+"#line 11 0 \n"
+"\n"
+"float sdLine( vec3 p, vec3 a, vec3 b )\n"
+"{\n"
+" vec3 pa = p - a;\n"
+" vec3 ba = b - a;\n"
+"\n"
+" float h = clamp( dot(pa,ba)/dot(ba,ba), 0.0, 1.0 );\n"
+" return length( pa - ba*h );\n"
+"}\n"
+"\n"
+"float compute_board_shadow()\n"
+"{\n"
+" // player shadow\n"
+" float dist_to_player = max( 0.0, sdLine( aWorldCo, uBoard0, uBoard1 )-0.1 );\n"
+" float player_shadow = max( 1.0-dist_to_player*2.7, 0.0 );\n"
+" player_shadow *= player_shadow*player_shadow*player_shadow;\n"
+"\n"
+" return 1.0 - player_shadow*0.8;\n"
+"}\n"