Camera Behavior In Pyglet

Question

I would like to know from you how I can make sure that the camera in pyglet (2D) always follows the player keeping it always in the middle of the screen. Also, I would like to know how I can make a linear zoom, with the mouse wheel, always holding the player in the middle of the screen. To be clear, if anyone knows Factorio, I would like the camera to behave the same way. Around I found only examples on how to do it by moving the mouse etc. Unfortunately, I have not found anything that interests me.

This is the script I'm currently using:

Main class (I do not report all the script, but the parts related to the camera):

def on_resize(self, width, height):
    self.camera.init_gl(width, height)

def on_mouse_scroll(self, x, y, dx, dy):
    self.camera.scroll(dy)

def _world(self):
    self.camera = camera(self)
    self.player = player(self, 0, 0)
    self.push_handlers(self.player.keyboard)

Camera script:

class camera(object):
    zoom_in_factor = 1.2
    zoom_out_factor = 1 / zoom_in_factor

    def __init__(self, game):
        self.game = game
        self.left = 0
        self.right = self.game.width
        self.bottom = 0
        self.top = self.game.height
        self.zoom_level = 1
        self.zoomed_width = self.game.width
        self.zoomed_height = self.game.height

    def init_gl(self, width, height):
        self.width = width
        self.height = height
        glViewport(0, 0, self.width, self.height)

    def draw(self):
        glPushMatrix()
        glOrtho(self.left, self.right, self.bottom, self.top, 1, -1)
        glTranslatef(-self.game.player.sprite.x + self.width / 2, -self.game.player.sprite.y + self.height / 2, 0)
        self.game.clear()
        if self.game.runGame:
            for sprite in self.game.mapDraw_3:
                self.game.mapDraw_3[sprite].draw()
        glPopMatrix()
        print(self.game.player.sprite.x, self.game.player.sprite.y)

    def scroll(self, dy):
        f = self.zoom_in_factor if dy > 0 else self.zoom_out_factor if dy < 0 else 1
        if .1 < self.zoom_level * f < 2:
            self.zoom_level *= f

            vx = self.game.player.sprite.x / self.width
            vy = self.game.player.sprite.y / self.height

            vx_in_world = self.left + vx * self.zoomed_width
            vy_in_world = self.bottom + vy * self.zoomed_height

            self.zoomed_width *= f
            self.zoomed_height *= f

            self.left = vx_in_world - vx * self.zoomed_width
            self.right = vx_in_world + (1 - vx) * self.zoomed_width
            self.bottom = vy_in_world - vy * self.zoomed_height
            self.top = vy_in_world + (1 - vy) * self.zoomed_height

This is what I get:

This is what I would like to get (use Factorio as an example):

The script that I use at the moment I took it from here and modified for my need:

How to pan and zoom properly in 2D?

However, the script I am using, as you see, is based on something that has been created by someone else and I hate using something this way, because it does not belong to me. So I'm using it just to experiment and create my own camera class. That's why I asked for advice.

Other examples I watched:

https://www.programcreek.com/python/example/91285/pyglet.gl.glOrtho

https://groups.google.com/forum/#!topic/pyglet-users/g4dfSGPNCOk

https://www.tartley.com/2d-graphics-with-pyglet-and-opengl

There are other places I've watched, but I do not remember the links

To avoid repetition, yes, I looked on pyglet's guide, but at least that I am so stupid (I do not exclude it), I did not find anything that would help me to understand how to do it.

Camera Behavior In Pyglet

Answers (1)

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