Add initial prototype.

3-mid/opengl/assets/shader/templates/directional_light.vert-template

@@ -0,0 +1,69 @@
+#version 120
+
+struct directional_light
+{
+   vec3   direction;        // Normalized light direction in eye space.
+   vec3   halfplane;        // Normalized half-plane vector.
+
+   vec4   ambient_color;     
+   vec4   diffuse_color;
+   vec4   specular_color;
+
+   bool   is_on;
+};
+
+
+uniform   mat3                inv_modelview_Matrix;
+uniform   directional_light   uLights [8];
+uniform   float               uShine;
+
+
+attribute vec3   aNormal;
+attribute vec4   aColor;
+
+
+varying   vec4   vColor;
+
+
+const float   c_zero      = 0.0;
+const float   c_one       = 1.0;
+
+
+
+vec4                                                        // Returns the computed color.
+directional_light_color (in vec3                normal,     // 'normal' has been transformed into eye space and normalized.
+                         in directional_light   light)
+{
+   if (!light.is_on)
+      return vec4 (0.0, 0.0, 0.0, 0.0);
+
+   vec4    computed_color = vec4 (c_zero, c_zero, c_zero, c_zero);
+   float   NdotL;                                            // Dot product of normal and light direction.
+   float   NdotH;                                            // Dot product of normal and half-plane vector.
+
+   NdotL = max (c_zero,  dot (normal, light.direction));
+   NdotH = max (c_zero,  dot (normal, light.halfplane));
+
+   computed_color += (        light.ambient_color * aColor);
+   computed_color += (NdotL * light.diffuse_color  * aColor);
+   
+   if (NdotH > c_zero)
+      computed_color += (pow (NdotH, uShine) * aColor * light.specular_color);
+
+   return computed_color;
+}
+
+
+
+void main()
+{
+   vec3   light_Normal = normalize (aNormal) * inv_modelview_Matrix;
+
+
+   vColor = vec4 (0.0, 0.0, 0.0, 0.0);
+
+   for (int i = 0; i < 8; i++)
+   {
+      vColor += directional_light_color (light_Normal, uLights [i]);
+   }
+}