/*      $NetBSD: rasops24.c,v 1.50 2019/08/14 00:51:10 rin Exp $        */

/*-
 * Copyright (c) 1999 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Andrew Doran.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: rasops24.c,v 1.50 2019/08/14 00:51:10 rin Exp $");

#ifdef _KERNEL_OPT
#include "opt_rasops.h"
#endif

#include <sys/param.h>
#include <sys/bswap.h>

#include <machine/endian.h>

#include <dev/wscons/wsdisplayvar.h>
#include <dev/wscons/wsconsio.h>

#define _RASOPS_PRIVATE
#define RASOPS_DEPTH    24
#include <dev/rasops/rasops.h>

static void     rasops24_erasecols(void *, int, int, int, long);
static void     rasops24_eraserows(void *, int, int, long);
static void     rasops24_putchar(void *, int, int, u_int, long);
static void     rasops24_putchar_aa(void *, int, int, u_int, long);
static __inline void
                rasops24_makestamp1(struct rasops_info *, uint32_t *,
                                    uint32_t, uint32_t, uint32_t, uint32_t);
#ifndef RASOPS_SMALL
static void     rasops24_putchar8(void *, int, int, u_int, long);
static void     rasops24_putchar12(void *, int, int, u_int, long);
static void     rasops24_putchar16(void *, int, int, u_int, long);
static void     rasops24_makestamp(struct rasops_info *, long);
#endif

#ifndef RASOPS_SMALL
/* stamp for optimized character blitting */
static uint32_t                 stamp[64];
static long                     stamp_attr;
static struct rasops_info       *stamp_ri;

/*
 * offset = STAMP_SHIFT(fontbits, nibble #) & STAMP_MASK
 * destination uint32_t[0] = STAMP_READ(offset)
 * destination uint32_t[1] = STAMP_READ(offset + 4)
 * destination uint32_t[2] = STAMP_READ(offset + 8)
 */
#define STAMP_SHIFT(fb, n)      ((n) ? (fb) : (fb) << 4)
#define STAMP_MASK              (0xf << 4)
#define STAMP_READ(o)           (*(uint32_t *)((uint8_t *)stamp + (o)))
#endif

/*
 * Initialize rasops_info struct for this colordepth.
 */
void
rasops24_init(struct rasops_info *ri)
{

        if (ri->ri_rnum == 0) {
                ri->ri_rnum = ri->ri_gnum = ri->ri_bnum = 8;

                ri->ri_rpos = 0;
                ri->ri_gpos = 8;
                ri->ri_bpos = 16;
        }

        ri->ri_ops.erasecols = rasops24_erasecols;
        ri->ri_ops.eraserows = rasops24_eraserows;

        if (FONT_IS_ALPHA(ri->ri_font)) {
                ri->ri_ops.putchar = rasops24_putchar_aa;
                return;
        }

        switch (ri->ri_font->fontwidth) {
#ifndef RASOPS_SMALL
        case 8:
                ri->ri_ops.putchar = rasops24_putchar8;
                break;
        case 12:
                ri->ri_ops.putchar = rasops24_putchar12;
                break;
        case 16:
                ri->ri_ops.putchar = rasops24_putchar16;
                break;
#endif
        default:
                ri->ri_ops.putchar = rasops24_putchar;
                return;
        }

#ifndef RASOPS_SMALL
        stamp_attr = -1;
        stamp_ri = NULL;
#endif
}

/* rasops24_putchar */
#undef  RASOPS_AA
#include <dev/rasops/rasops_putchar.h>

/* rasops24_putchar_aa */
#define RASOPS_AA
#include <dev/rasops/rasops_putchar.h>
#undef  RASOPS_AA

static __inline void
rasops24_makestamp1(struct rasops_info *ri, uint32_t *xstamp,
    uint32_t c1, uint32_t c2, uint32_t c3, uint32_t c4)
{

        xstamp[0] = (c1 <<  8) | (c2 >> 16);
        xstamp[1] = (c2 << 16) | (c3 >>  8);
        xstamp[2] = (c3 << 24) |  c4;

