How to make an object move in the direction of a touch event, but never stop

Getting Started Newbie Questions
#1

So I am new to Corona and I was wondering how to make a ball (which at first is not moving at all) go towards the direction of a touch event and never stopping while maintaining its speed and able to bounce off other objects.

Can do this with the physics library?

Here is my code for the ball:

ball = display.newCircle( display.contentWidth / 2, display.contentHeight / 2, 20 )

ball.strokeWidth = 2
ball:setStrokeColor( 0, 0, 0 )

physics.addBody(ball, “dynamic”, {friction=0, bounce = 1, radius=20})

local function shoot(event)
    if(event.phase == “ended”) then
        --this is where I need help
        
        
    end
end

Runtime:addEventListener(“touch”, shoot)

(there is more code, obviosly, but it isn’t relevant for this post)

#2

Yes, you can do it with the physics library.

  1. In the touch handler, find out where the touch event was in relation to the ball. Store the direction/force you need

  2. Register an enterFrame handler, and inside it, use ball:applyForce(xForce, yForce) to move the ball in the desired direction. Since the handler will be called on every frame, this will apply a continuous force to the ball.

#3

Hi @tyrotech123,

One thing to note is that “applyForce()” will apply a force (hence the name) to the ball recursively, so if you apply that continuously in a “moved” touch handler phase, the ball will continue to move faster and faster until it blasts off the screen. To maintain a more steady pace, you should use “setLinearVelocity()”

http://docs.coronalabs.com/api/type/Body/setLinearVelocity.html

Brent

#4

After some more research I found this, which addressed my question: http://gamedev.stackexchange.com/questions/62664/how-to-shoot-on-direction-of-touch

#5

Yes, you can do it with the physics library.

  1. In the touch handler, find out where the touch event was in relation to the ball. Store the direction/force you need

  2. Register an enterFrame handler, and inside it, use ball:applyForce(xForce, yForce) to move the ball in the desired direction. Since the handler will be called on every frame, this will apply a continuous force to the ball.

#6

Hi @tyrotech123,

One thing to note is that “applyForce()” will apply a force (hence the name) to the ball recursively, so if you apply that continuously in a “moved” touch handler phase, the ball will continue to move faster and faster until it blasts off the screen. To maintain a more steady pace, you should use “setLinearVelocity()”

http://docs.coronalabs.com/api/type/Body/setLinearVelocity.html

Brent

#7

After some more research I found this, which addressed my question: http://gamedev.stackexchange.com/questions/62664/how-to-shoot-on-direction-of-touch