+static void render_tiles( v2i start, v2i end, v4f const regular_colour, v4f const selected_colour )
+{
+ v2i full_start = { 0,0 };
+ v2i full_end = { world.w, world.h };
+
+ if( !start || !end )
+ {
+ start = full_start;
+ end = full_end;
+ }
+
+ glUniform4fv( SHADER_UNIFORM( shader_tile_main, "uColour" ), 1, regular_colour );
+
+ for( int y = start[1]; y < end[1]; y ++ )
+ {
+ for( int x = start[0]; x < end[0]; x ++ )
+ {
+ struct cell *cell = pcell((v2i){x,y});
+ int selected = world.selected == y*world.w + x;
+
+ int tile_offsets[][2] =
+ {
+ {2, 0}, {0, 3}, {0, 2}, {2, 2},
+ {1, 0}, {2, 3}, {3, 2}, {1, 3},
+ {3, 1}, {0, 1}, {1, 2}, {2, 1},
+ {1, 1}, {3, 3}, {2, 1}, {2, 1}
+ };
+
+ int uv[2] = { 3, 0 };
+
+ if( cell->state & FLAG_CANAL )
+ {
+ uv[0] = tile_offsets[ cell->config ][0];
+ uv[1] = tile_offsets[ cell->config ][1];
+ }
+
+ glUniform4f( SHADER_UNIFORM( shader_tile_main, "uOffset" ), (float)x, (float)y, uv[0], uv[1] );
+ if( selected )
+ {
+ glUniform4fv( SHADER_UNIFORM( shader_tile_main, "uColour" ), 1, selected_colour );
+ draw_mesh( 0, 2 );
+ glUniform4fv( SHADER_UNIFORM( shader_tile_main, "uColour" ), 1, regular_colour );
+ }
+ else
+ draw_mesh( 0, 2 );
+ }
+ }
+}
+