Polar Coordinates and NaN errors

Comments

• dave1707 Mod

  September 2017 Posts: 8,808

  @rydergaz Having an example with workable code would help a lot. Include minimum code for the setup, draw, and touched functions so your code can be run. That way anyone who wants to help doesn't have to figure out the other functions just to explain your problem.
• rydergaz

  September 2017 Posts: 35

  Sorry
• rydergaz

  September 2017 Posts: 35

  Here we go
• rydergaz

  September 2017 Posts: 35

  @dave1707 here's the whole programme

  
  
  --# Main
  -- Rocket
  
  displayMode(FULLSCREEN)
  w = 10
  h = 30
  TURN_ANGLE = 0.09
  
  -- Use this function to perform your initial setup
  function setup()
  
      target = Target(WIDTH/2, HEIGHT/2,WIDTH*0.05)
  
      rocket = Rocket(200,HEIGHT*0.1)
  
  
  end
  
  -- This function gets called once every frame
  function draw()
  
      background(200, 201, 212, 255)
  
      target:draw()
  
      rocket:draw()
  
      rocket:update(target)
  
  
  
  end
  
  
  function touch()
  
      target.touched(touch)
  
  
  
  
  end
  
  
  --# Rocket
  
  
  
  Rocket = class()
  
  function Rocket:init(x,y)
      -- you can accept and set parameters here
      -- initial position
      self.pos = vec2(x,y)
      -- inital velocity
      self.vel = vec2(0,1)
      -- vector that links rocket position to its target
      self.aim = target.pos - self.pos
  
      self.speed = math.pow(((math.pow(self.vel.x,2))+ (math.pow(self.vel.y,2))),0.5)
      -- the rockets angle, a vector pointing directly up has an angle of 0
      self.angle = 0
  
  
  end
  
  function Rocket:draw()
  
      pushMatrix()
      pushStyle()
  
  
      ellipse(self.pos.x + 5,self.pos.y + 15,10)
  
      -- the translation is used so that the rotate function rotates the rectangle from the centre
      translate(self.pos.x + w/2 ,self.pos.y + h/2)
  
      rotate(-self.angle)
  
      fill(255, 0, 229, 255)
      stroke(255, 255, 255, 255)
  
      rect(-w/2,-h/2,w,h)
      popStyle()
      popMatrix()
  
  
  end
  
  
  function Rocket:update(target)
      -- update position
      self.pos = self.pos + self.vel
  
      print(self.pos)
      print(self.vel)
      print(self.aim)
  
      -- update vector connecting ship and target position
      self.aim = target.pos - self.pos
  
  
      -- magnitude of the aim vector 
      self.aimMag =  math.pow(((self.aim.x)*(self.aim.x)+ (self.aim.y)*(self.aim.y)),0.5)
  
  
  
      -- angle between the ships velocity and vector between the ship to its target
      self.angleRelToTarget = math.acos((self.vel.x*self.aim.x + self.vel.y*self.aim.y)/self.aimMag)
  
  
  
  
      self.out = math.deg(self.angleRelToTarget)
    --  print(self.angleRelToTarget)
      text(self.out , self.pos.x + 50, self.pos.y + 50)
  
  
  
      pushStyle()
  
      strokeWidth(2)
      stroke(0, 0, 0, 255)
      -- this line shows the vector connecting the rocket to its target
      line(self.pos.x + w/2,self.pos.y + h/2,target.pos.x,target.pos.y)
  
      popStyle()
  
      -- this changes the ships velocity angle 
      self.angle = self.angle + self.angleRelToTarget/2
  
    --  print(math.deg(self.angle))
  
      -- updates velocity with this new angle
  
      self.vel = vec2(math.sin(self.angle),math.cos(self.angle))*self.speed
  
  
  end
  
  --# Target
  Target = class()
  
  function Target:init(x,y,radius)
      -- you can accept and set parameters here
  
      self.pos = vec2(x,y)
      self.radius = radius
  end
  
  function Target:draw()
  
      pushStyle()
  
      fill(0, 0, 0, 255)
  
      ellipse(self.pos.x,self.pos.y,self.radius)
      -- Codea does not automatically call this method
  
      popStyle()
  end
  
  function Target:touched(touch)
      -- Codea does not automatically call this method
  
     self.x = CurrentTouch.x 
      self.y = CurrentTouch.y
  end
  
  
• dave1707 Mod

  September 2017 Posts: 8,808

  You have a problem with math.acos() in rocket:update in the line

  self.angleRelToTarget = math.acos((self.vel.x*self.aim.x + self.vel.y*self.aim.y)/self.aimMag)
  

  the result of the calculation

  (self.vel.x*self.aim.x + self.vel.y*self.aim.y)/self.aimMag
  

  is greater than 1.0 which results in a nan when doing math.acos.

