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Google Earth style dragging

by Andrea Farid Marsili · in iTorque 2D · 04/10/2011 (7:59 am) · 13 replies

Hi, as you maybe know I'm converting my game from GameSalad. I'm a lot of stuff but I have some problem with my "Google Earth" style dragging.
if(actor.touch.pressed){
	actor.dragging = true;
	actor.dragOriginX = scene.Camera.Origin.X;
	actor.dragStartX = game.Touches.Touch1.X;
}

if(actor.dragging){
	constrain:
		scene.Camera.Origin.X
			TO
		min(526, max(0, actor.dragStartX - game.Touches.Touch1.X) + actor.DragOriginX);
}

if(actor.touch.released){
	actor.dragging = false;
}

PS:
minUsage: min(x,y)
Return the smaller value of two numbers or variable values.
Example: min(12,35) = 25

maxUsage: max(x,y)
Return the higher value of two numbers or variable values.

Constrain behavior:
This behavior continuously updates the value of one attribute to that of another. For instance, an actor's x and y position can continuously be constrained to that of the mouse.

Here an example of what i want to do (I'm doing it only for the X axis):
http://gamesalad.com/game/2380

And here my TorqueScript code:

function ActorName::onMouseDown(%this, %modifier, %worldPosition, %clicks){
	ActorName.dragStartX = getWord(%worldPosition, 0);
	ActorName.dragOriginX = getWord(sceneWindow2D.getCurrentCameraPosition(), 0);
	
	if(ActorName.dragging){
		return;
	}
	else{
		ActorName.dragging = true;   
	}
}

function oniPhoneTouchUp(%touchCount, %touchX, %touchY){
   ActorName.dragging = false;
}

function oniPhoneTouchMove(%touchCount, %touchX, %touchY){
	if(ActorName.dragging){
		%cameraX = t2dGetMin(526, t2dGetMax(0, ActorName.dragStartX - %touchX) + ActorName.dragOriginX);
		// if min() and max() would exist also in torqueScript:
		// min(526, max(0, ActorName.dragStartX - %touchX) + ActorName.dragOriginX);
		sceneWindow2D.setCurrentCameraPosition(%cameraX, 0)
	}
}

Obviously my code doesn't work because I don't know how to use the setter and the getter for the camera with iTorque2D and I don't know if they work also with iTorque2D (I have only some TGB experience).
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Torque 3D Owner Alistair Lowe3
#1
04/10/2011 (10:43 am)
The camera is essentially your t2dSceneWindow (by default named sceneWindow2d).

so it would be:

sceneWindow2D.setCurrentCameraPosition(%cameraX, 0, %width, %height);

Hope this helps.


Torque Owner Andrea Farid Marsili
Footprint Games
#2
04/10/2011 (12:43 pm)
Thank you. I modified the code in the main post.
The end is near, I only need to know how to replace the min() and max() function.

Torque 3D Owner Alistair Lowe3
#3
04/10/2011 (1:36 pm)
mClamp( number, min, max);

Torque Owner Andrea Farid Marsili
Footprint Games
#4
04/11/2011 (1:47 pm)
Cannot understand one thing the "number" argument...what is it?

Torque 3D Owner Alistair Lowe3
#5
04/11/2011 (6:11 pm)
Sorry better options:

t2dGetMin(526, t2dGetMax(0, ActorName.dragStartX - %touchX) + ActorName.dragOriginX);

Torque Owner Andrea Farid Marsili
Footprint Games
#6
04/11/2011 (11:35 pm)
Where did you find these function?
I've got a TorqueScript reference pdf but a lot of function is missing...
I'll try using t2dGetMin and t2dGetMax and letmyou know if they work.
Thank you again.

Torque Owner Andrea Farid Marsili
Footprint Games
#7
04/19/2011 (5:53 am)
Tried it and it doesn't work. I cannot figure why. Same logic work like a charm on GameSalad.

I found the problem thanks to some echo function.

function ActorName::onMouseDown(%this, %modifier, %worldPosition, %clicks){  
    ActorName.dragStartX = getWord(%worldPosition, 0);  //working
    ActorName.dragOriginX = getWord(sceneWindow2D.getCurrentCameraPosition(), 0);  //working
      
    if(ActorName.dragging){  
        return;  
    }  
    else{  
        ActorName.dragging = true;     
    }
    
    echo("DragStartX: " @ ActorName.dragStartX);
    echo("DragOriginX: " @ ActorName.dragOriginX);
    echo("CameraPositionOnClick: " @ sceneWindow2D.getCurrentCameraPosition());
}

function oniPhoneTouchUp(%touchCount, %touchX, %touchY){  
   ActorName.dragging = false;
}

function oniPhoneTouchMove(%touchCount, %touchX, %touchY){
    %xPosition = getWord(%touchX, 0); //working
    if(ActorName.dragging){
        %cameraX = t2dGetMin(526, t2dGetMax(0, ActorName.dragStartX - %xPosition) + ActorName.dragOriginX);
        sceneWindow2D.setCurrentCameraPosition(%cameraX, 0); //working (tried to set the camera to 10, 0)
    }  
    echo("xPosition: " @ %xPosition);
    echo("CameraX: " @ %cameraX);
}

%cameraX is always 0, I think that's the problem is the t2dGetMin and t2dGetMax.

Torque 3D Owner Alistair Lowe3
#8
04/19/2011 (8:42 am)
Hmmmmmmmmmmmmm

Not related to your issue but you should change:
if(ActorName.dragging){    
        return;    
    }    
    else{    
        ActorName.dragging = true;       
    }

to
ActorName.dragging = true;

It's generally faster just to redundantly set a single value rather than checking it first.

Going back to your issue at hand...

I'll have to give this a test, let me go and boot up the old mac!

Torque 3D Owner Alistair Lowe3
#9
04/19/2011 (9:34 am)
OK this works for me (not very smooth mind you) but only in one direction.

The reason is that of course moving in the opposite direction will always be smaller than 0 as it's a minus number.

Perhaps in GameSalad the starting location was something like 261 with 0 being the left side limit and 526 the right side limit?

Either way the 0 should represent your camera movement limit to the left and the 526 your camera movement limit to the right, in Torque by default your camera starts at 0,0.

Torque Owner Andrea Farid Marsili
Footprint Games
#10
04/19/2011 (12:37 pm)
How did you manage to get it working? Did you made some code change?
GameSalad camera works as iTGB one, I think.
The 526 was only the half size of my pic.

Torque 3D Owner Alistair Lowe3
#11
04/19/2011 (12:58 pm)
Made no notable changes, my callbacks are a little different as I've been fiddling around with mutli-touch but that shouldn't have mattered

Torque Owner Andrea Farid Marsili
Footprint Games
#12
04/19/2011 (9:41 pm)
So you made no change...why it doesn't work for me?
Could you post the code?

Torque Owner Andrea Farid Marsili
Footprint Games
#13
04/28/2011 (12:58 pm)
I solved my problem creating two button and setting the "backgroud" speed pressing the button.