/* Emulate the Toshiba 3100e plasma display. This display has a fixed 640x400
 * resolution. */
#include <stdlib.h>
#include "ibm.h"
#include "device.h"
#include "io.h"
#include "mem.h"
#include "timer.h"
#include "video.h"
#include "vid_cga.h"
#include "vid_t3100e.h"

#define T3100E_XSIZE 640
#define T3100E_YSIZE 400

#define T3100E_OUTPUT_DISPLAY_INTERNAL 1u
#define T3100E_OUTPUT_DISPLAY_EXTERNAL 0u
#define T3100E_OUTPUT_DISPLAY_UNSET 255u

/*Very rough estimate*/
#define VID_CLOCK (double)(651 * 416 * 60)

/* T3100e CRTC regs (from the ROM):
 *
 * Selecting a character height of 3 seems to be sufficient to convert the
 * 640x200 graphics mode to 640x400 (and, by analogy, 320x200 to 320x400).
 *
 *
 * Horiz-----> Vert------>  I ch
 * 38 28 2D 0A 1F 06 19 1C 02 07 06 07   CO40
 * 71 50 5A 0A 1F 06 19 1C 02 07 06 07   CO80
 * 38 28 2D 0A 7F 06 64 70 02 01 06 07   Graphics
 * 61 50 52 0F 19 06 19 19 02 0D 0B 0C   MONO
 * 2D 28 22 0A 67 00 64 67 02 03 06 07   640x400
 */
void updatewindowsize(int x, int y);

/* Mapping of attributes to colours */
static uint32_t amber, black;
static uint8_t boldcols[256]; /* Which attributes use the bold font */
static uint32_t blinkcols[256][2];
static uint32_t normcols[256][2];

/* Video options set by the motherboard; they will be picked up by the card
 * on the next poll.
 *
 * Bit  3:   Disable built-in video (for add-on card)
 * Bit  2:   Thin font
 * Bits 0,1: Font set (not currently implemented)
 */
static uint8_t st_video_options;
static uint8_t st_display_internal = T3100E_OUTPUT_DISPLAY_UNSET;

void t3100e_video_options_set(uint8_t options) { st_video_options = options; }

void t3100e_display_set(uint8_t internal) { st_display_internal = internal; }

uint8_t t3100e_display_get() { return st_display_internal; }

typedef struct t3100e_t {
        mem_mapping_t mapping;

        cga_t cga; /* The CGA is used for the external
                    * display; most of its registers are
                    * ignored by the plasma display. */

        int font;        /* Current font, 0-3 */
        int enabled;     /* Hardware enabled, 0 or 1 */
        int internal;    /* Using internal display? */
        uint8_t attrmap; /* Attribute mapping register */

        uint64_t dispontime, dispofftime;

        int linepos, displine;
        int vc;
        int dispon;
        int vsynctime;
        uint8_t video_options;

        uint8_t *vram;
} t3100e_t;

void t3100e_recalctimings(t3100e_t *t3100e);
void t3100e_write(uint32_t addr, uint8_t val, void *p);
uint8_t t3100e_read(uint32_t addr, void *p);
void t3100e_recalcattrs(t3100e_t *t3100e);

void t3100e_out(uint16_t addr, uint8_t val, void *p) {
        t3100e_t *t3100e = (t3100e_t *)p;
        switch (addr) {
                /* Emulated CRTC, register select */
        case 0x3d0:
        case 0x3d2:
        case 0x3d4:
        case 0x3d6:
                cga_out(addr, val, &t3100e->cga);
                break;

                /* Emulated CRTC, value */
        case 0x3d1:
        case 0x3d3:
        case 0x3d5:
        case 0x3d7:
                /* Register 0x12 controls the attribute mappings for the
                 * plasma screen. */
                if (t3100e->cga.crtcreg == 0x12) {
                        t3100e->attrmap = val;
                        t3100e_recalcattrs(t3100e);
                        return;
                }
                cga_out(addr, val, &t3100e->cga);

                t3100e_recalctimings(t3100e);
                return;

