/*!The Treasure Box Library
 * 
 * TBox is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2.1 of the License, or
 * (at your option) any later version.
 * 
 * TBox is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with TBox; 
 * If not, see <a href="http://www.gnu.org/licenses/"> http://www.gnu.org/licenses/</a>
 * 
 * Copyright (C) 2009 - 2015, ruki All rights reserved.
 *
 * @author      ruki
 * @file        fixed6.h
 * @ingroup     math
 *
 */
#ifndef TB_MATH_FIXED6_H
#define TB_MATH_FIXED6_H

/* //////////////////////////////////////////////////////////////////////////////////////
 * includes
 */
#include "prefix.h"
#include "fixed16.h"

/* //////////////////////////////////////////////////////////////////////////////////////
 * extern
 */
__tb_extern_c_enter__

/* //////////////////////////////////////////////////////////////////////////////////////
 * macros
 */

// constant
#define TB_FIXED6_ONE                   (64)
#define TB_FIXED6_HALF                  (32)
#define TB_FIXED6_MAX                   (TB_MAXS32)
#define TB_FIXED6_MIN                   (TB_MINS32)
#define TB_FIXED6_NAN                   ((tb_int_t)0x80000000)
#define TB_FIXED6_INF                   (TB_MAXS32)
#define TB_FIXED6_PI                    (0xc9)
#define TB_FIXED6_SQRT2                 (0x5a)
#define TB_FIXED6_NEAR0                 (0)

// conversion
#ifdef TB_CONFIG_TYPE_HAVE_FLOAT
#   ifndef tb_fixed6_to_float
#       define tb_fixed6_to_float(x)    (((x) * 0.015625))
#   endif
#   ifndef tb_float_to_fixed6
#       define tb_float_to_fixed6(x)    ((tb_fixed6_t)((x) * TB_FIXED6_ONE))
#   endif
#endif

#ifdef __tb_debug__
#   define tb_int_to_fixed6(x)          tb_long_to_fixed6_check(x)
#   define tb_fixed6_to_int(x)          tb_fixed6_to_long_check(x)

#   define tb_long_to_fixed6(x)         tb_long_to_fixed6_check(x)
#   define tb_fixed6_to_long(x)         tb_fixed6_to_long_check(x)
#else
#   define tb_int_to_fixed6(x)          (tb_fixed6_t)((x) << 6)
#   define tb_fixed6_to_int(x)          (tb_int_t)((x) >> 6)

#   define tb_long_to_fixed6(x)         (tb_fixed6_t)((x) << 6)
#   define tb_fixed6_to_long(x)         (tb_long_t)((x) >> 6)
#endif

#define tb_fixed6_to_fixed16(x)         ((x) << 10)
#define tb_fixed16_to_fixed6(x)         ((x) >> 10)

// round
#define tb_fixed6_round(x)              (((x) + TB_FIXED6_HALF) >> 6)

// ceil
#define tb_fixed6_ceil(x)               (((x) + TB_FIXED6_ONE - 1) >> 6)

// floor
#define tb_fixed6_floor(x)              ((x) >> 6)

// abs
#define tb_fixed6_abs(x)                tb_abs(x)

// avg
#define tb_fixed6_avg(x, y)             (((x) + (y)) >> 1)
 
// nearly equal?
#define tb_fixed6_near_eq(x, y)         (tb_fixed6_abs((x) - (y)) <= TB_FIXED6_NEAR0)
    
// mul
#ifndef tb_fixed6_mul
#   define tb_fixed6_mul(x, y)          tb_fixed6_mul_inline(x, y)
#endif

// div
#ifndef tb_fixed6_div
#   define tb_fixed6_div(x, y)          tb_fixed6_div_inline(x, y)
#endif

// imul
#ifndef tb_fixed6_imul
#   define tb_fixed6_imul(x, y)         tb_fixed16_imul(x, y)
#endif

// idiv
#ifndef tb_fixed6_idiv
#   define tb_fixed6_idiv(x, y)         tb_fixed16_idiv(x, y)
#endif

// imuldiv
#ifndef tb_fixed6_imuldiv
#   define tb_fixed6_imuldiv(x, y, z)   tb_fixed16_imuldiv(x, y, z)
#endif

// imulsub
#ifndef tb_fixed6_imulsub
#   define tb_fixed6_imulsub(x, y, z)   tb_fixed16_imulsub(x, y, z)
#endif

// lsh
#ifndef tb_fixed6_lsh
#   define tb_fixed6_lsh(x, y)          tb_fixed16_lsh(x, y)
#endif
    
// rsh
#ifndef tb_fixed6_rsh
#   define tb_fixed6_rsh(x, y)          tb_fixed16_rsh(x, y)
#endif

/* //////////////////////////////////////////////////////////////////////////////////////
 * inlines
 */

#ifdef __tb_debug__
static __tb_inline__ tb_fixed6_t tb_long_to_fixed6_check(tb_long_t x)
{
    // check overflow
    tb_assert(x >= (TB_MINS32 >> 10) && x <= (TB_MAXS32 >> 10));

    // ok
    return (tb_fixed6_t)(x << 6);
}
static __tb_inline__ tb_long_t tb_fixed6_to_int_check(tb_fixed6_t x)
{
    // check overflow
    tb_assert(x >= TB_FIXED6_MIN && x <= TB_FIXED6_MAX);

    // ok
    return (tb_fixed6_t)(x >> 6);
}
#endif
static __tb_inline__ tb_fixed6_t tb_fixed6_mul_inline(tb_fixed6_t x, tb_fixed6_t y)
{
    // done
    tb_hong_t v = (((tb_hong_t)x * y) >> 6);

    // check overflow
    tb_assert(v == (tb_int32_t)v);

    // ok
    return (tb_fixed16_t)v;
}
static __tb_inline__ tb_fixed16_t tb_fixed6_div_inline(tb_fixed6_t x, tb_fixed6_t y)
{
    // check
    tb_assert(y);

    // no overflow? compute it fastly
    if (x == (tb_int16_t)x) return (x << 16) / y;
    
    // done
    return tb_fixed16_div(x, y);
}

/* //////////////////////////////////////////////////////////////////////////////////////
 * extern
 */
__tb_extern_c_leave__

#endif