  One way to fix this is to do something like

  val=(self.vel.x*self.aim.x + self.vel.y*self.aim.y)/self.aimMag)
  if val>1 then
     val=1
  end
  self.angleRelToTarget = math.acos(val)
  
• rydergaz

  September 2017 Posts: 35

  The result shouldn't be over 1.0 since I'm taking the dot product right?
• rydergaz

  September 2017 Posts: 35

  I've sorted the Nan error now, the issue was that when relative angle between the missiles velocity vector and the vector connecting it to its target become nearly 180 degrees (i.e the rocket is flying away from target.) the code gets stuck at 180 and the rocket doesn't turn
• rydergaz

  September 2017 Posts: 35

  The new code is

  
  
  --# Main
  -- Rocket
  
  displayMode(FULLSCREEN)
  w = 10
  h = 30
  TURN_ANGLE = 0.09
  
  -- Use this function to perform your initial setup
  function setup()
  
      target = Target(WIDTH/2, HEIGHT/2,WIDTH*0.05)
  
      rocket = Rocket(200,HEIGHT*0.1)
  
  
  end
  
  -- This function gets called once every frame
  function draw()
  
      background(200, 201, 212, 255)
  
      target:draw()
  
      rocket:draw()
  
      rocket:update(target)
  
  
  
  end
  
  
  function touched(t)
  
  
  
      target.pos.x = CurrentTouch.x
      target.pos.y = CurrentTouch.y
  
  
  
  
  end
  
  
  --# Rocket
  
  
  
  Rocket = class()
  
  function Rocket:init(x,y)
      -- you can accept and set parameters here
      -- initial position
      self.pos = vec2(x,y)
      -- inital velocity
      self.vel = vec2(0,1)
      -- vector that links rocket position to its target
      self.aim = target.pos - self.pos
  
    --  self.speed = math.pow(((math.pow(self.vel.x,2))+ (math.pow(self.vel.y,2))),0.5)
      self.speed = 1
      parameter.integer("speed",2,10)
      -- the rockets angle, a vector pointing directly up has an angle of 0
      self.angle = 0
  
  
  end
  
  function Rocket:draw()
  
      pushMatrix()
      pushStyle()
  
  
  
      ellipse(self.pos.x + 5,self.pos.y + 15,10)
  
      -- the translation is used so that the rotate function rotates the rectangle from the centre
      translate(self.pos.x + w/2 ,self.pos.y + h/2)
  
      rotate(-self.angle)
  
      fill(255, 0, 229, 255)
      stroke(255, 255, 255, 255)
  
      rect(-w/2,-h/2,w,h)
      popStyle()
      popMatrix()
  
  
  end
  
  
  function Rocket:update(target)
  
     -- print("----start----")
     -- print(self.vel)
     -- print(self.speed)
      --print(self.aim)
  
  
  
  
  
  
      -- update position
      self.pos = self.pos + self.vel*speed
  
    --  print(self.pos)
  --    print(self.vel)
    --  print(self.aim)
  
      -- update vector connecting ship and target position
      self.aim = target.pos - self.pos
  
  
      -- magnitude of the aim vector
      self.aimMag =  math.pow(((self.aim.x)*(self.aim.x)+ (self.aim.y)*(self.aim.y)),0.5)
  
      self.velMag = math.pow(((math.pow(self.vel.x,2))+ (math.pow(self.vel.y,2))),0.5)
  
  
      val=((self.vel.x*self.aim.x + self.vel.y*self.aim.y)/(self.aimMag*self.velMag))
  
  
  
  
  
  
      -- angle between the ships velocity and vector between the ship to its target
      self.angleRelToTarget = math.acos((self.vel.x*self.aim.x + self.vel.y*self.aim.y)/self.aimMag)
      relAngle = self.angleRelToTarget
  
