Help me find a way to make the lasers fire in a certain direction.

[BurntRice]

Whenever I press the shoot button, lasers fire down on the far left-hand side of the screen, and only go up. I am not getting any immediate errors, so I am investigating into the math.

[BurntRice]

I think its due to the fact that I haven’t implemented your tips correctly however.

[BurntRice]

I have assigned so the new_laser.rotation is = to the player rotation, this results in lasers popping on sides, not the right sides because I probably have to switch the math.pi equations around, but they are not moving.

[JonB]

Move the for l in self.lasers loop to the proper indentation level. This should not be inside any of the touch handling code.

You will then use the l.rotation to set the motion direction.

Also, you will eventually need code that deletes lasers once they are off screen ( in that loop, check if laser.bbox is in self.bbox)

[BurntRice]

Um, sorry? I don’t really understand. I have properly indented the for l in self.lasers part, I don’t know how to add l.rotation to set motion direction.

[JonB]

Post your code. The last version you posted had the laser motion code INSIDE the touch handling code, which means the code would only execute when the fire button was being pressed.

[BurntRice]

from scene import *
import math
A = Action()


#Setting up background colour for the entire scene
class Game(Scene):
    
    def setup(self):
        self.bg = SpriteNode('spc:BackgroundBlack')
        self.lasers = []
        
        #Creating the player
        self.Player = SpriteNode('shp:RoundRect')
        self.Player.color = ("cyan")
        self.Player.anchor_point = (0.5, 0.5)
        self.Player.position = (512, 400)
        self.Player.rotation = 0.0
        self.add_child(self.Player)
        
        self.UpCrtl = SpriteNode('iow:arrow_up_b_32')
        self.UpCrtl.x_scale = 3.5/1.0
        self.UpCrtl.y_scale = 3.5/1.0
        self.UpCrtl.alpha = 0.5
        self.UpCrtl.position = (175, 295)
        self.add_child(self.UpCrtl)
        
        self.DownCrtl = SpriteNode('iow:arrow_down_b_32')
        self.DownCrtl.x_scale = 3.5/1.0
        self.DownCrtl.y_scale = 3.5/1.0
        self.DownCrtl.alpha = 0.5
        self.DownCrtl.position = (175, 130)
        self.add_child(self.DownCrtl)
        
        self.RightCrtl = SpriteNode('iow:arrow_right_b_32')
        self.RightCrtl.x_scale = 3.5/1.0
        self.RightCrtl.y_scale = 3.5/1.0
        self.RightCrtl.alpha = 0.5
        self.RightCrtl.position = (250, 212.5)
        self.add_child(self.RightCrtl)
        
        self.LeftCrtl = SpriteNode('iow:arrow_left_b_32')
        self.LeftCrtl.x_scale = 3.5/1.0
        self.LeftCrtl.y_scale = 3.5/1.0
        self.LeftCrtl.alpha = 0.5
        self.LeftCrtl.position = (100, 212.5)
        self.add_child(self.LeftCrtl)
        
        #The button for shooting
        self.laserButton = SpriteNode('shp:Circle')
        self.laserButton.color = ('gray')
        self.laserButton.x_scale = 3/1
        self.laserButton.y_scale = 3/1
        self.add_child(self.laserButton)
        self.laserButton.position = (1000, 212.5)
        
        #The score label
        self.score_label = LabelNode(text='Score: 0')
        self.score_label.anchor_point = (0, 0)
        self.score_label.position = (10, 790)
        self.score_label.font = ('Arial Rounded MT Bold', 30)
        self.add_child(self.score_label)

    #Movement code.
    def update(self):
        for touch in self.touches.values():
            if touch.location in self.LeftCrtl.bbox:
                new_x = self.Player.position.x - 5
                self.Player.rotation = math.pi*3/2
                if new_x >= 0 and new_x <= 1100:
                    self.Player.position = (new_x, self.Player.position.y)
                    
            if touch.location in self.RightCrtl.bbox: 
                new_x = self.Player.position.x + 5
                self.Player.rotation = math.pi/2
                if new_x >= 0 and new_x <= 1100:
                    self.Player.position = (new_x, self.Player.position.y)
            
            if touch.location in self.UpCrtl.bbox:
                new_y = self.Player.position.y + 5
                self.Player.rotation = 0.0
                if new_y >= 0 and new_y <= 800:
                    self.Player.position = (self.Player.position.x, new_y)
                
            if touch.location in self.DownCrtl.bbox: 
                new_y = self.Player.position.y - 5
                self.Player.rotation = math.pi
                if new_y >= 0 and new_y <= 800:
                    self.Player.position = (self.Player.position.x, new_y)
                    
            if touch.location in self.laserButton.bbox:
                new_laser = SpriteNode('spc:LaserBlue6')
                new_laser.rotation = self.Player.rotation
                direction = Vector2(-math.sin(new_laser.rotation), math.cos(new_laser.rotation))
                self.add_child(new_laser)
                self.lasers.append(new_laser)
                            
            for l in self.lasers:
                l.position += direction*75


if __name__ == '__main__':
    run(Game(), LANDSCAPE, show_fps=True)

[ccc]

Can

            if touch.location in self.DownCrtl.bbox: 
                new_y = self.Player.position.y - 5
                self.Player.rotation = math.pi
                if new_y >= 0 and new_y <= 800:
                    self.Player.position = (self.Player.position.x, new_y)

be simplified to

            if touch.location in self.DownCrtl.bbox:
                self.Player.rotation = math.pi
                if 0 <= new_y <= 800:
                    self.Player.position.y -= 5

[JonB]

@BurntRice okay, so

l.position += direction*75

Let's think about this for a minute. Where have you defined direction? Remember, the goal here in the movement code is to figure out the direction for EACH laser that you are moving. So, you need to figure out the direction Vector2 based on each laser's rotation.

