Initial data commit

Task/Xiaolin-Wus-line-algorithm/J/xiaolin-wus-line-algorithm-1.j

@@ -0,0 +1,25 @@
+load'gl2'
+coinsert'jgl2'
+
+drawpt=:4 :0"0 1
+   glrgb <.(-.x)*255 255 255
+   glpixel y
+)
+
+drawLine=:3 :0 NB. drawline x1,y1,x2,y2
+   pts=. 2 2$y
+   isreversed=. </ |d=. -~/pts
+   r=. |.^:isreversed"1
+   pts=. /:~ pts \:"1 |d
+   gradient=. %~/ (\:|)d
+
+   'x y'=. |:pts
+   xend=. <.0.5+ x
+   yend=. y + gradient* xend-x
+   xgap=. -.1|x+0.5
+
+   n=. i. >: -~/ xend
+   'xlist ylist'=. (n*/~1,gradient) + ({.xend),({.yend)
+   weights=. ((2&}.,~ xgap*2&{.)&.(_1&|.) (,.~-.) 1|ylist)
+   weights (drawpt r)"1 2 (,:+&0 1)"1 xlist,.<.ylist
+)

Task/Xiaolin-Wus-line-algorithm/J/xiaolin-wus-line-algorithm-2.j

@@ -0,0 +1,4 @@
+   wd'pc win closeok; xywh 0 0 300 200;cc g isigraph; pas 0 0; pshow;' NB. J6 or earlier
+   wd'pc win closeok; minwh 600 400;cc g isidraw flush; pshow;'        NB. J802 or later
+   glpaint glclear ''
+   glpaint drawLine 10 10 590 390