Source code for sappho.layers

import pygame


[docs]class SurfaceLayers(object): """Ordered series of pygame surfaces, each the size of the target surface given at creation time. Arguments: target_surface (pygame.Surface): Surface that will have have the layers blitted to when render() is called. The size of this surface is used as the size of the generated layers. number_of_layers (int): Number of layers to generate. """ def __init__(self, target_surface, number_of_layers): self._target_surface = target_surface self._surface_layers = self.create_surface_layers(target_surface, number_of_layers) @staticmethod
[docs] def create_surface_layers(target_surface, number_of_layers): """Create a list of pygame surfaces the size of the target surface. Arguments: target_surface (pygame.Surface): The surface whose dimensions will be used for each layer. number_of_layers (int): The number of surfaces to create/return. Returns: list[pygame.Surface]: List of surfaces """ surface_layers = [] for i in range(number_of_layers): surface = pygame.surface.Surface(target_surface.get_size(), pygame.SRCALPHA, 32) surface_layers.append(surface) return surface_layers
def __getitem__(self, key): """Access a surface by z-index. Arguments: key (int): The z-index of the surface. Raises: IndexError: When the z-index is invalid. Returns: pygame.Surface: The surface belonging to the z-index specified. """ return self._surface_layers[key] def __len__(self): """Return the number of layers. Returns: int: Number of members in self.surface_layers. """ return len(self._surface_layers) def __iter__(self): """Iterate through the surface layers. Yields: pygame.surface.Surface """ for surface in self._surface_layers: yield surface
[docs] def render(self): """Draw each layer onto the target surface in the correct order. """ for surface in self._surface_layers: self._target_surface.blit(surface, (0, 0)) target_surface = self._target_surface number_of_layers = len(self._surface_layers) self._surface_layers = self.create_surface_layers(target_surface, number_of_layers)