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space-invaders: add some color

release
chris.double 2006-03-29 11:14:56 +00:00
parent c6bcdd774d
commit 231be04a4c
1 changed files with 17 additions and 1 deletions
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18
contrib/space-invaders/space-invaders.factor
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@ -187,6 +187,8 @@ M: invaders-gadget draw-gadget* ( gadget -- )
: black { 0 0 0 } ;
: white { 255 255 255 } ;
: green { 0 255 0 } ;
: red { 255 0 0 } ;
: addr>xy ( addr -- point )
#! Convert video RAM address to base X Y value. point is a {x y}.
@ -198,12 +200,26 @@ M: invaders-gadget draw-gadget* ( gadget -- )
#! point is a {x y}. color is a {r g b}.
swap bitmap get set-bitmap-pixel ;
: within ( n a b - bool )
#! n >= a and n <= b
rot tuck swap <= >r swap >= r> and ;
: get-point-color ( point -- color )
#! Return the color to use for the given x/y position.
first2
{
{ [ dup 184 238 within pick 0 223 within and ] [ 2drop green ] }
{ [ dup 240 247 within pick 16 133 within and ] [ 2drop green ] }
{ [ dup 247 215 - 247 184 - within pick 0 223 within and ] [ 2drop red ] }
{ [ t ] [ 2drop white ] }
} cond ;
: plot-bitmap-bits ( point byte bit -- )
#! point is a {x y}.
[ first2 ] dipd
dup swapd -1 * shift 1 bitand 0 =
[ - 2array ] dip
[ black ] [ white ] if
[ black ] [ dup get-point-color ] if
plot-bitmap-pixel ;
: do-bitmap-update ( value addr -- )