使用Python編寫簡單的畫圖板程序的示例教程
從這次開始,我會由簡單到困難(其實(shí)也不會困難到哪里去)講幾個(gè)例程,每一個(gè)例程都是我自己寫(或者修改,那樣的話我會提供原始出處)的,都具有一定的操作性和娛樂性。例程中匯盡量覆蓋到以前所講的pygame中方方面面,如果看到哪一步不明白,那就再回去復(fù)習(xí)復(fù)習(xí),基本沒有人會看一遍什么都記住什么都掌握的,重復(fù)是學(xué)習(xí)之母,實(shí)踐是掌握一門技藝的最好手段!
這次就先從一個(gè)最簡單的程序開始,說實(shí)話有些太簡單我都不好意思拿出手了,不過從簡單的開始,容易建立自信培養(yǎng)興趣。興趣是學(xué)習(xí)之母嘛。我們這次做一個(gè)畫板,類似Windows里自帶的畫板,還記不記得第一次接觸電腦用畫板時(shí)的驚嘆?現(xiàn)在想起來其實(shí)那個(gè)真的非常簡陋,不過我們的比那個(gè)還要樸素,因?yàn)榇蛩阋黄v完,就不追加很多功能了,等你把這一次講解的都理解了,很容易可以自己給它增加新的機(jī)能。沒準(zhǔn),你就開發(fā)出一個(gè)非常牛X的畫圖工具擊敗了Photoshop,然后日進(jìn)斗金名垂千古(眾:喂,別做夢了?。?/p>
功能樣式
做之前總要有個(gè)數(shù),我們的程序做出來會是個(gè)什么樣子。所謂從頂?shù)降谆蛘邚牡椎巾斏兜模劬筒谎芯苛?,這個(gè)小程序隨你怎么弄了,而且我們主要是來熟悉pygame,高級的軟件設(shè)計(jì)方法一概不談~
因?yàn)槭浅u畫圖板,也就是鼠標(biāo)按住了能在上面涂涂畫畫就是了,選區(qū)、放大鏡、滴管功能啥的就統(tǒng)統(tǒng)不要了。畫筆的話,基本的鉛筆畫筆總是要的,也可以考慮加一個(gè)刷子畫筆,這樣有一點(diǎn)變化;然后顏色應(yīng)該是要的,否則太過單調(diào)了,不過調(diào)色板啥的就暫時(shí)免了,提供幾個(gè)候選色就好了;然后橡皮……橡皮不就是白色的畫筆么?免了免了!還有啥?似乎夠了。。。 OK,開始吧!
框架
pygame程序的框架都是差不多的,考慮到我們這個(gè)程序的實(shí)際作用,大概建立這樣的一個(gè)代碼架子就可以了。
import pygame
from pygame.locals import *
class Brush():
def __init__(self):
pass
class Painter():
def __init__(self):
self.screen = pygame.display.set_mode((800, 600))
pygame.display.set_caption("Painter")
self.clock = pygame.time.Clock()
def run(self):
self.screen.fill((255, 255, 255))
while True:
# max fps limit
self.clock.tick(30)
for event in pygame.event.get():
if event.type == QUIT:
return
elif event.type == KEYDOWN:
pass
elif event.type == MOUSEBUTTONDOWN:
pass
elif event.type == MOUSEMOTION:
pass
elif event.type == MOUSEBUTTONUP:
pass
pygame.display.update()
if __name__ == '__main__':
app = Painter()
app.run()
import pygame
from pygame.locals import *
class Brush():
def __init__(self):
pass
class Painter():
def __init__(self):
self.screen = pygame.display.set_mode((800, 600))
pygame.display.set_caption("Painter")
self.clock = pygame.time.Clock()
def run(self):
self.screen.fill((255, 255, 255))
while True:
# max fps limit
self.clock.tick(30)
for event in pygame.event.get():
if event.type == QUIT:
return
elif event.type == KEYDOWN:
pass
elif event.type == MOUSEBUTTONDOWN:
pass
elif event.type == MOUSEMOTION:
pass
elif event.type == MOUSEBUTTONUP:
pass
pygame.display.update()
if __name__ == '__main__':
app = Painter()
app.run()
