"""
Texture Atlas for SpriteList
The long term goal is to rely on pyglet's texture atlas, but
it's still unclear what features we need supported in arcade
so need to prototype something to get started.
We're still building on pyglet's allocator.
Pyglet atlases are located here:
https://github.com/einarf/pyglet/blob/master/pyglet/image/atlas.py
"""
from __future__ import annotations
import copy
import math
import time
import logging
from pathlib import Path
from typing import (
Dict,
Optional,
Tuple,
Sequence,
Union,
TYPE_CHECKING,
List,
)
from array import array
from collections import deque
from contextlib import contextmanager
from weakref import WeakSet
import PIL
import PIL.Image
from PIL import Image, ImageDraw
from pyglet.image.atlas import (
Allocator,
AllocatorException,
)
from pyglet.math import Mat4
import arcade
from arcade.gl.framebuffer import Framebuffer
from arcade.texture.transforms import Transform
if TYPE_CHECKING:
from arcade import ArcadeContext, Texture
from arcade.gl import Texture2D
from arcade.texture import ImageData
# The amount of pixels we increase the atlas when scanning for a reasonable size.
# It must divide. Must be a power of two number like 64, 256, 512 etx
RESIZE_STEP = 128
UV_TEXTURE_WIDTH = 4096
LOG = logging.getLogger(__name__)
class AtlasRegion:
"""
Stores information about where a texture is located.
The texture coordinates are stored as a tuple of 8 floats
(4 points, 2 floats each) in the following order:
upper_left, upper_right, lower_left, lower_right.
Layout::
(0, 1) (1, 1)
+--------------------------------------+
| Atlas Texture |
| |
| (2) (3) |
+-----------------+ |
| Image | |
| | |
| | |
| | |
| | |
| (0) | (1) |
+-----------------+--------------------+
(0, 0) (1, 0)
:param atlas: The atlas this region belongs to
:param texture: The arcade texture
:param x: The x position of the texture
:param y: The y position of the texture
:param width: The width of the texture in pixels
:param height: The height of the texture in pixels
:param texture_coordinates: The texture coordinates (optional)
"""
__slots__ = (
"x",
"y",
"width",
"height",
"texture_coordinates",
)
def __init__(
self,
atlas: "TextureAtlas",
x: int,
y: int,
width: int,
height: int,
texture_coordinates: Optional[Tuple[float, float, float, float, float, float, float, float]] = None,
):
self.x = x
self.y = y
self.width = width
self.height = height
# Calculate texture coordinates if not provided
if texture_coordinates:
self.texture_coordinates = texture_coordinates
else:
# start_x, start_y, width, height
# Width and height
_width = self.width / atlas.width
_height = self.height / atlas.height
# upper_left, upper_right, lower_left, lower_right
self.texture_coordinates = (
# upper_left
self.x / atlas.width,
self.y / atlas.height,
# upper_right
(self.x / atlas.width) + _width,
(self.y / atlas.height),
# lower_left
(self.x / atlas.width),
(self.y / atlas.height) + _height,
# lower_right
(self.x / atlas.width) + _width,
(self.y / atlas.height) + _height,
)
def verify_image_size(self, image_data: "ImageData"):
"""
Verify the image has the right size.
The internal image of a texture can be tampered with
at any point causing an atlas update to fail.
"""
if image_data.size != (self.width, self.height):
raise ValueError((
f"ImageData '{image_data.hash}' change their internal image "
f"size from {self.width}x{self.height} to "
f"{image_data.width}x{image_data.height}. "
"It's not possible to fit this into the old allocated area in the atlas. "
))
def __repr__(self) -> str:
return (
f"<AtlasRegion x={self.x} y={self.y} width={self.width} "
f"height={self.height} uvs={self.texture_coordinates}>"
)
class ImageDataRefCounter:
"""
Helper class to keep track of how many times an image is used
by a texture in the atlas to determine when it's safe to remove it.
