25,161
edits
Changes
Created page with "'''Home * Engines * Winglet''' FILE:Winglet with attached tufts of an KC-135A.jpg|border|right|thumb| Winglet <ref>Winglet with attached [https://en.wikip..."
'''[[Main Page|Home]] * [[Engines]] * Winglet'''
[[FILE:Winglet with attached tufts of an KC-135A.jpg|border|right|thumb| Winglet <ref>Winglet with attached [https://en.wikipedia.org/wiki/Tuft_%28aeronautics%29 tufts] of an [https://en.wikipedia.org/wiki/Boeing_KC-135_Stratotanker KC-135A] during [https://en.wikipedia.org/wiki/NASA NASA] Winglet stu dy 1979. The tufts are needed to measure the [https://en.wikipedia.org/wiki/Airflow airflow], [https://en.wikipedia.org/wiki/Wingtip_device#Winglet Winglet from Wingtip device - Wikipedia], [http://www.dfrc.nasa.gov/Gallery/Photo/KC-135/HTML/EC79-11481.html KC-135 EC79-11481: KC-135A in flight - closeup of winglet with attached tufts], August 20, 1979</ref> ]]
'''Winglet''',<br/>
a didactic [[:Category:Open Source|open source chess engine]] by [[Stef Luijten]], written in [[Cpp|C++]] and licensed under the [[Free Software Foundation#GPL|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 [https://en.wikipedia.org/wiki/Wayback_Machine Wayback Machine] <ref>[http://web.archive.org/web/20120621100214/http://www.sluijten.com/winglet/ Winglet, Writing a Chess Program in 99 Steps] by [[Stef Luijten]], hosted by the [https://en.wikipedia.org/wiki/Wayback_Machine Wayback Machine]</ref>.
Winglet is intended as [[Bitboards|bitboard]] version of [[TSCP]] with [[WinBoard]] support <ref>[http://www.talkchess.com/forum/viewtopic.php?t=38787 Writing a chess program in xx steps] by [[Stef Luijten]], [[CCC]], April 18, 2011</ref>,
and is loosely derived from [[Wing]], Stef Luijten's former private engine <ref>[http://web.archive.org/web/20120621100214/http://www.sluijten.com/winglet/ Winglet, Writing a Chess Program in 99 Steps] by [[Stef Luijten]], hosted by the [https://en.wikipedia.org/wiki/Wayback_Machine Wayback Machine]</ref>,
in the meantime also open source <ref>[http://kirr.homeunix.org/chess/engines/Jim%20Ablett/WING/ Index of /chess/engines/Jim Ablett/WING] by [[Jim Ablett]], hosted by [[Kirill Kryukov]]</ref>.
=Description=
==Board Representation==
<span id="SlidingAttacks"></span>Winglet applies a mixture of [[Kindergarten Bitboards]] and [[Magic Bitboards]] <ref>[http://web.archive.org/web/20120621060943/http://www.sluijten.com/winglet/11movegen03.htm#Move_generation_for_sliding_pieces_-_magic_bitboards_ Writing a chess program in 99 steps - Move generation for sliding pieces] by [[Stef Luijten]], [https://en.wikipedia.org/wiki/Wayback_Machine Wayback Machine]</ref> to determine [[Sliding Piece Attacks|sliding piece attacks]] with 32 [https://en.wikipedia.org/wiki/Kibibyte KiB] precalculated lookup tables[64][64] each on [[Ranks|ranks]], [[Files|files]], [[Diagonals|diagonals]] and [[Anti-Diagonals|anti-diagonals]], indexed by [[Squares|square]] and hashed line [[Occupancy|occupancy]] - the [[First Rank Attacks#TheOuterSquares|inner six bits]] multiplied by a [[Magic Bitboards|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, ...
