(*

 * Hedgewars, a free turn based strategy game

 * Copyright (c) 2004-2015 Andrey Korotaev <unC0Rr@gmail.com>

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; version 2 of the License

 *

 * This program 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 General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

 *)

{$INCLUDE "options.inc"}

unit uFloat;

(*

 * This unit provides a custom data type, hwFloat.

 *

 * hwFloat represents a floating point number - the value and operations

 * of this numbers are independent from the hardware architecture

 * the game runs on.

 *

 * This is important for calculations that affect the course of the game

 * and would lead to different results if based on a hardware dependent

 * data type.

 *

 * Note: Not all comparisons are implemented.

 *

 * Note: Below you'll find a list of hwFloat constants:

 *       E.g. _1 is an hwFloat with value 1.0, and -_0_9 is -0.9

 *       Use and extend the list if needed, rather than using int2hwFloat()

 *       with integer constants.

 *)

interface

{$IFDEF ENDIAN_LITTLE}

type hwFloat = record

    isNegative: boolean;

    case byte of

        0: (Frac, Round: Longword);

        1: (QWordValue : QWord);

        end;

{$ELSE}

type hwFloat = record

    isNegative: boolean;

    case byte of

    0: (Round, Frac: Longword);

    1: (QWordValue : QWord);

    end;

{$ENDIF}

// Returns an hwFloat that represents the value of integer parameter i

function int2hwFloat (const i: LongInt) : hwFloat; inline;

function hwFloat2Float (const i: hwFloat) : extended; inline;

// The implemented operators

operator = (const z1, z2: hwFloat) z : boolean; inline;

{$IFDEF PAS2C}

operator <> (const z1, z2: hwFloat) z : boolean; inline;

{$ENDIF}

operator + (const z1, z2: hwFloat) z : hwFloat; inline;

operator - (const z1, z2: hwFloat) z : hwFloat; inline;

operator - (const z1: hwFloat) z : hwFloat; inline;

operator * (const z1, z2: hwFloat) z : hwFloat; inline;

operator * (const z1: hwFloat; const z2: LongInt) z : hwFloat; inline;

operator / (const z1: hwFloat; z2: hwFloat) z : hwFloat; inline;

operator / (const z1: hwFloat; const z2: LongInt) z : hwFloat; inline;

operator < (const z1, z2: hwFloat) b : boolean; inline;

operator > (const z1, z2: hwFloat) b : boolean; inline;

// Various functions for hwFloat (some are inlined in the resulting code for better performance)

function cstr(const z: hwFloat): shortstring; // Returns a shortstring representations of the hwFloat.

function hwRound(const t: hwFloat): LongInt; inline; // Does NOT really round but returns the integer representation of the hwFloat without fractional digits. (-_0_9 -> -0, _1_5 -> _1)

function hwAbs(const t: hwFloat): hwFloat; inline; // Returns the value of t with positive sign.

function hwSqr(const t: hwFloat): hwFloat; inline; // Returns the square value of parameter t.

function hwSqrt1(const t: hwFloat): hwFloat; inline; // Returns the the positive square root of parameter t.

function hwSqrt(const x: hwFloat): hwFloat; inline; // Returns the the positive square root of parameter t.

function Distance(const dx, dy: hwFloat): hwFloat; // Returns the distance between two points in 2-dimensional space, of which the parameters are the horizontal and vertical distance.

function DistanceI(const dx, dy: LongInt): hwFloat; // Same as above for integer parameters.

function AngleSin(const Angle: Longword): hwFloat;

function AngleCos(const Angle: Longword): hwFloat;

function vector2Angle(const x, y: hwFloat): LongInt;

function SignAs(const num, signum: hwFloat): hwFloat; inline; // Returns an hwFloat with the value of parameter num and the sign of signum.

function hwSign(r: hwFloat): LongInt; inline; // Returns an integer with value 1 and sign of parameter r.

function hwSignf(r: real): LongInt; inline; // Returns an integer with value 1 and sign of parameter r.

