阴影投射Python的优化
我一直在为我正在做的一个小型RPG制作阴影投射器 我的问题是，当我在游戏中使用它时，它只是一种缓慢的方式，并导致可怕的延迟 请不要被邮件的长度吓坏了。这相当简单，但是您可以运行我包含的所有Bresenham算法的代码 原则如下： -使表面变黑 -定义具有位置和半径的光源。 -使用Bresenham圆算法获取由该位置和半径定义的圆圆周上的所有点。 -对于圆周上的每个点，使用Bresenham直线算法从光源位置绘制一条直线。 -然后在直线的各个点上迭代，检查它们是否与屏幕上显示的每个障碍物发生碰撞。 -如果没有碰撞，则以该点为中心绘制一个半径为10像素左右的白色圆圈。 -如果发生碰撞，则沿圆周移动到下一点。 -最后，在一个表面上使用所有白色圆圈对该表面进行blit，该表面的黑色透明度值为100，白色透明度值为100 到目前为止，我尝试了以下几点： 这确实减少了滞后： -将障碍物列表限制为屏幕上显示的障碍物列表 -考虑屏幕边缘作为障碍，以减少不可见区域的迭代。 -仅在圆周围的每3个点和沿直线的12个点上迭代。 这并没有改变什么： -使用从光源到范围或障碍物边缘的椭圆，而不是沿着直线的许多圆圈。问题是，我必须为每个椭圆重新绘制曲面，然后旋转整个地块 如果你对如何提高效率有任何建议，我很乐意在这里发表 布雷森汉姆线算法：阴影投射Python的优化,python,optimization,pygame,shadow,bresenham,Python,Optimization,Pygame,Shadow,Bresenham,我一直在为我正在做的一个小型RPG制作阴影投射器 我的问题是，当我在游戏中使用它时，它只是一种缓慢的方式，并导致可怕的延迟 请不要被邮件的长度吓坏了。这相当简单，但是您可以运行我包含的所有Bresenham算法的代码 原则如下： -使表面变黑 -定义具有位置和半径的光源。 -使用Bresenham圆算法获取由该位置和半径定义的圆圆周上的所有点。 -对于圆周上的每个点，使用Bresenham直线算法从光源位置绘制一条直线。 -然后在直线的各个点上迭代，检查它们是否与屏幕上显示的每个障碍物发生碰撞。
def get_line(start, end):
"""Bresenham's Line Algorithm
Produces a list of tuples from start and end
>>> points1 = get_line((0, 0), (3, 4))
>>> points2 = get_line((3, 4), (0, 0))
>>> assert(set(points1) == set(points2))
>>> print points1
[(0, 0), (1, 1), (1, 2), (2, 3), (3, 4)]
>>> print points2
[(3, 4), (2, 3), (1, 2), (1, 1), (0, 0)]
"""
# Setup initial conditions
x1, y1 = start
x2, y2 = end
dx = x2 - x1
dy = y2 - y1
# Determine how steep the line is
is_steep = abs(dy) > abs(dx)
# Rotate line
if is_steep:
x1, y1 = y1, x1
x2, y2 = y2, x2
# Swap start and end points if necessary and store swap state
swapped = False
if x1 > x2:
x1, x2 = x2, x1
y1, y2 = y2, y1
swapped = True
# Recalculate differentials
dx = x2 - x1
dy = y2 - y1
# Calculate error
error = int(dx / 2.0)
ystep = 1 if y1 < y2 else -1
# Iterate over bounding box generating points between start and end
y = y1
points = []
for x in range(x1, x2 + 1):
coord = (y, x) if is_steep else (x, y)
points.append(coord)
error -= abs(dy)
if error < 0:
y += ystep
error += dx
# Reverse the list if the coordinates were swapped
if swapped:
points.reverse()
return points
def shadow_gen(shadow_surf,source,cir_pt,obstacles):
line_points = get_line(source.pos,cir_pt)
for line_pt in line_points[0::12]:
for obs in obstacles:
pygame.draw.circle(shadow_surf, WHITE, line_pt, 20, 0) #radius to 5px and 0 to fill the circle
if obs.rect.collidepoint(line_pt) or pygame.Rect(0,0,500,500).collidepoint(line_pt) == False:
return
pygame.init()
screen = pygame.display.set_mode((500, 500))
bg = pygame.Surface((500,500))
bg.fill(pygame.color.Color('yellow'))
ob_a = Obstacle(75,80)
ls = Light_Source(75,75,300)
night_m = Night_Mask()
night_m.light_sources.extend([ls])
while True:
screen.fill(pygame.color.Color('black'))
for event in pygame.event.get():
if event.type == pygame.QUIT:
pygame.quit()
sys.exit()
ls.pos = pygame.mouse.get_pos()
night_m.apply_shadows([ob_a])
screen.blit(bg, (0, 0))
screen.blit(ob_a.surf,ob_a.rect)
screen.blit(night_m.surf, (0, 0))
pygame.display.flip()
