d3.geo.tile = function() { var size = [960, 500], scale = 256, translate = [size[0] / 2, size[1] / 2], zoomDelta = 0; function tile() { var z = Math.max(Math.log(scale) / Math.LN2 - 8, 0), z0 = Math.round(z + zoomDelta), k = Math.pow(2, z - z0 + 8), origin = [(translate[0] - scale / 2) / k, (translate[1] - scale / 2) / k], tiles = [], cols = d3.range(Math.max(0, Math.floor(-origin[0])), Math.max(0, Math.ceil(size[0] / k - origin[0]))), rows = d3.range(Math.max(0, Math.floor(-origin[1])), Math.max(0, Math.ceil(size[1] / k - origin[1]))); rows.forEach(function(y) { cols.forEach(function(x) { tiles.push([x, y, z0]); }); }); tiles.translate = origin; tiles.scale = k; return tiles; } tile.size = function(_) { if (!arguments.length) return size; size = _; return tile; }; tile.scale = function(_) { if (!arguments.length) return scale; scale = _; return tile; }; tile.translate = function(_) { if (!arguments.length) return translate; translate = _; return tile; }; tile.zoomDelta = function(_) { if (!arguments.length) return zoomDelta; zoomDelta = +_; return tile; }; return tile; };