我想使用 glClear 和 glClearColor 用包括 alpha 透明度的颜色填充帧缓冲区。但是，当绑定到渲染到屏幕的纹理时，帧缓冲区始终呈现为不透明。
我希望渲染到帧缓冲区的所有内容都保持其透明度。我只是想改变背景。
请看下面的代码：
def create_texture(surface):
surface.texture = glGenTextures(1)
glMatrixMode(GL_MODELVIEW)
glLoadIdentity() #Loads model matrix
glBindTexture(GL_TEXTURE_2D, surface.texture) #Binds the current 2D texture to the texture to be drawn
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR) #Required to be set for maping the pixel data
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR) #Similar as above
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, surface.surface_size[0], surface.surface_size[1], 0, GL_RGBA,GL_UNSIGNED_BYTE, surface.data) #Put surface pixel data into texture
if surface.data == None:
setup_framebuffer(surface)
c = [float(sc)/255.0 for sc in surface.colour] #Divide colours by 255 because OpenGL uses 0-1
if surface.background_alpha:
c[3] = float(surface.background_alpha)/255.0
glClearColor(*c)
glClear(GL_COLOR_BUFFER_BIT)
end_framebuffer()
Surface.texture_ready.append(surface)
def setup_framebuffer(surface):
#Create texture if not done already
if surface.texture == None:
create_texture(surface)
#Render child to parent
if surface.frame_buffer == None:
surface.frame_buffer = glGenFramebuffersEXT(1)
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, surface.frame_buffer)
glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_2D, surface.texture, 0)
glPushAttrib(GL_VIEWPORT_BIT)
glViewport(0,0,surface._scale[0],surface._scale[1])
glMatrixMode(GL_PROJECTION)
glLoadIdentity() #Load the projection matrix
gluOrtho2D(0,surface._scale[0],0,surface._scale[1])
def end_framebuffer():
glPopAttrib()
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0)
glMatrixMode(GL_PROJECTION)
glLoadIdentity() #Load the projection matrix
gluOrtho2D(0,1280,720,0) #Set an orthorgraphic view
surface.background_alpha 应该是帧缓冲区背景的透明度。这是我的初始化代码：
def __init__(self,title,game_size,on_exit = sys.exit):
self.keys = [False] * 323
self.events = []
pygame.font.init()
pygame.mixer.init()
self.title = title
self.game_size = game_size
self.first_screen = (1280,720) #Take 120 pixels from the height because the menu bar, window bar and dock takes space
glutInit(sys.argv)
glutInitWindowPosition(0,0)
glutInitWindowSize(*game_size)
glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGBA)
glutGameModeString("1280x720:32@60") #720 HD
glutCreateWindow(title)
glutSetIconTitle(title)
self.callbacks()
self.game_gap = (0,0)
self.on_exit = on_exit
self.mod_key = 1024 if sys.platform == "darwin" else 64
Surface.__init__(self,game_size)
self.screen_change = True
self.frames = [time.time()]
self.fps = 60
self.last_time = 0
self.fade_surface = Surface([1280,720])
def callbacks(self):
glutReshapeFunc(self.reshaped)
glutKeyboardFunc(self.keydown)
glutKeyboardUpFunc(self.keyup)
glutSpecialFunc(self.specialdown)
glutSpecialUpFunc(self.specialup)
glutDisplayFunc(self.game_loop)
glutIdleFunc(self.game_loop)
glutMouseFunc(self.mouse_func)
glutPassiveMotionFunc(self.mouse_move)
glViewport(0,0,self.first_screen[0],self.first_screen[1]) #Creates the viewport which is mapped to the window
glEnable(GL_BLEND) #Enable alpha blending
glEnable(GL_TEXTURE_2D) #Enable 2D Textures
glEnable(GL_POLYGON_SMOOTH) #Enable antialiased polygons
glHint(GL_POLYGON_SMOOTH_HINT, GL_NICEST)
glHint(GL_LINE_SMOOTH_HINT, GL_NICEST)
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA)
glMatrixMode(GL_PROJECTION)
glLoadIdentity() #Load the projection matrix
gluOrtho2D(0,1280,720,0) #Set an orthorgraphic view
代码有点混乱，因为我做了很多调整以使事情正常工作，但我还没有正确整理所有内容。
如果有人能帮助我，我非常感谢。