      -- angle of direction rocket wants to head in
      self.aimAngle = math.atan(self.aim.x/self.aim.y)
      -- angle of velocity of rocket
      self.aimVel = math.atan(self.vel.x/self.vel.y)
  
     self.out = math.deg(self.angleRelToTarget)
      --  print(self.angleRelToTarget)
      text(self.out , self.pos.x + 50, self.pos.y + 50)
  
  
      pushStyle()
  
      strokeWidth(2)
      stroke(0, 0, 0, 78)
      -- this line shows the vector connecting the rocket to its target
      line(self.pos.x + w/2,self.pos.y + h/2,target.pos.x,target.pos.y)
  
      popStyle()
  
  
  
  
  
  
      if self.aimVel > self.aimAngle then
          print("left")
          self.turn = -5
          if math.abs(self.out) < 1 then
              self.turn = 1
          end
  
      elseif self.aimVel < self.aimAngle then
          self.turn = 5
          print("right")
  
          if math.abs(self.out) < 1 then
              self.turn = 1
          end
  
  
      end
  
  
      -- this changes the ships velocity angle
      self.angle = self.angle + self.turn
  
      --  print(math.deg(self.angle))
  
      -- updates velocity with this new angle
  
      self.vel = vec2(math.sin(math.rad(self.angle)),math.cos(math.rad(self.angle)))
  
      print(self.out)
  
  
  end
  
  --# Target
  Target = class()
  
  function Target:init(x,y,radius)
      -- you can accept and set parameters here
  
      self.pos = vec2(x,y)
      self.radius = radius
  end
  
  function Target:draw()
  
      pushStyle()
  
      fill(0, 0, 0, 255)
  
      ellipse(self.pos.x,self.pos.y,self.radius)
      -- Codea does not automatically call this method
  
      popStyle()
  end
  
  function Target:touched(touch)
      -- Codea does not automatically call this method
  
     self.pos.x = CurrentTouch.x 
      self.pos.y = CurrentTouch.y
  end
  
  
• dave1707 Mod

  September 2017 edited September 2017 Posts: 8,808

  @rydergaz Here's an image from the guided missile program that I completed yesterday. The missile starts in the lower left corner and goes at a 45 degree angle to the right leaving a white trail. I'm using backingmode(RETAINED) to keep all the plotted point on the screen as the missile moves. When I tap the screen, a target point is created in red and a blue missile point is created where the missile was when the target point was created. After the missile passes thru a red target point, I tap the screen again creating another red target point and a blue missile position point. I did it several times to show the path of the missile as it seeked out each target point as I created them.

  PS. I ran this in portrait mode.

  IMG_1125.PNG 301.2K
• rydergaz

  September 2017 Posts: 35

  Ah nice yours looks like it's working really smoothly, this is the latest update on mine it's almost there but for some reason the rocket chooses to turn away from the target sometimes. This screenshot shows you my rocket path, the orange dot is where I placed the target. You can see on the last target the rocket goes in the wrong direction.
• rydergaz

  September 2017 Posts: 35

  Here is my rocket path

  IMG_0141.PNG 145.9K
• rydergaz

  September 2017 Posts: 35

  How are you guiding your rocket ?
• rydergaz

  September 2017 Posts: 35

  @dave1707 this is the code for my latest rocket programme

  
  --# Main
  -- Rocket V2
  
  displayMode(FULLSCREEN)
  
  w = 10
  h = 30
  
  
  -- Use this function to perform your initial setup
  function setup()
  
      target = Target(WIDTH/2, HEIGHT/2,WIDTH*0.05)
  
      rocket = Rocket(200,HEIGHT*0.1)
  
  
  end
  
  -- This function gets called once every frame
  function draw()
  
      background(255, 255, 255, 255)
  
      target:draw()
  
      rocket:draw()
  
      rocket:update(target)
  
  
  
  end
  
  
  function touched(t)
  
  
  
      target.pos.x = CurrentTouch.x
      target.pos.y = CurrentTouch.y
  
  
  
  
  end
  --# Rocket
  Rocket = class()
  
  function Rocket:init(x,y)
      -- you can accept and set parameters here
      -- initial position
      self.pos = vec2(x,y)
  
      -- inital velocity
      self.vel = vec2(0,1)
  
      -- vector that links rocket position to its target
      self.aim = target.pos - self.pos
  
