| /* |
| * Copyright (c) 1996, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code 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 |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| /* |
| * This file contains macro definitions for the Encoding category of |
| * the macros used by the generic scaleloop function. |
| * |
| * This implementation uses an ordered dithering error matrix to |
| * produce a moderately high quality version of an image with only |
| * an 8-bit (or less) grayramp. The ordered dithering technique does |
| * not rely on the order in which the pixels are processed so this |
| * file can be used in cases where the ImageProducer has not specified |
| * the TopDownLeftRight delivery hint. The ordered dither technique |
| * is also much faster than the Floyd-Steinberg error diffusion |
| * algorithm so this implementation would also be appropriate for |
| * cases where performance is critical such as the processing of a |
| * video stream. |
| * |
| * This file can be used to provide the default implementation of the |
| * Encoding macros for grayscale displays. |
| */ |
| |
| /* |
| * These definitions vector the standard macro names to the "Gray" |
| * versions of those macros only if the "DitherDeclared" keyword has |
| * not yet been defined elsewhere. The "DitherDeclared" keyword is |
| * also defined here to claim ownership of the primary implementation |
| * even though this file does not rely on the definitions in any other |
| * files. |
| */ |
| #ifndef DitherDeclared |
| #define DitherDeclared |
| #define DeclareDitherVars DeclareAllGrayDitherVars |
| #define InitDither InitGrayDither |
| #define StartDitherLine StartGrayDitherLine |
| #define DitherPixel GrayDitherPixel |
| #define DitherBufComplete GrayDitherBufComplete |
| #endif |
| |
| #define DeclareAllGrayDitherVars \ |
| DeclareGrayDitherVars \ |
| int relx, rely; |
| |
| #define DeclareGrayDitherVars \ |
| extern unsigned char img_grays[256]; \ |
| extern unsigned char img_bwgamma[256]; \ |
| extern sgn_ordered_dither_array img_oda_gray; |
| |
| #define InitGrayDither(cvdata, clrdata, dstTW) \ |
| do {} while (0) |
| |
| #define StartGrayDitherLine(cvdata, dstX1, dstY) \ |
| do { \ |
| relx = dstX1 & 7; \ |
| rely = dstY & 7; \ |
| } while (0) |
| |
| #define GrayDitherPixel(dstX, dstY, pixel, red, green, blue) \ |
| do { \ |
| green = RGBTOGRAY(red, green, blue); \ |
| green += img_oda_gray[relx][rely]; \ |
| green = ComponentBound(green); \ |
| pixel = img_grays[img_bwgamma[green]]; \ |
| relx = (relx + 1) & 7; \ |
| } while (0) |
| |
| #define GrayDitherBufComplete(cvdata, dstX1) \ |
| do {} while (0) |
