我目前正在用 pygame 编写一个类似 Snes 的 RPG。
在我的地图上，我有 4 层：
0：地形，没有碰撞（在 char 下）
1：在地形上没有碰撞（在 char 下）
2：碰撞对象（在 char 下）
3：在 char 对象上
我想为第二层中的每个图块创建一个矩形，以防止角色越过这些对象。有没有一种有效的方法可以在每次角色移动时不检查每个矩形？谢谢。
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2
pygame 为此提供了许多优化功能，例如Rect.collidelist：
collidelist()
测试列表中的一个矩形是否相交碰撞列表（列表）-> 索引
测试矩形是否与矩形序列中的任何一个碰撞。返回找到的第一个碰撞的索引。如果没有发现冲突，则返回 -1 的索引。
如果您仍然遇到性能问题，您可以使用QuadTree。
from pygame import Rect
class QuadTree(object):
"""An implementation of a quad-tree.
This QuadTree started life as a version of [1] but found a life of its own
when I realised it wasn't doing what I needed. It is intended for static
geometry, ie, items such as the landscape that don't move.
This implementation inserts items at the current level if they overlap all
4 sub-quadrants, otherwise it inserts them recursively into the one or two
sub-quadrants that they overlap.
Items being stored in the tree must be a pygame.Rect or have have a
.rect (pygame.Rect) attribute that is a pygame.Rect
...and they must be hashable.
Acknowledgements:
[1] http://mu.arete.cc/pcr/syntax/quadtree/1/quadtree.py
"""
def __init__(self, items, depth=8, bounding_rect=None):
"""Creates a quad-tree.
@param items:
A sequence of items to store in the quad-tree. Note that these
items must be a pygame.Rect or have a .rect attribute.
@param depth:
The maximum recursion depth.
@param bounding_rect:
The bounding rectangle of all of the items in the quad-tree. For
internal use only.
"""
# The sub-quadrants are empty to start with.
self.nw = self.ne = self.se = self.sw = None
# If we've reached the maximum depth then insert all items into this
# quadrant.
depth -= 1
if depth == 0 or not items:
self.items = items
return
# Find this quadrant's centre.
if bounding_rect:
bounding_rect = Rect( bounding_rect )
else:
# If there isn't a bounding rect, then calculate it from the items.
bounding_rect = Rect( items[0] )
for item in items[1:]:
bounding_rect.union_ip( item )
cx = self.cx = bounding_rect.centerx
cy = self.cy = bounding_rect.centery
self.items = []
nw_items = []
ne_items = []
se_items = []
sw_items = []
for item in items:
# Which of the sub-quadrants does the item overlap?
in_nw = item.rect.left <= cx and item.rect.top <= cy
in_sw = item.rect.left <= cx and item.rect.bottom >= cy
in_ne = item.rect.right >= cx and item.rect.top <= cy
in_se = item.rect.right >= cx and item.rect.bottom >= cy
# If it overlaps all 4 quadrants then insert it at the current
# depth, otherwise append it to a list to be inserted under every
# quadrant that it overlaps.
if in_nw and in_ne and in_se and in_sw:
self.items.append(item)
else:
if in_nw: nw_items.append(item)
if in_ne: ne_items.append(item)
if in_se: se_items.append(item)
if in_sw: sw_items.append(item)
# Create the sub-quadrants, recursively.
if nw_items:
self.nw = QuadTree(nw_items, depth, (bounding_rect.left, bounding_rect.top, cx, cy))
if ne_items:
self.ne = QuadTree(ne_items, depth, (cx, bounding_rect.top, bounding_rect.right, cy))
if se_items:
self.se = QuadTree(se_items, depth, (cx, cy, bounding_rect.right, bounding_rect.bottom))
if sw_items:
self.sw = QuadTree(sw_items, depth, (bounding_rect.left, cy, cx, bounding_rect.bottom))
def hit(self, rect):
"""Returns the items that overlap a bounding rectangle.
Returns the set of all items in the quad-tree that overlap with a
bounding rectangle.
@param rect:
The bounding rectangle being tested against the quad-tree. This
must possess left, top, right and bottom attributes.
"""
# Find the hits at the current level.
hits = set( [ self.items[n] for n in rect.collidelistall( self.items ) ] )
# Recursively check the lower quadrants.
if self.nw and rect.left <= self.cx and rect.top <= self.cy:
hits |= self.nw.hit(rect)
if self.sw and rect.left <= self.cx and rect.bottom >= self.cy:
hits |= self.sw.hit(rect)
if self.ne and rect.right >= self.cx and rect.top <= self.cy:
hits |= self.ne.hit(rect)
if self.se and rect.right >= self.cx and rect.bottom >= self.cy:
hits |= self.se.hit(rect)
return hits
与在简单循环中检查每个图块相比，这将大大提高性能。
于 2013-07-25T11:42:25.597 回答
1
您可以使用recs并检查它们是否像 Dominic Kexel 所说的那样发生碰撞，但是如果您的图形不完全是正方形并且碰撞检测需要完美，我建议使用sprite带有 pygame 掩码的 pygame 对象。可以根据 alpha 值（透明度）设置蒙版，并且非常容易处理：
class Entity(pygame.sprite.Sprite):
def __init__(self, image): #where image is a pygame image with that has had the convert_alpha() function used on it
self.image = image
self.rect = image.get_rect() #you can use a rect and a mask
self.mask = pygame.mask.from_surface(self.image) #creates a mask from the image ans assigns it to the sprite object
然后您可以使用rect属性轻松检查碰撞（您可以使用 rects 处理各种不同类型的碰撞），或者您可以使用遮罩检查像素完美碰撞。
任何这些都可以使用 pygames sprite 碰撞函数来完成，例如pygame.sprite.spritecollide()or pygame.sprite.collide_mask()+ 更多！
阅读：
http://www.pygame.org/docs/ref/sprite.html
于 2013-07-25T12:08:31.813 回答