<pre>
U64 arrDiagonalAttacks[64][64]] /* requires initialization */
U64 diagonalKindergartenAttacks(U64 occ, enumSquare sq) {
occ = (diagonalMaskEx[sq] & occ) * C64(0x0202020202020202) >> 58;
return arrDiagonalAttacks[sq][occ];
}
</pre>
... 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 Bitboards|rotated bitboard]] indices for same attack table layout:
<pre>
/* 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
</pre>
==Search==
* [[Iterative Deepening]]
* [[Alpha-Beta]]
* [[Principal Variation Search]]
* [[Quiescence Search]]
* [[MVV-LVA]]
* [[Static Exchange Evaluation]]
* [[Null Move Pruning]]
==Evaluation==
* [[Material#Balance|Material Balance]]
* [[Piece-Square Tables]]
* [[Pawn Structure]]
: [[Passed Pawn]]
: [[Backward Pawn]]
: [[Doubled Pawn]]
: [[Isolated Pawn]]
* [[Bishop Pair]]
* [[Rook on Open File]]
* [[Tarrasch Rule|Rook behind Passers]]
* [[King Safety]] in [[Opening]], [[Middlegame]]
: [[King Safety#PawnShield|Pawn Shield]]
: [[King Safety#KingTropism|King Tropism]]
* [[King Centralization]] in [[Endgame]]
=See also=
* [[Chesser]] by [[Syed Fahad]] <ref>[http://www.talkchess.com/forum/viewtopic.php?t=54740 Chesser: A Chess Engine derived from wingletx] by [[Syed Fahad]], [[CCC]], December 24, 2014</ref>
* [[Godot]] by [[Ulysse Carion]] <ref>[https://github.com/ucarion/godot ucarion/godot · GitHub]</ref>
* [[Kenny]] by [[Kenshin Himura]] <ref>[https://github.com/kenshinthebattosai/kenny kenshinthebattosai/Kenny · GitHub]</ref> <ref>[http://www.talkchess.com/forum/viewtopic.php?t=46814 New Winboard Engine 'Kenny' - JA builds available] by [[Jim Ablett]], [[CCC]], January 08, 2013</ref>
* [[Vajolet]] by [[Marco Belli]] <ref>[http://www.talkchess.com/forum/viewtopic.php?t=52709&start=18 Re: where to start chess programming?] by [[Marco Belli]], [[CCC]], June 22, 2014</ref>
* [[Wing]] by [[Stef Luijten]]
=Forum Posts=
* [http://www.open-aurec.com/wbforum/viewtopic.php?f=4&t=51701 writing a chess engine in xx steps] by [[Stef Luijten|wing]], [[Computer Chess Forums|Winboard Forum]], April 18, 2011
* [http://www.talkchess.com/forum/viewtopic.php?t=38787 Writing a chess program in xx steps] by [[Stef Luijten]], [[CCC]], April 18, 2011
* [http://www.open-chess.org/viewtopic.php?f=5&t=1354 Chess Programming/Concepts for Beginners] by MoldyJacket, [[Computer Chess Forums|OpenChess Forum]], April 18, 2011
=External Links=
==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]]
* [https://github.com/PortugalTheMan/winglet/tree/master PortugalTheMan/winglet · GitHub] <ref>[http://schach.chess.com/forum/view/general/winglet-chess-engine-revived Winglet Chess Engine; Revived!] by [http://www.chess.com/members/view/PortugalTheMan PortugalTheMan], [https://en.wikipedia.org/wiki/Chess.com Chess.com], Septermber 24, 2014</ref>
* [http://aghaznawi.comuf.com/computer%20chess/winglet/ winglet, writing a chess program in 99 steps] by [[Stef Luijten]], hosted by [[Abdullah Al-Ghaznawi]] <ref>copy was taken in March 07, 2013, images and archives included</ref>
==Tutorial Archive==
{{Winglet to Include}}
==Misc==
* [https://en.wikipedia.org/wiki/Wingtip_device#Winglet Winglet from Wingtip device - Wikipedia]
