From 3361c239d95058b67f826ab7210e6447f4c59cd8 Mon Sep 17 00:00:00 2001
From: Dan Frumin <dfrumin@cs.ru.nl>
Date: Sat, 28 Dec 2019 16:55:17 +0100
Subject: [PATCH] add a road effect

---
 outrun.rkt | 61 +++++++++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 49 insertions(+), 12 deletions(-)

diff --git a/outrun.rkt b/outrun.rkt
index ed548cf..a7e9295 100644
--- a/outrun.rkt
+++ b/outrun.rkt
@@ -16,7 +16,46 @@
                             #:specular 0.3
                             #:roughness 0.5))
 
+(define (road t)
+  (define i-range-start -10)
+  (define i-range-end 10)
+  (define j-range-start -2)
+  (define j-range-end 10)
+  (define (calculate-noise-fn f)
+    (lambda (i j)
+      (scale-number (f (scale-number i i-range-start i-range-end -1 1)
+                       (scale-number j j-range-start j-range-end -1 1)
+                       (scale-number t 0 9000 -1 1))
+                    -1 1
+                    0 1)))
+  (define calculate-noise (calculate-noise-fn perlin))
+  (define calculate-noise-simplex (calculate-noise-fn simplex))
+  (let* ([rgba-noise (lambda (i j)
+                       (let* ([r (calculate-noise i j)]
+                              [g (calculate-noise-simplex i j)]
+                              [b (calculate-noise-simplex r g)])
+                         (rgba r g b 1)))]
+         [vertex-with-noise (lambda (i j)
+                              (vertex (pos i -1 j) #:color (rgba-noise i j)))]
+         [mesh
+          (for*/list ([i (in-range i-range-start i-range-end)]
+                      [j (in-range j-range-start j-range-end)])
+            (quad (vertex-with-noise (add1 i) (add1 j))
+                  (vertex-with-noise i (add1 j))
+                  (vertex-with-noise i j)
+                  (vertex-with-noise (add1 i) j)
+                  #:back? #t))])
+    (combine mesh)))
+
 (define (mesh t)
+  (define (calculate-noise i j)
+    (scale-number (perlin (scale-number i -10 10 -1 1)
+                          (scale-number j -1 10 -1 1)
+                          (scale-number t 0 3000 -1 1))
+                  -1 1
+                  0 4))
+  (define (calculate-pos i j)
+    (pos i (calculate-noise i j) j))
   (let* ([lines
           (for*/list ([i (in-range -10 10)]
                       [j (in-range 0 10)])
@@ -29,19 +68,15 @@
                               [j (in-range -1 10)])
                     (let ([x i]
                           [z j]
-                          [y (scale-number
-                              (perlin (scale-number i -10 10 -1 1)
-                                      (scale-number j -1 10 -1 1)
-                                      (scale-number t 0 2000 -1 1))
-                              -1 1
-                              0 4)]
+                          [y (calculate-noise i j)]
                           [alpha (scale-number
                                   (simplex (scale-number i -10 10 -1 1)
                                            (scale-number j -1 10 -1 1)
                                            (scale-number t 0 2000 -1 1))
                                   -1 1
-                                  0.1 0.8)])
-                      (with-color (rgba-hex "ff71ce" alpha) (sphere (pos x y z) 0.2))))])
+                                  0.33 1)])
+                      (with-color (rgba-hex "ff71ce" alpha)
+                        (sphere (pos x y z) 0.2))))])
     (combine lines-frozen
              spheres
              (move (rotate-y lines-frozen 90)
@@ -52,9 +87,10 @@
   (bend p
         (scale-number (perlin x y z) -1 1 -180 180)))
 (define (scene t)
-  (rotate-x
-   (bend+ my-pipe (/ t 1000) (/ t 1200) 69)
-   90))
+  (move-y (rotate-x
+           (bend+ my-pipe (/ t 3000) (/ t 4000) 69)
+           90)
+          2))
 
 (define (make-sunlight dsun)
   (sunlight
@@ -74,7 +110,8 @@
                             (camera-direction s)))
            (make-sunlight (scene-state-dsun s))
            (mesh t)
-           (move-y (scene t) 2)))
+           (road t)
+           (scene t)))
 
 (define (on-key s n t k)
   (case k