"""
def __init__(self) -> None:
self._data: Dict[str, int] = {}
def inc_ref(self, image_data: "ImageData") -> None:
self._data[image_data.hash] = self._data.get(image_data.hash, 0) + 1
def dec_ref(self, image_data: "ImageData") -> None:
# TODO: Should we raise an error if the ref count is 0?
if image_data.hash not in self._data:
return
self._data[image_data.hash] -= 1
if self._data[image_data.hash] == 0:
del self._data[image_data.hash]
def get_refs(self, image_data: "ImageData") -> int:
return self._data.get(image_data.hash, 0)
def count_refs(self) -> int:
"""Helper function to count the total number of references."""
return sum(self._data.values())
def __len__(self) -> int:
return len(self._data)
[docs]
class TextureAtlas:
"""
A texture atlas with a size in a context.
A texture atlas is a large texture containing several textures
so OpenGL can easily batch draw thousands or hundreds of thousands
of sprites on one draw operation.
This is a fairly simple atlas that stores horizontal strips were
the height of the strip is the texture/image with the larges height.
Adding a texture to this atlas generates a texture id.
This id is used the sprite list vertex data to reference what
texture each sprite is using. The actual texture coordinates
are located in a float32 texture this atlas is responsible for
keeping up to date.
The atlas deals with image and textures. The image is the actual
image data. The texture is the arcade texture object that contains
the image and other information about such as transforms.
Several textures can share the same image with different transforms
applied. The transforms are simply changing the order of the texture
coordinates to flip, rotate or mirror the image.
:param Tuple[int, int] size: The width and height of the atlas in pixels
:param border: Currently no effect; Should always be 1 to avoid textures bleeding
:param textures: The texture for this atlas
:param auto_resize: Automatically resize the atlas when full
:param ctx: The context for this atlas (will use window context if left empty)
:param capacity: The number of textures the atlas keeps track of.
This is multiplied by 4096. Meaning capacity=2 is 8192 textures.
This value can affect the performance of the atlas.
"""
def __init__(
self,
size: Tuple[int, int],
*,
border: int = 1,
textures: Optional[Sequence["Texture"]] = None,
auto_resize: bool = True,
ctx: Optional["ArcadeContext"] = None,
capacity: int = 2,
):
self._ctx = ctx or arcade.get_window().ctx
self._max_size = self._ctx.info.MAX_VIEWPORT_DIMS
self._size: Tuple[int, int] = size
self._allocator = Allocator(*self._size)
self._auto_resize = auto_resize
self._border: int = border
if self._border < 0:
raise ValueError("Border must be 0 or a positive integer")
# Decides the number of texture and images the atlas can hold.
# Must be a multiple of UV_TEXTURE_WIDTH due texture coordinates being
# stored in a float32 texture.
if not isinstance(capacity, int) or capacity < 1:
raise ValueError("Capacity must be a positive integer")
self._num_image_slots = UV_TEXTURE_WIDTH * capacity # 16k
self._num_texture_slots = UV_TEXTURE_WIDTH * capacity # 16k
self._check_size(self._size)
# The atlas texture
self._texture = self._ctx.texture(
size,
components=4,
wrap_x=self._ctx.CLAMP_TO_EDGE,
wrap_y=self._ctx.CLAMP_TO_EDGE,
)
# Creating an fbo makes us able to clear the texture or parts
# of the texture including rendering to a part of the texture.
# This also means we can resize the atlas in the gpu
# by rendering the old atlas into the new one.
self._fbo = self._ctx.framebuffer(color_attachments=[self._texture])
# A dictionary of all the allocated regions for images in the atlas
# The key is the cache name for a texture
self._image_regions: Dict[str, AtlasRegion] = dict()
self._texture_regions: Dict[str, AtlasRegion] = dict()
