ship mover, no constraint yet

autobrake_test.p8

@@ -40,11 +40,97 @@ function mknew(tt, more)
  end
 end
 
-function init()
+function _init()
+ pal(1,129,1)
+ the_ship = ship.new()
+ slomo = 0
+ sloc = 0
+ reroll()
+end
+
+function reroll()
+ the_ship:reroll()
 end
 
 function _update60()
+ if (btnp(4)) reroll()
+ slomo += btnp(2) and -1 or btnp(3) and 1 or 0
+ slomo = (slomo < 0) and 0 or (slomo > 60) and 60 or slomo
+ sloc += 1
+ if sloc > slomo then
+  the_ship:update()
+  sloc=0
+ end
 end
 
 function _draw()
+ cls(1)
+ the_ship:draw()
 end
+
+-->8
+-- ship
+
+ship = {
+ maxspd=4,
+ thrust=0.25,
+ drag=0.0625,
+ y=32,
+}
+mknew(ship)
+
+function ship:reroll()
+ self.x=rnd(128)
+ self.dx=rnd(2*self.maxspd)-self.maxspd
+end
+
+function ship:draw()
+ if self.x < -7 then
+  spr(2, 0, self.y-7)
+  spr(2, 0, self.y+8)
+ elseif self.x > 127 then
+  spr(2, 120, self.y-7, 1, 1, true)
+  spr(2, 120, self.y+8, 1, 1, true)
+ else
+  spr(1,self.x,self.y)
+ end
+end
+
+function ship:update()
+ local t = btn(0) and -1 or btn(1) and 1 or 0
+ t *= self.thrust
+ t = constrain(self, t)
+ local s,lim=self.dx+t,self.maxspd
+ local sg = sgn(s)
+ s -= sg*self.drag
+ if (sgn(s) != sg) s=0
+ if (abs(s)>lim) s=sg*lim
+
+ self.x += s
+ self.dx = s
+ self:add_sparks(t)
+end
+
+function ship:add_sparks(t)
+end
+
+-->8
+-- constraints
+
+function constrain(s, want)
+ return want
+end
+
+-->8
+-- fx
+
+-- todo: spark ring buffer
+
+__gfx__
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+00000000675555758008888000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
+00000000675000750800000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
+00000000067777500080000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
+00000000005555000008000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000