ref: 75e473f518dc4a649638bf69fbfa1c48a16a7388
dir: pico/examples
; hget http://9front.org/img/9bind.png | png -t9 > /tmp/bind ; hget http://9front.org/img/ninefront.bit > /tmp/nine ; pico # combining two images -> r nine /tmp/nine -> r bind /tmp/bind -> bind + (y > 100 ? nine[x,y-100,z] : 0) # extract red and alpha channels -> z == 3 ? bind : z == 0 ? bind : 0 # halve color intensity -> z < 3 ? bind/2 : Z # set black pixels' alpha to 0 -> bind[x,y,0] + bind[x,y,1] + bind[x,y,2] == 0 && z == 3 ? 0 : bind # set black pixels to cyan bind[x,y,0] + bind[x,y,1] + bind[x,y,2] == 0 ? z == 0 ? 0 : z == 1 ? Z : z == 2 ? Z : bind : bind # doug demo -> lerp = z != 3 ? (x < X/3 ? 0 : x > 2*X/3 ? 255 : (x-X/3)*Z/(X/3)) : Z -> rbind = bind[X-x,y,z] -> z != 3 ? (bind*lerp+rbind*(Z-lerp))/Z : Z -> z != 3 ? (rbind*lerp+bind*(Z-lerp))/Z : Z