actionscript 3 - Hit test with line -

so i'm making platformer style game , trying make hit test line if makes sense. right have object moves around , whenever you're moving right, if lower right or upper right side hit world stop moving. same thing set left. works if "world" movieclip small , doesn't hit of points can go right through it. need make solid line between points , have hittest that?

else if (keyisdown(keyboard.right))         {             //dude.gotoandstop("right");             //obj.scalex = 1;             (i = 0; i<speedx; i++)             {                 obj.x++;                 dude.ball.rotation++;                 if (status == "ground")                 {                     dude.height+= 0.05;                     dude.width += 0.05;                  }                     if (world.hittestpoint(obj.x + obj.width/8 - obj.width/2, obj.y - obj.height/4,true) || world.hittestpoint(obj.x + obj.width/2,obj.y - obj.height + obj.height/4,true)) //this dictates points hit, trying make test hit solid line between 2 points.                     //if (world.hittestobject(dude.hitd))                     {                          dude.ball.rotation--;       obj.x--;                     break;                 }             }         }         dude.gotoandstop(1);      } 

line code tried adding

else if (keyisdown(keyboard.right))         {             //dude.gotoandstop("right");             //obj.scalex = 1;             (i = 0; i<speedx; i++)             {                 obj.x++;                 dude.ball.rotation++;                 myshape.graphics.moveto(obj.x + obj.width/8 - obj.width/2,obj.y - obj.height/4);                  myshape.graphics.lineto(obj.x + obj.width/2, obj.y - obj.height + obj.height/4);                 // number in obj.y-4 affects climbing ability                 if (status == "ground")                 {                     //dude.height+= 0.05;                     //dude.width += 0.05;                 }                   if (obj.hittestobject(myshape))                 {                     dude.ball.rotation--;                     obj.x--;                     break;                 }             }         }         dude.gotoandstop(1);      } 

as far can understand, trying make platformer game player controls ball. need circular collision detection, @ least going right , left.

while implementing kind of program, on parts executed often, collision detection, should looking shortcuts.

i can suggest couple approaches;

1. shortcut case can having invisible box shape smaller ball, , making collision detection it. sure, reduce visual quality; e.g. when approach low edge can fit object's bottom left, object crash early, without visually touching block.

2. or ignore performance , increase number of points around circle. can write algorithm find positions on outer edge of circle spacing, , check if of them colliding. way collision detection cannot miss small objects.

3. however, there's better approach. can implement two-level collision detection. first have now, , second invisible box same height of ball, , smaller in width enough it's edges fall behind primary detection points. in way, secondary detection not miss anything, work when primary detection fails catch between or below.