* [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.airbus.com/innovation/proven-concepts/in-design/winglets/ Winglets | Airbus, a leading aircraft manufacturer]
=References=
<references />
'''[[Engines|Up one Level]]'''
[[Category:Open Source]]
[[Category:GPL]]
[[Category:WinBoard]]
[[FILE:Winglet with attached tufts of an KC-135A.jpg|border|right|thumb| Winglet <ref>Winglet with attached [https://en.wikipedia.org/wiki/Tuft_%28aeronautics%29 tufts] of an [https://en.wikipedia.org/wiki/Boeing_KC-135_Stratotanker KC-135A] during [https://en.wikipedia.org/wiki/NASA NASA] Winglet stu dy 1979. The tufts are needed to measure the [https://en.wikipedia.org/wiki/Airflow airflow], [https://en.wikipedia.org/wiki/Wingtip_device#Winglet Winglet from Wingtip device - Wikipedia], [http://www.dfrc.nasa.gov/Gallery/Photo/KC-135/HTML/EC79-11481.html KC-135 EC79-11481: KC-135A in flight - closeup of winglet with attached tufts], August 20, 1979</ref> ]]
'''Winglet''',<br/>
a didactic [[:Category:Open Source|open source chess engine]] by [[Stef Luijten]], written in [[Cpp|C++]] and licensed under the [[Free Software Foundation#GPL|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 [https://en.wikipedia.org/wiki/Wayback_Machine Wayback Machine] <ref>[http://web.archive.org/web/20120621100214/http://www.sluijten.com/winglet/ Winglet, Writing a Chess Program in 99 Steps] by [[Stef Luijten]], hosted by the [https://en.wikipedia.org/wiki/Wayback_Machine Wayback Machine]</ref>.
Winglet is intended as [[Bitboards|bitboard]] version of [[TSCP]] with [[WinBoard]] support <ref>[http://www.talkchess.com/forum/viewtopic.php?t=38787 Writing a chess program in xx steps] by [[Stef Luijten]], [[CCC]], April 18, 2011</ref>,
and is loosely derived from [[Wing]], Stef Luijten's former private engine <ref>[http://web.archive.org/web/20120621100214/http://www.sluijten.com/winglet/ Winglet, Writing a Chess Program in 99 Steps] by [[Stef Luijten]], hosted by the [https://en.wikipedia.org/wiki/Wayback_Machine Wayback Machine]</ref>,
in the meantime also open source <ref>[http://kirr.homeunix.org/chess/engines/Jim%20Ablett/WING/ Index of /chess/engines/Jim Ablett/WING] by [[Jim Ablett]], hosted by [[Kirill Kryukov]]</ref>.
=Description=
==Board Representation==
<span id="SlidingAttacks"></span>Winglet applies a mixture of [[Kindergarten Bitboards]] and [[Magic Bitboards]] <ref>[http://web.archive.org/web/20120621060943/http://www.sluijten.com/winglet/11movegen03.htm#Move_generation_for_sliding_pieces_-_magic_bitboards_ Writing a chess program in 99 steps - Move generation for sliding pieces] by [[Stef Luijten]], [https://en.wikipedia.org/wiki/Wayback_Machine Wayback Machine]</ref> to determine [[Sliding Piece Attacks|sliding piece attacks]] with 32 [https://en.wikipedia.org/wiki/Kibibyte KiB] precalculated lookup tables[64][64] each on [[Ranks|ranks]], [[Files|files]], [[Diagonals|diagonals]] and [[Anti-Diagonals|anti-diagonals]], indexed by [[Squares|square]] and hashed line [[Occupancy|occupancy]] - the [[First Rank Attacks#TheOuterSquares|inner six bits]] multiplied by a [[Magic Bitboards|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, ...