                /* CGA control register */
        case 0x3D8:
                cga_out(addr, val, &t3100e->cga);
                return;
                /* CGA colour register */
        case 0x3D9:
                cga_out(addr, val, &t3100e->cga);
                return;
        }
}

uint8_t t3100e_in(uint16_t addr, void *p) {
        t3100e_t *t3100e = (t3100e_t *)p;
        uint8_t val;

        switch (addr) {
        case 0x3d1:
        case 0x3d3:
        case 0x3d5:
        case 0x3d7:
                if (t3100e->cga.crtcreg == 0x12) {
                        val = t3100e->attrmap & 0x0F;
                        if (t3100e->internal)
                                val |= 0x30; /* Plasma / CRT */
                        return val;
                }
        }

        return cga_in(addr, &t3100e->cga);
}

void t3100e_write(uint32_t addr, uint8_t val, void *p) {
        t3100e_t *t3100e = (t3100e_t *)p;
        egawrites++;

        //        pclog("CGA_WRITE %04X %02X\n", addr, val);
        t3100e->vram[addr & 0x7fff] = val;
        cycles -= 4;
}

uint8_t t3100e_read(uint32_t addr, void *p) {
        t3100e_t *t3100e = (t3100e_t *)p;
        egareads++;
        cycles -= 4;

        //        pclog("CGA_READ %04X\n", addr);
        return t3100e->vram[addr & 0x7fff];
}

void t3100e_recalctimings(t3100e_t *t3100e) {
        double disptime;
        double _dispontime, _dispofftime;

        if (!t3100e->internal) {
                cga_recalctimings(&t3100e->cga);
                return;
        }
        disptime = 651;
        _dispontime = 640;
        _dispofftime = disptime - _dispontime;
        t3100e->dispontime = (uint64_t)(_dispontime * (cpuclock / VID_CLOCK) * (double)(1ull << 32));
        t3100e->dispofftime = (uint64_t)(_dispofftime * (cpuclock / VID_CLOCK) * (double)(1ull << 32));
}

/* Draw a row of text in 80-column mode */
void t3100e_text_row80(t3100e_t *t3100e) {
        uint32_t cols[2];
        int x, c;
        uint8_t chr, attr;
        int drawcursor;
        int cursorline;
        int bold;
        int blink;
        uint16_t addr;
        uint8_t sc;
        uint16_t ma = (t3100e->cga.crtc[13] | (t3100e->cga.crtc[12] << 8)) & 0x7fff;
        uint16_t ca = (t3100e->cga.crtc[15] | (t3100e->cga.crtc[14] << 8)) & 0x7fff;

        sc = (t3100e->displine) & 15;
        addr = ((ma & ~1) + (t3100e->displine >> 4) * 80) * 2;
        ma += (t3100e->displine >> 4) * 80;

        if ((t3100e->cga.crtc[10] & 0x60) == 0x20) {
                cursorline = 0;
        } else {
                cursorline = ((t3100e->cga.crtc[10] & 0x0F) * 2 <= sc) && ((t3100e->cga.crtc[11] & 0x0F) * 2 >= sc);
        }
        for (x = 0; x < 80; x++) {
                chr = t3100e->vram[(addr + 2 * x) & 0x7FFF];
                attr = t3100e->vram[(addr + 2 * x + 1) & 0x7FFF];
                drawcursor = ((ma == ca) && cursorline && (t3100e->cga.cgamode & 8) && (t3100e->cga.cgablink & 16));

                blink = ((t3100e->cga.cgablink & 16) && (t3100e->cga.cgamode & 0x20) && (attr & 0x80) && !drawcursor);

                if (t3100e->video_options & 4)
                        bold = boldcols[attr] ? chr + 256 : chr;
                else
                        bold = boldcols[attr] ? chr : chr + 256;
                bold += 512 * (t3100e->video_options & 3);

