diff options
| -rw-r--r-- | read_layers.py | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/read_layers.py b/read_layers.py index de1bd47..3a26b5d 100644 --- a/read_layers.py +++ b/read_layers.py @@ -117,26 +117,27 @@ class LayerLoader(object): class TileGenerator(object): - def __init__(self, layer, width=None, height=None, tile_size=None, scale=0): + def __init__(self, layer, width=None, height=None, tile_size=None, zoom_step=None, scale=-1): self.layer = layer self.size = (self.layer.width if width is None else width, self.layer.height if height is None else height) self.tile_size = 256 if tile_size is None else tile_size + self.zoom_step = 2.0 if zoom_step is None else float(zoom_step) self.scale = scale def create_tiles(self, path): # calculate how many zoom levels we need by getting the largest number with # 2 ** max_zoom_level >= max(layer_width / tile_size, layer_height / tile_size) max_zoom_level = max([ - int_ceil(math.log(float(self.size[0]) / self.tile_size, 2)), - int_ceil(math.log(float(self.size[1]) / self.tile_size, 2)) + int_ceil(math.log(float(self.size[0]) / self.tile_size, self.zoom_step)), + int_ceil(math.log(float(self.size[1]) / self.tile_size, self.zoom_step)) ]) if self.scale >= 0: - nice_size = self.tile_size * (2 ** max_zoom_level) + nice_size = self.tile_size * (self.zoom_step ** max_zoom_level) prescale = float(nice_size) / self.size[self.scale] maybe_greater_zoom_level = int_ceil(math.log(prescale * self.size[1 - self.scale] - / self.tile_size, 2)) + / self.tile_size, self.zoom_step)) if maybe_greater_zoom_level > max_zoom_level: max_zoom_level = maybe_greater_zoom_level else: @@ -151,7 +152,7 @@ class TileGenerator(object): layer_transform = cairo.Matrix(xx=prescale, yy=prescale) # Scale by Prescale for zoom_level in range(max_zoom_level + 1): - zoom_factor = 0.5 ** zoom_level + zoom_factor = self.zoom_step ** -zoom_level tiles_x = int_ceil(zoom_factor * scaled_size[0] / self.tile_size) tiles_y = int_ceil(zoom_factor * scaled_size[1] / self.tile_size) zoom_level_transform = layer_transform * cairo.Matrix(xx=zoom_factor, yy=zoom_factor) |