1 files changed, 57 insertions, 0 deletions
diff --git a/res/effectlib/refraction.glsllib b/res/effectlib/refraction.glsllib
new file mode 100644
index 0000000..c83ce42
--- /dev/null
+++ b/res/effectlib/refraction.glsllib
@@ -0,0 +1,57 @@
+// this is entirly phiysical incorrect
+// We just use this to fake distortion when we have no environment available
+// The displacement is calculated on ior
+vec3 refraction( in sampler2D sampler, in float materialIOR )
+{
+  vec3 displace = fresnel( viewDir, vec3( materialIOR ));
+
+  float xdir = abs( viewDir.x );
+  float ydir = abs( viewDir.y );
+
+  vec2 texSize = vec2( textureSize( sampler, 0 ) );
+  vec2 newUV = vec2(gl_FragCoord.xy/texSize);
+  if ( xdir > ydir)
+  {
+      newUV = ( viewDir.x > 0.0) ? newUV + displace.xy : newUV - displace.xy;
+  }
+  else
+  {
+      newUV = ( viewDir.y > 0.0) ? newUV - displace.xy : newUV + displace.xy;
+  }
+
+  vec3 refractColor = texture( sampler, newUV ).rgb;
+
+  return refractColor;
+}
+
+// This should really not be used, but it's there for the sake of testing.
+vec3 refractBlur( in sampler2D sampler, in vec3 viewDir, in float materialIOR, in float blurWidth )
+{
+  // This is really terrible, but at least is a little better than
+  vec3 displace = viewDir * materialIOR;
+
+  vec2 texSize = vec2( textureSize( sampler, 0 ) );
+  texSize = vec2(1.0) / texSize;
+  vec2 newUV = vec2(gl_FragCoord.xy * texSize);
+  newUV += displace.xy * 0.005;
+
+  //vec3 refractColor = texture( sampler, newUV ).rgb;
+  vec3 refractColor = vec3(0);
+  int sz = int(ceil(blurWidth));
+  float wtsum = 0.0;
+
+  for (int y = -sz; y <= sz; ++y)
+  {
+      for (int x = -sz; x <= sz; ++x)
+      {
+          float wt = float(x*x + y*y) / (blurWidth * 0.5);
+          wt = exp2(-wt);
+          //refractColor += wt * textureOffset( sampler, newUV, ivec2(x, y) ).rgb;
+          vec2 uvOfs = vec2(x, y) * texSize;
+          refractColor += wt * texture( sampler, newUV+uvOfs).rgb;
+          wtsum += wt;
+      }
+  }
+
+  return refractColor / wtsum;
+}