                if (t3100e->cga.cgamode & 0x20) /* Blink */
                {
                        cols[1] = blinkcols[attr][1];
                        cols[0] = blinkcols[attr][0];
                        if (blink)
                                cols[1] = cols[0];
                } else {
                        cols[1] = normcols[attr][1];
                        cols[0] = normcols[attr][0];
                }
                if (drawcursor) {
                        for (c = 0; c < 8; c++) {
                                ((uint32_t *)buffer32->line[t3100e->displine])[(x << 3) + c] =
                                        cols[(fontdatm[bold][sc] & (1 << (c ^ 7))) ? 1 : 0] ^ (amber ^ black);
                        }
                } else {
                        for (c = 0; c < 8; c++)
                                ((uint32_t *)buffer32->line[t3100e->displine])[(x << 3) + c] =
                                        cols[(fontdatm[bold][sc] & (1 << (c ^ 7))) ? 1 : 0];
                }
                ++ma;
        }
}

/* Draw a row of text in 40-column mode */
void t3100e_text_row40(t3100e_t *t3100e) {
        uint32_t cols[2];
        int x, c;
        uint8_t chr, attr;
        int drawcursor;
        int cursorline;
        int bold;
        int blink;
        uint16_t addr;
        uint8_t sc;
        uint16_t ma = (t3100e->cga.crtc[13] | (t3100e->cga.crtc[12] << 8)) & 0x7fff;
        uint16_t ca = (t3100e->cga.crtc[15] | (t3100e->cga.crtc[14] << 8)) & 0x7fff;

        sc = (t3100e->displine) & 15;
        addr = ((ma & ~1) + (t3100e->displine >> 4) * 40) * 2;
        ma += (t3100e->displine >> 4) * 40;

        if ((t3100e->cga.crtc[10] & 0x60) == 0x20) {
                cursorline = 0;
        } else {
                cursorline = ((t3100e->cga.crtc[10] & 0x0F) * 2 <= sc) && ((t3100e->cga.crtc[11] & 0x0F) * 2 >= sc);
        }
        for (x = 0; x < 40; x++) {
                chr = t3100e->vram[(addr + 2 * x) & 0x7FFF];
                attr = t3100e->vram[(addr + 2 * x + 1) & 0x7FFF];
                drawcursor = ((ma == ca) && cursorline && (t3100e->cga.cgamode & 8) && (t3100e->cga.cgablink & 16));

                blink = ((t3100e->cga.cgablink & 16) && (t3100e->cga.cgamode & 0x20) && (attr & 0x80) && !drawcursor);

                if (t3100e->video_options & 4)
                        bold = boldcols[attr] ? chr + 256 : chr;
                else
                        bold = boldcols[attr] ? chr : chr + 256;
                bold += 512 * (t3100e->video_options & 3);

                if (t3100e->cga.cgamode & 0x20) /* Blink */
                {
                        cols[1] = blinkcols[attr][1];
                        cols[0] = blinkcols[attr][0];
                        if (blink)
                                cols[1] = cols[0];
                } else {
                        cols[1] = normcols[attr][1];
                        cols[0] = normcols[attr][0];
                }
                if (drawcursor) {
                        for (c = 0; c < 8; c++) {
                                ((uint32_t *)buffer32->line[t3100e->displine])[(x << 4) + c * 2] =
                                        ((uint32_t *)buffer32->line[t3100e->displine])[(x << 4) + c * 2 + 1] =
                                                cols[(fontdatm[bold][sc] & (1 << (c ^ 7))) ? 1 : 0] ^ (amber ^ black);
                        }
                } else {
                        for (c = 0; c < 8; c++) {
                                ((uint32_t *)buffer32->line[t3100e->displine])[(x << 4) + c * 2] =
                                        ((uint32_t *)buffer32->line[t3100e->displine])[(x << 4) + c * 2 + 1] =
                                                cols[(fontdatm[bold][sc] & (1 << (c ^ 7))) ? 1 : 0];
                        }
                }
                ++ma;
        }
}

