--- /dev/null
+"""Optimized collision detection functions."""
+
+def overlaps(a, b):
+ """Return true if two circles are overlapping.
+
+ Usually, you'll want to use the 'collides' method instead, but
+ this one can be useful for just checking to see if the player has
+ entered an area or hit a stationary oject.
+
+ (This function is optimized.)
+
+ """
+
+ cdef float ax
+ cdef float bx
+ cdef float ay
+ cdef float by
+ cdef float dx
+ cdef float dy
+ cdef float radius_a
+ cdef float radius_b
+ cdef float radius
+
+ ax = a.x
+ bx = b.x
+ ay = a.y
+ by = b.y
+
+ dx = ax - bx
+ dy = ay - by
+ try:
+ radius = a.radius
+ except AttributeError:
+ radius = 0.5
+ try:
+ radius += b.radius
+ except AttributeError:
+ radius += 0.5
+
+ return dx * dx + dy * dy <= radius * radius
+
+
+cdef int _collides(float xa, float xb, float ya, float yb,
+ float pxa, float pxb, float pya, float pyb,
+ float radius_a, float radius_b):
+
+ """Check collision for two moving circles."""
+
+ cdef float dir_x
+ cdef float dir_y
+
+ cdef float diff_x
+ cdef float diff_y
+ cdef float dist_x
+ cdef float dist_y
+
+ cdef float dx
+ cdef float dy
+ cdef float t
+
+ cdef float radius
+
+ radius = radius_a + radius_b
+
+ # Translate b's final position to be relative to a's start.
+ # And now, circle/line collision.
+ dir_x = pxa + (xb - xa) - pxb
+ dir_y = pya + (yb - ya) - pyb
+
+ if (dir_x < 0.0001 and dir_x > -0.0001
+ and dir_y < 0.0001 and dir_y > -0.0001):
+ # b did not move relative to a, so do point/circle.
+ dx = pxb - pxa
+ dy = pyb - pya
+ return dx * dx + dy * dy < radius * radius
+
+ diff_x = pxa - pxb
+ diff_y = pya - pyb
+
+ # dot(diff, dir) / dot(dir, dir)
+ t = (diff_x * dir_x + diff_y * dir_y) / (dir_x * dir_x + dir_y * dir_y)
+ if t < 0:
+ t = 0
+ elif t > 1:
+ t = 1
+
+ dist_x = pxa - (pxb + dir_x * t)
+ dist_y = pya - (pyb + dir_y * t)
+
+ # dist_sq < radius_sq
+ return dist_x * dist_x + dist_y * dist_y <= radius * radius
+
+def collides(a, b):
+ """Return true if the two moving circles collide.
+
+ a and b should have the following attributes:
+
+ x, y - required, current position
+ px, py - not required, defaults to x, y, previous frame position
+ radius - not required, defaults to 0.5
+
+ (This function is optimized.)
+
+ """
+ cdef float xa
+ cdef float xb
+ cdef float ya
+ cdef float yb
+
+ cdef float pxa
+ cdef float pya
+ cdef float pxb
+ cdef float pyb
+
+ cdef float radius_a
+ cdef float radius_b
+
+ xa = a.x
+ xb = b.x
+ ya = a.y
+ yb = b.y
+
+ radius_a = getattr3(a, 'radius', 0.5)
+ radius_b = getattr3(b, 'radius', 0.5)
+
+ pxa = getattr3(a, 'px', xa)
+ pya = getattr3(a, 'py', ya)
+ pxb = getattr3(b, 'px', xb)
+ pyb = getattr3(b, 'py', yb)
+
+ return _collides(xa, xb, ya, yb, pxa, pxb, pya, pyb, radius_a, radius_b)
+
+def collides_all(a, others):
+ """Filter the second argument to those that collide with the first.
+
+ This is equivalent to filter(lambda o: collides(a, o), others),
+ but is much faster when the compiled extension is available (which
+ it is currently).
+
+ """
+ cdef float xa
+ cdef float xb
+ cdef float ya
+ cdef float yb
+
+ cdef float pxa
+ cdef float pya
+ cdef float pxb
+ cdef float pyb
+
+ cdef float radius_a
+ cdef float radius_b
+
+ cdef list bs
+ cdef int length
+
+ cdef list colliding
+
+ cdef int coll
+
+ colliding = []
+
+ xa = a.x
+ ya = a.y
+ radius_a = getattr3(a, 'radius', 0.5)
+ pxa = getattr3(a, 'px', xa)
+ pya = getattr3(a, 'py', ya)
+
+ bs = list(others)
+ length = len(bs)
+
+ for 0 <= i < length:
+ b = others[i]
+ xb = b.x
+ yb = b.y
+ radius_b = getattr3(b, 'radius', 0.5)
+ pxb = getattr3(b, 'px', xb)
+ pyb = getattr3(b, 'py', yb)
+
+ if _collides(xa, xb, ya, yb, pxa, pxb, pya, pyb, radius_a, radius_b):
+ colliding.append(b)
+ return colliding
shmups. It provides a routine to check whether two moving circles
collided during the past frame.
+If Pyrex was available when installing, this will used optimized
+versions of the functions.
+
Basic Usage:
from bulletml.collision import collides
Usually, you'll want to use the 'collides' method instead, but
this one can be useful for just checking to see if the player has
entered an area or hit a stationary oject.
+
+ (This function is unoptimized.)
"""
dx = a.x - b.x
px, py - not required, defaults to x, y, previous frame position
radius - not required, defaults to 0.5
+ (This function is unoptimized.)
+
"""
# Current locations.
xa = a.x
# dist_sq < radius_sq
return dist_x * dist_x + dist_y * dist_y <= radius * radius
+
+def collides_all(a, others):
+ """Filter the second argument to those that collide with the first.
+
+ This is equivalent to filter(lambda o: collides(a, o), others),
+ but is much faster when the compiled extension is available (which
+ it is not currently).
+
+ """
+ return filter(lambda o: collides(a, o), others)
+
+try:
+ from bulletml._collision import collides, overlaps, collides_all
+except ImportError:
+ pass
import shutil
import sys
-from distutils.core import setup, Command
+from distutils.core import setup, Command, Extension
+from Pyrex.Distutils import build_ext
+
from distutils.command.clean import clean as distutils_clean
from distutils.command.sdist import sdist as distutils_sdist
raise SystemExit("Test failures are listed above.")
if __name__ == "__main__":
- setup(cmdclass=dict(
- clean=clean, test=test_cmd, coverage=coverage_cmd, sdist=sdist),
+ setup(cmdclass=dict(clean=clean, test=test_cmd, coverage=coverage_cmd,
+ sdist=sdist, build_ext=build_ext),
name="python-bulletml", version="1",
url="http://code.google.com/p/python-bulletml/",
description="parse and run BulletML scripts",
packages=["bulletml"],
data_files=glob.glob("examples/*/*.xml") + ["examples/template.xml"],
scripts=["bulletml-runner", "bulletml-to-bulletyaml"],
+ ext_modules=[
+ Extension('bulletml._collision', ['bulletml/_collision.pyx'])],
long_description="""\
BulletML is the Bullet Markup Language. BulletML can describe the
barrage of bullets in shooting games. (For example Progear, Psyvariar,
projects / python-bulletml.git / commitdiff