在主循环之前,您需要创建一个分辨率小于窗口分辨率的Framebuffer Object。还可以参考Framebuffer Object扩展示例。
fb_size = [50, 50]
depth_buffer_obj = glGenRenderbuffers(1)
glBindRenderbuffer(GL_RENDERBUFFER, depth_buffer_obj)
glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT24, fb_size[0], fb_size[1])
color_buffer_obj = glGenRenderbuffers(1)
glBindRenderbuffer(GL_RENDERBUFFER, color_buffer_obj)
glRenderbufferStorage(GL_RENDERBUFFER, GL_RGBA, fb_size[0], fb_size[1])
fb_obj = glGenFramebuffers(1)
glBindFramebuffer(GL_FRAMEBUFFER, fb_obj)
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, depth_buffer_obj)
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, color_buffer_obj)
status = glCheckFramebufferStatus(GL_FRAMEBUFFER)
if status != GL_FRAMEBUFFER_COMPLETE:
print("incomplete framebuffer object")
glBindFramebuffer(GL_FRAMEBUFFER, 0)
将视口大小设置为帧缓冲区的大小,清除帧缓冲区并将立方体渲染到帧缓冲区:
while True:
for event in pygame.event.get():
if event.type == pygame.QUIT:
pygame.quit()
quit()
glBindFramebuffer(GL_FRAMEBUFFER, fb_obj)
glViewport (0, 0, fb_size[0], fb_size[1])
glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT)
glRotatef(1, 3, 1, 1)
Cube()
将视口大小设置为窗口大小,并使用GL_NEAREST
过滤器参数的glBlitFramebuffer
函数,从命名的帧缓冲对象复制像素到默认帧缓存。请注意,无需清除默认帧缓存,因为它会被完全覆盖:
while True:
glBindFramebuffer(GL_READ_FRAMEBUFFER, fb_obj)
glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0)
glViewport(0, 0, 500, 500)
glBlitFramebuffer(
0, 0, fb_size[0], fb_size[1],
0, 0, 500, 500,
GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT,
GL_NEAREST)
pygame.display.flip()
pygame.time.wait(10)
请注意,在这一点上,
fb_obj
已经绑定为读和写,因此不必执行
glBindFramebuffer(GL_READ_FRAMEBUFFER, fb_obj)
。
如果您的系统不支持
glBlitFramebuffer
,则可以创建一个带有纹理附加到其颜色平面的帧缓冲。
fb_size = [50, 50]
depth_buffer_obj = glGenRenderbuffers(1)
glBindRenderbuffer(GL_RENDERBUFFER, depth_buffer_obj)
glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT24, fb_size[0], fb_size[1])
#color_buffer_obj = glGenRenderbuffers(1)
#glBindRenderbuffer(GL_RENDERBUFFER, color_buffer_obj)
#glRenderbufferStorage(GL_RENDERBUFFER, GL_RGBA, fb_size[0], fb_size[1])
color_tex_obj = glGenTextures(1)
glBindTexture(GL_TEXTURE_2D, color_tex_obj)
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT)
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT)
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST)
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST)
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, fb_size[0], fb_size[1], 0, GL_RGBA, GL_UNSIGNED_BYTE, None)
fb_obj = glGenFramebuffers(1)
glBindFramebuffer(GL_FRAMEBUFFER, fb_obj)
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, depth_buffer_obj)
#glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, color_buffer_obj)
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, color_tex_obj, 0)
status = glCheckFramebufferStatus(GL_FRAMEBUFFER)
if status != GL_FRAMEBUFFER_COMPLETE:
print("incomplete framebuffer object")
glBindFramebuffer(GL_FRAMEBUFFER, 0)
glBindTexture(GL_TEXTURE_2D, 0)
将内容渲染到帧缓冲区并在整个窗口上绘制一个四边形纹理到默认帧缓冲区:
while True:
for event in pygame.event.get():
if event.type == pygame.QUIT:
pygame.quit()
quit()
glBindFramebuffer(GL_FRAMEBUFFER, fb_obj)
glViewport (0, 0, fb_size[0], fb_size[1])
glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT)
glRotatef(1, 3, 1, 1)
gluSphere(gluNewQuadric( ), 2.0, 32, 32)
glBindFramebuffer(GL_FRAMEBUFFER, 0)
glViewport(0, 0, 500, 500)
glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT)
glMatrixMode(GL_PROJECTION)
glPushMatrix()
glLoadIdentity()
glMatrixMode(GL_MODELVIEW)
glPushMatrix()
glLoadIdentity()
glEnable(GL_TEXTURE_2D)
glBindTexture(GL_TEXTURE_2D, color_tex_obj)
glBegin(GL_TRIANGLE_FAN)
glTexCoord2f(0,0)
glVertex2f(-1,-1)
glTexCoord2f(1,0)
glVertex2f(1,-1)
glTexCoord2f(1,1)
glVertex2f(1,1)
glTexCoord2f(0,1)
glVertex2f(-1,1)
glEnd()
glDisable(GL_TEXTURE_2D)
glMatrixMode(GL_PROJECTION)
glPopMatrix()
glMatrixMode(GL_MODELVIEW)
glPopMatrix()
pygame.display.flip()
pygame.time.wait(10)
GL_VERSION
,它显示"GL_VERSION(7938)
"。我找不到一种将我得到的数字转换为这些网站所谈论的版本的方法。你知道我正在使用哪个版本吗? - Harry AnthonyGL_VERSION
是一个枚举类型,你需要将其传递给glGetString()
函数。 - genpfault