# Ref counter for images and textures. Per atlas we need to keep
# track of ho many times an image is used in textures to determine
# when to remove an image from the atlas.
self._image_ref_count = ImageDataRefCounter()
# A list of all the images this atlas contains
self._images: WeakSet[ImageData] = WeakSet()
# A set of textures this atlas contains for fast lookups + set operations
self._textures: WeakSet["Texture"] = WeakSet()
# Texture containing texture coordinates for images and textures
# The 4096 width is a safe constant for all GL implementations
self._image_uv_texture = self._ctx.texture(
(UV_TEXTURE_WIDTH, self._num_texture_slots * 2 // UV_TEXTURE_WIDTH),
components=4,
dtype="f4",
)
self._texture_uv_texture = self._ctx.texture(
(UV_TEXTURE_WIDTH, self._num_image_slots * 2 // UV_TEXTURE_WIDTH),
components=4,
dtype="f4",
)
self._image_uv_texture.filter = self._ctx.NEAREST, self._ctx.NEAREST
self._texture_uv_texture.filter = self._ctx.NEAREST, self._ctx.NEAREST
self._image_uv_data = array("f", [0] * self._num_image_slots * 8)
self._texture_uv_data = array("f", [0] * self._num_texture_slots * 8)
# Free slots in the texture coordinate texture for images and textures
self._image_uv_slots_free = deque(i for i in range(0, self._num_image_slots))
self._texture_uv_slots_free = deque(i for i in range(0, self._num_texture_slots))
# Keep track of which slot each texture or image is in
self._image_uv_slots: Dict[str, int] = dict() # hash: slot
self._texture_uv_slots: Dict[str, int] = dict() # cache_name: slot
# Dirty flags for when texture coordinates are changed for each type
self._image_uv_data_changed = True
self._texture_uv_data_changed = True
# Add all the textures
for tex in textures or []:
self.add(tex)
@property
def width(self) -> int:
"""
The width of the texture atlas in pixels
"""
return self._size[0]
@property
def height(self) -> int:
"""
The height of the texture atlas in pixels
"""
return self._size[1]
@property
def size(self) -> Tuple[int, int]:
"""
The width and height of the texture atlas in pixels
"""
return self._size
@property
def max_width(self) -> int:
"""
The maximum width of the atlas in pixels
"""
return self._max_size[0]
@property
def max_height(self) -> int:
"""
The maximum height of the atlas in pixels
"""
return self._max_size[1]
@property
def max_size(self) -> Tuple[int, int]:
"""
The maximum size of the atlas in pixels (x, y)
"""
return self._max_size
@property
def auto_resize(self) -> bool:
"""
Get or set the auto resize flag for the atlas.
If enabled the atlas will resize itself when full.
"""
return self._auto_resize
@auto_resize.setter
def auto_resize(self, value: bool):
self._auto_resize = value
@property
def border(self) -> int:
"""
The texture border in pixels
"""
return self._border
@property
def texture(self) -> "Texture2D":
"""
The atlas texture.
"""
return self._texture
@property
def image_uv_texture(self) -> "Texture2D":
"""
Texture coordinate texture for images.
"""
return self._image_uv_texture
@property
def texture_uv_texture(self) -> "Texture2D":
"""
Texture coordinate texture for textures.
"""
return self._texture_uv_texture
@property
def fbo(self) -> Framebuffer:
"""The framebuffer object for this atlas"""
return self._fbo
@property
def textures(self) -> List["Texture"]:
"""
Return a list of all the textures in the atlas.
A new list is constructed from the internal weak set of textures.
"""
return list(self._textures)
@property
def images(self) -> List["ImageData"]:
"""
Return a list of all the images in the atlas.
A new list is constructed from the internal weak set of images.
"""
return list(self._images)
[docs]
def add(self, texture: "Texture") -> Tuple[int, AtlasRegion]:
"""
Add a texture to the atlas.
:param texture: The texture to add
:return: texture_id, AtlasRegion tuple
"""
# If the texture is already in the atlas we also have the image
# and can return early with the texture id and region
if self.has_texture(texture):
slot = self.get_texture_id(texture.atlas_name)
region = self.get_texture_region_info(texture.atlas_name)
return slot, region
LOG.info("Attempting to add texture: %s | %s", texture.atlas_name)
# Add the image if we don't already have it.
# If the atlas is full we will try to resize it.
if not self.has_image(texture.image_data):
try:
x, y, slot, region = self.allocate(texture.image_data)
except AllocatorException:
LOG.info("[%s] No room for %s size %s", id(self), texture.atlas_name, texture.image.size)
if self._auto_resize:
width = min(self.width * 2, self.max_width)
height = min(self.height * 2, self.max_height)
if self._size == (width, height):
raise
self.resize((width, height))
return self.add(texture)
else:
raise
self.write_image(texture.image_data.image, x, y)
self._image_ref_count.inc_ref(texture.image_data)
texture.add_atlas_ref(self)
return self._allocate_texture(texture)
def _allocate_texture(self, texture: "Texture") -> Tuple[int, AtlasRegion]:
"""
Add the texture to the atlas.
