| J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 1996 Sun Microsystems, Inc. All Rights Reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 5 | * This code is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 only, as |
| 7 | * published by the Free Software Foundation. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun in the LICENSE file that accompanied this code. |
| 10 | * |
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 14 | * version 2 for more details (a copy is included in the LICENSE file that |
| 15 | * accompanied this code). |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License version |
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | * |
| 21 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | /* |
| 27 | * This file contains macro definitions for the Encoding category of |
| 28 | * the macros used by the generic scaleloop function. |
| 29 | * |
| 30 | * This implementation uses a Floyd-Steinberg error diffusion technique |
| 31 | * to produce a very high quality version of an image with only an 8-bit |
| 32 | * (or less) RGB colormap or gray ramp. The error diffusion technique |
| 33 | * requires that the input color information be delivered in a special |
| 34 | * order from the top row to the bottom row and then left to right within |
| 35 | * each row, thus it is only valid in cases where the ImageProducer has |
| 36 | * specified the TopDownLeftRight delivery hint. If the data is not read |
| 37 | * in that order, no mathematical or memory access errors should occur, |
| 38 | * but the dithering error will be spread through the pixels of the output |
| 39 | * image in an unpleasant manner. |
| 40 | */ |
| 41 | |
| 42 | /* |
| 43 | * These definitions vector the standard macro names to the "Any" |
| 44 | * versions of those macros. The "DitherDeclared" keyword is also |
| 45 | * defined to indicate to the other include files that they are not |
| 46 | * defining the primary implementation. All other include files |
| 47 | * will check for the existance of the "DitherDeclared" keyword |
| 48 | * and define their implementations of the Encoding macros using |
| 49 | * more specific names without overriding the standard names. This |
| 50 | * is done so that the other files can be included here to reuse |
| 51 | * their implementations for the specific cases. |
| 52 | */ |
| 53 | #define DitherDeclared |
| 54 | #define DeclareDitherVars DeclareAnyDitherVars |
| 55 | #define InitDither InitAnyDither |
| 56 | #define StartDitherLine StartAnyDitherLine |
| 57 | #define DitherPixel AnyDitherPixel |
| 58 | #define DitherBufComplete AnyDitherBufComplete |
| 59 | |
| 60 | /* Include the specific implementations for color and grayscale displays */ |
| 61 | #include "img_fscolor.h" |
| 62 | #include "img_fsgray.h" |
| 63 | |
| 64 | #define DeclareAnyDitherVars \ |
| 65 | DeclareColorDitherVars \ |
| 66 | DeclareGrayDitherVars \ |
| 67 | int grayscale; |
| 68 | |
| 69 | #define InitAnyDither(cvdata, clrdata, dstTW) \ |
| 70 | do { \ |
| 71 | if (grayscale = clrdata->grayscale) { \ |
| 72 | InitGrayDither(cvdata, clrdata, dstTW); \ |
| 73 | } else { \ |
| 74 | InitColorDither(cvdata, clrdata, dstTW); \ |
| 75 | } \ |
| 76 | } while (0) |
| 77 | |
| 78 | #define StartAnyDitherLine(cvdata, dstX1, dstY) \ |
| 79 | do { \ |
| 80 | if (grayscale) { \ |
| 81 | StartGrayDitherLine(cvdata, dstX1, dstY); \ |
| 82 | } else { \ |
| 83 | StartColorDitherLine(cvdata, dstX1, dstY); \ |
| 84 | } \ |
| 85 | } while (0) |
| 86 | |
| 87 | #define AnyDitherPixel(dstX, dstY, pixel, red, green, blue) \ |
| 88 | do { \ |
| 89 | if (grayscale) { \ |
| 90 | GrayDitherPixel(dstX, dstY, pixel, red, green, blue); \ |
| 91 | } else { \ |
| 92 | ColorDitherPixel(dstX, dstY, pixel, red, green, blue); \ |
| 93 | } \ |
| 94 | } while (0) |
| 95 | |
| 96 | #define AnyDitherBufComplete(cvdata, dstX1) \ |
| 97 | do { \ |
| 98 | if (grayscale) { \ |
| 99 | GrayDitherBufComplete(cvdata, dstX1); \ |
| 100 | } else { \ |
| 101 | ColorDitherBufComplete(cvdata, dstX1); \ |
| 102 | } \ |
| 103 | } while (0) |