def update(self):
# install pixel shader for adjusting texture contrast
gl.glUseProgram(self.contrast_program)
gl.glUniform1i(self.texture_loc, 0)
gl.glUniform1f(self.contrast_loc, self.contrast)
def draw(self):
super(ShaderTextureStimulus, self).draw()
# uninstall shader program
gl.glUseProgram(0)