/* Draw a line in CGA 640x200 or T3100e 640x400 mode */
void t3100e_cgaline6(t3100e_t *t3100e) {
        int x, c;
        uint8_t dat;
        uint32_t ink = 0;
        uint16_t addr;
        uint32_t fg = (t3100e->cga.cgacol & 0x0F) ? amber : black;
        uint32_t bg = black;

        uint16_t ma = (t3100e->cga.crtc[13] | (t3100e->cga.crtc[12] << 8)) & 0x7fff;

        if (t3100e->cga.crtc[9] == 3) /* 640*400 */
        {
                addr = ((t3100e->displine) & 1) * 0x2000 + ((t3100e->displine >> 1) & 1) * 0x4000 + (t3100e->displine >> 2) * 80 +
                       ((ma & ~1) << 1);
        } else {
                addr = ((t3100e->displine >> 1) & 1) * 0x2000 + (t3100e->displine >> 2) * 80 + ((ma & ~1) << 1);
        }
        for (x = 0; x < 80; x++) {
                dat = t3100e->vram[addr & 0x7FFF];
                addr++;

                for (c = 0; c < 8; c++) {
                        ink = (dat & 0x80) ? fg : bg;
                        if (!(t3100e->cga.cgamode & 8))
                                ink = black;
                        ((uint32_t *)buffer32->line[t3100e->displine])[x * 8 + c] = ink;
                        dat = dat << 1;
                }
        }
}

/* Draw a line in CGA 320x200 mode. Here the CGA colours are converted to
 * dither patterns: colour 1 to 25% grey, colour 2 to 50% grey */
void t3100e_cgaline4(t3100e_t *t3100e) {
        int x, c;
        uint8_t dat, pattern;
        uint32_t ink0, ink1;
        uint16_t addr;

        uint16_t ma = (t3100e->cga.crtc[13] | (t3100e->cga.crtc[12] << 8)) & 0x7fff;
        if (t3100e->cga.crtc[9] == 3) /* 320*400 undocumented */
        {
                addr = ((t3100e->displine) & 1) * 0x2000 + ((t3100e->displine >> 1) & 1) * 0x4000 + (t3100e->displine >> 2) * 80 +
                       ((ma & ~1) << 1);
        } else /* 320*200 */
        {
                addr = ((t3100e->displine >> 1) & 1) * 0x2000 + (t3100e->displine >> 2) * 80 + ((ma & ~1) << 1);
        }
        for (x = 0; x < 80; x++) {
                dat = t3100e->vram[addr & 0x7FFF];
                addr++;

                for (c = 0; c < 4; c++) {
                        pattern = (dat & 0xC0) >> 6;
                        if (!(t3100e->cga.cgamode & 8))
                                pattern = 0;

                        switch (pattern & 3) {
                        case 0:
                                ink0 = ink1 = black;
                                break;
                        case 1:
                                if (t3100e->displine & 1) {
                                        ink0 = black;
                                        ink1 = black;
                                } else {
                                        ink0 = amber;
                                        ink1 = black;
                                }
                                break;
                        case 2:
                                if (t3100e->displine & 1) {
                                        ink0 = black;
                                        ink1 = amber;
                                } else {
                                        ink0 = amber;
                                        ink1 = black;
                                }
                                break;
                        case 3:
                                ink0 = ink1 = amber;
                                break;
                        }
                        ((uint32_t *)buffer32->line[t3100e->displine])[x * 8 + 2 * c] = ink0;
                        ((uint32_t *)buffer32->line[t3100e->displine])[x * 8 + 2 * c + 1] = ink1;
                        dat = dat << 2;
                }
        }
}

void t3100e_poll(void *p) {
        t3100e_t *t3100e = (t3100e_t *)p;

        if (t3100e->video_options != st_video_options) {
                t3100e->video_options = st_video_options;

                if (t3100e->video_options & 8) /* Disable internal CGA */
                        mem_mapping_disable(&t3100e->mapping);
                else
                        mem_mapping_enable(&t3100e->mapping);

