GLViewWidget.py 文件源码

def renderToArray(self, size, format=GL_BGRA, type=GL_UNSIGNED_BYTE, textureSize=1024, padding=256):
        w,h = map(int, size)

        self.makeCurrent()
        tex = None
        fb = None
        try:
            output = np.empty((w, h, 4), dtype=np.ubyte)
            fb = glfbo.glGenFramebuffers(1)
            glfbo.glBindFramebuffer(glfbo.GL_FRAMEBUFFER, fb )

            glEnable(GL_TEXTURE_2D)
            tex = glGenTextures(1)
            glBindTexture(GL_TEXTURE_2D, tex)
            texwidth = textureSize
            data = np.zeros((texwidth,texwidth,4), dtype=np.ubyte)

            ## Test texture dimensions first
            glTexImage2D(GL_PROXY_TEXTURE_2D, 0, GL_RGBA, texwidth, texwidth, 0, GL_RGBA, GL_UNSIGNED_BYTE, None)
            if glGetTexLevelParameteriv(GL_PROXY_TEXTURE_2D, 0, GL_TEXTURE_WIDTH) == 0:
                raise Exception("OpenGL failed to create 2D texture (%dx%d); too large for this hardware." % shape[:2])
            ## create teture
            glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, texwidth, texwidth, 0, GL_RGBA, GL_UNSIGNED_BYTE, data.transpose((1,0,2)))

            self.opts['viewport'] = (0, 0, w, h)  # viewport is the complete image; this ensures that paintGL(region=...) 
                                                  # is interpreted correctly.
            p2 = 2 * padding
            for x in range(-padding, w-padding, texwidth-p2):
                for y in range(-padding, h-padding, texwidth-p2):
                    x2 = min(x+texwidth, w+padding)
                    y2 = min(y+texwidth, h+padding)
                    w2 = x2-x
                    h2 = y2-y

                    ## render to texture
                    glfbo.glFramebufferTexture2D(glfbo.GL_FRAMEBUFFER, glfbo.GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, tex, 0)

                    self.paintGL(region=(x, h-y-h2, w2, h2), viewport=(0, 0, w2, h2))  # only render sub-region

                    ## read texture back to array
                    data = glGetTexImage(GL_TEXTURE_2D, 0, format, type)
                    data = np.fromstring(data, dtype=np.ubyte).reshape(texwidth,texwidth,4).transpose(1,0,2)[:, ::-1]
                    output[x+padding:x2-padding, y+padding:y2-padding] = data[padding:w2-padding, -(h2-padding):-padding]

        finally:
            self.opts['viewport'] = None
            glfbo.glBindFramebuffer(glfbo.GL_FRAMEBUFFER, 0)
            glBindTexture(GL_TEXTURE_2D, 0)
            if tex is not None:
                glDeleteTextures([tex])
            if fb is not None:
                glfbo.glDeleteFramebuffers([fb])

        return output