mlow/geom-demo
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Allow rotating shape in SAT

Browse Source 
Moved rendering of separating axes to function
Calculate overlaps instead of binary collision, write min distance to
resolve collision
This commit is contained in:
Matt Low 2020-11-15 00:24:44 +04:00
parent 3296d3a582
commit 5dfd84a2f6
2 changed files with 41 additions and 22 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
geom/__init__.py
View File

@ -7,7 +7,6 @@ HEIGHT = 720
surface = None surface = None
screen = None screen = None
def init(): def init():
pygame.display.set_caption("Geom Demo") pygame.display.set_caption("Geom Demo")
pygame.mouse.set_visible(False) pygame.mouse.set_visible(False)
@ -37,3 +36,6 @@ def loop():
def get_cursor_pos(): def get_cursor_pos():
return sub(*pygame.mouse.get_pos(), WIDTH / 2, HEIGHT / 2) return sub(*pygame.mouse.get_pos(), WIDTH / 2, HEIGHT / 2)
def get_inputs():
return pygame.key.get_pressed()

59
geom/demos/sat.py
View File

@ -1,9 +1,10 @@
from ..geom import Rect, Polygon from ..geom import Rect, Polygon
from .. import WIDTH, HEIGHT, get_cursor_pos from .. import WIDTH, HEIGHT, get_cursor_pos, get_inputs
from ..colors import * from ..colors import *
from ..math import * from ..math import *
from ..draw import * from ..draw import *
class SeparatingAxisTheorem: class SeparatingAxisTheorem:
title = "Separating Axis Theorem" title = "Separating Axis Theorem"
@ -23,9 +24,35 @@ class SeparatingAxisTheorem:
(-60, 60) (-60, 60)
]) ])
def render(self, surface): def handle_input(self):
self.shape2.set_position(*get_cursor_pos()) self.shape2.set_position(*get_cursor_pos())
inputs = get_inputs()
if inputs[pygame.K_q]:
self.shape2.rotate((1/60) * -90)
if inputs[pygame.K_e]:
self.shape2.rotate((1/60) * 90)
def draw_axis(self, surface, normal, colliding, min1, max1, min2, max2):
offset = scale(*rnormal(*normal), 300)
# axis
line(surface, WHITE,
add(*scale(*reverse(*normal), 1000), *offset),
add(*scale(*normal, 1000), *offset))
# shape 1
line(surface, YELLOW if not colliding else RED,
add(*scale(*normal, min1), *offset),
add(*scale(*normal, max1), *offset), 5)
# shape 2
line(surface, YELLOW if not colliding else RED,
add(*scale(*normal, min2), *offset),
add(*scale(*normal, max2), *offset), 5)
def render(self, surface):
self.handle_input()
normals = [] normals = []
def add_if_not_exists(normal): def add_if_not_exists(normal):
@ -46,32 +73,22 @@ class SeparatingAxisTheorem:
_max = max(_max, proj) _max = max(_max, proj)
return _min, _max return _min, _max
collisions = [] overlaps = []
for normal in normals: for normal in normals:
min1, max1 = get_min_max(normal, min1, max1 = get_min_max(normal,
self.shape1.get_translated_vertices()) self.shape1.get_translated_vertices())
min2, max2 = get_min_max(normal, min2, max2 = get_min_max(normal,
self.shape2.get_translated_vertices()) self.shape2.get_translated_vertices())
colliding = max1 > min2 and max2 > min1 overlap = max(min2 - max1, min1 - max2)
collisions.append(colliding) overlaps.append(overlap)
offset = scale(*rnormal(*normal), 300) self.draw_axis(surface, normal, overlap < 0, min1, max1, min2, max2)
# axis
line(surface, WHITE,
add(*scale(*reverse(*normal), 1000), *offset),
add(*scale(*normal, 1000), *offset))
# shape 1
line(surface, YELLOW if not colliding else RED,
add(*scale(*normal, min1), *offset),
add(*scale(*normal, max1), *offset), 5)
# shape 2
line(surface, YELLOW if not colliding else RED,
add(*scale(*normal, min2), *offset),
add(*scale(*normal, max2), *offset), 5)
colliding = all(overlap < 0 for overlap in overlaps)
if colliding:
text_screen(surface, WHITE, (10, HEIGHT - 20),
f"Min Distance to Resolve: {max(overlaps)}")
self.shape1.draw(surface, YELLOW, 4) self.shape1.draw(surface, YELLOW, 4)
self.shape2.draw(surface, RED if all(collisions) else WHITE, 4) self.shape2.draw(surface, RED if colliding else WHITE, 4)