#if BYTE_ORDER == LITTLE_ENDIAN
        if ((ri->ri_flg & RI_BSWAP) == 0)
#else
        if ((ri->ri_flg & RI_BSWAP) != 0)
#endif
        {
                xstamp[0] = bswap32(xstamp[0]);
                xstamp[1] = bswap32(xstamp[1]);
                xstamp[2] = bswap32(xstamp[2]);
        }
}

#ifndef RASOPS_SMALL
/*
 * Recompute the blitting stamp.
 */
static void
rasops24_makestamp(struct rasops_info *ri, long attr)
{
        int i;
        uint32_t bg, fg, c1, c2, c3, c4;

        stamp_attr = attr;
        stamp_ri = ri;

        bg = ATTR_BG(ri, attr) & 0xffffff;
        fg = ATTR_FG(ri, attr) & 0xffffff;

        for (i = 0; i < 64; i += 4) {
#if BYTE_ORDER == LITTLE_ENDIAN
                c1 = i & 32 ? fg : bg;
                c2 = i & 16 ? fg : bg;
                c3 = i &  8 ? fg : bg;
                c4 = i &  4 ? fg : bg;
#else
                c1 = i &  8 ? fg : bg;
                c2 = i &  4 ? fg : bg;
                c3 = i & 16 ? fg : bg;
                c4 = i & 32 ? fg : bg;
#endif
                rasops24_makestamp1(ri, &stamp[i], c1, c2, c3, c4);
        }
}

/*
 * Width-optimized putchar functions
 */
#define RASOPS_WIDTH    8
#include <dev/rasops/rasops_putchar_width.h>
#undef  RASOPS_WIDTH

#define RASOPS_WIDTH    12
#include <dev/rasops/rasops_putchar_width.h>
#undef  RASOPS_WIDTH

#define RASOPS_WIDTH    16
#include <dev/rasops/rasops_putchar_width.h>
#undef  RASOPS_WIDTH

#endif  /* !RASOPS_SMALL */

/*
 * Erase rows. This is nice and easy due to alignment.
 */
static void
rasops24_eraserows(void *cookie, int row, int num, long attr)
{
        struct rasops_info *ri = (struct rasops_info *)cookie;
        int bytes, full, slop, cnt;
        uint32_t bg, xstamp[3];
        uint32_t *dp, *rp, *hp;

        hp = NULL;      /* XXX GCC */

        /*
         * If the color is gray, we can cheat and use the generic routines
         * (which are faster, hopefully) since the r,g,b values are the same.
         */
        if ((attr & WSATTR_PRIVATE2) != 0) {
                rasops_eraserows(cookie, row, num, attr);
                return;
        }

#ifdef RASOPS_CLIPPING
        if (row < 0) {
                num += row;
                row = 0;
        }

        if (row + num > ri->ri_rows)
                num = ri->ri_rows - row;

        if (num <= 0)
                return;
#endif

        bg = ATTR_BG(ri, attr) & 0xffffff;
        rasops24_makestamp1(ri, xstamp, bg, bg, bg, bg);

        /*
         * XXX the wsdisplay_emulops interface seems a little deficient in
         * that there is no way to clear the *entire* screen. We provide a
         * workaround here: if the entire console area is being cleared, and
         * the RI_FULLCLEAR flag is set, clear the entire display.
         */
        if (num == ri->ri_rows && (ri->ri_flg & RI_FULLCLEAR) != 0) {
                bytes = ri->ri_stride;
                num = ri->ri_height;
                rp = (uint32_t *)ri->ri_origbits;
                if (ri->ri_hwbits)
                        hp = (uint32_t *)ri->ri_hworigbits;
        } else {
                bytes = ri->ri_emustride;
                num *= ri->ri_font->fontheight;
                rp = (uint32_t *)(ri->ri_bits + row * ri->ri_yscale);
                if (ri->ri_hwbits)
                        hp = (uint32_t *)(ri->ri_hwbits + row * ri->ri_yscale);
        }

