Started refactor to lazily compilable shaders.

shaders/fragment_mesh_face.glsl

@@ -0,0 +1,59 @@
+#pragma STAGE: FRAGMENT
+#pragma GEOMETRY: MESH
+#pragma FEATURES: FACE LINE V_L V_RGB V_A LIGHTING TEXTURE U_RGBA
+#pragma FEATURE_TOGGLES: LIGHTING TEXTURE
+
+
+//------------[ Uniforms ]------------//
+#ifdef TEXTURE
+layout (location = 3) uniform sampler2D tex;
+#endif
+#ifdef LIGHTING
+layout (location = 5) uniform vec3 view_pos;
+layout (location = 6) uniform vec3 point_light_direction;
+layout (location = 7) uniform vec3 point_light_color;
+layout (location = 8) uniform vec3 ambient_light_color;
+layout (location = 9) uniform vec3 ambient_filter;
+layout (location = 10) uniform vec3 diffuse_filter;
+layout (location = 11) uniform vec3 specular_filter;
+layout (location = 12) uniform float shininess;
+#endif
+
+
+//------------[ Inputs ]------------//
+layout (location = 0) in vec4 frag_color;
+#ifdef LIGHTING
+layout (location = 1) in vec3 frag_position;
+layout (location = 2) in vec3 frag_normal;
+#endif
+#ifdef TEXTURE
+layout (location = 2) in vec2 frag_tex_coord;
+#endif
+
+
+//------------[ Outputs ]------------//
+layout (location = 0) out vec4 pixel_color;
+
+
+void main()
+{
+    pixel_color = frag_color;
+
+#ifdef TEXTURE
+    pixel_color *= texture(tex, frag_tex_coord);
+#endif
+
+#ifdef LIGHTING
+    vec3 ambient = pixel_color.rgb * ambient_filter * ambient_light_color;
+
+    float point_light_alignment = max(dot(frag_normal, point_light_direction), 0.0);
+    vec3 diffuse = pixel_color.rgb * diffuse_filter * point_light_color * point_light_alignment;
+
+    vec3 reflection_dir = reflect(-point_light_direction, frag_normal);
+    vec3 view_dir = normalize(frag_position - view_pos);
+    float specular_strength = pow(max(dot(view_dir, reflection_dir), 0.0), shininess);
+    vec3 specular = specular_filter * point_light_color * specular_strength;
+
+    pixel_color.rgb *= ambient + diffuse + specular;
+#endif
+}