I was already helped graciously in figuring out how to translate a point in a plane along its local axes at a given orientation, but now need a bit of the inverse of the equation.
I need to know the (x, y) offset of a point at a given orientation and velocity. For example if a point is moving at an angle of 45 degrees (or radians, take your pick), what would its x and y coordinate be increased/decreased by? The variables I can think of would be: x1 (point's current x coordinate) y1 (point's current y coordinate) a (point's angle/orientation in degrees/radians) v (point's velocity) x2 (x coordinate offset of point's new position) y2 (y coordinate offset of point's new position) The calculation would take x1, y1 a and v as inputs and produce x2 and y2 as offsets (x1 + x2, y1 + y2 = point's new position). There really should be a list of basic things like this for graphics programmers. I've searched for years and found practically nothing. Weird, considering this has probably been done thousands of times since the days of DOS. :/ In case anyone's wondering why I need this, the equation will allow particles and projectiles to follow logical paths. Currently they're bound to local coordinates and ignore player orientation. Digging, shooting arrows, throwing objects, etc. can't work without it. -- Kevin Fishburne Eight Virtues www: http://sales.eightvirtues.com e-mail: sa...@eightvirtues.com phone: (770) 853-6271 ------------------------------------------------------------------------------ vRanger cuts backup time in half-while increasing security. With the market-leading solution for virtual backup and recovery, you get blazing-fast, flexible, and affordable data protection. Download your free trial now. http://p.sf.net/sfu/quest-d2dcopy1 _______________________________________________ Gambas-user mailing list Gambas-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/gambas-user
