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/*

 * QEMU VNC display driver: Zlib Run-length Encoding (ZRLE)

 *

 * From libvncserver/libvncserver/zrleencodetemplate.c

 * Copyright (C) 2002 RealVNC Ltd.  All Rights Reserved.

 * Copyright (C) 2003 Sun Microsystems, Inc.

 *

 * Copyright (C) 2010 Corentin Chary <corentin.chary@gmail.com>

 *

 * This work is licensed under the terms of the GNU GPL, version 2 or later.

 * See the COPYING file in the top-level directory.

 */

/*

 * Before including this file, you must define a number of CPP macros.

 *

 * ZRLE_BPP should be 8, 16 or 32 depending on the bits per pixel.

 *

 * Note that the buf argument to ZRLE_ENCODE needs to be at least one pixel

 * bigger than the largest tile of pixel data, since the ZRLE encoding

 * algorithm writes to the position one past the end of the pixel data.

 */

#include <assert.h>

#undef ZRLE_ENDIAN_SUFFIX

#if ZYWRLE_ENDIAN == ENDIAN_LITTLE

#define ZRLE_ENDIAN_SUFFIX le

#elif ZYWRLE_ENDIAN == ENDIAN_BIG

#define ZRLE_ENDIAN_SUFFIX be

#else

#define ZRLE_ENDIAN_SUFFIX ne

#endif

#ifndef ZRLE_CONCAT

#define ZRLE_CONCAT_I(a, b)    a##b

#define ZRLE_CONCAT2(a, b)     ZRLE_CONCAT_I(a, b)

#define ZRLE_CONCAT3(a, b, c)  ZRLE_CONCAT2(a, ZRLE_CONCAT2(b, c))

#endif

#ifdef ZRLE_COMPACT_PIXEL

#define ZRLE_ENCODE_SUFFIX   ZRLE_CONCAT2(ZRLE_COMPACT_PIXEL,ZRLE_ENDIAN_SUFFIX)

#define ZRLE_WRITE_SUFFIX    ZRLE_COMPACT_PIXEL

#define ZRLE_PIXEL           ZRLE_CONCAT3(uint,ZRLE_BPP,_t)

#define ZRLE_BPP_OUT         24

#elif ZRLE_BPP == 15

#define ZRLE_ENCODE_SUFFIX   ZRLE_CONCAT2(ZRLE_BPP,ZRLE_ENDIAN_SUFFIX)

#define ZRLE_WRITE_SUFFIX    16

#define ZRLE_PIXEL           uint16_t

#define ZRLE_BPP_OUT         16

#else

#define ZRLE_ENCODE_SUFFIX   ZRLE_CONCAT2(ZRLE_BPP,ZRLE_ENDIAN_SUFFIX)

#define ZRLE_WRITE_SUFFIX    ZRLE_BPP

#define ZRLE_BPP_OUT         ZRLE_BPP

#define ZRLE_PIXEL           ZRLE_CONCAT3(uint,ZRLE_BPP,_t)

#endif

#define ZRLE_WRITE_PIXEL     ZRLE_CONCAT2(zrle_write_u,       ZRLE_WRITE_SUFFIX)

#define ZRLE_ENCODE          ZRLE_CONCAT2(zrle_encode_,      ZRLE_ENCODE_SUFFIX)

#define ZRLE_ENCODE_TILE     ZRLE_CONCAT2(zrle_encode_tile,  ZRLE_ENCODE_SUFFIX)

#define ZRLE_WRITE_PALETTE   ZRLE_CONCAT2(zrle_write_palette,ZRLE_ENCODE_SUFFIX)

static void ZRLE_ENCODE_TILE(VncState *vs, ZRLE_PIXEL *data, int w, int h,

                             int zywrle_level);

#if ZRLE_BPP != 8

#include "vnc-enc-zywrle-template.c"

#endif

static void ZRLE_ENCODE(VncState *vs, int x, int y, int w, int h,

                        int zywrle_level)

{

    int ty;

    for (ty = y; ty < y + h; ty += VNC_ZRLE_TILE_HEIGHT) {

        int tx, th;

        th = MIN(VNC_ZRLE_TILE_HEIGHT, y + h - ty);

        for (tx = x; tx < x + w; tx += VNC_ZRLE_TILE_WIDTH) {

            int tw;

            ZRLE_PIXEL *buf;

            tw = MIN(VNC_ZRLE_TILE_WIDTH, x + w - tx);

            buf = zrle_convert_fb(vs, tx, ty, tw, th, ZRLE_BPP);

            ZRLE_ENCODE_TILE(vs, buf, tw, th, zywrle_level);

        }

    }

}

static void ZRLE_ENCODE_TILE(VncState *vs, ZRLE_PIXEL *data, int w, int h,

                             int zywrle_level)

