more shader work

engine/art/shaderlib/model_fs.glsl

@@ -41,3 +41,5 @@ vec4 shadowing() {
 
 uniform vec3 u_cam_pos;
 uniform vec3 u_cam_dir;
+uniform float frame_time;
+uniform uint frame_count;

engine/art/shaderlib/utils.glsl

@@ -0,0 +1,114 @@
+
+//  Classic Perlin 3D Noise 
+//  by Stefan Gustavson
+//
+vec4 permute(vec4 x){return mod(((x*34.0)+1.0)*x, 289.0);}
+vec4 taylorInvSqrt(vec4 r){return 1.79284291400159 - 0.85373472095314 * r;}
+vec3 fade(vec3 t) {return t*t*t*(t*(t*6.0-15.0)+10.0);}
+
+float cnoise(vec3 P){
+  vec3 Pi0 = floor(P); // Integer part for indexing
+  vec3 Pi1 = Pi0 + vec3(1.0); // Integer part + 1
+  Pi0 = mod(Pi0, 289.0);
+  Pi1 = mod(Pi1, 289.0);
+  vec3 Pf0 = fract(P); // Fractional part for interpolation
+  vec3 Pf1 = Pf0 - vec3(1.0); // Fractional part - 1.0
+  vec4 ix = vec4(Pi0.x, Pi1.x, Pi0.x, Pi1.x);
+  vec4 iy = vec4(Pi0.yy, Pi1.yy);
+  vec4 iz0 = Pi0.zzzz;
+  vec4 iz1 = Pi1.zzzz;
+
+  vec4 ixy = permute(permute(ix) + iy);
+  vec4 ixy0 = permute(ixy + iz0);
+  vec4 ixy1 = permute(ixy + iz1);
+
+  vec4 gx0 = ixy0 / 7.0;
+  vec4 gy0 = fract(floor(gx0) / 7.0) - 0.5;
+  gx0 = fract(gx0);
+  vec4 gz0 = vec4(0.5) - abs(gx0) - abs(gy0);
+  vec4 sz0 = step(gz0, vec4(0.0));
+  gx0 -= sz0 * (step(0.0, gx0) - 0.5);
+  gy0 -= sz0 * (step(0.0, gy0) - 0.5);
+
+  vec4 gx1 = ixy1 / 7.0;
+  vec4 gy1 = fract(floor(gx1) / 7.0) - 0.5;
+  gx1 = fract(gx1);
+  vec4 gz1 = vec4(0.5) - abs(gx1) - abs(gy1);
+  vec4 sz1 = step(gz1, vec4(0.0));
+  gx1 -= sz1 * (step(0.0, gx1) - 0.5);
+  gy1 -= sz1 * (step(0.0, gy1) - 0.5);
+
+  vec3 g000 = vec3(gx0.x,gy0.x,gz0.x);
+  vec3 g100 = vec3(gx0.y,gy0.y,gz0.y);
+  vec3 g010 = vec3(gx0.z,gy0.z,gz0.z);
+  vec3 g110 = vec3(gx0.w,gy0.w,gz0.w);
+  vec3 g001 = vec3(gx1.x,gy1.x,gz1.x);
+  vec3 g101 = vec3(gx1.y,gy1.y,gz1.y);
+  vec3 g011 = vec3(gx1.z,gy1.z,gz1.z);
+  vec3 g111 = vec3(gx1.w,gy1.w,gz1.w);
+
+  vec4 norm0 = taylorInvSqrt(vec4(dot(g000, g000), dot(g010, g010), dot(g100, g100), dot(g110, g110)));
+  g000 *= norm0.x;
+  g010 *= norm0.y;
+  g100 *= norm0.z;
+  g110 *= norm0.w;
+  vec4 norm1 = taylorInvSqrt(vec4(dot(g001, g001), dot(g011, g011), dot(g101, g101), dot(g111, g111)));
+  g001 *= norm1.x;
+  g011 *= norm1.y;
+  g101 *= norm1.z;
+  g111 *= norm1.w;
+
+  float n000 = dot(g000, Pf0);
+  float n100 = dot(g100, vec3(Pf1.x, Pf0.yz));
+  float n010 = dot(g010, vec3(Pf0.x, Pf1.y, Pf0.z));
+  float n110 = dot(g110, vec3(Pf1.xy, Pf0.z));
+  float n001 = dot(g001, vec3(Pf0.xy, Pf1.z));
+  float n101 = dot(g101, vec3(Pf1.x, Pf0.y, Pf1.z));
+  float n011 = dot(g011, vec3(Pf0.x, Pf1.yz));
+  float n111 = dot(g111, Pf1);
+
+  vec3 fade_xyz = fade(Pf0);
+  vec4 n_z = mix(vec4(n000, n100, n010, n110), vec4(n001, n101, n011, n111), fade_xyz.z);
+  vec2 n_yz = mix(n_z.xy, n_z.zw, fade_xyz.y);
+  float n_xyz = mix(n_yz.x, n_yz.y, fade_xyz.x); 
+  return 2.2 * n_xyz;
+}
+
+vec2 random2(vec2 p) {
+    return fract(sin(vec2(dot(p, vec2(127.1, 311.7)),
+                          dot(p, vec2(269.5, 183.3)))) * 43758.5453);
+}
+
+float cellNoise(vec2 p) {
+    float K = 1.0/7.0; // Scale
+    float K2 = K/2.0; // Half scale
+    vec2 i = floor(p*K);
+    vec2 f = fract(p*K);
+    float minDist = 1.0; // Initialize minimum distance with a high value
+
+    for(int y=-1; y<=1; y++) {
+        for(int x=-1; x<=1; x++) {
+            vec2 neighbor = vec2(float(x), float(y));
+            vec2 point = random2(i + neighbor);
+            vec2 diff = neighbor + point - f;
+            float dist = length(diff);
+            minDist = min(minDist, dist);
+        }
+    }
+    return minDist/K2;
+}
+vec3 rgb2hsv(vec3 c) {
+    vec4 K = vec4(0.0, -1.0 / 3.0, 2.0 / 3.0, -1.0);
+    vec4 p = mix(vec4(c.bg, K.wz), vec4(c.gb, K.xy), step(c.b, c.g));
+    vec4 q = mix(vec4(p.xyw, c.r), vec4(c.r, p.yzx), step(p.x, c.r));
+
+    float d = q.x - min(q.w, q.y);
+    float e = 1.0e-10;
+    return vec3(abs(q.z + (q.w - q.y) / (6.0 * d + e)), d / (q.x + e), q.x);
+}
+
+vec3 hsv2rgb(vec3 c) {
+    vec4 K = vec4(1.0, 2.0 / 3.0, 1.0 / 3.0, 3.0);
+    vec3 p = abs(fract(c.xxx + K.xyz) * 6.0 - K.www);
+    return c.z * mix(K.xxx, clamp(p - K.xxx, 0.0, 1.0), c.y);
+}