This reserves a slot in the texture coordinate texture
and returns the slot and region. The region is a copy of
the image region with the texture coordinates transformed
using the texture's vertex order.
"""
if len(self._texture_uv_slots_free) == 0:
raise AllocatorException((
"No more free texture slots in the atlas. "
f"Max number of slots: {self._num_texture_slots}"
))
# Add the texture to the atlas
existing_slot = self._texture_uv_slots.get(texture.atlas_name)
slot = existing_slot if existing_slot is not None else self._texture_uv_slots_free.popleft()
self._texture_uv_slots[texture.atlas_name] = slot
image_region = self.get_image_region_info(texture.image_data.hash)
texture_region = copy.deepcopy(image_region)
# Since we copy the original image region we can always apply the
# transform without worrying about multiple transforms.
texture_region.texture_coordinates = Transform.transform_texture_coordinates_order(
texture_region.texture_coordinates, texture._vertex_order
)
self._texture_regions[texture.atlas_name] = texture_region
# Put texture coordinates into uv buffer
offset = slot * 8
for i in range(8):
self._texture_uv_data[offset + i] = texture_region.texture_coordinates[i]
self._texture_uv_data_changed = True
self._textures.add(texture)
return slot, texture_region
[docs]
def allocate(self, image_data: "ImageData") -> Tuple[int, int, int, AtlasRegion]:
"""
Attempts to allocate space for an image in the atlas.
This doesn't write the texture to the atlas texture itself.
It only allocates space.
:return: The x, y texture_id, TextureRegion
"""
image = image_data.image
if len(self._image_uv_slots_free) == 0:
raise AllocatorException((
"No more free image slots in the atlas. "
f"Max number of slots: {self._num_image_slots}"
))
# Allocate space for texture
try:
x, y = self._allocator.alloc(
image.width + self._border * 2,
image.height + self._border * 2,
)
except AllocatorException:
raise AllocatorException(
f"No more space for image {image_data.hash} size={image.size}. "
f"Curr size: {self._size}. "
f"Max size: {self._max_size}"
)
LOG.debug("Allocated new space for image %s : %s %s", image_data.hash, x, y)
# Store a texture region for this allocation
# The xy position must be offset by the border size
# while the image size must stay as its true size
region = AtlasRegion(
self,
x + self._border,
y + self._border,
image.width,
image.height,
)
self._image_regions[image_data.hash] = region
# Get the existing slot for this texture or grab a new one.
# Existing slots for textures will only happen when re-building
# the atlas since we want to keep the same slots to avoid
# re-building the sprite list
existing_slot = self._image_uv_slots.get(image_data.hash)
slot = existing_slot if existing_slot is not None else self._image_uv_slots_free.popleft()
self._image_uv_slots[image_data.hash] = slot
# Put texture coordinates into uv buffer
offset = slot * 8
for i in range(8):
self._image_uv_data[offset + i] = region.texture_coordinates[i]
self._image_uv_data_changed = True
self._images.add(image_data)
return x, y, slot, region
# def write_texture(self, texture: "Texture", x: int, y: int):
# """
# Writes an arcade texture to a subsection of the texture atlas
# """
# self.write_image(texture.image, x, y)
[docs]
def write_image(self, image: PIL.Image.Image, x: int, y: int) -> None:
"""
Write a PIL image to the atlas in a specific region.
