/*      $NetBSD: video.c,v 1.7 2005/12/11 12:17:04 christos Exp $       */

/*-
 * Copyright (C) 1995-1997 Gary Thomas (gdt@linuxppc.org)
 * All rights reserved.
 *
 * 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Gary Thomas.
 * 4. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 */

#ifdef CONS_BE
#include <lib/libsa/stand.h>
#include "boot.h"
#include "iso_font.h"

#define FONT_WIDTH      8
#define FONT_HEIGHT     16
#define VRAM_WIDTH      640
#define VRAM_HEIGHT     480
#define VRAM_SIZE       (VRAM_WIDTH * VRAM_HEIGHT)
#define ROW     (VRAM_WIDTH / FONT_WIDTH)
#define COL     (VRAM_HEIGHT / FONT_HEIGHT)

u_char *VramBase;
u_char save_cursor[FONT_WIDTH];

/*
 * The current state of virtual displays
 */
struct screen {
        enum state {
                NORMAL,         /* no pending escape */
                ESC,            /* saw ESC */
                EBRAC,          /* saw ESC[ */
                EBRACEQ         /* saw ESC[= */
        } state;                /* command parser state */
        int     cx;             /* the first escape seq argument */
        int     cy;             /* the second escap seq argument */
        int     *accp;          /* pointer to the current processed argument */
        int     row;
        int     col;
        u_char fgcolor;
        u_char bgcolor;
} screen;


void
video_init(u_char *buffer)
{
        struct screen *d = &screen;

        VramBase = buffer;
        d->fgcolor = 0x1f;      /* WHITE */
        d->bgcolor = 0x00;      /* BLACK */
        d->row = 0;
        d->col = 0;
        d->state = NORMAL;
        memset(VramBase, d->bgcolor, VRAM_SIZE);
        memset(save_cursor, d->bgcolor, FONT_WIDTH);
}

static void
wrtchar(u_char c, struct screen *d)
{
        u_char *p = VramBase +
                (d->col * VRAM_WIDTH * FONT_HEIGHT) + (d->row * FONT_WIDTH);
        int fontbase = c * 16;
        int x, y;

        for (y = 0; y < FONT_HEIGHT; y++) {
                for (x = 0; x < FONT_WIDTH; x++) {
                        if ((font[fontbase + y] >> (FONT_WIDTH - x)) & 1)
                                *(p + x + (y * VRAM_WIDTH)) = d->fgcolor;
                        else
                                *(p + x + (y * VRAM_WIDTH)) = d->bgcolor;
                }
        }
        d->row++;
}

static void
cursor(struct screen *d, int flag)
{
        int x;
        int y = FONT_HEIGHT - 1;

        u_char *p = VramBase +
                (d->col * VRAM_WIDTH * FONT_HEIGHT) + (d->row * FONT_WIDTH);
        for (x = 0; x < FONT_WIDTH - 1; x++) {
                if (flag) {
                        save_cursor[x] = *(p + x + (y * VRAM_WIDTH));
                        *(p + x + (y * VRAM_WIDTH)) = d->fgcolor;
                } else {
                        *(p + x + (y * VRAM_WIDTH)) = save_cursor[x];
                }
        }
}

/*
 * vga_putc (nee sput) has support for emulation of the 'ibmpc' termcap entry.
 * This is a bare-bones implementation of a bare-bones entry
 * One modification: Change li#24 to li#25 to reflect 25 lines
 * "ca" is the color/attributes value (left-shifted by 8)
 * or 0 if the current regular color for that screen is to be used.
 */
void
video_putc(int c)
{
        struct screen *d = &screen;

        cursor(d, 0);

        switch (d->state) {
        case NORMAL:
                switch (c) {
                case 0x0:               /* Ignore pad characters */
                        return;

                case 0x1B:
                        d->state = ESC;
                        break;

                case '\t':
                        do {
                                wrtchar(' ', d);
                        } while (d->row % 8);
                        break;

                case '\b':  /* non-destructive backspace */
                        d->row--;
                        if (d->row < 0) {
                                if (d->col > 0) {
                                        d->col--;
                                        d->row += ROW;  /* prev column */
                                } else {
                                        d->row = 0;
                                }
                        }
                        break;

                case '\n':
                        d->col++;
                        /* FALLTHROUGH */
                case '\r':
                        d->row = 0;
                        break;

                case '\007':
                        break;

                default:
                        wrtchar(c, d);
                        if (d->row >= ROW) {
                                d->row = 0;
                                d->col++;
                        }
                        break;
                }
                break;

        case ESC:
        case EBRAC:
        case EBRACEQ:
                break;
        }
        if (d->col >= COL) {            /* scroll check */
                memcpy(VramBase, VramBase + VRAM_WIDTH * FONT_HEIGHT,
                        VRAM_SIZE - VRAM_WIDTH * FONT_WIDTH);
                memset(VramBase + VRAM_SIZE - VRAM_WIDTH * FONT_HEIGHT,
                        d->bgcolor, VRAM_WIDTH * FONT_HEIGHT);
                d->col = COL - 1;
        }
        cursor(d, 1);
}
#endif