Working Simplex Noise shader with play-clj

core.clj

(ns pixmappery.core
  (:require [play-clj.core :refer :all]
            [play-clj.entities :as e]
            [play-clj.g2d :refer :all]
            [play-clj.ui :refer :all])
  (:import  [com.badlogic.gdx.graphics.g2d Batch SpriteBatch]
            [com.badlogic.gdx.graphics.glutils ShaderProgram]))

(defn vert [] "attribute vec4 a_position;
attribute vec4 a_color;
attribute vec2 a_texCoord0;
uniform mat4 u_projTrans;
varying vec4 v_color;
varying vec2 v_texCoords;
uniform float u_frame;

void main()
{
   v_color = a_color;
   v_color.a = v_color.a * (256.0/255.0);
   v_texCoords =  a_texCoord0;
   gl_Position = u_projTrans * a_position;
}")

(defn frag [] "varying vec4 v_color;
varying vec2 v_texCoords;
uniform sampler2D u_texture;
uniform float u_frame;

//
// Description : Array and textureless GLSL 2D/3D/4D simplex 
//               noise functions.
//      Author : Ian McEwan, Ashima Arts.
//  Maintainer : ijm
//     Lastmod : 20110822 (ijm)
//     License : Copyright (C) 2011 Ashima Arts. All rights reserved.
//               Distributed under the MIT License. See LICENSE file.
//               https://github.com/ashima/webgl-noise
// 

vec3 mod289(vec3 x) {
  return x - floor(x * (1.0 / 289.0)) * 289.0;
}

vec4 mod289(vec4 x) {
  return x - floor(x * (1.0 / 289.0)) * 289.0;
}

vec4 permute(vec4 x) {
     return mod289(((x*34.0)+1.0)*x);
}

vec4 taylorInvSqrt(vec4 r)
{
  return 1.79284291400159 - 0.85373472095314 * r;
}

float snoise(vec3 v)
  { 
  const vec2  C = vec2(1.0/6.0, 1.0/3.0) ;
  const vec4  D = vec4(0.0, 0.5, 1.0, 2.0);

// First corner
  vec3 i  = floor(v + dot(v, C.yyy) );
  vec3 x0 =   v - i + dot(i, C.xxx) ;

// Other corners
  vec3 g = step(x0.yzx, x0.xyz);
  vec3 l = 1.0 - g;
  vec3 i1 = min( g.xyz, l.zxy );
  vec3 i2 = max( g.xyz, l.zxy );

  //   x0 = x0 - 0.0 + 0.0 * C.xxx;
  //   x1 = x0 - i1  + 1.0 * C.xxx;
  //   x2 = x0 - i2  + 2.0 * C.xxx;
  //   x3 = x0 - 1.0 + 3.0 * C.xxx;
  vec3 x1 = x0 - i1 + C.xxx;
  vec3 x2 = x0 - i2 + C.yyy; // 2.0*C.x = 1/3 = C.y
  vec3 x3 = x0 - D.yyy;      // -1.0+3.0*C.x = -0.5 = -D.y

// Permutations
  i = mod289(i); 
  vec4 p = permute( permute( permute( 
             i.z + vec4(0.0, i1.z, i2.z, 1.0 ))
           + i.y + vec4(0.0, i1.y, i2.y, 1.0 )) 
           + i.x + vec4(0.0, i1.x, i2.x, 1.0 ));

// Gradients: 7x7 points over a square, mapped onto an octahedron.
// The ring size 17*17 = 289 is close to a multiple of 49 (49*6 = 294)
  float n_ = 0.142857142857; // 1.0/7.0
  vec3  ns = n_ * D.wyz - D.xzx;

  vec4 j = p - 49.0 * floor(p * ns.z * ns.z);  //  mod(p,7*7)

  vec4 x_ = floor(j * ns.z);
  vec4 y_ = floor(j - 7.0 * x_ );    // mod(j,N)

  vec4 x = x_ *ns.x + ns.yyyy;
  vec4 y = y_ *ns.x + ns.yyyy;
  vec4 h = 1.0 - abs(x) - abs(y);

  vec4 b0 = vec4( x.xy, y.xy );
  vec4 b1 = vec4( x.zw, y.zw );

