# atlas.ludic — the namespaced spritesheet / atlas API (#81): load one sheet and
# address a cell by grid coords or by name, including sprites that span more than
# one cell, instead of one png_load per 16x16 file. Cells are sub-rects of the kept
# image, so they are not restricted to the 16x16 sprite table. Draws go through the
# camera / zoom / clip.
#
# Deterministic; a full run prints:  16 16 32 48 1 1 1 16 1
program AtlasDemo {
  # a model so the program runs the ECS and links the core runtime / framebuffer.
  property Cam { z: fixed = 1.0 }
  model V { Cam }

  function bi(b: bool) -> int { if b { return 1 };  return 0 }

  entry {
    let sheet = Sprite.sheet("assets/kenney/tiny-dungeon/Tilemap/tilemap_packed.png", 16, 16)
    let cell = Sprite.cell(sheet, 0, 0)
    print(Sprite.width(cell))                        # 16
    print(Sprite.height(cell))                       # 16

    let span = Sprite.cell_span(sheet, 0, 0, 2, 3)   # a sprite spanning 2x3 cells
    print(Sprite.width(span))                        # 32
    print(Sprite.height(span))                       # 48

    let d = Sprite.define("hero", sheet, 2, 3)       # name a cell
    print(bi(Sprite.named("hero") == d))             # 1 — looked up by name
    print(bi(Assets.get("hero") == d))               # 1 — Assets.get is the same lookup
    print(bi(Sprite.named("nope") == (-1)))       # 1 — an unknown name is -1

    let whole = Assets.image("assets/kenney/tiny-dungeon/Tiles/tile_0096.png")
    print(Sprite.width(whole))                       # 16 — a whole tile as one sprite

    # draw verification: clear, draw the tile, count non-transparent pixels drawn.
    Screen.clear(0)
    Sprite.draw(whole, 10, 10)
    var n = 0
    for yy in 10 .. 26 { for xx in 10 .. 26 { if Screen.pixel(xx, yy) != 0 { n += 1 } } }
    print(bi(n > 0))                                 # 1 — the sprite drew content
  }
}