這個(gè)非常簡單,準(zhǔn)備好畫板類,畫筆類,暫時(shí)還都是空的,其實(shí)也就是做了一些pygame的初始化工作。如果這樣還不能讀懂的話,您需要把前面22篇從頭再看看,有幾句話不懂就看幾遍:)
這里只有一點(diǎn)要注意一下,我們把幀率控制在了30,沒有人希望在畫畫的時(shí)候,CPU風(fēng)扇狂轉(zhuǎn)的。而且只是畫板,沒有自動運(yùn)動的物體,純粹的交互驅(qū)動,我們也不需要很高的刷新率。
第一次的繪圖代碼
按住鼠標(biāo)然后在上面移動就畫東西,我們很容易可以想到這個(gè)流程:
按下左鍵 → 繪制flag開
移動鼠標(biāo) → flag開的時(shí)候,在移動坐標(biāo)上留下痕跡
放開左鍵 → 繪制flag關(guān)
按下左鍵 → 繪制flag開
移動鼠標(biāo) → flag開的時(shí)候,在移動坐標(biāo)上留下痕跡
放開左鍵 → 繪制flag關(guān)
立刻試一試吧:
class Brush():
def __init__(self, screen):
self.screen = screen
self.color = (0, 0, 0)
self.size = 1
self.drawing = False
def start_draw(self):
self.drawing = True
def end_draw(self):
self.drawing = False
def draw(self, pos):
if self.drawing:
pygame.draw.circle(self.screen, self.color, pos, self.size)
class Painter():
def __init__(self):
#*#*#*#*#
self.brush = Brush(self.screen)
def run(self):
#*#*#*#*#
elif event.type == KEYDOWN:
# press esc to clear screen
if event.key == K_ESCAPE:
self.screen.fill((255, 255, 255))
elif event.type == MOUSEBUTTONDOWN:
self.brush.start_draw()
elif event.type == MOUSEMOTION:
self.brush.draw(event.pos)
elif event.type == MOUSEBUTTONUP:
self.brush.end_draw()
class Brush():
def __init__(self, screen):
self.screen = screen
self.color = (0, 0, 0)
self.size = 1
self.drawing = False
def start_draw(self):
self.drawing = True
def end_draw(self):
self.drawing = False
def draw(self, pos):
if self.drawing:
pygame.draw.circle(self.screen, self.color, pos, self.size)
class Painter():
def __init__(self):
#*#*#*#*#
self.brush = Brush(self.screen)
def run(self):
#*#*#*#*#
elif event.type == KEYDOWN:
# press esc to clear screen
if event.key == K_ESCAPE:
self.screen.fill((255, 255, 255))
elif event.type == MOUSEBUTTONDOWN:
self.brush.start_draw()
elif event.type == MOUSEMOTION:
self.brush.draw(event.pos)
elif event.type == MOUSEBUTTONUP:
self.brush.end_draw()
框架中有的代碼我就不貼了,用#*#*#*#*#代替,最后會給出完整代碼的。
這里主要是給Brush類增加了一些功能,也就是上面我們提到的流程想對應(yīng)的功能。留下痕跡,我們是使用了在坐標(biāo)上畫圓的方法,這也是最容易想到的方法。這樣的效果好不好呢?我們試一試:

哦,太糟糕了,再劣質(zhì)的鉛筆也不會留下這樣斷斷續(xù)續(xù)的筆跡。上面是當(dāng)我們鼠標(biāo)移動的快一些的時(shí)候,點(diǎn)之間的間距很大;下面是移動慢一些的時(shí)候,勉勉強(qiáng)強(qiáng)顯得比較連續(xù)。從這里我們也可以看到pygame事件響應(yīng)的頻度(這個(gè)距離和上面設(shè)置的最大幀率有關(guān))。
怎么辦?要修改幀率讓pygame平滑的反應(yīng)么?不,那樣做得不償失,換一個(gè)角度思考,如果有間隙,我們讓pygame把這個(gè)間隙連接起來不好么?
