Chapter 0 Exercises 8 and 9

notebooks/chapter_0.md

@@ -225,3 +225,30 @@ Of course in clojure we can't do that [^um-actually], so I took the approach of
 Click that reset button to see it regenerated!
 
 [^um-actually]: Well, technically we can using dynamic vars or an atom, but that's pretty nasty and should only be used as an escape hatch when necessary.
+
+
+## [Exercise 0.8: A Perlin Noise Technicolor](https://natureofcode.com/random/#exercise-08)
+
+```clojure
+^{::clerk/no-cache true ::clerk/viewer clerk/code}
+(slurp "src/noc/chapter_0_8e.cljs")
+(show-sketch :c0.8e)
+```
+
+
+## [Exercise 0.9: Perlin Noise Animation](https://natureofcode.com/random/#exercise-08)
+
+```clojure
+^{::clerk/no-cache true ::clerk/viewer clerk/code}
+(slurp "src/noc/chapter_0_9e.cljs")
+(show-sketch :c0.9e)
+```
+
+Well this one is pretty cool. The sliders control (in order from left to right):
+
+* Perlin noise `octaves`
+* Perlin noise octave `fallof`
+* Amount `xoff` is incremented by
+* Amount `yoff` is incremented by
+
+Finally there is a checkbox to enable animation using the 3rd dimension of the perlin noise.

src/noc/chapter_0_8e.cljs

@@ -0,0 +1,89 @@
+(ns noc.chapter-0-8e
+  (:require
+   [goog.string :as gstring]
+   [goog.string.format]
+   [quil.core :as q]))
+
+(def size [640 240])
+
+(defn init-state [_]
+  {:ui {:octaves {:type :slider
+                  :min 1 :max 20
+                  :step 1 :value 4}
+        :falloff {:type :slider
+                  :min 0 :max 0.5
+                  :step 0.01
+                  :label "test"
+                  :value 0}
+        :xoff-incr {:type :slider
+                    :min 0 :max 0.1
+                    :step 0.01
+                    :value 0.01}
+
+        :yoff-incr {:type :slider
+                    :min 0 :max 0.1
+                    :step 0.01
+                    :value 0.01}}})
+
+(defn setup! [{:keys [width height]}]
+  (q/noise-seed (rand-int (-> js/Number (.-MAX_SAFE_INTEGER))))
+  (q/background 255))
+
+(defn gen-noise-image [width height xoff-incr yoff-incr]
+  (let [rand-color (fn [t1 t2]
+                     (Math/floor (q/map-range (q/noise t1 t2) 0 1 0 255)))
+        img  (q/create-image width height)
+        roff 0
+        goff 10000
+        boff 100000
+        px (q/pixels img)
+        xoffs (take width (iterate #(+ % xoff-incr) 0.0))]
+    (doseq [[x xoff] (map-indexed vector xoffs)]
+      (let [yoffs (take height (iterate #(+ % yoff-incr) 0.0))]
+        (doseq [[y yoff] (map-indexed vector yoffs)]
+          (let [idx (* 4 (+ x (* y width)))
+                r  (rand-color (+ roff xoff) (+ roff yoff))
+                g  (rand-color (+ goff xoff) (+ goff yoff))
+                b  (rand-color (+ boff xoff) (+ boff yoff))]
+            (aset px idx r)
+            (aset px (+ 1 idx) g)
+            (aset px (+ 2 idx) b)
+            (aset px (+ 3 idx) 255)))))
+    (q/update-pixels img)
+    img))
+
+(defn tick [{:keys [old-octaves old-falloff old-yoff-incr old-xoff-incr width height] :as state}]
+  (let [octaves (-> state :ui :octaves :value)
+        falloff (-> state :ui :falloff :value)
+        xoff-incr (-> state :ui :xoff-incr :value)
+        yoff-incr (-> state :ui :yoff-incr :value)]
+    (if (or (not= octaves old-octaves)
+            (not= falloff old-falloff)
+            (not= yoff-incr old-yoff-incr)
+            (not= xoff-incr old-xoff-incr))
+      (do
+        (q/noise-detail octaves falloff)
+        (assoc state
+               :old-octaves octaves
+               :old-falloff falloff
+               :old-xoff-incr xoff-incr
+               :old-yoff-incr yoff-incr
+               :img (gen-noise-image width height xoff-incr yoff-incr)))
+      state)))
+
+(defn draw! [{:keys [ui img]}]
+  (let [octaves (-> ui :octaves :value)
+        falloff (-> ui :falloff :value)
+        xoff-incr (-> ui :xoff-incr :value)
+        yoff-incr (-> ui :yoff-incr :value)]
+
+    (when img
+      (q/image img 0 0))
+    (q/no-stroke)
+    (q/fill 255)
+    (q/rect 0 0 100 55)
+    (q/fill 0)
+    (q/text (gstring/format "octaves: %.2f" octaves) 10 20)
+    (q/text (gstring/format "falloff: %.2f" falloff) 10 30)
+    (q/text (gstring/format "xoff-incr: %.2f" xoff-incr) 10 40)
+    (q/text (gstring/format "yoff-incr: %.2f" yoff-incr) 10 50)))

