[PyOpenGL-Users] DrawArrays for a bunch of (unconnected) lines

[Philippe S. <ph...@ph...>]

Hello,

I'm playing with opengl for a tiny chart ploting application,
and facing the following problem:

the line representing the data is displayed, but I cannot
get the horizontal and vertical grid to be displayed.

initialization:

        pygame.init()
        self.surface = pygame.display.set_mode((self.width, self.height), OPENGL|DOUBLEBUF)
        glClearColor(0.0, 0.0, 0.0, 0.0)
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
        glOrtho(0, 1, 0, 1, 0, 1)
        glEnableClientState(GL_VERTEX_ARRAY)
        glDisable(GL_LIGHTING)

data drawing loop:

        glColor(0.8, 0.8, 0.8, 0.0)
        glVertexPointerd(self.gridH)
        glDrawArrays(GL_LINES, 1, len(self.gridH))
        glVertexPointer(4, GL_DOUBLE, 0, self.gridV)
        glDrawArrays(GL_LINES, 1, len(self.gridV))
        glColor(0.65, 1.0, 1.0, 0.0)
        #glVertexPointer(2, GL_DOUBLE, 0, self.points)
        glVertexPointerd(self.points)
        glDrawArrays(GL_LINE_STRIP, 1, self.N/2)
        pygame.display.flip()

self.gridH and gridV are list of 4 elements tuple [(xa0, ya0, xa1, ya1), ...]
self.points is a simple list.

Also, if I replace glVertexPointerd(self.points) with the line just above it,
nothing is displayed.

I'm a newbie, someone can probably help me!

thanks.