/* Copyright (C) 2001-2023 Artifex Software, Inc.
   All Rights Reserved.

   This software is provided AS-IS with no warranty, either express or
   implied.

   This software is distributed under license and may not be copied,
   modified or distributed except as expressly authorized under the terms
   of the license contained in the file LICENSE in this distribution.

   Refer to licensing information at http://www.artifex.com or contact
   Artifex Software, Inc.,  39 Mesa Street, Suite 108A, San Francisco,
   CA 94129, USA, for further information.
*/


/*
 * Private Eye display driver
 *
 * Hacked by Fran Taylor, Reflection Technology Inc.
 */

#include "memory_.h"
#include "gx.h"
#include "gxdevice.h"

char *getenv(char *name);

typedef struct gx_device_pe_s {
        gx_device_common;
        byte *fbaddr;
        unsigned regs;
} gx_device_pe;
#define pedev ((gx_device_pe *)dev)

typedef struct {
        ushort reg, val;
} regval;

#define XSIZE 720
#define YSIZE 280
#define BPL 90
#define XPPI 160.0
#define YPPI 96.0
#define DEFAULT_ADDRESS ((byte *) 0xb8000000)
#define DEFAULT_REGISTERS 0x3d0

dev_proc_open_device(pe_open);
dev_proc_close_device(pe_close);
dev_proc_fill_rectangle(pe_fill_rectangle);
dev_proc_copy_mono(pe_copy_mono);

static void
pe_initialize_device_procs(gx_device *dev)
{
    set_dev_proc(dev, open_device, pe_open);
    set_dev_proc(dev, close_device, pe_close);
    set_dev_proc(dev, fill_rectangle, pe_fill_rectangle);
    set_dev_proc(dev, copy_mono, pe_copy_mono);
}

gx_device_pe far_data gs_pe_device =
{	std_device_std_body(gx_device_pe, pe_initialize_device_procs, "pe",
          XSIZE, YSIZE, XPPI, YPPI),
         { 0 },		/* std_procs */
        DEFAULT_ADDRESS, DEFAULT_REGISTERS
};

static regval peinit[] = {{0x04, 0x1e}, {0x05, 0x00},
                          {0x04, 0x0c}, {0x05, 0x21},
                          {0x04, 0x0d}, {0x05, 0x98},
                          {0x08, 0x00}, {0x08, 0x1e},
                          {0x04, 0x1e}, {0x05, 0x01}};

static regval pedone[] = {{0x04, 0x1e}, {0x05, 0x10},
                          {0x04, 0x0a}, {0x05, 0x00},
                          {0x04, 0x0b}, {0x05, 0x07},
                          {0x04, 0x0c}, {0x05, 0x00},
                          {0x04, 0x0d}, {0x05, 0x00},
                          {0x04, 0x0e}, {0x05, 0x00},
                          {0x04, 0x0f}, {0x05, 0x00},
                          {0x08, 0x00}, {0x08, 0x29}};

int pe_open(gx_device *dev)
{
        char *str;
        int i;

        if ((str = getenv("PEFBADDR")) != 0)
        {
                if (!sscanf(str, "%lx", &(pedev->fbaddr)))
                {
                        emprintf(dev->memory,
                                 "Private Eye: PEFBADDR environment string format error\n");
                        exit(1);
                }
        }

        if ((str = getenv("PEREGS")) != 0)
        {
                if (!sscanf(str, "%x", &(pedev->regs)))
                {
                        emprintf(dev->memory,
                                 "Private Eye: PEREGS environment string format error\n");
                        exit(1);
                }
        }

        for (i = 0; i < 10; i++)
                outportb(pedev->regs + peinit[i].reg, peinit[i].val);

        return 0;
}

int pe_close(gx_device *dev)
{
        int i;

        /* restore the screen */
        for (i = 0; i < 16; i++)
                outportb(pedev->regs + pedone[i].reg, pedone[i].val);

        /* clear the frame buffer */
        memset(pedev->fbaddr, 0, 4000);

        return 0;
}

int pe_fill_rectangle(gx_device *dev, int x1, int y1, int w, int h,
                      gx_color_index color)
{
        int x2, y2, xlen;
        byte led, red, d;
        byte *ptr;

        /* cull */

        if ((w <= 0) || (h <= 0) || (x1 > XSIZE) || (y1 > YSIZE))
                return 0;

        x2 = x1 + w - 1;
        y2 = y1 + h - 1;

        /* cull some more */

        if ((x2 < 0) || (y2 < 0))
                return 0;

        /* clip */

        if (x1 < 0) x1 = 0;
        if (x2 > XSIZE-1) x2 = XSIZE-1;
        if (y1 < 0) y1 = 0;
        if (y2 > YSIZE-1) y2 = YSIZE-1;

        w = x2 - x1 + 1;
        h = y2 - y1 + 1;
        xlen = (x2 >> 3) - (x1 >> 3) - 1;
        led = 0xff >> (x1 & 7);
        red = 0xff << (7 - (x2 & 7));

        ptr = pedev->fbaddr + (y1 * BPL) + (x1 >> 3);

        if (color)
        {
                /* here to set pixels */

                if (xlen == -1)
                {
                        /* special for rectangles that fit in a byte */

