geom-demo/geom/demos/aabb.py

from pygame import draw
from ..geom import AxisAlignedBB
from .. import WIDTH, HEIGHT, get_cursor_pos
from ..colors import *
from ..math import *
from ..draw import *

class AABBDistance:

    title = "AABB Distance"

    def handle_key_down(self, key):
        pass

    def render(self, surface):
        rect_a = AxisAlignedBB(
            -(WIDTH / 8),
            -(HEIGHT / 8),
            WIDTH / 4,
            HEIGHT / 4,
        )
        rect_b = AxisAlignedBB(
            *get_cursor_pos(),
            WIDTH / 5,
            HEIGHT / 5
        )

        # cx, cy = center
        dist_x = abs(rect_b.cx - rect_a.cx)
        dist_y = abs(rect_b.cy - rect_a.cy)

        gap_x = dist_x - rect_a.halfwidth - rect_b.halfwidth
        gap_y = dist_y - rect_a.halfheight - rect_b.halfheight

        distance = 0

        if gap_x < 0 and gap_y < 0:
            distance = max(gap_x, gap_y)
        else:
            if gap_x < 0:
                distance = gap_y
            elif gap_y < 0:
                distance = gap_x
            else:
                distance = length(gap_x, gap_y)

        text_screen(surface, WHITE, (10, HEIGHT - 20), f"Distance: {distance}")
        rect_a.draw(surface, YELLOW, 1)
        rect_b.draw(surface, WHITE, 1)
        line(surface, RED if distance < 0 else GREEN,
                  rect_a.get_center(), rect_b.get_center())

class PointAABBDistance:

    title = "Point-AABB Distance"

    def handle_key_down(self, key):
        pass

    def render(self, surface):
        rect_a = AxisAlignedBB(
            -(WIDTH / 8),
            -(HEIGHT / 8),
            WIDTH / 4,
            HEIGHT / 4,
        )
        cx, cy = get_cursor_pos()

        # cx, cy = point
        dist_x = abs(cx - rect_a.cx)
        dist_y = abs(cy - rect_a.cy)

        gap_x = dist_x - rect_a.halfwidth
        gap_y = dist_y - rect_a.halfheight

        distance = 0

        if gap_x < 0 and gap_y < 0:
            distance = max(gap_x, gap_y)
        else:
            if gap_x < 0:
                distance = gap_y
            elif gap_y < 0:
                distance = gap_x
            else:
                distance = length(gap_x, gap_y)

        text_screen(surface, WHITE, (10, HEIGHT - 20), f"Distance: {distance}")
        rect_a.draw(surface, YELLOW, 1)
        line(surface, RED if distance < 0 else GREEN,
                  rect_a.get_center(), (cx, cy))