {
	return 0.5;
}

- (BOOL)isFirstResponder {
	return YES;
}

@end

main.m:

Code:

#import <UIKit/UIKit.h>

#import "EDApplication.h"

int main(int argc, char **argv)
{
    NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
    return UIApplicationMain(argc, argv, [EDApplication class]);
}

Just uncomment one of the test blocks and have fun... Test 3 is not very accurate, but you can get the idea.

Originally Posted by Gregsen

maybe i dont get it because im new to iphysics, but how exactly do i manage to move more then one field simultanously? When i draw something and then touch it i can move it, but when i touch the screen in another place at the same time to draw something other or move another object it just doesnt react.

Does this only works with special levels or what else am i doing wrong?

Right now I'm not implementing any new input style, so all drawing and stuff is just for 1 touch mode. Where multi-touch is going to be used now is in triggers, which can be used as on-screen buttons, in single and multi-player games... But I welcome suggestions on how to use multi-touch to make more interesting input methods...