Detecting if a sprite is touched

Comments

• Doffer

  June 2012 edited June 2012 Posts: 50

  Create a class for the sprites with its own touched method that checks the bounding box of the sprite. The bounding box can be determined by the size of the sprite. For example this code drags a vehicle when touched:

  Vehicle = class()
  
  function Vehicle:init(startVec)
      -- you can accept and set parameters here
      self.pos = startVec
      self.height = 70
      self.width = 100
  end
  
  function Vehicle:draw()
      spriteMode(CENTER)
      sprite("SpaceCute:Health Heart", self.pos.x, self.pos.y,100)
  end
  
  function Vehicle:hit(point)
      if point.x > (self.pos.x - self.width) and
         point.x < (self.pos.x + self.width) and
         point.y > (self.pos.y - self.height) and
         point.y < (self.pos.y + self.height) then
          return true
      end        
      return false
  end
  
  function Vehicle:touched(road, touch)
      if self:hit( vec2(touch.x, touch.y) ) and
       touch.state == MOVING then
          self.pos = self.pos + vec2( touch.deltaX, touch.deltaY )
      end
  end
  
• fglette

  June 2012 Posts: 9

  Doffer,

  Thanks for the reply. Very helpful. Got my code working now thanks to your help.
• DJMoffinz

  September 2020 Posts: 15

  Can I use this? Will give credit!
• dave1707 Mod

  September 2020 Posts: 8,781

  @DJMoffinz Heres a version if you don’t want to use a class. Use this for whatever you want.

  displayMode(FULLSCREEN)
  
  function setup()  
      fill(255)
      sp=readImage(asset.builtin.Space_Art.Icon)
      spw2=sp.width/2     -- sprite width / 2
      sph2=sp.height/2    -- sprite height / 2
      spx=WIDTH/2         -- sprite x position
      spy=HEIGHT/2        -- sprite y position
  end
  
  function draw()
      background(0)
      sprite(sp,spx,spy)
      if hit then
          text("sprite touched",WIDTH/2,HEIGHT/2+200)
      end
      text("touch or slide your finger on/off the sprite",WIDTH/2,HEIGHT-50)
  end
  
  function touched(t)
      if t.state==BEGAN or t.state==CHANGED then
          if t.x>spx-spw2 and t.x<spx+spw2 and t.y>spy-sph2 and t.y<spy+sph2 then
              hit=true
          else
              hit=false
          end
      end
      if t.state==ENDED then
          hit=false
      end
  end
  
• DJMoffinz

  September 2020 Posts: 15

  Thanks!