June 2018 Update

Task/Brownian-tree/Julia/brownian-tree.julia

@@ -1,43 +1,42 @@
-using Color, Images, FixedPointNumbers
+using Images, FileIO
 
-const W = 512
-const W0 = W>>1
-const H = 512
-const H0 = H>>1
-const N = iceil(1.0*W*H)
-const SIDESTICK = false
+function main(h::Integer, w::Integer, side::Bool=false)
+    W0 = w >> 1
+    H0 = h >> 1
+    @inline function motecolor(x::Integer, y::Integer)
+        h = clamp(180 * (atan2(y - H0, x - W0) / π + 1.0), 0.0, 360.0)
+        return HSV(h, 0.5, 0.5)
+    end
 
-
-function motecolor(x::Int, y::Int)
-    h = clamp(180*(atan2(y-H0, x-W0)/pi + 1.0), 0.0, 360.0)
-    return HSV(h, 0.5, 0.5)
-end
-
-img = Image(zeros(RGB{Ufixed8}, H, W))
-img["x", W0, "y", H0] = RGB(1, 1, 1)
-isfree = trues(W, H)
-isfree[W0, H0] = false
-for i in 1:N
-    x = rand(1:W)
-    y = rand(1:H)
-    isfree[x, y] || continue
-    mc = motecolor(x, y)
-    for j in 1:10^3
-        xp = x + rand(-1:1)
-        yp = y + rand(-1:1)
-        iscontained = 0 < xp <= W && 0 < yp <= H
-        if  iscontained && isfree[xp, yp]
-            x = xp
-            y = yp
-            continue
-        else
-            if SIDESTICK || (iscontained && !isfree[xp, yp])
-                isfree[x, y] = false
-                img["x", x, "y", y] = mc
+    img = zeros(RGB{N0f8}, h, w)
+    img[H0, W0] = RGB(1, 1, 1)
+    free = trues(h, w)
+    free[H0, W0] = false
+    for i in eachindex(img)
+        x = rand(1:h)
+        y = rand(1:w)
+        free[x, y] || continue
+        mc = motecolor(x, y)
+        for j in 1:1000
+            xp = x + rand(-1:1)
+            yp = y + rand(-1:1)
+            contained = checkbounds(Bool, img, xp, yp)
+            if contained && free[xp, yp]
+                x, y = xp, yp
+                continue
+            else
+                if side || (contained && !free[xp, yp])
+                    free[x, y] = false
+                    img[x, y] = mc
+                end
+                break
             end
-            break
         end
     end
+    return img
 end
 
-imwrite(img, "brownian_tree.png")
+imgnoside = main(256, 256)
+imgwtside = main(256, 256, true)
+save("data/browniantree_noside.jpg", imgnoside)
+save("data/browniantree_wtside.jpg", imgwtside)