import pygame
import sys
WHITE = (255,255,255)
'''FUNCTIONS'''
def get_line(start, end):
"""Bresenham's Line Algorithm
Produces a list of tuples from start and end
>>> points1 = get_line((0, 0), (3, 4))
>>> points2 = get_line((3, 4), (0, 0))
>>> assert(set(points1) == set(points2))
>>> print points1
[(0, 0), (1, 1), (1, 2), (2, 3), (3, 4)]
>>> print points2
[(3, 4), (2, 3), (1, 2), (1, 1), (0, 0)]
"""
# Setup initial conditions
x1, y1 = start
x2, y2 = end
dx = x2 - x1
dy = y2 - y1
# Determine how steep the line is
is_steep = abs(dy) > abs(dx)
# Rotate line
if is_steep:
x1, y1 = y1, x1
x2, y2 = y2, x2
# Swap start and end points if necessary and store swap state
swapped = False
if x1 > x2:
x1, x2 = x2, x1
y1, y2 = y2, y1
swapped = True
# Recalculate differentials
dx = x2 - x1
dy = y2 - y1
# Calculate error
error = int(dx / 2.0)
ystep = 1 if y1 < y2 else -1
# Iterate over bounding box generating points between start and end
y = y1
points = []
for x in range(x1, x2 + 1):
coord = (y, x) if is_steep else (x, y)
points.append(coord)
error -= abs(dy)
if error < 0:
y += ystep
error += dx
# Reverse the list if the coordinates were swapped
if swapped:
points.reverse()
return points
def get_circle((dx,dy),radius):
"Bresenham complete circle algorithm in Python"
# init vars
switch = 3 - (2 * radius)
points = set()
x = 0
y = radius
# first quarter/octant starts clockwise at 12 o'clock
while x <= y:
# first quarter first octant
points.add((x,-y))
# first quarter 2nd octant
points.add((y,-x))
# second quarter 3rd octant
points.add((y,x))
# second quarter 4.octant
points.add((x,y))
# third quarter 5.octant
points.add((-x,y))
# third quarter 6.octant
points.add((-y,x))
# fourth quarter 7.octant
points.add((-y,-x))
# fourth quarter 8.octant
points.add((-x,-y))
if switch < 0:
switch = switch + (4 * x) + 6
else:
switch = switch + (4 * (x - y)) + 10
y = y - 1
x = x + 1
offset_points = set()
for pt in points:
offset_points.add((pt[0]+dx,pt[1]+dy))
return offset_points
def shadow_gen(shadow_surf,source,cir_pt,obstacles):
line_points = get_line(source.pos,cir_pt)
for line_pt in line_points[0::12]:
for obs in obstacles:
pygame.draw.circle(shadow_surf, WHITE, line_pt, 20, 0) #radius to 5px and 0 to fill the circle
if obs.rect.collidepoint(line_pt) or pygame.Rect(0,0,500,500).collidepoint(line_pt) == False:
return
'''CLASSES'''
class Obstacle(object):
def __init__(self,x,y):
self.surf = pygame.Surface((150,150))
self.rect = pygame.Rect((x,y),(150,150))
self.surf.fill(pygame.color.Color('blue'))
class Light_Source(object):
def __init__(self,x,y,range_):
self.range = range_
self.pos = (x,y)
class Night_Mask(object):
def __init__(self):
self.surf = pygame.Surface((500,500)) #Screenwidth and height
self.alpha = 100
self.light_sources = []
'''setting initial alpha and colorkey'''
self.surf.set_colorkey(WHITE)
self.surf.set_alpha(self.alpha)
def apply_shadows(self, obstacles):
shadow_surf = pygame.Surface((500,500))
for source in self.light_sources:
circle_pts = list(get_circle(source.pos,source.range))
for cir_pt in circle_pts[0::3]:
shadow_gen(shadow_surf,source,cir_pt,obstacles)
self.surf.blit(shadow_surf, (0, 0))
'''MAIN GAME'''
pygame.init()
screen = pygame.display.set_mode((500, 500))
bg = pygame.Surface((500,500))
bg.fill(pygame.color.Color('yellow'))
ob_a = Obstacle(75,80)
ls = Light_Source(75,75,300)
night_m = Night_Mask()
night_m.light_sources.extend([ls])
while True:
screen.fill(pygame.color.Color('black'))
for event in pygame.event.get():
if event.type == pygame.QUIT:
pygame.quit()
sys.exit()
ls.pos = pygame.mouse.get_pos()
night_m.apply_shadows([ob_a])
screen.blit(bg, (0, 0))
screen.blit(ob_a.surf,ob_a.rect)
screen.blit(night_m.surf, (0, 0))
pygame.display.flip()
导入pygame
导入系统
白色=（255255）
“功能”
def get_线（开始、结束）：
“Bresenham直线算法
从开始和结束生成元组列表
>>>点1=获取线（（0,0）、（3,4））
>>>点S2=获取线（（3,4），（0,0））
>>>断言（集合（点s1）=集合（点s2））
>>>打印点1
[(0, 0), (1, 1), (1, 2), (2, 3), (3, 4)]
>>>打印点2
[(3, 4), (2, 3), (1, 2), (1, 1), (0, 0)]
"""
#设置初始条件
x1，y1=开始
x2，y2=结束
dx=x2-x1
dy=y2-y1
#确定这条线有多陡
是否陡峭=abs（dy）>abs（dx）
#旋转线
如果是陡峭的：
x1，y1=y1，x1
x2，y2=y2，x2
#如有必要，交换起点和终点，并存储交换状态
交换=错误
如果x1>x2：
x1，x2=x2，x1
y1，y2=y2，y1
交换=真
#重新计算差异
dx=x2-x1
dy=y2-y1
#计算误差
错误=int（dx/2.0）
如果y1夜间遮罩。应用阴影（自身、障碍物）
。这似乎是由于嵌套for循环需要经过大量的迭代
减少光源（x，y，range）
构造器中范围的值
通过减少上述方法的迭代次数来减少延迟，但视觉效果更差。我发现在将变量设置为超过~65-70后，fps开始真正下降
有一个Pygame图形库，可以很好地处理阴影
链接到页面：
从以下站点直接下载8.1.1版：
以下是网站上的库说明：
这是一个通用的图形库，可以轻松快速地创建复杂的效果，并且只需最少的代码。运行注释非常好的示例，每个示例都不到一页长（不包括注释），并学习如何制作阴影和抗锯齿等复杂效果
这是一张显示阴影示例的页面图像。
我下载并测试了这个库，它运行得非常好。我在Pygame1.9.2a0上测试了python 3.4
我相信这是解决您的问题的最简单的方法，也应该对您将来的项目有所帮助。我希望这能有所帮助。谢谢你的建议。我最终成功地让它工作了，但它的效率仍然远远低于您推荐的这个库。所以我会用它来代替：我很高兴我能帮上忙。
pygame.init()
screen = pygame.display.set_mode((500, 500))
bg = pygame.Surface((500,500))
bg.fill(pygame.color.Color('yellow'))
ob_a = Obstacle(75,80)
ls = Light_Source(75,75,300)
night_m = Night_Mask()
night_m.light_sources.extend([ls])
while True:
screen.fill(pygame.color.Color('black'))
for event in pygame.event.get():
if event.type == pygame.QUIT:
pygame.quit()
sys.exit()
ls.pos = pygame.mouse.get_pos()
night_m.apply_shadows([ob_a])
screen.blit(bg, (0, 0))
screen.blit(ob_a.surf,ob_a.rect)
screen.blit(night_m.surf, (0, 0))
pygame.display.flip()
import pygame
import sys
WHITE = (255,255,255)
'''FUNCTIONS'''
def get_line(start, end):
"""Bresenham's Line Algorithm
Produces a list of tuples from start and end
>>> points1 = get_line((0, 0), (3, 4))
>>> points2 = get_line((3, 4), (0, 0))
>>> assert(set(points1) == set(points2))
>>> print points1
[(0, 0), (1, 1), (1, 2), (2, 3), (3, 4)]
>>> print points2
[(3, 4), (2, 3), (1, 2), (1, 1), (0, 0)]
"""
# Setup initial conditions
x1, y1 = start
x2, y2 = end
dx = x2 - x1
dy = y2 - y1
# Determine how steep the line is
is_steep = abs(dy) > abs(dx)
# Rotate line
if is_steep:
x1, y1 = y1, x1
x2, y2 = y2, x2
# Swap start and end points if necessary and store swap state
swapped = False
if x1 > x2:
x1, x2 = x2, x1
y1, y2 = y2, y1
swapped = True
