#### /packages/hermes/src/hermes_dither.inc

Pascal | 92 lines | 53 code | 6 blank | 33 comment | 6 complexity | 7cd38b733cf76a7470f0384cc73e7ce0 MD5 | raw file

Possible License(s): LGPL-2.0, LGPL-2.1, LGPL-3.0

1{ 2 Free Pascal port of the Hermes C library. 3 Copyright (C) 2001-2003 Nikolay Nikolov (nickysn@users.sourceforge.net) 4 Original C version by Christian Nentwich (c.nentwich@cs.ucl.ac.uk) 5 6 This library is free software; you can redistribute it and/or 7 modify it under the terms of the GNU Lesser General Public 8 License as published by the Free Software Foundation; either 9 version 2.1 of the License, or (at your option) any later version 10 with the following modification: 11 12 As a special exception, the copyright holders of this library give you 13 permission to link this library with independent modules to produce an 14 executable, regardless of the license terms of these independent modules,and 15 to copy and distribute the resulting executable under terms of your choice, 16 provided that you also meet, for each linked independent module, the terms 17 and conditions of the license of that module. An independent module is a 18 module which is not derived from or based on this library. If you modify 19 this library, you may extend this exception to your version of the library, 20 but you are not obligated to do so. If you do not wish to do so, delete this 21 exception statement from your version. 22 23 This library is distributed in the hope that it will be useful, 24 but WITHOUT ANY WARRANTY; without even the implied warranty of 25 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 26 Lesser General Public License for more details. 27 28 You should have received a copy of the GNU Lesser General Public 29 License along with this library; if not, write to the Free Software 30 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 31} 32 33{ Everything in here (C)1998 The Rasterman } 34 35{ Rasterman's dither matrix } 36 37const 38 DitherMatrix_44: array [0..3, 0..3] of Uint8 = ( 39 (0, 4, 1, 5), 40 (6, 2, 7, 3), 41 (1, 5, 0, 4), 42 (7, 3, 6, 2)); 43 44var 45 DitherTab_r565_44: array [0..3, 0..3, 0..255] of Uint16; 46 DitherTab_g565_44: array [0..3, 0..3, 0..255] of Uint16; 47 DitherTab_b565_44: array [0..3, 0..3, 0..255] of Uint16; 48 49 DitherTab_r332_44: array [0..3, 0..3, 0..255] of Uint8; 50 DitherTab_g332_44: array [0..3, 0..3, 0..255] of Uint8; 51 DitherTab_b332_44: array [0..3, 0..3, 0..255] of Uint8; 52 53procedure Dither_SetupMatrices; 54var 55 i, x, y: LongInt; 56begin 57 for y := 0 to 3 do 58 for x := 0 to 3 do 59 for i := 0 to 255 do 60 begin 61 if (DitherMatrix_44[x, y] < (i and $7)) and (i < (256 - 8)) then 62 begin 63 DitherTab_r565_44[x, y, i] := ((i + 8) and $f8) shl 8; 64 DitherTab_r332_44[x, y, i] := ((i + 8) and $e0); 65 end 66 else 67 begin 68 DitherTab_r565_44[x, y, i] := (i and $f8) shl 8; 69 DitherTab_r332_44[x, y, i] := i and $e0; 70 end; 71 if (DitherMatrix_44[x, y] < ((i and $3) shl 1)) and (i < (256 - 4)) then 72 begin 73 DitherTab_g565_44[x, y, i] := (((i + 4) and $fc) shl 8) shr 5; 74 DitherTab_g332_44[x, y, i] := ((i + 4) and $e0) shr 3; 75 end 76 else 77 begin 78 DitherTab_g565_44[x, y, i] := ((i and $fc) shl 8) shr 5; 79 DitherTab_g332_44[x, y, i] := (i and $e0) shr 3; 80 end; 81 if (DitherMatrix_44[x, y] < (i and $7)) and (i < (256 - 8)) then 82 begin 83 DitherTab_b565_44[x, y, i] := (((i + 8) and $f8) shl 16) shr 19; 84 DitherTab_b332_44[x, y, i] := ((i + 8) shr 6) and $3; 85 end 86 else 87 begin 88 DitherTab_b565_44[x, y, i] := ((i and $f8) shl 16) shr 19; 89 DitherTab_b332_44[x, y, i] := (i shr 6) and $3; 90 end; 91 end; 92end;