        full = bytes / (4 * 3);
        slop = (bytes - full * (4 * 3)) / 4;

        while (num--) {
                dp = rp;

                for (cnt = full; cnt; cnt--) {
                        dp[0] = xstamp[0];
                        dp[1] = xstamp[1];
                        dp[2] = xstamp[2];
                        dp += 3;
                }

                for (cnt = 0; cnt < slop; cnt++)
                        *dp++ = xstamp[cnt];

                if (ri->ri_hwbits) {
                        memcpy(hp, rp, bytes);
                        DELTA(hp, ri->ri_stride, uint32_t *);
                }

                DELTA(rp, ri->ri_stride, uint32_t *);
        }
}

/*
 * Erase columns.
 */
static void
rasops24_erasecols(void *cookie, int row, int col, int num, long attr)
{
        struct rasops_info *ri = (struct rasops_info *)cookie;
        int height, slop1, slop2, full, cnt;
        uint32_t bg, xstamp[3];
        uint32_t *dp;
        uint8_t *bp, *rp, *hp;

        hp = NULL;      /* XXX GCC */

        /*
         * If the color is gray, we can cheat and use the generic routines
         * (which are faster, hopefully) since the r,g,b values are the same.
         */
        if ((attr & WSATTR_PRIVATE2) != 0) {
                rasops_erasecols(cookie, row, col, num, attr);
                return;
        }

#ifdef RASOPS_CLIPPING
        /* Catches 'row < 0' case too */
        if ((unsigned)row >= (unsigned)ri->ri_rows)
                return;

        if (col < 0) {
                num += col;
                col = 0;
        }

        if (col + num > ri->ri_cols)
                num = ri->ri_cols - col;

        if (num <= 0)
                return;
#endif

        height = ri->ri_font->fontheight;
        num *= ri->ri_xscale;

        rp = ri->ri_bits + row * ri->ri_yscale + col * ri->ri_xscale;
        if (ri->ri_hwbits)
                hp = ri->ri_hwbits + row * ri->ri_yscale + col * ri->ri_xscale;

        bg = ATTR_BG(ri, attr) & 0xffffff;
        rasops24_makestamp1(ri, xstamp, bg, bg, bg, bg);

        /*
         * Align to word boundary by 24-bit-wise operations:
         *
         * rp % 4 == 1 ---> slop1 = 3:
         *      0123
         *      -RGB
         *
         * rp % 4 == 2 ---> slop1 = 6:
         *      0123 0123
         *      --RG BRGB
         *
         * rp % 4 == 3 ---> slop1 = 9:
         *      0123 0123 0123
         *      ---R GBRG BRGB
         */
        slop1 = 3 * ((uintptr_t)rp % 4);
        slop2 = (num - slop1) % 12;
        full = (num - slop1 /* - slop2 */) / 12;

        while (height--) {
                /* Align to word boundary */
                bp = rp;
                for (cnt = slop1; cnt; cnt -= 3) {
                        *bp++ = (bg >> 16);
                        *bp++ = (bg >> 8);
                        *bp++ = bg;
                }

                /* 4 pels per loop */
                dp = (uint32_t *)bp;
                for (cnt = full; cnt; cnt--) {
                        dp[0] = xstamp[0];
                        dp[1] = xstamp[1];
                        dp[2] = xstamp[2];
                        dp += 3;
                }

                /* Trailing slop */
                bp = (uint8_t *)dp;
                for (cnt = slop2; cnt; cnt -= 3) {
                        *bp++ = (bg >> 16);
                        *bp++ = (bg >> 8);
                        *bp++ = bg;
                }

                if (ri->ri_hwbits) {
                        memcpy(hp, rp, num);
                        hp += ri->ri_stride;
                }

                rp += ri->ri_stride;
        }
}