~arkadini/fogg/trunk

import org.xiph.system.Bytes;

import flash.Vector;

class System {

    /*

     * Note: modifies .position of both src and dst!

     */

    public static inline function

    bytescopy(src : Bytes, src_pos : Int,

              dst : Bytes, dst_pos : Int, length : Int) : Void {

        src.position = src_pos;

        if (src == dst && dst_pos > src_pos) {

            var tmp : Bytes = new Bytes();

            tmp.length = length;

            src.readBytes(tmp, 0, length);

            tmp.position = 0;

            tmp.readBytes(dst, dst_pos, length);

        } else {

            src.readBytes(dst, dst_pos, length);

        }

    }

    /*

     * That one, though a tiny bit faster, doesn't handle overlapping if:

     * - src and dst are the same object, and

     * - dst_pos > src_pos

     */

    public static inline function

    unsafe_bytescopy(src : Bytes, src_pos : Int,

                     dst : Bytes, dst_pos : Int, length : Int) : Void {

        src.position = src_pos;

        src.readBytes(dst, dst_pos, length);

    }

    public static inline function

    fromString(str : String) : Bytes {

        var b = new Bytes();

        b.writeUTFBytes(str);

        b.position = 0;

        return b;

    }

    public static inline function

    fromBytes(b : Bytes, start : Int, length : Int) : String {

        b.position = start;

        return b.readUTFBytes(length);

    }

    public static function

    alloc(size : Int) : Bytes {

        var b = new Bytes();

        b.length = size;

        b[size - 1] = 0;

        b.position = 0;

        return b;

    }

    public static inline function

    resize(b : Bytes, new_size : Int) : Void {

        b.length = new_size;

        // do we need to do: "b[new_size - 1] = 0" (even if only when growing)?

    }

    public static inline function

    abs(n : Int) : Int {

        return n < 0 ? -n : n;

    }

    public static inline function

    max(a : Int, b : Int) : Int {

        return a > b ? a : b;

    }

    public static function

    floatToIntBits(value : Float) : Int {

        var b : Bytes = new Bytes();

        b.writeFloat(value);

        b.position = 0;

        var i : Int = b.readInt();

        return i;

    }

    public static function

    intBitsToFloat(value : Int) : Float {

        var b : Bytes = new Bytes();

        b.writeInt(value);

        b.position = 0;

        var f : Float = b.readFloat();

        return f;

    }

}