:param image: The pillow image
:param x: The x position to write the texture
:param y: The y position to write the texture
"""
# Write into atlas at the allocated location + border
viewport = (
x,
y,
image.width + self._border * 2,
image.height + self._border * 2,
)
# Only do extrusion if we have a border
if self._border > 0:
# Make new image with room for borders
tmp = Image.new(
'RGBA',
size=(
image.width + self._border * 2,
image.height + self._border * 2
),
color=(0, 0, 0, 0),
)
# Paste the image into the center of the new image
tmp.paste(image, (self._border, self._border))
# Copy 1 pixel strips from each side of the image to the border
# so we can repeat this pixel data in the border region
# left, top, right, bottom
strip_top = image.crop((0, 0, image.width, 1))
strip_bottom = image.crop((0, image.height - 1, image.width, image.height))
strip_left = image.crop((0, 0, 1, image.height))
strip_right = image.crop((image.width - 1, 0, image.width, image.height))
# Resize the strips to the border size if larger than 1
if self._border > 1:
strip_top = strip_top.resize((image.width, self._border), Image.NEAREST)
strip_bottom = strip_bottom.resize((image.width, self._border), Image.NEAREST)
strip_left = strip_left.resize((self._border, image.height), Image.NEAREST)
strip_right = strip_right.resize((self._border, image.height), Image.NEAREST)
tmp.paste(strip_top, (self._border, 0))
tmp.paste(strip_bottom, (self._border, tmp.height - self._border))
tmp.paste(strip_left, (0, self._border))
tmp.paste(strip_right, (tmp.width - self._border, self._border))
else:
tmp = image
# Write the image directly to graphics memory in the allocated space
self._texture.write(tmp.tobytes(), 0, viewport=viewport)
[docs]
def remove(self, texture: "Texture") -> None:
"""
Remove a texture from the atlas.
This doesn't erase the pixel data from the atlas texture
itself, but leaves the area unclaimed.
:param texture: The texture to remove
"""
self._textures.remove(texture)
# Reclaim the texture uv slot
del self._texture_regions[texture.atlas_name]
slot = self._texture_uv_slots[texture.atlas_name]
del self._texture_uv_slots[texture.atlas_name]
self._texture_uv_slots_free.appendleft(slot)
# Decrement the reference count for the image
self._image_ref_count.dec_ref(texture.image_data)
# print("Dec ref", texture.image_data.hash, self._image_ref_count.get_refs(texture.image_data))
# Reclaim the image in the atlas if it's not used by any other texture
if self._image_ref_count.get_refs(texture.image_data) == 0:
self._images.remove(texture.image_data)
del self._image_regions[texture.image_data.hash]
slot = self._image_uv_slots[texture.image_data.hash]
del self._image_uv_slots[texture.image_data.hash]
self._image_uv_slots_free.appendleft(slot)
# print("Reclaimed image", texture.image_data.hash)
[docs]
def update_texture_image(self, texture: "Texture"):
"""
Updates the internal image of a texture in the atlas texture.
The new image needs to be the exact same size as the original
one meaning the texture already need to exist in the atlas.
This can be used in cases were the image is manipulated in some way
and we need a quick way to sync these changes to graphics memory.
This operation is fairly expensive, but still orders of magnitude
faster than removing the old texture, adding the new one and
re-building the entire atlas.
:param texture: The texture to update
"""
region = self._image_regions[texture.image_data.hash]
region.verify_image_size(texture.image_data)
viewport = (
region.x,
region.y,
region.width,
region.height,
)
self._texture.write(texture.image.tobytes(), 0, viewport=viewport)
[docs]
def get_image_region_info(self, hash: str) -> AtlasRegion:
"""
Get the region info for and image by has
:param hash: The hash of the image
:return: The AtlasRegion for the given texture name
"""
return self._image_regions[hash]
[docs]
def get_texture_region_info(self, atlas_name: str) -> AtlasRegion:
"""
Get the region info for a texture by atlas name
:return: The AtlasRegion for the given texture name
"""
return self._texture_regions[atlas_name]
[docs]
def get_texture_id(self, atlas_name: str) -> int:
"""
Get the uv slot for a texture by atlas name
:param atlas_name: The name of the texture in the atlas
:return: The texture id for the given texture name
"""
return self._texture_uv_slots[atlas_name]
[docs]
def get_image_id(self, hash: str) -> int:
"""
Get the uv slot for a image by hash
:param hash: The hash of the image
:return: The texture id for the given texture name
"""
return self._image_uv_slots[hash]
[docs]
def has_texture(self, texture: "Texture") -> bool:
"""Check if a texture is already in the atlas"""
return texture in self._textures
[docs]
def has_image(self, image_data: "ImageData") -> bool:
"""Check if a image is already in the atlas"""
return image_data in self._images
[docs]
def resize(self, size: Tuple[int, int]) -> None:
"""
Resize the atlas on the gpu.
