[RELEASE] u22-v03

This version is submitted to U22 breau.

core/loshader/ground.fshader

@@ -0,0 +1,9 @@
+in float v_ground_id;
+in vec2  v_size;
+in vec2  v_uv;
+
+out vec4 o_color;
+
+void main(void) {
+  o_color = vec4(0., 0., 0., .6);
+}