      --  self.speed = math.pow(((math.pow(self.vel.x,2))+ (math.pow(self.vel.y,2))),0.5)
  
      parameter.integer("speed",2,10)
  
      -- the rockets angle, a vector pointing directly up has an angle of 0
      self.angle = 0
  
  end
  
  function Rocket:draw()
  
      pushMatrix()
      pushStyle()
  
  
      ellipse(self.pos.x + 5,self.pos.y + 15,10)
  
      -- the translation is used so that the rotate function rotates the rectangle from the centre
      translate(self.pos.x + w/2 ,self.pos.y + h/2)
  
      rotate(-self.angle)
  
      fill(255, 0, 229, 255)
      stroke(0, 0, 0, 255)
      strokeWidth(1)
  
      rect(-w/2,-h/2,w,h)
      popStyle()
      popMatrix()
  
  
  end
  
  
  function Rocket:update(target)
  
  
      -- update position
      self.pos = self.pos + self.vel*speed
  
  
  
      -- update vector connecting ship and target position
      self.aim = target.pos - self.pos
  
  
      -- magnitude of the aim vector
      -- self.aimMag =  math.pow(((self.aim.x)*(self.aim.x)+ (self.aim.y)*(self.aim.y)),0.5)
      -- self.velMag = math.pow(((math.pow(self.vel.x,2))+ (math.pow(self.vel.y,2))),0.5)
      -- val=((self.vel.x*self.aim.x + self.vel.y*self.aim.y)/(self.aimMag*self.velMag))
      -- angle between the ships velocity and vector between the ship to its target
      --    self.angleRelToTarget = math.acos((self.vel.x*self.aim.x + self.vel.y*self.aim.y)/self.aimMag)
      --   relAngle = self.angleRelToTarget
  
  
      -- angle of direction rocket wants to head in
      --self.aimAngle = math.deg(math.atan(self.aim.x/self.aim.y))
  
      self.aimAngle = self:angleMachine(self.aim)
  
      -- angle of velocity of rocket
      --self.velAngle = math.deg(math.atan(self.vel.x/self.vel.y))
  
      self.velAngle = self:angleMachine(self.vel)
  
  
  
  
  
  
  
  
  
      --  self.out = math.deg(self.angleRelToTarget)
      --  print(self.angleRelToTarget)
      --  text(self.out , self.pos.x + 50, self.pos.y + 50)
  
  
      pushStyle()
  
      strokeWidth(2)
      stroke(0, 0, 0, 78)
      -- this line shows the vector connecting the rocket to its target
      line(self.pos.x + w/2,self.pos.y + h/2,target.pos.x,target.pos.y)
  
      popStyle()
  
  --    pushMatrix()
  --    translate(500,500)
  
  --    text(self.aimAngle - self.aimVel, WIDTH*0.5,HEIGHT*0.7,100)
  --    print("------------")
  --    print(self.aimAngle)
  --    print(self.aimVel)
  --    print(self.aimAngle - self.aimVel)
  --   popMatrix()
  
      if self.angle> self.aimAngle then
  
          if self.angle - self.aimAngle> 180 then
          print("working")
          self.turn = -10
          end
  
          self.turn = -1
  
          --   print("left")
          --    if math.abs(self.aimVel - self.aimAngle) < 1 then
          --        self.turn = 1
          --   end
  
      elseif self.angle < self.aimAngle then
  
          if self.aimAngle - self.angle > 180 then
              print("working2")
          self.turn = -50
          speed = 0.1
          end
          speed = 2
          self.turn = 1
  
          --     print("right")
          --  if math.abs(self.aimVel - self.aimAngle) < 1 then
          --     self.turn = 1
          --   end
  
       end
  
  
      -- this changes the ships velocity angle
  
      self.angle = self.angle + self.turn
  
      --  print(math.deg(self.angle))
      -- updates velocity with this new angle
  
      self.vel = vec2(math.sin(math.rad(self.angle)),math.cos(math.rad(self.angle)))
  
      pushStyle()
  
      stroke(0, 0, 0, 255)
      strokeWidth(3)
      line(target.pos.x,target.pos.y,target.pos.x+math.sin(math.rad(self.angle))*16,target.pos.y+math.cos(math.rad(self.angle))*16)
  
  
      pushMatrix()
  
      translate(600,800,0)
      text(self.aimAngle,600,900,10)
      translate(0,-50)
      text(self.velAngle,600,800,10)
      translate(0,-50)
      text(self.angle,600,700,10)
      translate(0,-50)
      text(self.aimAngle - self.velAngle,600,600,10)
  
      popMatrix()
  
       popStyle()
  
