+"float world_depth_sample( vec3 pos )\n"
+"{\n"
+" vec2 depth_coord = (pos.xz - g_depth_bounds.xy) * g_depth_bounds.zw; \n"
+" return texture( g_world_depth, depth_coord ).r;\n"
+"}\n"
+"\n"
+"float shadow_sample( vec3 vdir )\n"
+"{\n"
+" vec3 sample_pos = aCo + vdir;\n"
+" float height_sample = world_depth_sample( sample_pos );\n"
+"\n"
+" float fdelta = height_sample - sample_pos.y;\n"
+" return clamp( fdelta, 0.1, 0.2 )-0.1;\n"
+"}\n"
+"\n"
+"vec3 do_light_shadowing( vec3 vfrag )\n"
+"{\n"
+" float faccum = 0.0;\n"
+" faccum += shadow_sample( vec3( 0.0, 0.5, 0.0 ));\n"
+" faccum += shadow_sample( vec3( 2.0, 0.3, 0.0 ));\n"
+" faccum += shadow_sample( vec3( 3.0, 1.0, 0.0 ));\n"
+" faccum += shadow_sample( vec3( 5.0, 1.0, 0.0 ));\n"
+" faccum += shadow_sample( vec3( 0.0, 0.5, 0.0 )*1.5);\n"
+" faccum += shadow_sample( vec3( 2.0, 0.3, 0.0 )*1.5);\n"
+" faccum += shadow_sample( vec3( 3.0, 1.0, 0.0 )*1.5);\n"
+" faccum += shadow_sample( vec3( 5.0, 1.0, 0.0 )*1.5);\n"
+" return mix( vfrag, g_shadow_colour, faccum );\n"
+"}\n"
+"\n"
+"\n"
+"#line 18 0 \n"
+"\n"
+"vec4 water_surf( vec3 halfview, vec3 vnorm, float depthvalue, \n"
+" vec4 beneath, vec4 above )\n"
+"{\n"