function isZero(const z: hwFloat): boolean; inline;

{$WARNINGS OFF}

// some hwFloat constants

const  _1div1024: hwFloat = (isNegative: false; QWordValue:     4194304);

      _1div10000: hwFloat = (isNegative: false; QWordValue:      429496);

      _1div50000: hwFloat = (isNegative: false; QWordValue:       85899);

     _1div100000: hwFloat = (isNegative: false; QWordValue:       42950);

          _1div3: hwFloat = (isNegative: false; QWordValue:  1431655766);

            hwPi: hwFloat = (isNegative: false; QWordValue: 13493037704);

       _0_000004: hwFloat = (isNegative: false; QWordValue:       17179);

       _0_000064: hwFloat = (isNegative: false; QWordValue:      274878);

         _0_0002: hwFloat = (isNegative: false; QWordValue:      858993);

         _0_0005: hwFloat = (isNegative: false; QWordValue:     2147484);

          _0_001: hwFloat = (isNegative: false; QWordValue:     4294967);

          _0_003: hwFloat = (isNegative: false; QWordValue:    12884902);

         _0_0032: hwFloat = (isNegative: false; QWordValue:    13743895);

          _0_004: hwFloat = (isNegative: false; QWordValue:    17179869);

          _0_005: hwFloat = (isNegative: false; QWordValue:    21474836);

          _0_008: hwFloat = (isNegative: false; QWordValue:    34359738);

           _0_01: hwFloat = (isNegative: false; QWordValue:    42949673);

         _0_0128: hwFloat = (isNegative: false; QWordValue:    54975581);

           _0_02: hwFloat = (isNegative: false; QWordValue:    85899345);

           _0_03: hwFloat = (isNegative: false; QWordValue:   128849018);

           _0_05: hwFloat = (isNegative: false; QWordValue:   214748365);

           _0_07: hwFloat = (isNegative: false; QWordValue:   300647710);

           _0_08: hwFloat = (isNegative: false; QWordValue:   343597383);

            _0_1: hwFloat = (isNegative: false; QWordValue:   429496730);

           _0_15: hwFloat = (isNegative: false; QWordValue:   644245094);

            _0_2: hwFloat = (isNegative: false; QWordValue:   858993459);

           _0_25: hwFloat = (isNegative: false; QWordValue:  1073741824);

            _0_3: hwFloat = (isNegative: false; QWordValue:  1288490189);

           _0_35: hwFloat = (isNegative: false; QWordValue:  1503238553);

          _0_375: hwFloat = (isNegative: false; QWordValue:  4294967296 * 3 div 8);

           _0_39: hwFloat = (isNegative: false; QWordValue:  1675037245);

            _0_4: hwFloat = (isNegative: false; QWordValue:  1717986918);

           _0_45: hwFloat = (isNegative: false; QWordValue:  1932735283);

            _0_5: hwFloat = (isNegative: false; QWordValue:  2147483648);

           _0_55: hwFloat = (isNegative: false; QWordValue:  2362232012);

            _0_6: hwFloat = (isNegative: false; QWordValue:  2576980377);

           _0_64: hwFloat = (isNegative: false; QWordValue:  2748779064);

            _0_7: hwFloat = (isNegative: false; QWordValue:  3006477107);

            _0_8: hwFloat = (isNegative: false; QWordValue:  3435973837);

           _0_84: hwFloat = (isNegative: false; QWordValue:  3607772528);

           _0_87: hwFloat = (isNegative: false; QWordValue:  3736621547);

            _0_9: hwFloat = (isNegative: false; QWordValue:  3865470566);

           _0_93: hwFloat = (isNegative: false; QWordValue:  3994319585);

           _0_96: hwFloat = (isNegative: false; QWordValue:  4123168604);

          _0_995: hwFloat = (isNegative: false; QWordValue:  4273492459);

          _0_999: hwFloat = (isNegative: false; QWordValue:  4290672328);

              _0: hwFloat = (isNegative: false; QWordValue:           0);

