GLScatterPlotItem.py 文件源码

def initializeGL(self):

        ## Generate texture for rendering points
        w = 64
        def fn(x,y):
            r = ((x-w/2.)**2 + (y-w/2.)**2) ** 0.5
            return 255 * (w/2. - np.clip(r, w/2.-1.0, w/2.))
        pData = np.empty((w, w, 4))
        pData[:] = 255
        pData[:,:,3] = np.fromfunction(fn, pData.shape[:2])
        #print pData.shape, pData.min(), pData.max()
        pData = pData.astype(np.ubyte)

        if getattr(self, "pointTexture", None) is None:
            self.pointTexture = glGenTextures(1)
        glActiveTexture(GL_TEXTURE0)
        glEnable(GL_TEXTURE_2D)
        glBindTexture(GL_TEXTURE_2D, self.pointTexture)
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, pData.shape[0], pData.shape[1], 0, GL_RGBA, GL_UNSIGNED_BYTE, pData)

        self.shader = shaders.getShaderProgram('pointSprite')

    #def getVBO(self, name):
        #if name not in self.vbo:
            #self.vbo[name] = vbo.VBO(getattr(self, name).astype('f'))
        #return self.vbo[name]

    #def setupGLState(self):
        #"""Prepare OpenGL state for drawing. This function is called immediately before painting."""
        ##glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA)  ## requires z-sorting to render properly.
        #glBlendFunc(GL_SRC_ALPHA, GL_ONE)
        #glEnable( GL_BLEND )
        #glEnable( GL_ALPHA_TEST )
        #glDisable( GL_DEPTH_TEST )

        ##glEnable( GL_POINT_SMOOTH )

        ##glHint(GL_POINT_SMOOTH_HINT, GL_NICEST)
        ##glPointParameterfv(GL_POINT_DISTANCE_ATTENUATION, (0, 0, -1e-3))
        ##glPointParameterfv(GL_POINT_SIZE_MAX, (65500,))
        ##glPointParameterfv(GL_POINT_SIZE_MIN, (0,))