ludic/docs/language/screen/screen-put_pixel.md

id	name	category	kind	tokens	sig	tip	order	ns	member
screen-put_pixel	Screen.put_pixel	screen	namespace-method	Screen.put_pixel	Screen.put_pixel(x, y, color)	Set a single pixel at a pixel coordinate to one color.	3	Screen	put_pixel

Sets exactly one pixel at (x, y) to the given color — the finest-grained drawing operation Ludic offers. Reach for it when you are plotting individual points such as stars, particles, a scatter of sparks, or hand-drawn curves where a full rectangle would be too coarse. For anything larger than a point prefer Screen.fill_rectangle, since one call per pixel is far more expensive than one call per block. Coordinates are pixels from the top-left of the screen, and out-of-range coordinates are ignored.

Parameters:

• x — the pixel column, in pixels from the left of the screen
• y — the pixel row, in pixels from the top of the screen
• color — the pixel color, e.g. a Color.* name or a 0xRRGGBB literal

program Starfield {
  property Position { column: int = 0, row: int = 0 }
  model Star { Position }

  handler SeedStars phase Start {
    Random.seed(value: 1)
    for spawn_index in 0 .. 40 {
      spawn Star {
        Position {
          column: Random.range(low: 0, high: 255),
          row: Random.range(low: 0, high: 223)
        }
      }
    }
  }

  handler DrawWorld phase Render {
    Screen.clear(Color.MidnightBlue)
    for (Position) in query [Position, {Star}] {
      Screen.put_pixel(x: Position.column, y: Position.row, color: Color.White)
    }
    Screen.show()
  }
}