  
  
  end
  
  
  function Rocket:angleMachine(aim)
      angle = math.deg(math.atan(aim.x/aim.y))
      if aim.x > 0 and aim.y > 0 then
          angle = angle
      elseif aim.x > 0 and aim.y < 0 then
  
          angle = 180 + angle
      elseif aim.x < 0 and aim.y < 0 then
  
          angle = 180 + angle
  
      elseif aim.x < 0 and aim.y > 0 then
  
          angle = 360 + angle
  
      end
  
      return angle 
  
  
  
  
  end
  
  --# Target
  Target = class()
  
  function Target:init(x,y,radius)
      -- you can accept and set parameters here
  
      self.pos = vec2(x,y)
      self.radius = radius
  end
  
  function Target:draw()
  
      pushStyle()
  
      fill(241, 119, 44, 255)
  
      ellipse(self.pos.x,self.pos.y,self.radius)
      -- Codea does not automatically call this method
  
      popStyle()
  end
  
  function Target:touched(touch)
      -- Codea does not automatically call this method
  
     self.pos.x = CurrentTouch.x 
      self.pos.y = CurrentTouch.y
  end
  
• rydergaz

  September 2017 Posts: 35

  Update: managed to get it fully functioning runs like a dream now.

  
  --# Main
  -- Rocket V2
  
  displayMode(FULLSCREEN)
  
  w = 10
  h = 30
  
  
  -- Use this function to perform your initial setup
  function setup()
  
  
  
      target = Target(WIDTH/2, HEIGHT/2,WIDTH*0.02)
  
      rocket = Rocket(200,HEIGHT*0.1)
  
  
  end
  
  -- This function gets called once every frame
  function draw()
  
      background(225, 224, 224, 255)
  
      target:draw()
  
      rocket:draw()
  
      rocket:update(target)
  
  
  
  end
  
  
  function touched(t)
  
  
  
      target.pos.x = CurrentTouch.x
      target.pos.y = CurrentTouch.y
  
  
  
      end
  --# Rocket
  Rocket = class()
  
  function Rocket:init(x,y)
      -- you can accept and set parameters here
      -- initial position
      self.pos = vec2(x,y)
  
      -- inital velocity
      self.vel = vec2(0,1)
  
      -- vector that links rocket position to its target
      self.aim = target.pos - self.pos
  
      --  self.speed = math.pow(((math.pow(self.vel.x,2))+ (math.pow(self.vel.y,2))),0.5)
  
      parameter.integer("speed",2,10)
  
      -- the rockets angle, a vector pointing directly up has an angle of 0
      self.angle = 0
  
      self.aimAngle = 0
      self.velAngle = 0
      out = "nothing"
  
  end
  
  function Rocket:draw()
  
  
  
      pushMatrix()
      pushStyle()
  
  
      ellipse(self.pos.x + 5,self.pos.y + 15,10)
  
      -- the translation is used so that the rotate function rotates the rectangle from the centre
      translate(self.pos.x + w/2 ,self.pos.y + h/2)
  
      rotate(-self.velAngle)
  
      fill(1, 255, 0, 255)
      stroke(0, 0, 0, 255)
      strokeWidth(1)
  
      rect(-w/2,-h/2,w,h)
      popStyle()
      popMatrix()
  
  
  end
  
  
  function Rocket:update(target)
  
  
  
  
      -- update position
      self.pos = self.pos + self.vel*speed
  
      -- update vector connecting ship and target position
      self.aim = target.pos - self.pos
  
      self.aimAngle = self:angleMachine(self.aim)
  
      self.velAngle = self:angleMachine(self.vel)
  
  
      pushStyle()
  
      strokeWidth(2)
      stroke(0, 0, 0, 78)
      -- this line shows the vector connecting the rocket to its target
       line(self.pos.x + w/2,self.pos.y + h/2,target.pos.x,target.pos.y)
  
      popStyle()
  
