.{Color} := @use("./lib.hb");
.{memory, log} := @use("../../stn/src/lib.hb")

Image := struct {
	buf: ^Color,
	width: i32,
	height: i32,
}

BitmapFileHeader := packed struct {
	img_type: u16,
	size: u32,
	reserved_1: u16,
	reserved_2: u16,
	offset: u32,
}

BitmapInfoHeader := packed struct {
	size: u32,
	width: i32,
	height: i32,
	planes: u16,
	bits: u16,
	compression: u32,
	image_size: u32,
	x_resolution: i32,
	y_resolution: i32,
	n_colours: u32,
	important_colours: u32,
}

BitmapColorHeader := packed struct {
	red_mask: u32,
	green_mask: u32,
	blue_mask: u32,
	alpha_mask: u32,
	color_space_type: u32,
	unused: u32,
}

from_bmp := fn(bmp: ^u8): Image {
	file_header := @as(^BitmapFileHeader, @bitcast(bmp))
	if file_header.img_type != 0x4D42 {
		log.error("failed to load bmp image: not a bmp image, idiot\0")
		return @as(Image, idk)
	}
	info_header := @as(^BitmapInfoHeader, @bitcast(bmp + @sizeof(BitmapFileHeader)))
	bmp += file_header.offset

	return .(@bitcast(bmp), @bitcast(info_header.width), @bitcast(info_header.height))
}