              _1: hwFloat = (isNegative: false; QWordValue:  4294967296);

            _1_2: hwFloat = (isNegative: false; QWordValue:  4294967296 * 6 div 5 + 1);

            _1_5: hwFloat = (isNegative: false; QWordValue:  4294967296 * 3 div 2);

            _1_6: hwFloat = (isNegative: false; QWordValue:  4294967296 * 8 div 5);

            _1_9: hwFloat = (isNegative: false; QWordValue:  8160437862);

              _2: hwFloat = (isNegative: false; QWordValue:  4294967296 * 2);

            _2_4: hwFloat = (isNegative: false; QWordValue:  4294967296 * 12 div 5);

              _3: hwFloat = (isNegative: false; QWordValue:  4294967296 * 3);

            _3_2: hwFloat = (isNegative: false; QWordValue:  4294967296 * 16 div 5);

             _PI: hwFloat = (isNegative: false; QWordValue: 13493037704);

              _4: hwFloat = (isNegative: false; QWordValue:  4294967296 * 4);

            _4_5: hwFloat = (isNegative: false; QWordValue:  4294967296 * 9 div 2);

              _5: hwFloat = (isNegative: false; QWordValue:  4294967296 * 5);

              _6: hwFloat = (isNegative: false; QWordValue:  4294967296 * 6);

            _6_4: hwFloat = (isNegative: false; QWordValue:  4294967296 * 32 div 5);

              _7: hwFloat = (isNegative: false; QWordValue:  4294967296 * 7);

             _10: hwFloat = (isNegative: false; QWordValue:  4294967296 * 10);

             _12: hwFloat = (isNegative: false; QWordValue:  4294967296 * 12);

             _16: hwFloat = (isNegative: false; QWordValue:  4294967296 * 16);

             _19: hwFloat = (isNegative: false; QWordValue:  4294967296 * 19);

             _20: hwFloat = (isNegative: false; QWordValue:  4294967296 * 20);

             _25: hwFloat = (isNegative: false; QWordValue:  4294967296 * 25);

             _30: hwFloat = (isNegative: false; QWordValue:  4294967296 * 30);

             _40: hwFloat = (isNegative: false; QWordValue:  4294967296 * 40);

             _41: hwFloat = (isNegative: false; QWordValue:  4294967296 * 41);

             _49: hwFloat = (isNegative: false; QWordValue:  4294967296 * 49);

             _50: hwFloat = (isNegative: false; QWordValue:  4294967296 * 50);

             _70: hwFloat = (isNegative: false; QWordValue:  4294967296 * 70);

             _90: hwFloat = (isNegative: false; QWordValue:  4294967296 * 90);

            _128: hwFloat = (isNegative: false; QWordValue:  4294967296 * 128);

            _180: hwFloat = (isNegative: false; QWordValue:  4294967296 * 180);

            _250: hwFloat = (isNegative: false; QWordValue:  4294967296 * 250);

            _256: hwFloat = (isNegative: false; QWordValue:  4294967296 * 256);

            _300: hwFloat = (isNegative: false; QWordValue:  4294967296 * 300);

            _360: hwFloat = (isNegative: false; QWordValue:  4294967296 * 360);

            _450: hwFloat = (isNegative: false; QWordValue:  4294967296 * 450);

           _1000: hwFloat = (isNegative: false; QWordValue:  4294967296 * 1000);

           _1024: hwFloat = (isNegative: false; QWordValue:  4294967296 * 1024);

           _2048: hwFloat = (isNegative: false; QWordValue:  4294967296 * 2048);

           _4096: hwFloat = (isNegative: false; QWordValue:  4294967296 * 4096);