[ccc]

Perhaps

            for l in self.lasers:
                l.position += direction*75

needs to be indented under the if touch.location in self.laserButton.bbox: block where direction is defined.

[JonB]

No. Trying the Socratic method to get him to think about his own code...

This would be simpler if the touch code and laser update code were their own functions, as they are completely independent. The fact that he shares a direction variable name is what is confusing him.

The touch code creates a laser. The laser created is spawned, and the code that sets the rotation and initial offset.

The code that moves the lasers is completely separate (one needn't have touch code at all to move laser objects). Lasers move even when buttons are not touched. So, how can you figure out what direction a given laser should travel?

[BurntRice]

I’ve made it so my laser shoots in the direction that I want it to, but, they are not moving. Once one laser pops up, the next one goes 75 pixels ahead, for ad infinitum. I don’t know if this is because of where I indented my direction value, but I don’t think so as that is mostly for rotation; nothing about moving forward etc.

[JonB]

So you have code which is moving your laser, but it is only running once?

Go back and look at all of your code to see if your indentation is correct. If you want laser movement code to run every update cycle, and it isn't, there must be some control code (if, for, with, while, etc ) that is preventing it from running.

What will help you in this case is to break your update function into functions that you call, so that you can better follow the program flow. Once an indented section of code gets to be longer than a screenfull, that's a good indication that you might need a function.

For instance, if each button had it's own method. Or, if all of your touch handling had it's own method. Then your update method would be easier for you to follow:

def update (self):
   handleTouches(self)
   moveLasers(self)
   checkCollisions(self)
   spawnEnemies(self)

[BurntRice]

I have been looking for quite a bit, and I’m really blind, but I can’t find any indentation errors.

from scene import *
import math
A = Action()


#Setting up background colour for the entire scene
class Game(Scene):

    def setup(self):
        self.bg = SpriteNode('spc:BackgroundBlack')
        self.lasers = []

        #Creating the player
        self.Player = SpriteNode('spc:Fire1')
        self.Player.color = ("cyan")
        self.Player.anchor_point = (0.5, 0.5)
        self.Player.x_scale = 2/1.0
        self.Player.y_scale = 1.5/1.0
        self.Player.position = (512, 400)
        self.Player.rotation = 0.0
        self.add_child(self.Player)

        self.UpCrtl = SpriteNode('iow:arrow_up_b_32')
        self.UpCrtl.x_scale = 3.5/1.0
        self.UpCrtl.y_scale = 3.5/1.0
        self.UpCrtl.alpha = 0.5
        self.UpCrtl.position = (175, 295)
        self.add_child(self.UpCrtl)

        self.DownCrtl = SpriteNode('iow:arrow_down_b_32')
        self.DownCrtl.x_scale = 3.5/1.0
        self.DownCrtl.y_scale = 3.5/1.0
        self.DownCrtl.alpha = 0.5
        self.DownCrtl.position = (175, 130)
        self.add_child(self.DownCrtl)

        self.RightCrtl = SpriteNode('iow:arrow_right_b_32')
        self.RightCrtl.x_scale = 3.5/1.0
        self.RightCrtl.y_scale = 3.5/1.0
        self.RightCrtl.alpha = 0.5
        self.RightCrtl.position = (250, 212.5)
        self.add_child(self.RightCrtl)

        self.LeftCrtl = SpriteNode('iow:arrow_left_b_32')
        self.LeftCrtl.x_scale = 3.5/1.0
        self.LeftCrtl.y_scale = 3.5/1.0
        self.LeftCrtl.alpha = 0.5
        self.LeftCrtl.position = (100, 212.5)
        self.add_child(self.LeftCrtl)

        #The button for shooting
        self.laserButton = SpriteNode('shp:Circle')
        self.laserButton.color = ('gray')
        self.laserButton.x_scale = 3/1
        self.laserButton.y_scale = 3/1
        self.add_child(self.laserButton)
        self.laserButton.position = (1000, 212.5)

        #The score label
        self.score_label = LabelNode(text='Score: 0')
        self.score_label.anchor_point = (0, 0)
        self.score_label.position = (10, 790)
        self.score_label.font = ('Arial Rounded MT Bold', 30)
        self.add_child(self.score_label)

