X-Git-Url: http://git.lukelau.me/?p=opengl.git;a=blobdiff_plain;f=equirectangularfrag.glsl;fp=equirectangularfrag.glsl;h=dfe855e6ea5453cfddc6d67e7f8509cbbe5c2b01;hp=0000000000000000000000000000000000000000;hb=a03f2bc751bbd7f91cbc2f52d2f0f6e753d6f776;hpb=210d1b08cec40845d849e89baea8a9cc96917f60

diff --git a/equirectangularfrag.glsl b/equirectangularfrag.glsl
new file mode 100644
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);
+}