          _10000: hwFloat = (isNegative: false; QWordValue:  4294967296 * 10000);

         cLittle: hwFloat = (isNegative: false; QWordValue:           1);

         cHHKick: hwFloat = (isNegative: false; QWordValue:    42949673);  // _0_01

{$WARNINGS ON}

implementation

uses uSinTable;

function int2hwFloat (const i: LongInt) : hwFloat; inline;

begin

int2hwFloat.isNegative:= i < 0;

int2hwFloat.Round:= abs(i);

int2hwFloat.Frac:= 0

end;

function hwFloat2Float (const i: hwFloat) : extended; inline;

begin

hwFloat2Float:= i.Frac / $100000000 + i.Round;

if i.isNegative then

    hwFloat2Float:= -hwFloat2Float;

end;

operator = (const z1, z2: hwFloat) z : boolean; inline;

begin

    z:= (z1.isNegative = z2.isNegative) and (z1.QWordValue = z2.QWordValue);

end;

{$IFDEF PAS2C}

operator <> (const z1, z2: hwFloat) z : boolean; inline;

begin

    z:= (z1.isNegative <> z2.isNegative) or (z1.QWordValue <> z2.QWordValue);

end;

{$ENDIF}

operator + (const z1, z2: hwFloat) z : hwFloat; inline;

begin

if z1.isNegative = z2.isNegative then

    begin

    z.isNegative:= z1.isNegative;

    z.QWordValue:= z1.QWordValue + z2.QWordValue

    end

else

    if z1.QWordValue > z2.QWordValue then

        begin

        z.isNegative:= z1.isNegative;

        z.QWordValue:= z1.QWordValue - z2.QWordValue

        end

    else

        begin

        z.isNegative:= z2.isNegative;

        z.QWordValue:= z2.QWordValue - z1.QWordValue

        end

end;

operator - (const z1, z2: hwFloat) z : hwFloat; inline;

begin

if z1.isNegative = z2.isNegative then

    if z1.QWordValue > z2.QWordValue then

        begin

        z.isNegative:= z1.isNegative;

        z.QWordValue:= z1.QWordValue - z2.QWordValue

        end

    else

        begin

        z.isNegative:= not z2.isNegative;

        z.QWordValue:= z2.QWordValue - z1.QWordValue

        end

else

    begin

    z.isNegative:= z1.isNegative;

    z.QWordValue:= z1.QWordValue + z2.QWordValue

    end

end;

function isZero(const z: hwFloat): boolean; inline;

begin

isZero := z.QWordValue = 0;

end;

operator < (const z1, z2: hwFloat) b : boolean; inline;

begin

if z1.isNegative xor z2.isNegative then

    b:= z1.isNegative

else

    if z1.QWordValue = z2.QWordValue then

        b:= false

    else

        b:= (z2.QWordValue < z1.QWordValue) = z1.isNegative

end;

operator > (const z1, z2: hwFloat) b : boolean; inline;

begin

if z1.isNegative xor z2.isNegative then

    b:= z2.isNegative

else

    if z1.QWordValue = z2.QWordValue then

        b:= false

    else

        b:= (z1.QWordValue > z2.QWordValue) <> z2.isNegative

end;

operator - (const z1: hwFloat) z : hwFloat; inline;

begin

    z:= z1;

    z.isNegative:= not z.isNegative

end;

operator * (const z1, z2: hwFloat) z : hwFloat; inline;

begin

    z.isNegative:= z1.isNegative xor z2.isNegative;

end;

operator * (const z1: hwFloat; const z2: LongInt) z : hwFloat; inline;

begin

    z.isNegative:= z1.isNegative xor (z2 < 0);

    z.QWordValue:= z1.QWordValue * abs(z2)

end;

operator / (const z1: hwFloat; z2: hwFloat) z : hwFloat; inline;

var t: QWord;

begin

    z.isNegative:= z1.isNegative xor z2.isNegative;

    z.Round:= z1.QWordValue div z2.QWordValue;

    t:= z1.QWordValue - z2.QWordValue * z.Round;

    z.Frac:= 0;

    if t <> 0 then

        begin

        while ((t and $FF00000000000000) = 0) and ((z2.QWordValue and $FF00000000000000) = 0) do

            begin

            t:= t shl 8;

            z2.QWordValue:= z2.QWordValue shl 8

            end;

        if z2.Round > 0 then

            inc(z.QWordValue, t div z2.Round);

