用Python和Pygame写游戏-从入门到精通（实战一：涂鸦画板）

import pygame
from pygame.locals import *
import sys
import math

class Brush():
def __init__(self, screen):
self.screen = screen
self.color = (0, 0, 0)
self.size = 1
self.drawing = False
self.last_pos = None
# if style is True, normal solid brush
# if style is False, png brush
self.style = False
# load brush style png
self.brush = pygame.image.load("brush.png").convert_alpha()
# set the current brush depends on size
self.brush_now = self.brush.subsurface((0, 0), (1, 1))

def start_draw(self, pos):
self.drawing = True
self.last_pos = pos

def end_draw(self):
self.drawing = False

def set_brush_style(self, style):
print("* set brush style to", style)
self.style = style

def get_brush_style(self):
return self.style

def get_current_brush(self):
return self.brush_now

def set_size(self, size):
if size < 0.5: size = 0.5
elif size > 50: size = 50
print("* set brush size to", size)
self.size = size
self.brush_now = self.brush.subsurface((0,0), (size*2, size*2))

def get_size(self):
return self.size

def set_color(self, color):
self.color = color
for i in range(self.brush.get_width()):
for j in range(self.brush.get_height()):
self.brush.set_at((i, j),
color + (self.brush.get_at((i, j)).a,))
def get_color(self):
return self.color

def draw(self, pos):
if self.drawing:
#            pygame.draw.circle(self.screen, self.color, pos, self.size)
#            pygame.draw.line(self.screen, self.color, self.last_pos, pos, self.size*2)
for p in self._get_points(pos):
if self.style == False:
pygame.draw.circle(self.screen, self.color, p, int(self.size))
else:
self.screen.blit(self.brush_now, p)

self.last_pos = pos

def _get_points(self, pos):
""" Get all points between last_point ~ now_point. """
points = [ (self.last_pos[0], self.last_pos[1]) ]
len_x = pos[0] - self.last_pos[0]
len_y = pos[1] - self.last_pos[1]
length = math.sqrt(len_x ** 2 + len_y ** 2)
step_x = len_x / length
step_y = len_y / length
for i in range(int(length)):
points.append(
(points[-1][0] + step_x, points[-1][1] + step_y))
points = map(lambda x:(int(0.5+x[0]), int(0.5+x[1])), points)
# return light-weight, uniq list
return list(set(points))

class Menu():
def __init__(self, screen):
self.screen = screen
self.brush  = None
self.colors = [
(0xff, 0x00, 0xff), (0x80, 0x00, 0x80),
(0x00, 0x00, 0xff), (0x00, 0x00, 0x80),
(0x00, 0xff, 0xff), (0x00, 0x80, 0x80),
(0x00, 0xff, 0x00), (0x00, 0x80, 0x00),
(0xff, 0xff, 0x00), (0x80, 0x80, 0x00),
(0xff, 0x00, 0x00), (0x80, 0x00
a1e7
, 0x00),
(0xc0, 0xc0, 0xc0), (0xff, 0xff, 0xff),
(0x00, 0x00, 0x00), (0x80, 0x80, 0x80),
]
self.colors_rect = []
for (i, rgb) in enumerate(self.colors):
rect = pygame.Rect(10 + i % 2 * 32, 254 + i / 2 * 32, 32, 32)
self.colors_rect.append(rect)

self.pens = [
pygame.image.load("pen1.png").convert_alpha(),
pygame.image.load("pen2.png").convert_alpha()
]
self.pens_rect = []
for (i, img) in enumerate(self.pens):
rect = pygame.Rect(10, 10 + i * 64, 64, 64)
self.pens_rect.append(rect)

self.sizes = [
pygame.image.load("big.png").convert_alpha(),
pygame.image.load("small.png").convert_alpha()
]
self.sizes_rect = []
for (i, img) in enumerate(self.sizes):
rect = pygame.Rect(10 + i * 32, 138, 32, 32)
self.sizes_rect.append(rect)

def set_brush(self, brush):
self.brush = brush

def draw(self):
# draw pen style button
for (i, img) in enumerate(self.pens):
self.screen.blit(img, self.pens_rect[i].topleft)
# draw < > buttons
for (i, img) in enumerate(self.sizes):
self.screen.blit(img, self.sizes_rect[i].topleft)
# draw current pen / color
self.screen.fill((255, 255, 255), (10, 180, 64, 64))
pygame.draw.rect(self.screen, (0, 0, 0), (10, 180, 64, 64), 1)
size = self.brush.get_size()
x = 10 + 32
y = 180 + 32
if self.brush.get_brush_style():
x = x - size
y = y - size
self.screen.blit(self.brush.get_current_brush(), (x, y))
else:
pygame.draw.circle(self.screen,
self.brush.get_color(), (x, y), int(size))
# draw colors panel
for (i, rgb) in enumerate(self.colors):
pygame.draw.rect(self.screen, rgb, self.colors_rect[i])

def click_button(self, pos):
# pen buttons
for (i, rect) in enumerate(self.pens_rect):
if rect.collidepoint(pos):
self.brush.set_brush_style(bool(i))
return True
# size buttons
for (i, rect) in enumerate(self.sizes_rect):
if rect.collidepoint(pos):
if i:   # i == 1, size down
self.brush.set_size(self.brush.get_size() - 0.5)
else:
self.brush.set_size(self.brush.get_size() + 0.5)
return True
# color buttons
for (i, rect) in enumerate(self.colors_rect):
if rect.collidepoint(pos):
self.brush.set_color(self.colors[i])
return True
return False

class Painter():
def __init__(self):
self.screen = pygame.display.set_mode((800, 600))
pygame.display.set_caption("Painter")
self.clock = pygame.time.Clock()
self.brush = Brush(self.screen)
self.menu  = Menu(self.screen)
self.menu.set_brush(self.brush)

def run(self):
self.screen.fill((255, 255, 255))
close = False
while True:
# max fps limit
self.clock.tick(30)
for event in pygame.event.get():
if event.type == QUIT:
pygame.quit()
exit
close = True
elif event.type == KEYDOWN:
# press esc to clear screen
if event.key == K_ESCAPE:
self.screen.fill((255, 255, 255))

elif event.type == MOUSEBUTTONDOWN:
# <= 74, coarse judge here can save much time
if ((event.pos)[0] <= 74 and
self.menu.click_button(event.pos)):
# if not click on a functional button, do drawing
pass
else:
self.brush.start_draw(event.pos)

elif event.type == MOUSEMOTION:
self.brush.draw(event.pos)

elif event.type == MOUSEBUTTONUP:
self.brush.end_draw()

if close:
break

self.menu.draw()
pygame.display.update()

if __name__ == '__main__':
app = Painter()
app.run()