Eccelerators.Matrix

src/MatrixPainter.lvt

namespace Eccelerators.Matrix

/**
 * Portable bitmap drawing using borrowed display and bitmap contracts.
 * Own one painter per serialized drawing client in the shared context.
 * Display, bitmap and converter are borrowed separately for one drawing operation.
 */
component MatrixPainter
{
	/**
	 * Draw a borrowed bitmap at an offset, clipping to the display without clearing.
	 * Bitmap dimensions must be positive; calls are serialized in this context.
	 */
	public fn DrawBitmap(display: IMatrixDisplay, bitmap: IMatrixBitmap, left: int, top: int)
	{
		var displayWidth = display.GetWidth()
		var displayHeight = display.GetHeight()
		var width = bitmap.GetWidth()
		var height = bitmap.GetHeight()

		if (width <= 0 || height <= 0 || left >= displayWidth || top >= displayHeight || left <= -width || top <= -height) {
			return
		}

		for (var y = 0; y < displayHeight; y++) {
			for (var x = 0; x < displayWidth; x++) {
				if (x >= left && y >= top) {
					// Compare before subtracting to avoid overflowing at extreme offsets.
					if (left > x - width && top > y - height) {
						display.SetPixel(x, y, bitmap.GetPixel(x - left, y - top))
					}
				}
			}
		}
	}

	/**
	 * Initialize to black, draw at the origin and present the complete image.
	 */
	public fn ShowBitmap(display: IMatrixDisplay, bitmap: IMatrixBitmap) bool
	{
		display.Clear(0 as logic[24])
		var width = display.GetWidth()
		var height = display.GetHeight()
		var imageWidth = bitmap.GetWidth()
		var imageHeight = bitmap.GetHeight()

		for (var y = 0; y < height; y++) {
			for (var x = 0; x < width; x++) {
				if (x < imageWidth && y < imageHeight) {
					display.SetPixel(x, y, bitmap.GetPixel(x, y))
				}
			}
		}

		return display.Present()
	}

	/**
	 * Clears to black, converts each source pixel and presents the complete image.
	 * Keep converter settings stable until completion. Borrow each dependency
	 * through one drawing path; do not mix direct and borrowed Convert calls.
	 */
	public fn ShowConvertedBitmap(display: IMatrixDisplay, bitmap: IMatrixBitmap, converter: IColorConverter) bool
	{
		display.Clear(0 as logic[24])
		var width = display.GetWidth()
		var height = display.GetHeight()
		var imageWidth = bitmap.GetWidth()
		var imageHeight = bitmap.GetHeight()

		for (var y = 0; y < height; y++) {
			for (var x = 0; x < width; x++) {
				if (x < imageWidth && y < imageHeight) {
					var pixel = bitmap.GetPixel(x, y)
					var converted = converter.Convert(pixel)
					display.SetPixel(x, y, converted)
				}
			}
		}

		return display.Present()
	}
}