def update(self):
        """
        Generate the output from the matrix.
        """
        pixels = len(self.matrix)
        for x in range(self.width):
            for y in range(self.height):
                pixel = y * self.width * 3 + x * 3
                #TODO: sometimes the matrix is not as big as it should
                if pixel < pixels:
                    pygame.draw.circle(self.screen,
                                       (self.matrix[pixel], self.matrix[pixel + 1], self.matrix[pixel + 2]),
                                       (x * self.dotsize + self.dotsize / 2, y * self.dotsize + self.dotsize / 2), self.dotsize / 2, 0)
Generate the output from the matrix.