factor/extra/terrain/generation/generation.factor

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2.7 KiB
Factor

USING: accessors alien.data.map arrays byte-arrays combinators
combinators.smart fry grouping images kernel math
math.matrices.simd math.order math.vectors noise random
sequences math.vectors.simd typed ;
FROM: alien.c-types => float uchar ;
IN: terrain.generation
CONSTANT: terrain-segment-size { 512 512 }
CONSTANT: terrain-segment-size-vector float-4{ 512.0 512.0 1.0 1.0 }
CONSTANT: terrain-big-noise-scale float-4{ 0.002 0.002 0.002 0.002 }
CONSTANT: terrain-small-noise-scale float-4{ 0.05 0.05 0.05 0.05 }
TUPLE: terrain
{ big-noise-table byte-array }
{ small-noise-table byte-array }
{ tiny-noise-seed integer } ;
: <terrain> ( -- terrain )
<perlin-noise-table> <perlin-noise-table>
32 random-bits terrain boa ;
: seed-at ( seed at -- seed' )
first2 [ >integer ] bi@ [ + ] dip [ 32 random-bits + ] curry with-seed ;
: big-noise-segment ( terrain at -- bytes )
[ big-noise-table>> terrain-big-noise-scale scale-matrix4 ] dip
terrain-segment-size-vector v* translation-matrix4 m4.
terrain-segment-size perlin-noise-image bitmap>> ; inline
: small-noise-segment ( terrain at -- bytes )
[ small-noise-table>> terrain-small-noise-scale scale-matrix4 ] dip
terrain-segment-size-vector v* translation-matrix4 m4.
terrain-segment-size perlin-noise-image bitmap>> ; inline
: tiny-noise-segment ( terrain at -- bytes )
[ tiny-noise-seed>> ] dip seed-at
terrain-segment-size normal-noise-image bitmap>> ; inline
: padding ( terrain at -- padding )
2drop terrain-segment-size product 255 <repetition> >byte-array ; inline
TUPLE: segment image ;
: fold-rgba-planes ( r g b a -- rgba )
[ vmerge-transpose vmerge-transpose ]
data-map( uchar-16 uchar-16 uchar-16 uchar-16 -- uchar-16[4] ) ;
: <terrain-image> ( big small tiny padding -- image )
fold-rgba-planes
<image>
swap >>bitmap
RGBA >>component-order
ubyte-components >>component-type
terrain-segment-size >>dim ;
TYPED: terrain-segment ( terrain: terrain at: float-4 -- image )
{
[ big-noise-segment ]
[ small-noise-segment ]
[ tiny-noise-segment ]
[ padding ]
} 2cleave <terrain-image> ;
: 4max ( a b c d -- max )
max max max ; inline
: mipmap ( pixels quot: ( aa ab ba bb -- c ) -- pixels' )
[ [ 2 <groups> ] map 2 <groups> ] dip
'[ first2 [ [ first2 ] bi@ @ ] 2map ] map ; inline
: group-pixels ( bitmap dim -- scanlines )
[ 4 <groups> ] [ first <groups> ] bi* ;
: concat-pixels ( scanlines -- bitmap )
[ concat ] map concat ;
: segment-mipmap ( image -- image' )
[ clone ] [ bitmap>> ] [ dim>> ] tri
group-pixels [ 4max ] mipmap concat-pixels >>bitmap
[ 2 v/n ] change-dim ;