day-night loop, dynamic skybox, clock on debug panel

res/shaders/background.glslv

@@ -0,0 +1,14 @@
+#version 330 core
+
+layout (location = 0) in vec2 v_position;
+
+out vec3 v_coord;
+
+uniform mat4 u_view;
+uniform float u_ar;
+uniform float u_zoom;
+
+void main(){
+	v_coord = (vec4(v_position*vec2(u_ar, 1.0f)*u_zoom, -1.0, 1.0) * u_view).xyz;
+	gl_Position = vec4(v_position, 0.0, 1.0);
+}