Code follows, where "self.image" is a surface and "self.drawing_area" is a Rect showing the area to fill. "self.background_color" and "self.background_gradient" are two color tuples, eg. (0,255,255) for cyan.

``` x1 = self.drawing_area[0] x2 = x1 + self.drawing_area[2] a, b = self.background_color, self.background_gradient y1 = self.drawing_area[1] y2 = y1 + self.drawing_area[3] h = y2-y1 rate = (float((b[0]-a[0])/h), (float(b[1]-a[1])/h), (float(b[2]-a[2])/h) ) for line in range(y1,y2): color = (min(max(a[0]+(rate[0]*line),0),255), min(max(a[1]+(rate[1]*line),0),255), min(max(a[2]+(rate[2]*line),0),255) ) pygame.draw.line(self.image,color,(x1,line),(x2,line)) ```

Original code reworked into a function, adding control of gradient direction, and making the rect optional.

``` def fill_gradient(surface, color, gradient, rect=None, vertical=True, forward=True): """fill a surface with a gradient pattern Parameters: color -> starting color gradient -> final color rect -> area to fill; default is surface's rect vertical -> True=vertical; False=horizontal forward -> True=forward; False=reverse Pygame recipe: http://www.pygame.org/wiki/GradientCode """ if rect is None: rect = surface.get_rect() x1,x2 = rect.left, rect.right y1,y2 = rect.top, rect.bottom if vertical: h = y2-y1 else: h = x2-x1 if forward: a, b = color, gradient else: b, a = color, gradient rate = ( float(b[0]-a[0])/h, float(b[1]-a[1])/h, float(b[2]-a[2])/h ) fn_line = pygame.draw.line if vertical: for line in range(y1,y2): color = ( min(max(a[0]+(rate[0]*(line-y1)),0),255), min(max(a[1]+(rate[1]*(line-y1)),0),255), min(max(a[2]+(rate[2]*(line-y1)),0),255) ) fn_line(surface, color, (x1,line), (x2,line)) else: for col in range(x1,x2): color = ( min(max(a[0]+(rate[0]*(col-x1)),0),255), min(max(a[1]+(rate[1]*(col-x1)),0),255), min(max(a[2]+(rate[2]*(col-x1)),0),255) ) fn_line(surface, color, (col,y1), (col,y2)) ```