11 + //Remember x1,x2,y1,y2 are guint unsigned integers
12 + //substract a greater number from a lower is undefined
13 + //this guard that.
Good explanation. However please use correct English grammar.
// Remember that x1, x2, y1 and y2 are guint unsigned integers.
// Subtracting a greater number from a lower one is undefined.
// This guards against that.
14 + if ( x1 > x2)
18 + if ( y1 > y2)
Please use no space after the opening brace ie. "if (y1 > y2)".
11 + //Remember x1,x2,y1,y2 are guint unsigned integers
12 + //substract a greater number from a lower is undefined
13 + //this guard that.
Good explanation. However please use correct English grammar.
// Remember that x1, x2, y1 and y2 are guint unsigned integers.
// Subtracting a greater number from a lower one is undefined.
// This guards against that.
14 + if ( x1 > x2)
18 + if ( y1 > y2)
Please use no space after the opening brace ie. "if (y1 > y2)".
30 + if (fabsf (angle - dir_angle) < DEVIANCE || fabsf (angle - dir_angle + 2 *(float)(M_PI)) < DEVIANCE)
Please leave a space after the asterisk ie. "+ 2 * (float)(M_PI)".
Sorry to be nit picking. With these stylistic changes it'll be good to go!