/*
 * Copyright 1996 Sun Microsystems, Inc.  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.  Sun designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.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 with
 * signed error adjustments to produce a moderately high quality
 * version of an image with only an 8-bit (or less) RGB colormap and
 * a "closest color" lookup table.  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 RGB colormapped displays.
 */

/*
 * These definitions vector the standard macro names to the "Color"
 * 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       DeclareAllColorDitherVars
#define InitDither              InitColorDither
#define StartDitherLine         StartColorDitherLine
#define DitherPixel             ColorDitherPixel
#define DitherBufComplete       ColorDitherBufComplete
#endif

#define DeclareAllColorDitherVars                       \
    DeclareColorDitherVars                              \
    int relx, rely;

#define DeclareColorDitherVars                          \
    extern sgn_ordered_dither_array img_oda_red;        \
    extern sgn_ordered_dither_array img_oda_green;      \
    extern sgn_ordered_dither_array img_oda_blue;

#define InitColorDither(cvdata, clrdata, dstTW)                 \
    do {} while (0)

#define StartColorDitherLine(cvdata, dstX1, dstY)               \
    do {                                                        \
        relx = dstX1 & 7;                                       \
        rely = dstY & 7;                                        \
    } while (0)

#define ColorDitherPixel(dstX, dstY, pixel, red, green, blue)   \
    do {                                                        \
        red += img_oda_red[relx][rely];                         \
        red = ComponentBound(red);                              \
        green += img_oda_green[relx][rely];                     \
        green = ComponentBound(green);                          \
        blue += img_oda_blue[relx][rely];                       \
        blue = ComponentBound(blue);                            \
        pixel = ColorCubeOrdMapSgn(red, green, blue);           \
        relx = (relx + 1) & 7;                                  \
    } while (0)

#define ColorDitherBufComplete(cvdata, dstX1)                   \
    do {} while (0)