From b252c52ffea467701e528a46339d8c1844e05f39 Mon Sep 17 00:00:00 2001
From: jgk <justin.g.kruger@gmail.com>
Date: Fri, 25 Jun 2021 02:27:33 +0200
Subject: [PATCH] Add surface lighting shader

---
 shader/lighting/surface.frag |  9 +++++++++
 shader/lighting/surface.vert | 13 +++++++++++++
 2 files changed, 22 insertions(+)
 create mode 100644 shader/lighting/surface.frag
 create mode 100644 shader/lighting/surface.vert

diff --git a/shader/lighting/surface.frag b/shader/lighting/surface.frag
new file mode 100644
index 000000000..de48e1bad
--- /dev/null
+++ b/shader/lighting/surface.frag
@@ -0,0 +1,9 @@
+#version 430 core
+in float lum;
+in vec3 dField;
+out vec4 fColor;
+void main()
+{
+  float c = pow (1 - min(1, dot(dField,dField)) , 2) * lum ;
+  fColor = vec4(c,c,c,c);
+}
diff --git a/shader/lighting/surface.vert b/shader/lighting/surface.vert
new file mode 100644
index 000000000..a32ec8815
--- /dev/null
+++ b/shader/lighting/surface.vert
@@ -0,0 +1,13 @@
+#version 430 core
+layout (location = 0) in vec3 position;
+layout (std140, binding = 0) uniform TheMat { mat4 theMat; } ;
+uniform vec3 lightPos;
+uniform vec2 radLum;
+out vec3 dField;
+out float lum;
+void main()
+{
+    dField = (position - lightPos) / radLum.x;
+    lum = radLum.y;
+    gl_Position = theMat * vec4(position,1);
+}