(*
* Hedgewars, a free turn based strategy game
* Copyright (c) 2004-2011 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, 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 FPC}
{$IFDEF ENDIAN_LITTLE}
type hwFloat = record
isNegative: boolean;
case byte of
0: (Frac, Round: Longword);
1: (QWordValue : QWord);
end;
{$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 : 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 hwSqrt(const t: 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 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.
{$IFDEF FPC}
{$J-}
{$ENDIF}
{$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_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_02: hwFloat = (isNegative: false; QWordValue: 85899345);
_0_03: hwFloat = (isNegative: false; QWordValue: 128849018);
_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_5: hwFloat = (isNegative: false; QWordValue: 4294967296 * 3 div 2);
_1_9: hwFloat = (isNegative: false; QWordValue: 8160437862);
_2: hwFloat = (isNegative: false; QWordValue: 4294967296 * 2);
_3: hwFloat = (isNegative: false; QWordValue: 4294967296 * 3);
_4: hwFloat = (isNegative: false; QWordValue: 4294967296 * 4);
_5: hwFloat = (isNegative: false; QWordValue: 4294967296 * 5);
_6: hwFloat = (isNegative: false; QWordValue: 4294967296 * 6);
_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);
_50: hwFloat = (isNegative: false; QWordValue: 4294967296 * 50);
_70: hwFloat = (isNegative: false; QWordValue: 4294967296 * 70);
_128: hwFloat = (isNegative: false; QWordValue: 4294967296 * 128);
_250: hwFloat = (isNegative: false; QWordValue: 4294967296 * 250);
_256: hwFloat = (isNegative: false; QWordValue: 4294967296 * 256);
_300: hwFloat = (isNegative: false; QWordValue: 4294967296 * 300);
_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}
{$ENDIF}
{$IFNDEF FPC}
type hwFloat = Extended;
{$ENDIF}
implementation
uses uSinTable;
{$IFDEF FPC}
function int2hwFloat (const i: LongInt) : hwFloat;
begin
int2hwFloat.isNegative:= i < 0;
int2hwFloat.Round:= abs(i);
int2hwFloat.Frac:= 0
end;
function hwFloat2Float (const i: hwFloat) : extended;
begin
hwFloat2Float:= i.QWordValue / $100000000;
if i.isNegative then hwFloat2Float:= -hwFloat2Float;
end;
operator + (const z1, z2: hwFloat) z : hwFloat;
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;
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;
operator - (const z1: hwFloat) z : hwFloat;
begin
z:= z1;
z.isNegative:= not z.isNegative
end;
operator * (const z1, z2: hwFloat) z : hwFloat;
begin
z.isNegative:= z1.isNegative xor z2.isNegative;
z.QWordValue:= QWord(z1.Round) * z2.Frac +
QWord(z1.Frac) * z2.Round +
((QWord(z1.Frac) * z2.Frac) shr 32);
z.Round:= z.Round + QWord(z1.Round) * z2.Round;
end;
operator * (const z1: hwFloat; const z2: LongInt) z : hwFloat;
begin
z.isNegative:= z1.isNegative xor (z2 < 0);
z.QWordValue:= z1.QWordValue * abs(z2)
end;
operator / (const z1: hwFloat; z2: hwFloat) z : hwFloat;
var t: hwFloat;
begin
z.isNegative:= z1.isNegative xor z2.isNegative;
z.Round:= z1.QWordValue div z2.QWordValue;
t:= z1 - z2 * z.Round;
if t.QWordValue = 0 then
z.Frac:= 0
else
begin
while ((t.QWordValue and $8000000000000000) = 0) and
((z2.QWordValue and $8000000000000000) = 0) do
begin
t.QWordValue:= t.QWordValue shl 1;
z2.QWordValue:= z2.QWordValue shl 1
end;
if z2.Round > 0 then z.Frac:= (t.QWordValue) div (z2.Round)
else z.Frac:= 0
end
end;
operator / (const z1: hwFloat; const z2: LongInt) z : hwFloat;
begin
z.isNegative:= z1.isNegative xor (z2 < 0);
z.QWordValue:= z1.QWordValue div abs(z2)
end;
operator < (const z1, z2: hwFloat) b : boolean;
begin
if z1.isNegative xor z2.isNegative then
b:= z1.isNegative
else
if z1.QWordValue = z2.QWordValue then
b:= false
else
b:= (z1.QWordValue < z2.QWordValue) xor z1.isNegative
end;
operator > (const z1, z2: hwFloat) b : boolean;
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) xor z2.isNegative
end;
function cstr(const z: hwFloat): shortstring;
var tmpstr: shortstring;
begin
str(z.Round, cstr);
if z.Frac <> 0 then
begin
str(z.Frac / $100000000:1:15, tmpstr);
delete(tmpstr, 1, 2);
cstr:= cstr + '.' + tmpstr
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;
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 hwSqrt(const t: hwFloat): hwFloat;
var l, r: QWord;
c: hwFloat;
begin
hwSqrt.isNegative:= false;
if t.Round = 0 then
begin
l:= t.QWordValue;
r:= $100000000
end else
begin
l:= $100000000;
r:= t.QWordValue div 2 + $80000000; // r:= t / 2 + 0.5
if r > $FFFFFFFFFFFF then r:= $FFFFFFFFFFFF
end;
repeat
c.QWordValue:= (l + r) div 2;
if hwSqr(c).QWordValue > t.QWordValue then r:= c.QWordValue else l:= c.QWordValue
until r - l <= 1;
hwSqrt.QWordValue:= l
end;
function Distance(const dx, dy: hwFloat): hwFloat;
begin
Distance:= hwSqrt(hwSqr(dx) + hwSqr(dy))
end;
function DistanceI(const dx, dy: LongInt): hwFloat;
begin
DistanceI:= hwSqrt(int2hwFloat(sqr(dx) + sqr(dy)))
end;
function SignAs(const num, signum: hwFloat): hwFloat;
begin
SignAs.QWordValue:= num.QWordValue;
SignAs.isNegative:= signum.isNegative
end;
function hwSign(r: hwFloat): LongInt;
begin
// yes, we have negative zero for a reason
if r.isNegative then hwSign:= -1 else hwSign:= 1
end;
function AngleSin(const Angle: Longword): hwFloat;
begin
//TryDo((Angle >= 0) and (Angle <= 2048), 'Sin param exceeds limits', true);
AngleSin.isNegative:= false;
if Angle < 1024 then AngleSin.QWordValue:= SinTable[Angle]
else AngleSin.QWordValue:= SinTable[2048 - Angle]
end;
function AngleCos(const Angle: Longword): hwFloat;
begin
//TryDo((Angle >= 0) and (Angle <= 2048), 'Cos param exceeds limits', true);
AngleCos.isNegative:= Angle > 1024;
if Angle < 1024 then AngleCos.QWordValue:= SinTable[1024 - Angle]
else AngleCos.QWordValue:= SinTable[Angle - 1024]
end;
{$ENDIF}
end.