optimize

shader.glsl

@@ -1,3 +1,9 @@
+/* uses some snippets from:
+ * "Seascape" by Alexander Alekseev aka TDM - 2014
+ * License Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.
+ * Contact: tdmaav@gmail.com
+ */
+
 precision mediump float;
 uniform vec2 u_resolution;
 uniform float u_time;
@@ -15,33 +21,27 @@ float smax( float a, float b, float k )
     return max(a, b) + h*h*0.25/k;
 }
 
-float hash(vec2 p)
-{
-    p = 50.*fract( p*0.3183099);
+float hash(vec2 p, int algo)
+{        
+    if (algo == 1) {
+        float h = dot(p,vec2(127.1,311.7));	
+        return fract(sin(h)*43758.5453123);
+    }
+    p = 50.*fract( p*0.3183099);    
     return fract( p.x*p.y*(p.x+p.y) );
 }
 
-float noise(vec2 p, float scale )
+float noise(vec2 p, float scale, int a)
 {
     vec2 i = floor( p ),
     f = fract( p ),
 	u = f*f*(3.-2.*f);
-    return -scale+scale*mix( mix( hash( i + vec2(0.) ), 
-                              hash( i + vec2(1.0,0.0) ), u.x),
-                         mix( hash( i + vec2(0.0,1.0) ), 
-                              hash( i + vec2(1.) ), u.x), u.y);
-}
-
-float hash2( vec2 p ) {
-	float h = dot(p,vec2(127.1,311.7));	
-    return fract(sin(h)*43758.5453123);
-}
-float noise2( in vec2 p ) {
-    vec2 i = floor( p ), f = fract( p ), u = f*f*(3.0-2.0*f);
-    return -1.0+2.0*mix( mix( hash2( i + vec2(0.) ), 
-                     hash2( i + vec2(1.0,0.0) ), u.x),
-                mix( hash2( i + vec2(0.0,1.0) ), 
-                     hash2( i + vec2(1.) ), u.x), u.y);
+    float sc = scale;
+    if (a == 1) sc = 2.;        
+    return -scale+sc*mix( mix( hash( i + vec2(0.), a), 
+                              hash( i + vec2(1.0,0.0), a ), u.x),
+                         mix( hash( i + vec2(0.0,1.0), a), 
+                              hash( i + vec2(1.), a), u.x), u.y);
 }
 
 /////////////////
@@ -140,7 +140,7 @@ float prismAnim(vec2 i) {
 //   SCENE  //
 //////////////
 float sea_octave(vec2 uv, float choppy) {
-    uv += noise2(uv);        
+    uv += noise(uv, 1., 1);        
     vec2 wv = 1.0-abs(sin(uv));
     vec2 swv = abs(cos(uv));    
     wv = mix(wv,swv,wv);
@@ -220,7 +220,7 @@ vec2 map(vec3 p, int displace)
     if (d==d2) mat = 2.0;
     
     // sand
-    d2 = (p.y + 4.25) + noise((vec2((p.x*.04),(p.z-40.)*.04))+100., 15.)*1.5;    
+    d2 = (p.y + 4.25) + noise((vec2((p.x*.04),(p.z-40.)*.04))+100., 15., 0)*1.5;    
     d = min(d,d2);
     if (d==d2) mat = 3.0; 
     
@@ -408,7 +408,7 @@ vec3 sceneGate(vec2 uv)
         else if(mat==2.)
             col *= vec3(.3, .1, .0); // - 0.2*noise((vec2(100.*p.x+300.,75.*p.z+150.0)), -2.2) * noise((vec2(15.*p.x+2.0,3.*p.z+2.)), -1.) + noise((vec2(15.*p.x+2.4,3.*p.z+2.)), -0.25);        
         else if(mat==3.)
-            col *= vec3(.8, .8, .5) + noise(p.xz*500.+100., .3); // + noise(p.xz*1000.+5000., 0.1) + noise(p.xz*1000.+5000., 0.1);        
+            col *= vec3(.8, .8, .5) + noise(p.xz*500.+100., .3,0); // + noise(p.xz*1000.+5000., 0.1) + noise(p.xz*1000.+5000., 0.1);        
         else if(mat==4.)
             col *= vec3(.1);
         else if(mat ==5.)