refactor: make the whole thing more generic

modules/home-manager/desktops/hyprland/hypr/shaders/gaussian.frag

@@ -0,0 +1,31 @@
+//---------------------------------------------------------------------------
+// Fragment
+//---------------------------------------------------------------------------
+#version 420 core
+//---------------------------------------------------------------------------
+precision mediump float;
+in vec2 pos;                    // screen position <-1,+1>
+out vec4 gl_FragColor;          // fragment output color
+uniform sampler2D txr;          // texture to blur
+uniform float xs,ys;            // texture resolution
+uniform float r = 6.0;          // blur radius
+
+varying vec2 v_texcoord;
+uniform sampler2D tex;
+//---------------------------------------------------------------------------
+void main()
+    {
+    float x,y,xx,yy,rr=r*r,dx,dy,w,w0;
+    w0=0.3780/pow(r,1.975);
+    vec2 p;
+    vec4 pixColor = texture2D(tex, v_texcoord);
+    for (dx=1.0/xs,x=-r,p.x=0.5+(pos.x*0.5)+(x*dx);x<=r;x++,p.x+=dx){ xx=x*x;
+     for (dy=1.0/ys,y=-r,p.y=0.5+(pos.y*0.5)+(y*dy);y<=r;y++,p.y+=dy){ yy=y*y;
+      if (xx+yy<=rr)
+        {
+        w=w0*exp((-xx-yy)/(2.0*rr));
+        pixColor+=texture2D(txr,p)*w;
+        }}}
+    gl_FragColor = pixColor;
+    }
+//---------------------------------------------------------------------------