<pre>
U64 arrDiagonalAttacks[64][64]] /* requires initialization */
U64 diagonalKindergartenAttacks(U64 occ, enumSquare sq) {
occ = (diagonalMaskEx[sq] & occ) * C64(0x0202020202020202) >> 58;
return arrDiagonalAttacks[sq][occ];
}
</pre>
... 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 Bitboards|rotated bitboard]] indices for same attack table layout:
<pre>
/* 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
</pre>
==Search==
* [[Iterative Deepening]]
* [[Alpha-Beta]]
* [[Principal Variation Search]]
* [[Quiescence Search]]
* [[MVV-LVA]]
* [[Static Exchange Evaluation]]
* [[Null Move Pruning]]
==Evaluation==
* [[Material#Balance|Material Balance]]
* [[Piece-Square Tables]]
* [[Pawn Structure]]
: [[Passed Pawn]]
: [[Backward Pawn]]
: [[Doubled Pawn]]
: [[Isolated Pawn]]
* [[Bishop Pair]]
* [[Rook on Open File]]
* [[Tarrasch Rule|Rook behind Passers]]
* [[King Safety]] in [[Opening]], [[Middlegame]]
: [[King Safety#PawnShield|Pawn Shield]]
: [[King Safety#KingTropism|King Tropism]]
* [[King Centralization]] in [[Endgame]]
=See also=
* [[Chesser]] by [[Syed Fahad]] <ref>[http://www.talkchess.com/forum/viewtopic.php?t=54740 Chesser: A Chess Engine derived from wingletx] by [[Syed Fahad]], [[CCC]], December 24, 2014</ref>
* [[Godot]] by [[Ulysse Carion]] <ref>[https://github.com/ucarion/godot ucarion/godot · GitHub]</ref>
* [[Kenny]] by [[Kenshin Himura]] <ref>[https://github.com/kenshinthebattosai/kenny kenshinthebattosai/Kenny · GitHub]</ref> <ref>[http://www.talkchess.com/forum/viewtopic.php?t=46814 New Winboard Engine 'Kenny' - JA builds available] by [[Jim Ablett]], [[CCC]], January 08, 2013</ref>
* [[Vajolet]] by [[Marco Belli]] <ref>[http://www.talkchess.com/forum/viewtopic.php?t=52709&start=18 Re: where to start chess programming?] by [[Marco Belli]], [[CCC]], June 22, 2014</ref>
* [[Wing]] by [[Stef Luijten]]
=Forum Posts=
* [http://www.open-aurec.com/wbforum/viewtopic.php?f=4&t=51701 writing a chess engine in xx steps] by [[Stef Luijten|wing]], [[Computer Chess Forums|Winboard Forum]], April 18, 2011
* [http://www.talkchess.com/forum/viewtopic.php?t=38787 Writing a chess program in xx steps] by [[Stef Luijten]], [[CCC]], April 18, 2011
* [http://www.open-chess.org/viewtopic.php?f=5&t=1354 Chess Programming/Concepts for Beginners] by MoldyJacket, [[Computer Chess Forums|OpenChess Forum]], April 18, 2011
=External Links=
==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]]
* [https://github.com/PortugalTheMan/winglet/tree/master PortugalTheMan/winglet · GitHub] <ref>[http://schach.chess.com/forum/view/general/winglet-chess-engine-revived Winglet Chess Engine; Revived!] by [http://www.chess.com/members/view/PortugalTheMan PortugalTheMan], [https://en.wikipedia.org/wiki/Chess.com Chess.com], Septermber 24, 2014</ref>
* [http://aghaznawi.comuf.com/computer%20chess/winglet/ winglet, writing a chess program in 99 steps] by [[Stef Luijten]], hosted by [[Abdullah Al-Ghaznawi]] <ref>copy was taken in March 07, 2013, images and archives included</ref>
==Tutorial Archive==
{{Winglet to Include}}
==Misc==
* [https://en.wikipedia.org/wiki/Wingtip_device#Winglet Winglet from Wingtip device - Wikipedia]
* [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.airbus.com/innovation/proven-concepts/in-design/winglets/ Winglets | Airbus, a leading aircraft manufacturer]
=References=
<references />
'''[[Engines|Up one Level]]'''
[[Category:Open Source]]
[[Category:GPL]]
[[Category:WinBoard]]