This will copy the pixel data from the old to the
new atlas retaining the exact same data.
This is useful if the atlas was rendered into directly
and we don't have to transfer each texture individually
from system memory to graphics memory.
:param size: The new size
"""
LOG.info("[%s] Resizing atlas from %s to %s", id(self), self._size, size)
# Only resize if the size actually changed
if size == self._size:
return
resize_start = time.perf_counter()
self._check_size(size)
self._size = size
# Keep the old atlas texture and uv texture
self._image_uv_texture.write(self._image_uv_data, 0)
image_uv_texture_old = self._image_uv_texture
# Keep a reference to the old atlas texture so we can copy it into the new one
atlas_texture_old = self._texture
# Create new image uv texture as input for the copy shader
self._image_uv_texture = self._ctx.texture(
(UV_TEXTURE_WIDTH, self._num_image_slots * 2 // UV_TEXTURE_WIDTH),
components=4,
dtype="f4",
)
# Create new atlas texture and framebuffer
self._texture = self._ctx.texture(size, components=4)
self._fbo = self._ctx.framebuffer(color_attachments=[self._texture])
# Store old images and textures before clearing the atlas
images = list(self._images)
textures = list(self._textures)
# Clear the atlas without wiping the image and texture ids
self.clear(clear_texture_ids=False, clear_image_ids=False, texture=False)
for image in sorted(images, key=lambda x: x.height):
self.allocate(image)
# Write the new image uv data
self._image_uv_texture.write(self._image_uv_data, 0)
self._image_uv_data_changed = False
# Update the texture regions. We need to copy the image regions
# and re-apply the transforms on each texture
for texture in textures:
self._allocate_texture(texture)
self.texture_uv_texture.write(self._texture_uv_data)
self._texture_uv_data_changed = False
# Bind textures for atlas copy shader
atlas_texture_old.use(0)
self._texture.use(1)
image_uv_texture_old.use(2)
self._image_uv_texture.use(3)
self._ctx.atlas_resize_program["border"] = float(self._border)
self._ctx.atlas_resize_program["projection"] = Mat4.orthogonal_projection(
0, self.width, self.height, 0, -100, 100,
)
with self._fbo.activate():
# Ensure no context flags are enabled
with self._ctx.enabled_only():
self._ctx.atlas_geometry.render(
self._ctx.atlas_resize_program,
mode=self._ctx.POINTS,
vertices=self.max_width,
)
duration = time.perf_counter() - resize_start
LOG.info("[%s] Atlas resize took %s seconds", id(self), duration)
# print(duration)
[docs]
def rebuild(self) -> None:
"""Rebuild the underlying atlas texture.
This method also tries to organize the textures more efficiently ordering them by size.
The texture ids will persist so the sprite list don't need to be rebuilt.
"""
# Hold a reference to the old textures
textures = list(self._textures)
# Clear the atlas but keep the uv slot mapping
self.clear(clear_image_ids=False, clear_texture_ids=False)
# Add textures back sorted by height to potentially make more room
for texture in sorted(textures, key=lambda x: x.image.size[1]):
self.add(texture)
[docs]
def clear(
self,
*,
clear_image_ids: bool = True,
clear_texture_ids: bool = True,
texture: bool = True,
) -> None:
"""
Clear and reset the texture atlas.
Note that also clearing "texture_ids" makes the atlas
lose track of the old texture ids. This
means the sprite list must be rebuild from scratch.
