David Gwilliam
bfd94fe046
- Add Canvas class for 2D surface management - Add CanvasStage for pipeline integration - Add FontStage as Transform for font rendering - Update Camera with x, y, w, h, zoom and guardrails - Add get_dimensions() to Display protocol
147 lines
4.4 KiB
Python
147 lines
4.4 KiB
Python
"""
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Canvas - 2D surface for rendering.
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The Canvas represents a full rendered surface that can be larger than the display.
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The Camera then defines the visible viewport into this canvas.
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"""
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from dataclasses import dataclass
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@dataclass
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class CanvasRegion:
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"""A rectangular region on the canvas."""
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x: int
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y: int
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width: int
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height: int
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def is_valid(self) -> bool:
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"""Check if region has positive dimensions."""
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return self.width > 0 and self.height > 0
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class Canvas:
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"""2D canvas for rendering content.
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The canvas is a 2D grid of cells that can hold text content.
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It can be larger than the visible viewport (display).
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Attributes:
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width: Total width in characters
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height: Total height in characters
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"""
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def __init__(self, width: int = 80, height: int = 24):
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self.width = width
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self.height = height
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self._grid: list[list[str]] = [
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[" " for _ in range(width)] for _ in range(height)
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]
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def clear(self) -> None:
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"""Clear the entire canvas."""
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self._grid = [[" " for _ in range(self.width)] for _ in range(self.height)]
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def get_region(self, x: int, y: int, width: int, height: int) -> list[list[str]]:
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"""Get a rectangular region from the canvas.
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Args:
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x: Left position
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y: Top position
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width: Region width
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height: Region height
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Returns:
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2D list of characters (height rows, width columns)
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"""
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region: list[list[str]] = []
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for py in range(y, y + height):
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row: list[str] = []
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for px in range(x, x + width):
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if 0 <= py < self.height and 0 <= px < self.width:
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row.append(self._grid[py][px])
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else:
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row.append(" ")
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region.append(row)
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return region
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def get_region_flat(self, x: int, y: int, width: int, height: int) -> list[str]:
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"""Get a rectangular region as flat list of lines.
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Args:
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x: Left position
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y: Top position
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width: Region width
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height: Region height
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Returns:
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List of strings (one per row)
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"""
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region = self.get_region(x, y, width, height)
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return ["".join(row) for row in region]
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def put_region(self, x: int, y: int, content: list[list[str]]) -> None:
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"""Put content into a rectangular region on the canvas.
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Args:
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x: Left position
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y: Top position
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content: 2D list of characters to place
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"""
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for py, row in enumerate(content):
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for px, char in enumerate(row):
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canvas_x = x + px
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canvas_y = y + py
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if 0 <= canvas_y < self.height and 0 <= canvas_x < self.width:
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self._grid[canvas_y][canvas_x] = char
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def put_text(self, x: int, y: int, text: str) -> None:
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"""Put a single line of text at position.
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Args:
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x: Left position
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y: Row position
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text: Text to place
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"""
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for i, char in enumerate(text):
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canvas_x = x + i
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if 0 <= canvas_x < self.width and 0 <= y < self.height:
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self._grid[y][canvas_x] = char
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def fill(self, x: int, y: int, width: int, height: int, char: str = " ") -> None:
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"""Fill a rectangular region with a character.
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Args:
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x: Left position
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y: Top position
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width: Region width
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height: Region height
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char: Character to fill with
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"""
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for py in range(y, y + height):
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for px in range(x, x + width):
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if 0 <= py < self.height and 0 <= px < self.width:
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self._grid[py][px] = char
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def resize(self, width: int, height: int) -> None:
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"""Resize the canvas.
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Args:
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width: New width
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height: New height
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"""
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if width == self.width and height == self.height:
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return
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new_grid: list[list[str]] = [[" " for _ in range(width)] for _ in range(height)]
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for py in range(min(self.height, height)):
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for px in range(min(self.width, width)):
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new_grid[py][px] = self._grid[py][px]
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self.width = width
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self.height = height
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self._grid = new_grid
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