  
  
      if self.velAngle> self.aimAngle then
  
          if self.velAngle - self.aimAngle> 180 then
        --  print("right2")
          out = "right2"
          self.turn = 3
          else
        --  print("left")
          out = "left"
  
          self.turn = -3
          end
  
      elseif self.velAngle < self.aimAngle then
  
          if self.aimAngle - self.velAngle > 180 then
  
            --  print("left2")
             -- print(self.aimAngle-self.angle)
              out = "left2"
          self.turn = -3
  
          else
  
          self.turn = 3
       --   print("right")
          out = "right"
  
       end
  end
  
  
      -- this changes the ships velocity angle
  
      self.velAngle = self.velAngle + self.turn
  
      --  print(math.deg(self.angle))
      -- updates velocity with this new angle
  
      self.vel = vec2(math.sin(math.rad(self.velAngle)),math.cos(math.rad(self.velAngle)))
  
      pushStyle()
  
      stroke(0, 0, 0, 255)
      strokeWidth(3)
      line(target.pos.x,target.pos.y,target.pos.x+math.sin(math.rad(self.velAngle))*16,target.pos.y+math.cos(math.rad(self.velAngle))*16)
  
  
      pushMatrix()
  
      translate(500,500)
  
      text(self.aimAngle,350,600,20)
      translate(0,-15)
      text(self.velAngle,350,590,20)
      translate(0,-15)
     -- text(self.angle,350,590,20)
     -- translate(0,-15)
      text(self.aimAngle - self.velAngle,350,580,20)
      translate(0,-15)
      text(self.velAngle - self.aimAngle,350,570,20)
      translate(0,-15)
      text(out,350,560,20)
      translate(0,-15)
  
  
  
      popMatrix()
  
       popStyle()
  
  
  
  end
  
  
  function Rocket:angleMachine(aim)
      angle = math.deg(math.atan(aim.x/aim.y))
      if aim.x > 0 and aim.y > 0 then
          angle = angle
      elseif aim.x > 0 and aim.y < 0 then
  
          angle = 180 + angle
      elseif aim.x < 0 and aim.y < 0 then
  
          angle = 180 + angle
  
      elseif aim.x < 0 and aim.y > 0 then
  
          angle = 360 + angle
  
      end
  
      return angle 
  
  
  
  
  end
  
  --# Target
  Target = class()
  
  function Target:init(x,y,radius)
      -- you can accept and set parameters here
  
      self.pos = vec2(x,y)
      self.radius = radius
  end
  
  function Target:draw()
  
      pushStyle()
  
      fill(241, 119, 44, 255)
  
      ellipse(self.pos.x,self.pos.y,self.radius)
      -- Codea does not automatically call this method
  
      popStyle()
  end
  
  function Target:touched(touch)
      -- Codea does not automatically call this method
  
     self.pos.x = CurrentTouch.x 
      self.pos.y = CurrentTouch.y
  end
  
• rydergaz

  September 2017 Posts: 35

  @dave1707 I'm still interested to see how you went about designing your homing missile. I took the bearings from the velocity vector and the vector connecting the rocket position to the target position and changed the velocity vectors angle till it's at the same angle as the position vector. If that makes sense
• dave1707 Mod

  September 2017 edited September 2017 Posts: 8,808

  @rydergaz Here's my version. I removed the blue dot since it isn't necessary. I left the backingMode in here. You can comment it out and uncomment background. The value of speed can be changed.

  displayMode(FULLSCREEN)
  
  function setup()
      mx,my=0,0
      x,y=0,0
      vx,vy=1,1
      speed=2
      backingMode(RETAINED)
  end
  
  function draw()
      --background(0)
      fill(255)
      ellipse(x,y,5)
      if px~=nil then
          fill(255,0,0)
          ellipse(px,py,10)
          dx=px-x
          dy=py-y
          if not hit then
              move()
              if math.abs(dx)<3 and math.abs(dy)<3 then
                  hit=true
              end
          end
      end
      x=x+vx*speed
      y=y+vy*speed
  end
  
  function move()
      v1=vec2(dx,dy)
      v1=v1:normalize()
      if vx<v1.x then
          vx=vx+speed*.005
      else
          vx=vx-speed*.005
      end
      if vy<v1.y then
          vy=vy+speed*.005
      else
          vy=vy-speed*.005
      end
  end
  
  function touched(t)
      if t.state==BEGAN then
          px=t.x
          py=t.y
          hit=false
      end
  end
  
