Merge pull request #68 from alexkh/master

Changed background to Lyapunov fractal

glass-theme/glass_theme/default.py

@@ -51,6 +51,17 @@ def __init__(self, *args, **kw):
     define_BORDER_ACTIVE_COLOR_2 = "vec4(1., 1., 1., 1.)"
     define_BORDER_ACTIVE_COLOR_3 = "vec4(0., 0., 0., 1.)"
     define_BORDER_ACTIVE_COLOR_4 = "vec4(0., 0., 0., 1.)"
+
+    # See glass-theme/glass_theme/shaders/root/fragment.glsl for list of possible values
+    define_BACKGROUND_TYPE = 1
+    # 200 gives a much better picture, but is super slow in software...
+    define_FRACTAL_PRECISION = 10
+    define_BACKGROUND_COLOR_TRANSFORM = ("transpose(mat4(" +
+                                         "-0.5, 0.0, 0.0, 1.0," +
+                                         "-0.5, 0.0, 0.0, 1.0," +
+                                         "-0.5, 0.0, 0.0, 1.0," +
+                                         "0.0, 0.0, 0.0, 1.0" +
+                                         "))")
 
     def linestrings2texture(self, f):
         coastline = json.load(f)

glass-theme/glass_theme/shaders/root/fragment.glsl

@@ -1,12 +1,72 @@
 #version 330 core
 precision highp float;
 
+/* Copyright (c) 2020 alexkh
+   This code is available as a stand-alone fractal demo
+   at https://github.com/alexkh/gllyap
+*/
+
 uniform ivec2 size;
+uniform vec4 root_IG_VIEW_DESKTOP_VIEW;
 
 in vec2 px_coord;
 
 out vec4 fragColor;
 
+vec2 iResolution = vec2(float(size.x), float(size.y));
+
+vec3 calc(in vec2 p) {
+  float w1, w2, w3, w4, w5;
+  /*
+    w1 = 0.97 + 0.04*sin(0.0 + 1.3*iGlobalTime*0.2);
+    w2 = 0.97 + 0.04*sin(1.0 + 1.7*iGlobalTime*0.2);
+    w3 = 0.97 + 0.04*sin(4.0 + 1.1*iGlobalTime*0.2);
+    w4 = 0.97 + 0.04*sin(2.0 + 1.5*iGlobalTime*0.2);
+    w5 = 0.97 + 0.04*sin(5.0 + 1.9*iGlobalTime*0.2);
+  */
+  // w3 = w5 = 1.0;
+  w1 = w2 = w3 = w4 = w5 = 1.0;
+
+  float x = 0.5;
+  float h = 0.0;
+  for (int i = 0; i < FRACTAL_PRECISION; i++) {
+    x = w1*p.x*x*(1.0-x); h += log2(abs(w1*p.x*(1.0-2.0*x)));
+    x = w2*p.x*x*(1.0-x); h += log2(abs(w2*p.x*(1.0-2.0*x)));
+    x = w3*p.y*x*(1.0-x); h += log2(abs(w3*p.y*(1.0-2.0*x)));
+    x = w4*p.x*x*(1.0-x); h += log2(abs(w4*p.x*(1.0-2.0*x)));
+    x = w5*p.y*x*(1.0-x); h += log2(abs(w5*p.y*(1.0-2.0*x)));
+  }
+  h /= 200.0 * 5.0;
+
+  vec3 col = vec3(0.0);
+  if (h < 0.0) {
+    h = abs(h);
+    col = vec3(0.5+0.5*sin(0.0+2.5*h),
+               0.5+0.5*sin(0.4+2.5*h),
+               0.5+0.5*sin(0.7+2.5*h));
+    col *= vec3(1.1)*pow(h,0.25);
+  }
+
+  return col;
+}
+
 void main() {
-  fragColor = vec4(1., 1., 1., 1.);
+  vec3 col;
+  vec2 coord = px_coord;
+  coord.y = iResolution.y - coord.y;
+
+  if (BACKGROUND_TYPE == 1) {
+    #if 1
+      col = calc(3.0 + (1.0 * coord / iResolution.xy) * root_IG_VIEW_DESKTOP_VIEW.zw + root_IG_VIEW_DESKTOP_VIEW.xy);
+    #else
+      col = calc(3.0 + 1.0*(gl_FragCoord.xy+vec2(0.0,0.0)) / iResolution.xy) +
+            calc(3.0 + 1.0*(gl_FragCoord.xy+vec2(0.0,0.5)) / iResolution.xy) +
+            calc(3.0 + 1.0*(gl_FragCoord.xy+vec2(0.5,0.0)) / iResolution.xy) +
+            calc(3.0 + 1.0*(gl_FragCoord.xy+vec2(0.5,0.5)) / iResolution.xy);
+      col /= 4.0;
+    #endif
+  } else {
+    col = vec3(1., 1., 1.);
+  }
+  gl_FragColor = BACKGROUND_COLOR_TRANSFORM * vec4(col, 1.0);
 }