# Recalculate differentials
dx = x2 - x1
dy = y2 - y1
# Calculate error
error = int(dx / 2.0)
ystep = 1 if y1 < y2 else -1
# Iterate over bounding box generating points between start and end
y = y1
points = []
for x in range(x1, x2 + 1):
coord = (y, x) if is_steep else (x, y)
points.append(coord)
error -= abs(dy)
if error < 0:
y += ystep
error += dx
# Reverse the list if the coordinates were swapped
if swapped:
points.reverse()
return points
def get_circle((dx,dy),radius):
"Bresenham complete circle algorithm in Python"
# init vars
switch = 3 - (2 * radius)
points = set()
x = 0
y = radius
# first quarter/octant starts clockwise at 12 o'clock
while x <= y:
# first quarter first octant
points.add((x,-y))
# first quarter 2nd octant
points.add((y,-x))
# second quarter 3rd octant
points.add((y,x))
# second quarter 4.octant
points.add((x,y))
# third quarter 5.octant
points.add((-x,y))
# third quarter 6.octant
points.add((-y,x))
# fourth quarter 7.octant
points.add((-y,-x))
# fourth quarter 8.octant
points.add((-x,-y))
if switch < 0:
switch = switch + (4 * x) + 6
else:
switch = switch + (4 * (x - y)) + 10
y = y - 1
x = x + 1
offset_points = set()
for pt in points:
offset_points.add((pt[0]+dx,pt[1]+dy))
return offset_points
def shadow_gen(shadow_surf,source,cir_pt,obstacles):
line_points = get_line(source.pos,cir_pt)
for line_pt in line_points[0::12]:
for obs in obstacles:
pygame.draw.circle(shadow_surf, WHITE, line_pt, 20, 0) #radius to 5px and 0 to fill the circle
if obs.rect.collidepoint(line_pt) or pygame.Rect(0,0,500,500).collidepoint(line_pt) == False:
return
'''CLASSES'''
class Obstacle(object):
def __init__(self,x,y):
self.surf = pygame.Surface((150,150))
self.rect = pygame.Rect((x,y),(150,150))
self.surf.fill(pygame.color.Color('blue'))
class Light_Source(object):
def __init__(self,x,y,range_):
self.range = range_
self.pos = (x,y)
class Night_Mask(object):
def __init__(self):
self.surf = pygame.Surface((500,500)) #Screenwidth and height
self.alpha = 100
self.light_sources = []
'''setting initial alpha and colorkey'''
self.surf.set_colorkey(WHITE)
self.surf.set_alpha(self.alpha)
def apply_shadows(self, obstacles):
shadow_surf = pygame.Surface((500,500))
for source in self.light_sources:
circle_pts = list(get_circle(source.pos,source.range))
for cir_pt in circle_pts[0::3]:
shadow_gen(shadow_surf,source,cir_pt,obstacles)
self.surf.blit(shadow_surf, (0, 0))
'''MAIN GAME'''
pygame.init()
screen = pygame.display.set_mode((500, 500))
bg = pygame.Surface((500,500))
bg.fill(pygame.color.Color('yellow'))
ob_a = Obstacle(75,80)
ls = Light_Source(75,75,300)
night_m = Night_Mask()
night_m.light_sources.extend([ls])
while True:
screen.fill(pygame.color.Color('black'))
for event in pygame.event.get():
if event.type == pygame.QUIT:
pygame.quit()
sys.exit()
ls.pos = pygame.mouse.get_pos()
night_m.apply_shadows([ob_a])
screen.blit(bg, (0, 0))
screen.blit(ob_a.surf,ob_a.rect)
screen.blit(night_m.surf, (0, 0))
pygame.display.flip()