第二次的繪圖代碼
思路還是很簡單,當(dāng)移動的時(shí)候,Brush在上一次和這一次的點(diǎn)之間連一條線就好了:
class Brush():
def __init__(self, screen):
self.screen = screen
self.color = (0, 0, 0)
self.size = 1
self.drawing = False
self.last_pos = None # <--
def start_draw(self, pos):
self.drawing = True
self.last_pos = pos # <--
def end_draw(self):
self.drawing = False
def draw(self, pos):
if self.drawing:
pygame.draw.line(self.screen, self.color,
self.last_pos, pos, self.size * 2)
self.last_pos = pos

在__init__和start_draw中各加了一句,用來存儲上一個(gè)點(diǎn)的位置,然后draw也由剛剛的話圓變成畫線,效果如何?我們來試試。嗯,好多了,如果你動作能溫柔一些的話,線條已經(jīng)很圓潤了,至少沒有斷斷續(xù)續(xù)的存在了。
滿足了么?我希望你的回答是“NO”,為什么,如果你劃線很快的話,你就能明顯看出棱角來,就好像左圖上半部分,還是能看出是由幾個(gè)線段組合的。只有永不滿足,我們才能不停進(jìn)步。
不過對我們這個(gè)例程而言,差不多了,一般人在真正畫東西的時(shí)候,也不會動那么快的:)
那么這個(gè)就是我們最終的繪圖機(jī)制了么?回頭看看我們的樣式,好用還需要加一個(gè)筆刷……所謂筆刷,不僅僅是很粗,而且是由很多細(xì)小的毛組成,畫出來的線是給人一種一縷一縷的感覺,用這個(gè)方法可以實(shí)現(xiàn)么?好像非常非常的困難。。。孜孜不倦的我們再次進(jìn)入了沉思……
這個(gè)時(shí)候,如果沒有頭緒,就得借鑒一下前輩的經(jīng)驗(yàn)了??纯慈思沂侨绾螌?shí)現(xiàn)的?

如果你的Photoshop不錯(cuò),應(yīng)該知道它里面復(fù)雜的筆刷設(shè)定,而Photoshop畫出來的筆畫,并不是真正一直線的,而是由無數(shù)細(xì)小的點(diǎn)組成的,這些點(diǎn)之間的間距是如此的密,以至于我們誤會它是一直線……所以說,我們還得回到第一種方法上,把它發(fā)揚(yáng)光大一下~ 這沒有什么不好意思的,放棄第二種方法并不意味著我們是多么的愚蠢,而是說明我們從自己身上又學(xué)到了很多!
(公元前1800年)醫(yī)生:來,試試吃點(diǎn)兒這種草根,感謝偉大的部落守護(hù)神賜與我們神藥!
(公元900年)醫(yī)生:別再吃那種草根,簡直是野蠻不開化不尊重上帝,這是一篇祈禱詞,每天虔誠地向上帝祈禱一次,不久就會治愈你的疾病。
(公元1650年)醫(yī)生:祈禱?!封建迷信!??!來,只要喝下這種藥水,什么病都能治好!
(公元1960年)醫(yī)生:什么藥水?早就不用了!別喝那騙人的”萬靈藥”,還是這種藥片的療效快!