                        d = led & red;
                        for(; h >= 0; h--, ptr += BPL)
                                *ptr |= d;
                        return 0;
                }

                /* normal fill */

                for(; h >= 0; h--, ptr += BPL)
                {	register int x = xlen;
                        register byte *p = ptr;
                        *p++ |= led;
                        while ( x-- ) *p++ = 0xff;
                        *p |= red;
                }
        }

        /* here to clear pixels */

        led = ~led;
        red = ~red;

        if (xlen == -1)
        {
                /* special for rectangles that fit in a byte */

                d = led | red;
                for(; h >= 0; h--, ptr += BPL)
                        *ptr &= d;
                return 0;
        }

        /* normal fill */

        for(; h >= 0; h--, ptr += BPL)
        {	register int x = xlen;
                register byte *p = ptr;
                *p++ &= led;
                while ( x-- ) *p++ = 0x00;
                *p &= red;
        }
        return 0;
}

int pe_copy_mono(gx_device *dev,
                 const byte *base, int sourcex, int raster, gx_bitmap_id id,
                 int x, int y, int w, int h,
                 gx_color_index zero, gx_color_index one)
{
        const byte *line;
        int sleft, dleft;
        int mask, rmask;
        int invert, zmask, omask;
        byte *dest;
        int offset;

#define izero (int)zero
#define ione (int)one

if ( ione == izero )		/* vacuous case */
                return pe_fill_rectangle(dev, x, y, w, h, zero);

        /* clip */

        if ((x > XSIZE) || (y > YSIZE) || ((x + w) < 0) || ((y + h) < 0))
                return 0;

        offset = x >> 3;
        dest = pedev->fbaddr + (y * BPL) + offset;
        line = base + (sourcex >> 3);
        sleft = 8 - (sourcex & 7);
        dleft = 8 - (x & 7);
        mask = 0xff >> (8 - dleft);
        if ( w < dleft )
                mask -= mask >> w;
        else
                rmask = 0xff00 >> ((w - dleft) & 7);

        /* Macros for writing partial bytes. */
        /* bits has already been inverted by xor'ing with invert. */

#define write_byte_masked(ptr, bits, mask)\
  *ptr = ((bits | ~mask | zmask) & *ptr | (bits & mask & omask))

#define write_byte(ptr, bits)\
  *ptr = ((bits | zmask) & *ptr | (bits & omask))

/*	if ( dev->invert )
        {
                if ( izero != (int)gx_no_color_index ) zero ^= 1;
                if ( ione != (int)gx_no_color_index ) one ^= 1;
        } */
        invert = (izero == 1 || ione == 0 ? -1 : 0);
        zmask = (izero == 0 || ione == 0 ? 0 : -1);
        omask = (izero == 1 || ione == 1 ? -1 : 0);

#undef izero
#undef ione

        if (sleft == dleft)		/* optimize the aligned case */
        {
                w -= dleft;
                while ( --h >= 0 )
                {
                        register const byte *bptr = line;
                        int count = w;
                        register byte *optr = dest;
                        register int bits = *bptr ^ invert;	/* first partial byte */

                        write_byte_masked(optr, bits, mask);

                        /* Do full bytes. */

                        while ((count -= 8) >= 0)
                        {
                                bits = *++bptr ^ invert;
                                ++optr;
                                write_byte(optr, bits);
                        }

                        /* Do last byte */

                        if (count > -8)
                        {
                                bits = *++bptr ^ invert;
                                ++optr;
                                write_byte_masked(optr, bits, rmask);
                        }
                        dest += BPL;
                        line += raster;
                }
        }
        else
        {
                int skew = (sleft - dleft) & 7;
                int cskew = 8 - skew;

                while (--h >= 0)
                {
                        const byte *bptr = line;
                        int count = w;
                        byte *optr = dest;
                        register int bits;

                        /* Do the first partial byte */

                        if (sleft >= dleft)
                        {
                                bits = *bptr >> skew;
                        }
                        else /* ( sleft < dleft ) */
                        {
                                bits = *bptr++ << cskew;
                                if (count > sleft)
                                        bits += *bptr >> skew;
                        }
                        bits ^= invert;
                        write_byte_masked(optr, bits, mask);
                        count -= dleft;
                        optr++;

                        /* Do full bytes. */

                        while ( count >= 8 )
                        {
                                bits = *bptr++ << cskew;
                                bits += *bptr >> skew;
                                bits ^= invert;
                                write_byte(optr, bits);
                                count -= 8;
                                optr++;
                        }

                        /* Do last byte */

                        if (count > 0)
                        {
                                bits = *bptr++ << cskew;
                                if (count > skew)
                                        bits += *bptr >> skew;
                                bits ^= invert;
                                write_byte_masked(optr, bits, rmask);
                        }
                        dest += BPL;
                        line += raster;
                }
        }
        return 0;
}