src/noc/chapter_0_9e.cljs

@@ -0,0 +1,95 @@
+(ns noc.chapter-0-9e
+  (:require
+   [goog.string :as gstring]
+   [goog.string.format]
+   [quil.core :as q]))
+
+(def size [640 240])
+
+(defn init-state [_]
+  {:z 0.0
+   :ui {:octaves {:type :slider
+                  :min 1 :max 20
+                  :step 1 :value 4}
+        :falloff {:type :slider
+                  :min 0 :max 0.5
+                  :step 0.01
+                  :label "test"
+                  :value 0}
+        :xoff-incr {:type :slider
+                    :min 0 :max 0.1
+                    :step 0.01
+                    :value 0.01}
+
+        :yoff-incr {:type :slider
+                    :min 0 :max 0.1
+                    :step 0.01
+                    :value 0.01}
+        :animate {:type :checkbox :checked? false}}})
+
+(defn setup! [{:keys [width height]}]
+  (q/noise-seed (rand-int (-> js/Number (.-MAX_SAFE_INTEGER))))
+  (q/background 255))
+
+(defn gen-noise-image [width height xoff-incr yoff-incr z]
+  (let [rand-color (fn [t1 t2]
+                     (Math/floor (q/map-range (q/noise t1 t2 z) 0 1 0 255)))
+        img  (q/create-image width height)
+        roff 0
+        goff 10000
+        boff 100000
+        px (q/pixels img)
+        xoffs (take width (iterate #(+ % xoff-incr) 0.0))]
+    (doseq [[x xoff] (map-indexed vector xoffs)]
+      (let [yoffs (take height (iterate #(+ % yoff-incr) 0.0))]
+        (doseq [[y yoff] (map-indexed vector yoffs)]
+          (let [idx (* 4 (+ x (* y width)))
+                r  (rand-color (+ roff xoff) (+ roff yoff))
+                g  (rand-color (+ goff xoff) (+ goff yoff))
+                b  (rand-color (+ boff xoff) (+ boff yoff))]
+            (aset px idx r)
+            (aset px (+ 1 idx) g)
+            (aset px (+ 2 idx) b)
+            (aset px (+ 3 idx) 255)))))
+    (q/update-pixels img)
+    img))
+
+(defn tick [{:keys [old-octaves old-falloff old-yoff-incr old-xoff-incr width height z] :as state}]
+  (let [octaves (-> state :ui :octaves :value)
+        falloff (-> state :ui :falloff :value)
+        xoff-incr (-> state :ui :xoff-incr :value)
+        yoff-incr (-> state :ui :yoff-incr :value)
+        animate? (-> state :ui :animate :checked?)
+        z (+ 0.1 z)]
+    (if (or animate?
+            (not= octaves old-octaves)
+            (not= falloff old-falloff)
+            (not= yoff-incr old-yoff-incr)
+            (not= xoff-incr old-xoff-incr))
+      (do
+        (q/noise-detail octaves falloff)
+        (assoc state
+               :z z
+               :old-octaves octaves
+               :old-falloff falloff
+               :old-xoff-incr xoff-incr
+               :old-yoff-incr yoff-incr
+               :img (gen-noise-image width height xoff-incr yoff-incr z)))
+      state)))
+
+(defn draw! [{:keys [ui img]}]
+  (let [octaves (-> ui :octaves :value)
+        falloff (-> ui :falloff :value)
+        xoff-incr (-> ui :xoff-incr :value)
+        yoff-incr (-> ui :yoff-incr :value)]
+
+    (when img
+      (q/image img 0 0))
+    (q/no-stroke)
+    (q/fill 255)
+    (q/rect 0 0 100 55)
+    (q/fill 0)
+    (q/text (gstring/format "octaves: %.2f" octaves) 10 20)
+    (q/text (gstring/format "falloff: %.2f" falloff) 10 30)
+    (q/text (gstring/format "xoff-incr: %.2f" xoff-incr) 10 40)
+    (q/text (gstring/format "yoff-incr: %.2f" yoff-incr) 10 50)))

src/noc/sketch.cljs

@@ -15,7 +15,9 @@
             [noc.chapter-0-6e :as c0.6e]
             [noc.chapter-0-6 :as c0.6]
             [noc.chapter-0-7e :as c0.7e]
-            [noc.chapter-0-7 :as c0.7]))
+            [noc.chapter-0-7 :as c0.7]
+            [noc.chapter-0-8e :as c0.8e]
+            [noc.chapter-0-9e :as c0.9e]))
 
 (def sketches {:walker (sketch-> c0.1)
                :rand-dist (sketch-> c0.2)
@@ -28,7 +30,9 @@
                :c0.6e (sketch-> c0.6e)
                :c0.6 (sketch-> c0.6)
                :c0.7e (sketch-> c0.7e)
-               :c0.7 (sketch-> c0.7)})
+               :c0.7 (sketch-> c0.7)
+               :c0.8e (sketch-> c0.8e)
+               :c0.9e (sketch-> c0.9e)})
 
 (defn load-sketch [s]
   (when-let [sk (get sketches s)]