Difference between revisions of "Winglet"
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==Chess Engine== | ==Chess Engine== | ||
* [http://kirr.homeunix.org/chess/engines/Jim%20Ablett/WINGLET/ Index of /chess/engines/Jim Ablett/WINGLET] by [[Jim Ablett]], hosted by [[Kirill Kryukov]] | * [http://kirr.homeunix.org/chess/engines/Jim%20Ablett/WINGLET/ Index of /chess/engines/Jim Ablett/WINGLET] by [[Jim Ablett]], hosted by [[Kirill Kryukov]] | ||
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==Tutorial Archive== | ==Tutorial Archive== | ||
{{Winglet to Include}} | {{Winglet to Include}} | ||
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* [http://theflyingengineer.com/flightdeck/winglets-and-sharklets/ Winglets and Sharklets | The Flying Engineer] | * [http://theflyingengineer.com/flightdeck/winglets-and-sharklets/ Winglets and Sharklets | The Flying Engineer] | ||
* [http://www.b737.org.uk/winglets.htm Boeing 737 Winglets] | * [http://www.b737.org.uk/winglets.htm Boeing 737 Winglets] | ||
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=References= | =References= | ||
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[[Category:GPL]] | [[Category:GPL]] | ||
[[Category:WinBoard]] | [[Category:WinBoard]] | ||
| + | [[Category:Didactic]] | ||
Latest revision as of 17:15, 31 August 2020
Winglet [1]
Winglet,
a didactic open source chess engine by Stef Luijten, written in C++ and licensed under the GNU General Public License.
The development of Winglet was documented on the website tutorial Winglet, Writing a Chess Program in 99 Steps, started in 2011, now hosted by the Wayback Machine [2].
Winglet is intended as bitboard version of TSCP with WinBoard support [3],
and is loosely derived from Wing, Stef Luijten's former private engine [4],
in the meantime also open source [5].
Contents
Description
Board Representation
Winglet applies a mixture of Kindergarten Bitboards and Magic Bitboards [6] to determine sliding piece attacks with 32 KiB precalculated lookup tables[64][64] each on ranks, files, diagonals and anti-diagonals, indexed by square and hashed line occupancy - the inner six bits multiplied by a magic factor and shifted right by the strange looking 57, while 58 is more natural to ensure a six bit index range, using a constant factor (b-File) for all squares of a diagonal or anti-diagonal, ...
U64 arrDiagonalAttacks[64][64]] /* requires initialization */
U64 diagonalKindergartenAttacks(U64 occ, enumSquare sq) {
occ = (diagonalMaskEx[sq] & occ) * C64(0x0202020202020202) >> 58;
return arrDiagonalAttacks[sq][occ];
}
... but "magic" Winglet factors are designed such that the most significant bit of the 64-bit product will always be clear, that is positive if interpreted as signed 64-bit integer. It seems, Winglet's occupied index calculations emulate Wing's rotated bitboard indices for same attack table layout:
/* Winglet's occupancy state == Wing's occupancy state */ (occ & MG_DIAGA8H1MASK[sq]) * MG_DIAGA8H1MAGIC[sq] >> 57 == (occ045 >> DIAGA8H1_ATTACK_SHIFT[sq]) & 63 (occ & MG_DIAGA1H8MASK[sq]) * MG_DIAGA1H8MAGIC[sq] >> 57 == (occ315 >> DIAGA1H8_ATTACK_SHIFT[sq]) & 63 (occ & MG_FILEMASK[sq]) * MG_FILEMAGIC[sq]) >> 57 == (occ090 >> FILE_ATTACK_SHIFT[sq]) & 63
Search
- Iterative Deepening
- Alpha-Beta
- Principal Variation Search
- Quiescence Search
- MVV-LVA
- Static Exchange Evaluation
- Null Move Pruning
Evaluation
See also
- Chesser by Syed Fahad [7]
- Godot by Ulysse Carion [8]
- Kenny by Kenshin Himura [9] [10]
- Vajolet by Marco Belli [11]
- Wing by Stef Luijten
Forum Posts
- writing a chess engine in xx steps by wing, Winboard Forum, April 18, 2011
- Writing a chess program in xx steps by Stef Luijten, CCC, April 18, 2011
- Chess Programming/Concepts for Beginners by MoldyJacket, OpenChess Forum, April 18, 2011
External Links
Chess Engine
Tutorial Archive
- Winglet, Writing a Chess Program in 99 Steps by Stef Luijten, hosted by the Wayback Machine
- 01 Introduction - 05 First steps with Visual Studio C++
- 06 Reading user commands
- 07 Internal representation of the chess board - bitboards » Board Representation, Bitboards
- 08 Displaying the position » Chess Position
- 09 Reading a FEN string » Forsyth-Edwards Notation
- 10 Setting up the board manually
- 11 The move generator » Move Generation
- 12 Making the moves » Make Move
- 13 The evaluation function » Evaluation
- 14 Search » Search, Minimax, Alpha-Beta, PVS
- 15 Mate and draw detection » Checkmate, Stalemate
- 16 Repetition detection - Zobrist keys » Repetitions, Zobrist Keys
- 17 Iterative deepening and move ordering » Iterative Deepening, Move Ordering
- 18 Quiescence search and SEE » Quiescence Search, MVV-LVA, SEE
- 19 Null move pruning » Null Move Pruning
- 20 Time control and running test suites » Time Management
- 21 Connecting to Winboard » CECP, WinBoard
Misc
- Winglet from Wingtip device - Wikipedia
- Winglets and Sharklets | The Flying Engineer
- Boeing 737 Winglets
References
- ↑ Winglet with attached tufts of an KC-135A during NASA Winglet stu dy 1979. The tufts are needed to measure the airflow, Winglet from Wingtip device - Wikipedia, KC-135 EC79-11481: KC-135A in flight - closeup of winglet with attached tufts, August 20, 1979
- ↑ Winglet, Writing a Chess Program in 99 Steps by Stef Luijten, hosted by the Wayback Machine
- ↑ Writing a chess program in xx steps by Stef Luijten, CCC, April 18, 2011
- ↑ Winglet, Writing a Chess Program in 99 Steps by Stef Luijten, hosted by the Wayback Machine
- ↑ Index of /chess/engines/Jim Ablett/WING by Jim Ablett, hosted by Kirill Kryukov
- ↑ Writing a chess program in 99 steps - Move generation for sliding pieces by Stef Luijten, Wayback Machine
- ↑ Chesser: A Chess Engine derived from wingletx by Syed Fahad, CCC, December 24, 2014
- ↑ ucarion/godot · GitHub
- ↑ kenshinthebattosai/Kenny · GitHub
- ↑ New Winboard Engine 'Kenny' - JA builds available by Jim Ablett, CCC, January 08, 2013
- ↑ Re: where to start chess programming? by Marco Belli, CCC, June 22, 2014
