Add an effect for rendering a procedurally generated sky

[libs/gl.git] / builtin_data / _sky_transmittance.glsl

diff --git a/builtin_data/_sky_transmittance.glsl b/builtin_data/_sky_transmittance.glsl
new file mode 100644 (file)
index 0000000..9d7b719
--- /dev/null
+++ b/builtin_data/_sky_transmittance.glsl
@@ -0,0 +1,13 @@
+import flat_effect;
+import _sky;
+
+#pragma MSP stage(fragment)
+layout(location=0) out vec3 frag_color;
+void main()
+{
+       float height = texcoord.x*texcoord.x*atmosphere_thickness;
+       float z = texcoord.y;
+       float r = sqrt(1.0-z*z);
+       vec3 look_dir = vec3(r, 0.0, z);
+       frag_color = exp(-raymarch_path(height, look_dir).optical_depth);
+}