Fixed a number of bugs caused by using abs() on floats and long ints. Added support for selectively inverting bits of the stepping port. Debugged, optimized and cleaned up timing code for the step-pulses.

gcode.c

@@ -118,7 +118,7 @@ void gc_init() {
 }
 
 inline float to_millimeters(double value) {
-  return(gc.inches_mode ? value * INCHES_PER_MM : value);
+  return(gc.inches_mode ? (value * INCHES_PER_MM) : value);
 }
 
 
@@ -139,7 +139,7 @@ uint8_t gc_execute_line(char *line) {
   
   double p = 0, r = 0;
   int int_value;
-
+  
   clear_vector(target);
   clear_vector(offset);