1 files changed, 55 insertions, 0 deletions

diff --git a/assets/shaders/Mandel.frag.glsl b/assets/shaders/Mandel.frag.glsl
new file mode 100644
index 00000000..6465899d
--- /dev/null
+++ b/assets/shaders/Mandel.frag.glsl
@@ -0,0 +1,55 @@
+#ifdef GL_ES
+precision highp float;
+#endif
+
+uniform vec2 u_resolution;
+uniform float u_time;
+
+void main(void)
+{
+    vec2 p = -1.0 + 2.0 * gl_FragCoord.xy / u_resolution.xy;
+    p.x *= u_resolution.x/u_resolution.y;
+
+    float zoo = .62+.38*sin(.1*u_time);
+    float coa = cos( 0.1*(1.0-zoo)*u_time );
+    float sia = sin( 0.1*(1.0-zoo)*u_time );
+    zoo = pow( zoo,8.0);
+    vec2 xy = vec2( p.x*coa-p.y*sia, p.x*sia+p.y*coa);
+    vec2 cc = vec2(-.745,.186) + xy*zoo;
+
+    vec2 z  = vec2(0.0);
+    vec2 z2 = z*z;
+    float m2;
+    float co = 0.0;
+
+
+    // chrome/angelproject/nvidia/glslES don't seem to like to "break" a loop...
+    // so we have to rewrite it in another way
+/*
+    for( int i=0; i<256; i++ )
+    {
+        z = cc + vec2( z.x*z.x - z.y*z.y, 2.0*z.x*z.y );
+        m2 = dot(z,z);
+        if( m2>1024.0 ) break;
+        co += 1.0;
+    }
+*/
+
+    for( int i=0; i<256; i++ )
+    {
+        if( m2<1024.0 )
+        {
+            z = cc + vec2( z.x*z.x - z.y*z.y, 2.0*z.x*z.y );
+            m2 = dot(z,z);
+            co += 1.0;
+        }
+    }
+
+    co = co + 1.0 - log2(.5*log2(m2));
+
+    co = sqrt(co/256.0);
+    gl_FragColor = vec4( .5+.5*cos(6.2831*co+0.0),
+                         .5+.5*cos(6.2831*co+0.4),
+                         .5+.5*cos(6.2831*co+0.7),
+                         1.0 );
+}
\ No newline at end of file