(公元1995年)醫(yī)生:哪個(gè)庸醫(yī)給你開的處方?那種藥片吃半瓶也抵不上這一粒,來來來,試試科技新成果—抗生素
(公元2003年)醫(yī)生:據(jù)最新科學(xué)研究,抗生素副作用太強(qiáng),畢竟是人造的東西呀……來,試試吃點(diǎn)兒這種草根!早在公元前1800年,文獻(xiàn)就有記載了。
返璞歸真,大抵如此了。
第三次的繪圖代碼
這次我們考慮的更多,希望在點(diǎn)與點(diǎn)之間充滿我們的筆畫,很自然的我們就需要一個(gè)循環(huán)來做這樣的事情。我們的筆畫有兩種,普通的實(shí)心和刷子,實(shí)心的話,用circle來畫也不失為一個(gè)好主意;刷子的話,我們可能需要一個(gè)刷子的圖案來填充了。
下面是我們新的Brush類:
class Brush():
def __init__(self, screen):
self.screen = screen
self.color = (0, 0, 0)
self.size = 1
self.drawing = False
self.last_pos = None
self.space = 1
# 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 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 draw(self, pos):
if self.drawing:
for p in self._get_points(pos):
# draw eveypoint between them
if self.style == False:
pygame.draw.circle(self.screen,
self.color, p, 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 xrange(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 Brush():
def __init__(self, screen):
self.screen = screen
self.color = (0, 0, 0)
self.size = 1
self.drawing = False
self.last_pos = None
self.space = 1
# 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 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 draw(self, pos):
if self.drawing:
for p in self._get_points(pos):
# draw eveypoint between them
if self.style == False:
pygame.draw.circle(self.screen,
self.color, p, 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 xrange(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))
我們增加了幾個(gè)方法,_get_points()返回上一個(gè)點(diǎn)到現(xiàn)在點(diǎn)之間所有的點(diǎn)(這話聽著真別扭),draw根據(jù)這些點(diǎn)填充。
同時(shí)我們把get_size()、set_size()也加上了,用來設(shè)定當(dāng)前筆刷的大小。
而變化最大的,則是set_style()和get_style(),我們現(xiàn)在載入一個(gè)PNG圖片作為筆刷的樣式,當(dāng)style==True的時(shí)候,draw不再使用circle填充,而是使用這個(gè)PNG樣式,當(dāng)然,這個(gè)樣式大小也是應(yīng)該可調(diào)的,所有我們在set_size()中,會根據(jù)size大小實(shí)時(shí)的調(diào)整PNG筆刷。
當(dāng)然,我們得在主循環(huán)中調(diào)用set方法,才能讓這些東西工作起來~ 過一會兒再講。再回顧下我們的樣式,還有什么?顏色……我們馬上把顏色設(shè)置代碼也加進(jìn)去吧,太簡單了!我這里就先偷偷懶了~
控制代碼
到現(xiàn)在,我們已經(jīng)完成了繪圖部分的所有功能了。現(xiàn)在已經(jīng)可以在屏幕上自由發(fā)揮了,但是筆刷的顏色和大小好像不能改啊……我們有這樣的接口你卻不調(diào)用,浪費(fèi)了。
趁熱打鐵趕快把我們這個(gè)畫板完成吧~

現(xiàn)在實(shí)際寫的時(shí)候才發(fā)現(xiàn),因?yàn)槲覀冊O(shè)置了顏色需要對刷子也有效,所以實(shí)際上set_color方法還有一點(diǎn)點(diǎn)收尾工作需要做:
def set_color(self, color):
self.color = color
for i in xrange(self.brush.get_width()):
for j in xrange(self.brush.get_height()):
self.brush.set_at((i, j),
color + (self.brush.get_at((i, j)).a,))
def set_color(self, color):
self.color = color
for i in xrange(self.brush.get_width()):
for j in xrange(self.brush.get_height()):
self.brush.set_at((i, j),
color + (self.brush.get_at((i, j)).a,))
也就是在設(shè)定color的時(shí)候,順便把筆刷的顏色也改了,但是要保留原來的alpha值,其實(shí)也很簡單就是了……
按鈕菜單部分
上圖可以看到,按鈕部分分別為鉛筆、毛筆、尺寸大小、(當(dāng)前樣式)、顏色選擇者幾個(gè)組成。我們只以筆刷選擇為例講解一下,其他的都是類似的。
# 初始化部分
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)
# 繪制部分
for (i, img) in enumerate(self.pens):
self.screen.blit(img, self.pens_rect[i].topleft)
# 點(diǎn)擊判斷部分
for (i, rect) in enumerate(self.pens_rect):
if rect.collidepoint(pos):
self.brush.set_brush_style(bool(i))
return True
# 初始化部分
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)
# 繪制部分
for (i, img) in enumerate(self.pens):
self.screen.blit(img, self.pens_rect[i].topleft)
# 點(diǎn)擊判斷部分
for (i, rect) in enumerate(self.pens_rect):
if rect.collidepoint(pos):
self.brush.set_brush_style(bool(i))
