CONSTANT: PLAYER-START-LOCATION float-4{ 0.5 0.51 0.5 1.0 }
CONSTANT: VELOCITY-MODIFIER-NORMAL float-4{ 1.0 1.0 1.0 0.0 }
CONSTANT: VELOCITY-MODIFIER-FAST float-4{ 2.0 1.0 2.0 0.0 }
+CONSTANT: BOUNCE float-4{ 1.0 -0.2 1.0 1.0 }
CONSTANT: PLAYER-HEIGHT 1/256.
CONSTANT: GRAVITY float-4{ 0.0 -1/4096. 0.0 0.0 }
CONSTANT: JUMP 1/1024.
indices [ pixels nth COMPONENT-SCALE v. 255.0 / ] map
first4 pixel-mantissa bilerp ;
-: collide ( segment location -- location' )
- [ [ first ] [ third ] bi 2array terrain-height-at PLAYER-HEIGHT + ]
- [ [ 1 ] 2dip [ max ] with change-nth ]
- [ ] tri ;
+: (collide) ( segment location -- location' )
+ [
+ { 0 2 3 3 } vshuffle terrain-height-at PLAYER-HEIGHT +
+ -1/0. swap -1/0. -1/0. float-4-boa
+ ] keep vmax ;
+
+:: collide ( world player -- )
+ world terrain-segment>> :> segment
+ player location>> :> location
+ segment location (collide) :> location'
+
+ location location' = not [
+ player
+ location' >>location
+ [ BOUNCE v* ] change-velocity
+ drop
+ ] when ;
: scaled-velocity ( player -- velocity )
[ velocity>> ] [ velocity-modifier>> ] bi v* ;
: tick-player-forward ( world player -- )
2dup save-history
[ apply-friction apply-gravity ] change-velocity
- dup scaled-velocity [ v+ [ terrain-segment>> ] dip collide ] curry with change-location
- drop ;
+ dup scaled-velocity [ v+ ] curry change-location
+ collide ;
: tick-player ( world player -- )
dup reverse-time>>