                /* Set the font used for the external display */
                t3100e->cga.fontbase = (512 * (t3100e->video_options & 3)) + ((t3100e->video_options & 4) ? 256 : 0);
        }
        /* Switch between internal plasma and external CRT display. */
        if (st_display_internal != T3100E_OUTPUT_DISPLAY_UNSET && st_display_internal != t3100e->internal) {
                t3100e->internal = st_display_internal;
                t3100e_recalctimings(t3100e);
        }
        if (!t3100e->internal) {
                cga_poll(&t3100e->cga);
                return;
        }

        if (!t3100e->linepos) {
                timer_advance_u64(&t3100e->cga.timer, t3100e->dispofftime);
                t3100e->cga.cgastat |= 1;
                t3100e->linepos = 1;
                if (t3100e->dispon) {
                        if (t3100e->displine == 0) {
                                video_wait_for_buffer();
                        }

                        /* Graphics */
                        if (t3100e->cga.cgamode & 0x02) {
                                if (t3100e->cga.cgamode & 0x10)
                                        t3100e_cgaline6(t3100e);
                                else
                                        t3100e_cgaline4(t3100e);
                        } else if (t3100e->cga.cgamode & 0x01) /* High-res text */
                        {
                                t3100e_text_row80(t3100e);
                        } else {
                                t3100e_text_row40(t3100e);
                        }
                }
                t3100e->displine++;
                /* Hardcode a fixed refresh rate and VSYNC timing */
                if (t3100e->displine == 400) /* Start of VSYNC */
                {
                        t3100e->cga.cgastat |= 8;
                        t3100e->dispon = 0;
                }
                if (t3100e->displine == 416) /* End of VSYNC */
                {
                        t3100e->displine = 0;
                        t3100e->cga.cgastat &= ~8;
                        t3100e->dispon = 1;
                }
        } else {
                if (t3100e->dispon) {
                        t3100e->cga.cgastat &= ~1;
                }
                timer_advance_u64(&t3100e->cga.timer, t3100e->dispontime);
                t3100e->linepos = 0;

                if (t3100e->displine == 400) {
                        /* Hardcode 640x400 window size */
                        if (T3100E_XSIZE != xsize || T3100E_YSIZE != ysize) {
                                xsize = T3100E_XSIZE;
                                ysize = T3100E_YSIZE;
                                if (xsize < 64)
                                        xsize = 656;
                                if (ysize < 32)
                                        ysize = 200;
                                updatewindowsize(xsize, ysize);
                        }
                        video_blit_memtoscreen(0, 0, 0, ysize, xsize, ysize);

                        frames++;
                        /* Fixed 640x400 resolution */
                        video_res_x = T3100E_XSIZE;
                        video_res_y = T3100E_YSIZE;

                        if (t3100e->cga.cgamode & 0x02) {
                                if (t3100e->cga.cgamode & 0x10)
                                        video_bpp = 1;
                                else
                                        video_bpp = 2;

                        } else
                                video_bpp = 0;
                        t3100e->cga.cgablink++;
                }
        }
}

void t3100e_recalcattrs(t3100e_t *t3100e) {
        int n;

        /* val behaves as follows:
         *     Bit 0: Attributes 01-06, 08-0E are inverse video
         *     Bit 1: Attributes 01-06, 08-0E are bold
         *     Bit 2: Attributes 11-16, 18-1F, 21-26, 28-2F ... F1-F6, F8-FF
         * 	      are inverse video
         *     Bit 3: Attributes 11-16, 18-1F, 21-26, 28-2F ... F1-F6, F8-FF
         * 	      are bold */

        /* Set up colours */
        amber = makecol(0xf7, 0x7C, 0x34);
        black = makecol(0x17, 0x0C, 0x00);

        /* Initialise the attribute mapping. Start by defaulting everything
         * to black on amber, and with bold set by bit 3 */
        for (n = 0; n < 256; n++) {
                boldcols[n] = (n & 8) != 0;
                blinkcols[n][0] = normcols[n][0] = amber;
                blinkcols[n][1] = normcols[n][1] = black;
        }