{

    VncPalette *palette = &vs->zrle.palette;

    int runs = 0;

    int single_pixels = 0;

    bool use_rle;

    bool use_palette;

    int i;

    ZRLE_PIXEL *ptr = data;

    ZRLE_PIXEL *end = ptr + h * w;

    *end = ~*(end-1); /* one past the end is different so the while loop ends */

    /* Real limit is 127 but we wan't a way to know if there is more than 127 */

    palette_init(palette, 256, ZRLE_BPP);

    while (ptr < end) {

        ZRLE_PIXEL pix = *ptr;

        if (*++ptr != pix) { /* FIXME */

            single_pixels++;

        } else {

            while (*++ptr == pix) ;

            runs++;

        }

        palette_put(palette, pix);

    }

    /* Solid tile is a special case */

    if (palette_size(palette) == 1) {

        bool found;

        vnc_write_u8(vs, 1);

        ZRLE_WRITE_PIXEL(vs, palette_color(palette, 0, &found));

        return;

    }

    zrle_choose_palette_rle(vs, w, h, palette, ZRLE_BPP_OUT,

                            runs, single_pixels, zywrle_level,

                            &use_rle, &use_palette);

    if (!use_palette) {

        vnc_write_u8(vs, (use_rle ? 128 : 0));

    } else {

        uint32_t colors[VNC_PALETTE_MAX_SIZE];

        size_t size = palette_size(palette);

        vnc_write_u8(vs, (use_rle ? 128 : 0) | size);

        palette_fill(palette, colors);

        for (i = 0; i < size; i++) {

            ZRLE_WRITE_PIXEL(vs, colors[i]);

        }

    }

    if (use_rle) {

        ZRLE_PIXEL *ptr = data;

        ZRLE_PIXEL *end = ptr + w * h;

        ZRLE_PIXEL *run_start;

        ZRLE_PIXEL pix;

        while (ptr < end) {

            int len;

            int index = 0;

            run_start = ptr;

            pix = *ptr++;

            while (*ptr == pix && ptr < end) {

                ptr++;

            }

            len = ptr - run_start;

            if (use_palette)

                index = palette_idx(palette, pix);

            if (len <= 2 && use_palette) {

                if (len == 2) {

                    vnc_write_u8(vs, index);

                }

                vnc_write_u8(vs, index);

                continue;

            }

            if (use_palette) {

                vnc_write_u8(vs, index | 128);

            } else {

                ZRLE_WRITE_PIXEL(vs, pix);

            }

            len -= 1;

            while (len >= 255) {

                vnc_write_u8(vs, 255);

                len -= 255;

            }

            vnc_write_u8(vs, len);

        }

    } else if (use_palette) { /* no RLE */

        int bppp;

        ZRLE_PIXEL *ptr = data;

        /* packed pixels */

        assert (palette_size(palette) < 17);

        bppp = bits_per_packed_pixel[palette_size(palette)-1];

        for (i = 0; i < h; i++) {

            uint8_t nbits = 0;

            uint8_t byte = 0;

            ZRLE_PIXEL *eol = ptr + w;

            while (ptr < eol) {

                ZRLE_PIXEL pix = *ptr++;

                uint8_t index = palette_idx(palette, pix);

                byte = (byte << bppp) | index;

                nbits += bppp;

                if (nbits >= 8) {

                    vnc_write_u8(vs, byte);

                    nbits = 0;

                }

            }

            if (nbits > 0) {

                byte <<= 8 - nbits;

                vnc_write_u8(vs, byte);

            }

        }

    } else {

        /* raw */

#if ZRLE_BPP != 8

        if (zywrle_level > 0 && !(zywrle_level & 0x80)) {

            ZYWRLE_ANALYZE(data, data, w, h, w, zywrle_level, vs->zywrle.buf);

            ZRLE_ENCODE_TILE(vs, data, w, h, zywrle_level | 0x80);

        }

        else

#endif

        {

#ifdef ZRLE_COMPACT_PIXEL

            ZRLE_PIXEL *ptr;

            for (ptr = data; ptr < data + w * h; ptr++) {

                ZRLE_WRITE_PIXEL(vs, *ptr);

            }

#else

            vnc_write(vs, data, w * h * (ZRLE_BPP / 8));

#endif

        }

    }

}

#undef ZRLE_PIXEL

#undef ZRLE_WRITE_PIXEL

#undef ZRLE_ENCODE

#undef ZRLE_ENCODE_TILE

#undef ZYWRLE_ENCODE_TILE

#undef ZRLE_BPP_OUT

#undef ZRLE_WRITE_SUFFIX

#undef ZRLE_ENCODE_SUFFIX