    #Movement code.
    def update(self):
        for touch in self.touches.values():
            if touch.location in self.LeftCrtl.bbox:
                new_x = self.Player.position.x - 5
                self.Player.rotation = math.pi/2
                if new_x >= 0 and new_x <= 1100:
                    self.Player.position = (new_x, self.Player.position.y)

            if touch.location in self.RightCrtl.bbox:
                new_x = self.Player.position.x + 5
                self.Player.rotation = math.pi*3/2
                if new_x >= 0 and new_x <= 1100:
                    self.Player.position = (new_x, self.Player.position.y)

            if touch.location in self.UpCrtl.bbox:
                new_y = self.Player.position.y + 5
                self.Player.rotation = 0.0
                if new_y >= 0 and new_y <= 800:
                    self.Player.position = (self.Player.position.x, new_y)

            if touch.location in self.DownCrtl.bbox:
                new_y = self.Player.position.y - 5
                self.Player.rotation = math.pi
                if new_y >= 0 and new_y <= 800:
                    self.Player.position = (self.Player.position.x, new_y)

            if touch.location in self.laserButton.bbox:
                new_laser = SpriteNode('shp:Circle')
                new_laser.x_scale = 0.25/1.0
                new_laser.y_scale = 0.25/1.0
                new_laser.position = self.Player.position
                new_laser.rotation = self.Player.rotation
                direction = Vector2(-math.sin(new_laser.rotation), math.cos(new_laser.rotation))
                self.add_child(new_laser)
                self.lasers.append(new_laser)
                for l in self.lasers:
                    l.position += direction*75


if __name__ == '__main__':
    run(Game(), LANDSCAPE, show_fps=True)

[JonB]

Think about what should happen when you lifr your finger. Remember, update gets called 60 times per second.

Do you want the existing lasers to keep moving? Or move only when your finger is down, and freeze when your finger is up.

I would suggest rewriting your update function as follows, to make it easier for you to follow:

   def update(self):
      self.handle_button_presses()
      self.move_lasers()

Your touch handling code then moves to one method, and other game logic moves to their own functions, and get called from update. For example, eventually you might be moving enemies or asteroids or the map. You might be spawning enemies at certain intervals, which would also be it's own method. Thus, you would create a spawn_enemies, and move_enemies methods, maybe a scroll_map if this is scroller type game, perhaps a check_collisions which checks if the player hit any obstacles or enemies, etc. You should be able to write your entire update method using dummy methods that sort of lay out what you need to work in, and can implement the methods one at a time, since they should all be mostly independent of each other, just depending on a common set of attributes or positions.

[BurntRice]

I want my existing lasers to keep on moving. I have also implemented your idea of rewriting my update function.
I really don’t know how to though. If I use a touch.began method, it runs once, but stays in it’s place.
Am I forgetting to add something?

[JonB]

Okay, let's try this again.

If you want your laser to move, the movement code must be called EVERY time update is called. There should be no if statements around the for loop that moves the lasers.

In your old code the laser loop was inside the if statement that checked for the laser button touch. That's why it doesn't move when your finger is up. You will need to update your loop because the direction variable that you use for moving the lasers must be define inside the loop, because it can be different for every laser. You'll need to grab the laser rotation for each laser to figure that out.

Post your new updated 5 line update method. And post your update_laser_postions function or whatever you called it.

[BurntRice]

def update(self):
self.handle_button_presses()
self.move_lasers()
if random.random() < 0.01:
self.spawn_item()

def handle_button_presses(self):
    for touch in self.touches.values():
        if touch.location in self.LeftCrtl.bbox:
            new_x = self.Player.position.x - 5
            self.Player.rotation = math.pi/2
            if new_x >= 0 and new_x <= 1100:
                self.Player.position = (new_x, self.Player.position.y)

        if touch.location in self.RightCrtl.bbox:
            new_x = self.Player.position.x + 5
            self.Player.rotation = math.pi*3/2
            if new_x >= 0 and new_x <= 1100:
                self.Player.position = (new_x, self.Player.position.y)

        if touch.location in self.UpCrtl.bbox:
            new_y = self.Player.position.y + 5
            self.Player.rotation = 0.0
            if new_y >= 0 and new_y <= 800:
                self.Player.position = (self.Player.position.x, new_y)

        if touch.location in self.DownCrtl.bbox:
            new_y = self.Player.position.y - 5
            self.Player.rotation = math.pi
            if new_y >= 0 and new_y <= 800:
                self.Player.position = (self.Player.position.x, new_y)

def move_lasers(self):
    for touch in self.touches.values():
        if touch.location in self.laserButton.bbox:
            new_laser = SpriteNode('shp:Circle')
            new_laser.x_scale = 0.25/1.0
            new_laser.y_scale = 0.25/1.0
            new_laser.position = self.Player.position
            new_laser.rotation = self.Player.rotation
            direction = Vector2(-math.sin(new_laser.rotation), math.cos(new_laser.rotation))
            self.add_child(new_laser)
            self.lasers.append(new_laser)
            for l in self.lasers:
                l.position += direction*75

[dereq]

This post is deleted!

[JonB]

for l in self.lasers:
                l.position += direction*75

That is the code that moves a laser beam, right?

In words, can you explain under what conditions this code runs?

Does that code execute EVERY time update is called, or is there some logic that controls when it will run?

Hint, look above it for any for loops or if statements.