• rydergaz

  September 2017 Posts: 35

  Thanks! Your programme works so well and it's very fluid. The move() function is so smart, would it be okay if I used this same concept in a bigger project of mine?
• dave1707 Mod

  September 2017 Posts: 8,808

  @rydergaz Anything that's posted in the forum is free to use by anyone unless it says that it's not. So go ahead and use it wherever you want.
• dave1707 Mod

  September 2017 Posts: 8,808

  @rydergaz I'm not sure how you're going to use the code, but here's another version. I removed things not used. Try holding the iPad in portrait and landscape position. This is just a missile targeting another missile.

  displayMode(FULLSCREEN)
  
  function setup()
      x,y,vx,vy=0,0,0,0
      speed=5
      px=WIDTH
      py=HEIGHT*.8
      backingMode(RETAINED)
  end
  
  function draw()
      fill(255)
      dx=px-x
      dy=py-y
      if not hit then
          ellipse(x,y,5)
          px=px-3.1
          py=py+.3
          move()
          if math.abs(dx)<3 and math.abs(dy)<3 then
              hit=true
          end
      end
      fill(255,0,0)
      ellipse(px,py,10)
      x=x+vx*speed
      y=y+vy*speed
  end
  
  function move()
      v1=vec2(dx,dy)
      v1=v1:normalize()
      if vx<v1.x then
          vx=vx+(v1.x-vx)/4
      else
          vx=vx-(vx-v1.x)/4
      end
      if vy<v1.y then
          vy=vy+(v1.y-vy)/4
      else
          vy=vy-(vy-v1.y)/4
      end
  end
  
• rydergaz

  September 2017 edited September 2017 Posts: 35

  @dave1707 thanks! I'll post an image of your rocket in use in the game I'm making. Here are the changes I made to your code so that it suits the style of my game, I'm very happy with how it's turned out.
  
  ~~~
  
  --# Main
  -- Rocket V3
  
  displayMode(FULLSCREEN)
  
  function setup()
  mx,my=0,0
  x,y=WIDTH/2,0
  vx,vy=0,1
  speed=4
  gas = {}
  --backingMode(RETAINED)
  end
  
  function draw()
  aim = vec2(vx,vy)
  
  angle = angleMachine(aim)
  
  background(0)
  
  fumes(x,y)
  
  
  
  
  fill(255)
  
  pushMatrix()
  
  translate(x,y)
  
  
  
  rotate(-angle)
  
  
  rect(-5,-15,10,30)
  popMatrix()
  
  
  if px~=nil then
  fill(255,0,0)
  ellipse(px,py,10)
  dx=px-x
  dy=py-y
  if not hit then
  move()
  if math.abs(dx) 0 then
  
  angle = 360 + angle
  
  end
  
  return angle
  end
  
  function fumes(xx,yy)
  
  randomNum = math.random(1,10)
  
  if randomNum > 5 then
  
  table.insert(gas,Smoke(xx,yy))
  
  end
  
  for a,b in pairs(gas) do
  
  b:draw()
  
  if b.status == "delete" then
  
  table.remove(gas)
  
  
  
  end
  
  
  
  end
  
  end
  
  
  --# Smoke
  Smoke = class()
  
  function Smoke:init(xx,yy)
  
  -- you can accept and set parameters here
  self.startPos = vec2(xx,yy)
  
  self.radius = math.random(1,30)
  self.alpha = 255
  self.angle = angle
  self.timer = 0
  self.status = "alive"
  
  
  pushMatrix()
  
  translate(x,y)
  
  rotate(-angle)
  
  fill(255,0,228,255)
  
  ellipse(0,-15,self.radius)
  
  popMatrix()
  
  end
  
  function Smoke:draw()
  self.r = math.random(1,255)
  self.g = math.random(1,255)
  self.b = math.random(1,255)
  
  
  pushMatrix()
  
  translate(self.startPos.x,self.startPos.y)
  
  rotate(-self.angle)
  
  
  
  
  self.alpha = self.alpha*0.97
  fill(self.r, self.g,self.b, self.alpha)
  ellipse(0,-15,self.radius)
  popMatrix()
  
  self.timer = self.timer + 1
  
  if self.timer > 800 then
  self.status = "delete"
  end
  
  end
  ~~~