  //vec4 s0 = vec4(lessThan(b0,0.0))*2.0 - 1.0;
  //vec4 s1 = vec4(lessThan(b1,0.0))*2.0 - 1.0;
  vec4 s0 = floor(b0)*2.0 + 1.0;
  vec4 s1 = floor(b1)*2.0 + 1.0;
  vec4 sh = -step(h, vec4(0.0));

  vec4 a0 = b0.xzyw + s0.xzyw*sh.xxyy ;
  vec4 a1 = b1.xzyw + s1.xzyw*sh.zzww ;

  vec3 p0 = vec3(a0.xy,h.x);
  vec3 p1 = vec3(a0.zw,h.y);
  vec3 p2 = vec3(a1.xy,h.z);
  vec3 p3 = vec3(a1.zw,h.w);

//Normalise gradients
  vec4 norm = taylorInvSqrt(vec4(dot(p0,p0), dot(p1,p1), dot(p2, p2), dot(p3,p3)));
  p0 *= norm.x;
  p1 *= norm.y;
  p2 *= norm.z;
  p3 *= norm.w;

// Mix final noise value
  vec4 m = max(0.6 - vec4(dot(x0,x0), dot(x1,x1), dot(x2,x2), dot(x3,x3)), 0.0);
  m = m * m;
  return 42.0 * dot( m*m, vec4( dot(p0,x0), dot(p1,x1), 
                                dot(p2,x2), dot(p3,x3) ) );
  }
void main()
{
//  float simped = snoise(v_texCoords * (2.0 + u_frame));
  vec3 v_texCoord3D = vec3(v_texCoords, 0.0);
  vec3 uvw = v_texCoord3D + 0.1*vec3(snoise(v_texCoord3D + vec3(0.0, 0.0, u_frame)),
    snoise(v_texCoord3D + vec3(43.0, 17.0, u_frame)),
	  snoise(v_texCoord3D + vec3(-17.0, -43.0, u_frame)));
  float n = snoise(uvw - vec3(0.0, 0.0, u_frame));
  n += 0.5 * snoise(uvw * 2.0 - vec3(0.0, 0.0, u_frame*1.4)); 
  n += 0.25 * snoise(uvw * 4.0 - vec3(0.0, 0.0, u_frame*2.0)); 
  n += 0.125 * snoise(uvw * 8.0 - vec3(0.0, 0.0, u_frame*2.8)); 
  n += 0.0625 * snoise(uvw * 16.0 - vec3(0.0, 0.0, u_frame*4.0)); 
  n += 0.03125 * snoise(uvw * 32.0 - vec3(0.0, 0.0, u_frame*5.6)); 
  n = n * 0.7;
  gl_FragColor = vec4(vec3(1.0, 0.5, 0.0) + vec3(n, n, n), 1.0);
//  gl_FragColor = vec4(0.5 + 0.5 * vec3(simped, simped, simped), 1.0);
}
")

(def atm (atom 0))
    
(defscreen main-screen
  :on-show
  (fn [screen entities]
    (set! ShaderProgram/pedantic false)
    (def shader (let [s (ShaderProgram. (vert) (frag))] (println (.getLog s)) s))
    (update! screen :renderer (stage))
    (texture "box.png")
    )
  
  :on-render
  (fn [screen entities]
    (clear!)
    (swap! atm inc)
    (.setShader (.getBatch (:renderer screen)) shader)
    ;(.setColor (.getBatch (:renderer screen)) 1.0 1.0 1.0 1.0)
    (let [^Batch batch (.getBatch (:renderer screen))]
      (.begin batch)
      (.setUniformf shader "u_frame" (float (* @atm 0.01)))
      (doseq [entity entities]
        (e/draw! entity screen batch))
      (.end batch))
    (graphics! :set-title (str "Simplex Demo at " (game :fps) " FPS"))
    entities))

(defgame pixmappery
  :on-create
  (fn [this]
    (set-screen! this main-screen)))