PBR checkpoint

[opengl.git] / equirectangularfrag.glsl

diff --git a/equirectangularfrag.glsl b/equirectangularfrag.glsl
new file mode 100644 (file)
index 0000000..dfe855e
--- /dev/null
+++ b/equirectangularfrag.glsl
@@ -0,0 +1,19 @@
+#version 330
+
+in vec3 localPos;
+out vec4 fragColor;
+
+uniform sampler2D equirectangularMap;
+
+const vec2 invAtan = vec2(0.1591, 0.3183);
+
+vec2 sampleSphericalMap(vec3 v) {
+       vec2 uv = vec2(atan(v.z, v.x), asin(v.y));
+       uv *= invAtan;
+       return uv + 0.5;
+}
+
+void main() {
+       vec2 uv = sampleSphericalMap(normalize(localPos));
+       fragColor = vec4(texture(equirectangularMap, uv).rgb, 1.f);
+}