:param texture_ids: Clear the assigned texture ids
:param texture: Clear the contents of the atlas texture itself
"""
if texture:
self._fbo.clear()
self._textures = WeakSet()
self._images = WeakSet()
self._image_ref_count = ImageDataRefCounter()
self._image_regions = dict()
self._texture_regions = dict()
self._allocator = Allocator(*self._size)
if clear_image_ids:
self._image_uv_slots_free = deque(i for i in range(self._num_image_slots))
self._image_uv_slots = dict()
if clear_texture_ids:
self._texture_uv_slots_free = deque(i for i in range(self._num_texture_slots))
self._texture_uv_slots = dict()
[docs]
def use_uv_texture(self, unit: int = 0) -> None:
"""
Bind the texture coordinate texture to a channel.
In addition this method writes the texture
coordinate to the texture if the data is stale.
This is to avoid a full update every time a texture
is added to the atlas.
:param unit: The texture unit to bind the uv texture
"""
if self._image_uv_data_changed:
self._image_uv_texture.write(self._image_uv_data, 0)
self._image_uv_data_changed = False
if self._texture_uv_data_changed:
self._texture_uv_texture.write(self._texture_uv_data, 0)
self._texture_uv_data_changed = False
self._texture_uv_texture.use(unit)
[docs]
@contextmanager
def render_into(
self, texture: "Texture",
projection: Optional[Tuple[float, float, float, float]] = None,
):
"""
Render directly into a sub-section of the atlas.
The sub-section is defined by the already allocated space
of the texture supplied in this method.
By default the projection will be set to match the texture area size
were `0, 0` is the lower left corner and `width, height` (of texture)
is the upper right corner.
This method should should be used with the ``with`` statement::
with atlas.render_into(texture):
# Draw commands here
# Specify projection
with atlas.render_into(texture, projection=(0, 100, 0, 100))
# Draw geometry
:param texture: The texture area to render into
:param projection: The ortho projection to render with.
This parameter can be left blank if no projection changes are needed.
The tuple values are: (left, right, button, top)
"""
region = self._texture_regions[texture.atlas_name]
proj_prev = self._ctx.projection_2d
# Use provided projection or default
projection = projection or (0, region.width, 0, region.height)
# Flip the top and bottom because we need to render things upside down
projection = projection[0], projection[1], projection[3], projection[2]
self._ctx.projection_2d = projection
with self._fbo.activate() as fbo:
fbo.viewport = region.x, region.y, region.width, region.height
try:
yield fbo
finally:
fbo.viewport = 0, 0, *self._fbo.size
self._ctx.projection_2d = proj_prev
[docs]
@classmethod
def create_from_texture_sequence(cls, textures: Sequence["Texture"], border: int = 1) -> "TextureAtlas":
"""
Create a texture atlas of a reasonable size from a sequence of textures.
:param textures: A sequence of textures (list, set, tuple, generator etc.)
:param border: The border for the atlas in pixels (space between each texture)
"""
textures = sorted(set(textures), key=lambda x: x.image.size[1])
size = TextureAtlas.calculate_minimum_size(textures)
return TextureAtlas(size, textures=textures, border=border)
[docs]
@classmethod
def calculate_minimum_size(cls, textures: Sequence["Texture"], border: int = 1):
"""
Calculate the minimum atlas size needed to store the
the provided sequence of textures
:param textures: Sequence of textures
:param border: The border around each texture in pixels
:return: An estimated minimum size as a (width, height) tuple
"""
# Try to guess some sane minimum size to reduce the brute force iterations
total_area = sum(t.image.size[0] * t.image.size[1] for t in textures)
sqrt_size = int(math.sqrt(total_area))
start_size = sqrt_size or RESIZE_STEP
if start_size % RESIZE_STEP:
start_size = sqrt_size + (64 - sqrt_size % RESIZE_STEP)
# For now we just brute force a solution by gradually
# increasing the atlas size using the allocator as a guide.
for size in range(start_size, 16385, RESIZE_STEP):
allocator = Allocator(size, size)
try:
for texture in textures:
allocator.alloc(
texture.image.width + border * 2,
texture.image.height + border * 2,
)
except AllocatorException:
continue
break
else:
raise ValueError("Too many textures to fit into one atlas")
return size, size
[docs]
def get_texture_image(self, texture: "Texture") -> Image.Image:
"""
Get a Pillow image of a texture's region in the atlas.