        end

end;

operator / (const z1: hwFloat; const z2: LongInt) z : hwFloat; inline;

begin

    z.isNegative:= z1.isNegative xor (z2 < 0);

    z.QWordValue:= z1.QWordValue div abs(z2)

end;

function cstr(const z: hwFloat): shortstring;

var tmpstr: shortstring;

begin

    str(z.Round, cstr);

    if z.Frac <> 0 then

        begin

        str(z.Frac / $100000000, tmpstr);

        delete(tmpstr, 1, 2);

        cstr:= cstr + '.' + copy(tmpstr, 1, 10)

        end;

    if z.isNegative then

        cstr:= '-' + cstr

end;

function hwRound(const t: hwFloat): LongInt;

begin

    if t.isNegative then

        hwRound:= -(t.Round and $7FFFFFFF)

    else

        hwRound:= t.Round and $7FFFFFFF

end;

function hwAbs(const t: hwFloat): hwFloat;

begin

    hwAbs:= t;

    hwAbs.isNegative:= false

end;

function hwSqr(const t: hwFloat): hwFloat; inline;

begin

    hwSqr.isNegative:= false;

    hwSqr.QWordValue:= ((QWord(t.Round) * t.Round) shl 32) + QWord(t.Round) * t.Frac * 2 + ((QWord(t.Frac) * t.Frac) shr 32);

end;

function hwSqrt1(const t: hwFloat): hwFloat;

const pwr = 8; // even value, feel free to adjust

      rThreshold: QWord = QWord(1) shl (pwr + 32);

      lThreshold: QWord = QWord(1) shl (pwr div 2 + 32);

var l, r: QWord;

    c: hwFloat;

begin

    hwSqrt1.isNegative:= false;

    if t.Round = 0 then

        begin

        l:= t.QWordValue;

        r:= $100000000

        end

    else

        begin

        if t.QWordValue > $FFFFFFFFFFFF then // t.Round > 65535.9999

            begin

            l:= $10000000000; // 256

            r:= $FFFFFFFFFFFF; // 65535.9999

            end

        else

            if t.QWordValue >= rThreshold then

                begin

                l:= lThreshold;

                r:= $10000000000; // 256

                end

            else

                begin

                l:= $100000000;

                r:= lThreshold;

                end;

    end;

    repeat

        c.QWordValue:= (l + r) shr 1;

        if hwSqr(c).QWordValue > t.QWordValue then

            r:= c.QWordValue

        else

            l:= c.QWordValue

    until r - l <= 1;

    hwSqrt1.QWordValue:= l

end;

function hwSqrt(const x: hwFloat): hwFloat;

var r, t, s, q: QWord;

    i: integer;

begin

    hwSqrt.isNegative:= false;

    t:= $4000000000000000;

    r:= 0;

    q:= x.QWordValue;

    for i:= 0 to 31 do

        begin

        s:= r + t;

        r:= r shr 1;

        if s <= q then

            begin

            dec(q, s);

            inc(r, t);

            end;

        t:= t shr 2;

        end;

    hwSqrt.QWordValue:= r shl 16

end;

function Distance(const dx, dy: hwFloat): hwFloat;

var r: QWord;

begin

    r:= dx.QWordValue or dy.QWordValue;

    if r < $10000 then

        begin

        Distance.QWordValue:= r;

        Distance.isNegative:= false

        end

    else

        Distance:= hwSqrt(hwSqr(dx) + hwSqr(dy))

end;

function DistanceI(const dx, dy: LongInt): hwFloat;

begin

    DistanceI:= hwSqrt(int2hwFloat(sqr(dx) + sqr(dy)))

end;

function SignAs(const num, signum: hwFloat): hwFloat;

begin

    SignAs.QWordValue:= num.QWordValue;

    SignAs.isNegative:= signum.isNegative

end;

function hwSign(r: hwFloat): LongInt;

begin

// yes, we have negative zero for a reason

if r.isNegative then

    hwSign:= -1