return True
這些代碼實(shí)際上是我這個(gè)例子最想給大家說明的地方,按鈕式我們從未接觸過的東西,然而游戲中按鈕的應(yīng)用我都不必說。
不過這代碼也都不困難,基本都是我們學(xué)過的東西,只不過變換了一下組合而已,我稍微說明一下:
初始化部分:讀入圖標(biāo),并給每個(gè)圖標(biāo)一個(gè)Rect
繪制部分: 根據(jù)圖表的Rect繪制圖表
點(diǎn)擊判斷部分:根據(jù)點(diǎn)擊的位置,依靠“碰撞”來判斷這個(gè)按鈕是否被點(diǎn)擊,若點(diǎn)擊了,則做相應(yīng)的操作(這里是設(shè)置樣式)后返回True。這里的collidepoint()是新內(nèi)容,也就是Rect的“碰撞”函數(shù),它接收一個(gè)坐標(biāo),如果在Rect內(nèi)部,就返回True,否則False。
好像也就如此,有了一定的知識積累后,新東西的學(xué)習(xí)也變得易如反掌了。
在這個(gè)代碼中,為了明晰,我把各個(gè)按鈕按照功能都分成了好幾組,在實(shí)際應(yīng)用中按鈕數(shù)量很多的時(shí)候可能并不合適,請自己斟酌。
完整代碼
OK,這就結(jié)束了~ 下面把整個(gè)代碼貼出來。不過,我是一邊寫代碼一遍寫文章,思路不是很連貫,而且python也好久不用了……如果有哪里寫的有問題(沒有就怪了),還請不吝指出!
import pygame
from pygame.locals import *
import math
# 2011/08/27 Version 1, first imported
class Brush():
def __init__(self, screen):
self.screen = screen
self.color = (0, 0, 0)
self.size = 1
self.drawing = False
self.last_pos = None
self.space = 1
# 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 > 32: size = 32
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 xrange(self.brush.get_width()):
for j in xrange(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:
for p in self._get_points(pos):
# draw eveypoint between them
if self.style == False:
pygame.draw.circle(self.screen, self.color, p, 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 xrange(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 integer point 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, 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), 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))
while True:
# max fps limit
self.clock.tick(30)
for event in pygame.event.get():
if event.type == QUIT:
return
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()
self.menu.draw()
pygame.display.update()
if __name__ == '__main__':
app = Painter()
app.run()
import pygame
from pygame.locals import *
import math
# 2011/08/27 Version 1, first imported
class Brush():
def __init__(self, screen):
self.screen = screen
self.color = (0, 0, 0)
self.size = 1
self.drawing = False
self.last_pos = None
self.space = 1
# 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 > 32: size = 32
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 xrange(self.brush.get_width()):
for j in xrange(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:
for p in self._get_points(pos):
# draw eveypoint between them
if self.style == False:
pygame.draw.circle(self.screen, self.color, p, 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 xrange(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 integer point 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, 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), 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))
while True:
# max fps limit
self.clock.tick(30)
for event in pygame.event.get():
if event.type == QUIT:
return
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()
self.menu.draw()
pygame.display.update()
if __name__ == '__main__':
app = Painter()
app.run()
200行左右,注釋也不是很多,因?yàn)樵谶@兩篇文章里都講了,有哪里不明白的請留言,我會根據(jù)實(shí)際情況再改改。
本次使用的資源文件打包
這次的pygame知識點(diǎn):
- 屏幕Surface和圖像Surface
- 圖像繪制和圖形繪制(是不是有人不明白“圖像”和“圖形”的區(qū)別?簡單的說,圖像指的是那些圖片文件,圖形指的是用命令畫出來形狀)
- 按鈕的實(shí)現(xiàn)(新內(nèi)容)
認(rèn)真的朋友一定發(fā)現(xiàn)了本次沒有涉及到動畫和聲音,畢竟這次只是簡單的例子,太復(fù)雜了不免讓人生畏。
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