This can be used to inspect the contents of the atlas
or to save the texture to disk.
:param texture: The texture to get the image for
:return: A pillow image containing the pixel data in the atlas
"""
region = self.get_image_region_info(texture.image_data.hash)
viewport = (
region.x + self._border,
region.y + self._border,
region.width,
region.height,
)
data = self.fbo.read(viewport=viewport, components=4)
return Image.frombytes("RGBA", (region.width, region.height), data)
[docs]
def sync_texture_image(self, texture: "Texture") -> None:
"""
Updates a texture's image with the contents in the
texture atlas. This is usually not needed, but if
you have altered a texture in the atlas directly
this can be used to copy the image data back into
the texture.
Updating the image will not change the texture's
hash or the texture's hit box points.
.. warning::
This method is somewhat expensive and should be used sparingly.
Altering the internal image of a texture is not recommended
unless you know exactly what you're doing. Textures are
supposed to be immutable.
:param texture: The texture to update
"""
texture.image_data.image = self.get_texture_image(texture)
[docs]
def to_image(
self,
flip: bool = False,
components: int = 4,
draw_borders: bool = False,
border_color: Tuple[int, int, int] = (255, 0, 0),
) -> Image.Image:
"""
Convert the atlas to a Pillow image.
Borders can also be drawn into the image to visualize the
regions of the atlas.
:param flip: Flip the image horizontally
:param components: Number of components. (3 = RGB, 4 = RGBA)
:param draw_borders: Draw region borders into image
:param color: RGB color of the borders
:return: A pillow image containing the atlas texture
"""
if components not in (3, 4):
raise ValueError(f"Components must be 3 or 4, not {components}")
mode = "RGBA"[:components]
image = Image.frombytes(
mode,
self._texture.size,
bytes(self._fbo.read(components=components)),
)
if draw_borders:
draw = ImageDraw.Draw(image)
for rg in self._image_regions.values():
p1 = rg.x, rg.y
p2 = rg.x + rg.width - 1, rg.y + rg.height - 1
draw.rectangle((p1, p2), outline=border_color, width=1)
if flip:
image = image.transpose(Image.Transpose.FLIP_TOP_BOTTOM)
return image
[docs]
def show(
self,
flip: bool = False,
components: int = 4,
draw_borders: bool = False,
border_color: Tuple[int, int, int] = (255, 0, 0),
) -> None:
"""
Show the texture atlas using Pillow.
Borders can also be drawn into the image to visualize the
regions of the atlas.
:param flip: Flip the image horizontally
:param components: Number of components. (3 = RGB, 4 = RGBA)
:param draw_borders: Draw region borders into image
:param color: RGB color of the borders
"""
self.to_image(
flip=flip,
components=components,
draw_borders=draw_borders,
border_color=border_color,
).show()
[docs]
def save(
self,
path: Union[str, Path],
flip: bool = False,
components: int = 4,
draw_borders: bool = False,
border_color: Tuple[int, int, int] = (255, 0, 0),
) -> None:
"""
Save the texture atlas to a png.
Borders can also be drawn into the image to visualize the
regions of the atlas.
:param path: The path to save the atlas on disk
:param flip: Flip the image horizontally
:param components: Number of components. (3 = RGB, 4 = RGBA)
:param color: RGB color of the borders
:return: A pillow image containing the atlas texture
"""
self.to_image(
flip=flip,
components=components,
draw_borders=draw_borders,
border_color=border_color,
).save(path, format="png")
def _check_size(self, size: Tuple[int, int]) -> None:
"""Check it the atlas exceeds the hardware limitations"""
if size[0] > self._max_size[0] or size[1] > self._max_size[1]:
raise ValueError(
"Attempting to create or resize an atlas to "
f"{size} past its maximum size of {self._max_size}"
)
[docs]
def print_contents(self):
"""Debug method to print the contents of the atlas"""
print("Textures:")
for texture in self._textures:
print("->", texture)
print("Images:")
for image in self._images:
print("->", image)