        /* Colours 0x11-0xFF are controlled by bits 2 and 3 of the
         * passed value. Exclude x0 and x8, which are always black on
         * amber. */
        for (n = 0x11; n <= 0xFF; n++) {
                if ((n & 7) == 0)
                        continue;
                if (t3100e->attrmap & 4) /* Inverse */
                {
                        blinkcols[n][0] = normcols[n][0] = amber;
                        blinkcols[n][1] = normcols[n][1] = black;
                } else /* Normal */
                {
                        blinkcols[n][0] = normcols[n][0] = black;
                        blinkcols[n][1] = normcols[n][1] = amber;
                }
                if (t3100e->attrmap & 8)
                        boldcols[n] = 1; /* Bold */
        }
        /* Set up the 01-0E range, controlled by bits 0 and 1 of the
         * passed value. When blinking is enabled this also affects 81-8E. */
        for (n = 0x01; n <= 0x0E; n++) {
                if (n == 7)
                        continue;
                if (t3100e->attrmap & 1) {
                        blinkcols[n][0] = normcols[n][0] = amber;
                        blinkcols[n][1] = normcols[n][1] = black;
                        blinkcols[n + 128][0] = amber;
                        blinkcols[n + 128][1] = black;
                } else {
                        blinkcols[n][0] = normcols[n][0] = black;
                        blinkcols[n][1] = normcols[n][1] = amber;
                        blinkcols[n + 128][0] = black;
                        blinkcols[n + 128][1] = amber;
                }
                if (t3100e->attrmap & 2)
                        boldcols[n] = 1;
        }
        /* Colours 07 and 0F are always amber on black. If blinking is
         * enabled so are 87 and 8F. */
        for (n = 0x07; n <= 0x0F; n += 8) {
                blinkcols[n][0] = normcols[n][0] = black;
                blinkcols[n][1] = normcols[n][1] = amber;
                blinkcols[n + 128][0] = black;
                blinkcols[n + 128][1] = amber;
        }
        /* When not blinking, colours 81-8F are always amber on black. */
        for (n = 0x81; n <= 0x8F; n++) {
                normcols[n][0] = black;
                normcols[n][1] = amber;
                boldcols[n] = (n & 0x08) != 0;
        }

        /* Finally do the ones which are solid black. These differ between
         * the normal and blinking mappings */
        for (n = 0; n <= 0xFF; n += 0x11) {
                normcols[n][0] = normcols[n][1] = black;
        }
        /* In the blinking range, 00 11 22 .. 77 and 80 91 A2 .. F7 are black */
        for (n = 0; n <= 0x77; n += 0x11) {
                blinkcols[n][0] = blinkcols[n][1] = black;
                blinkcols[n + 128][0] = blinkcols[n + 128][1] = black;
        }
}

void *t3100e_init() {
        t3100e_t *t3100e = malloc(sizeof(t3100e_t));
        memset(t3100e, 0, sizeof(t3100e_t));
        cga_init(&t3100e->cga);

        t3100e->internal = 1;

        /* 32k video RAM */
        t3100e->vram = malloc(0x8000);

        timer_set_callback(&t3100e->cga.timer, t3100e_poll);
        timer_set_p(&t3100e->cga.timer, t3100e);

        /* Occupy memory between 0xB8000 and 0xBFFFF */
        mem_mapping_add(&t3100e->mapping, 0xb8000, 0x8000, t3100e_read, NULL, NULL, t3100e_write, NULL, NULL, NULL, 0, t3100e);
        /* Respond to CGA I/O ports */
        io_sethandler(0x03d0, 0x000c, t3100e_in, NULL, NULL, t3100e_out, NULL, NULL, t3100e);

        /* Default attribute mapping is 4 */
        t3100e->attrmap = 4;
        t3100e_recalcattrs(t3100e);

        /* Start off in 80x25 text mode */
        t3100e->cga.cgastat = 0xF4;
        t3100e->cga.vram = t3100e->vram;
        t3100e->enabled = 1;
        t3100e->video_options = 0xFF;
        return t3100e;
}

void t3100e_close(void *p) {
        t3100e_t *t3100e = (t3100e_t *)p;

        free(t3100e->vram);
        free(t3100e);
}

void t3100e_speed_changed(void *p) {
        t3100e_t *t3100e = (t3100e_t *)p;

        t3100e_recalctimings(t3100e);
}

device_t t3100e_device = {"Toshiba T3100e", 0, t3100e_init, t3100e_close, NULL, t3100e_speed_changed, NULL, NULL};
