apple2ix/src/display.c

/*
 * Apple // emulator for Linux: Video support
 *
 * Copyright 1994 Alexander Jean-Claude Bottema
 * Copyright 1995 Stephen Lee
 * Copyright 1997, 1998 Aaron Culliney
 * Copyright 1998, 1999, 2000 Michael Deutschmann
 *
 * This software package is subject to the GNU General Public License
 * version 2 or later (your choice) as published by the Free Software
 * Foundation.
 *
 * THERE ARE NO WARRANTIES WHATSOEVER.
 *
 */

#include "common.h"

#define DYNAMIC_SZ 11 // 7 pixels (as bytes) + 2pre + 2post

#define TEXT_ROWS 24
#define BEGIN_MIX 20
#define TEXT_COLS 40

// framebuffers
static uint8_t vga_mem_page_0[SCANWIDTH*SCANHEIGHT];
static uint8_t vga_mem_page_1[SCANWIDTH*SCANHEIGHT];

extern A2Color colormap[256] = { 0 };

uint8_t video__wider_font[0x8000];
uint8_t video__font[0x4000];

// Precalculated framebuffer offsets given VM addr
unsigned int video__screen_addresses[8192];
uint8_t video__columns[8192];

uint8_t *video__fb1 = NULL;
uint8_t *video__fb2 = NULL;

uint8_t video__hires_even[0x800];
uint8_t video__hires_odd[0x800];

uint8_t video__dhires1[256];
uint8_t video__dhires2[256];

// Interface font
static uint8_t video__int_font[3][0x4000];

int video__current_page; // current visual page
int video__strictcolors = 1;// refactor : should be static

void video_loadfont(int first, int quantity, const uint8_t *data, int mode) {
    uint8_t fg = 0;
    uint8_t bg = 0;
    switch (mode) {
        case 2:
            fg = COLOR_BLACK;
            bg = COLOR_LIGHT_WHITE;
            break;
        case 3:
            fg = COLOR_FLASHING_WHITE;
            bg = COLOR_FLASHING_BLACK;
            break;
        default:
            fg = COLOR_LIGHT_WHITE;
            bg = COLOR_BLACK;
            break;
    }

    unsigned int i = quantity * 8;
    while (i--) {
        unsigned int j = 8;
        uint8_t x = data[i];
        while (j--) {
            uint8_t y = (x & 128) ? fg : bg;
            video__wider_font[(first << 7) + (i << 4) + (j << 1)] = video__wider_font[(first << 7) + (i << 4) + (j << 1) + 1] =
            video__font[(first << 6) + (i << 3) + j] = y;
            x <<= 1;
        }
    }
}

uint8_t video__odd_colors[2] = { COLOR_LIGHT_PURPLE, COLOR_LIGHT_BLUE };
uint8_t video__even_colors[2] = { COLOR_LIGHT_GREEN, COLOR_LIGHT_RED };

// 40col/80col/lores/hires/dhires line offsets
unsigned short video__line_offset[TEXT_ROWS] = {
  0x000, 0x080, 0x100, 0x180, 0x200, 0x280, 0x300, 0x380,
  0x028, 0x0A8, 0x128, 0x1A8, 0x228, 0x2A8, 0x328, 0x3A8,
  0x050, 0x0D0, 0x150, 0x1D0, 0x250, 0x2D0, 0x350, 0x3D0
};

uint8_t video__dhires1[256] = {
    0x0,0x1,0x2,0x3,0x4,0x5,0x6,0x7,0x8,0x9,0xa,0xb,0xc,0xd,0xe,0xf,
    0x0,0x1,0x3,0x3,0x5,0x5,0x7,0x7,0x9,0x9,0xb,0xb,0xd,0xd,0xf,0xf,
    0x0,0x1,0x2,0x3,0x6,0x5,0x6,0x7,0xa,0x9,0xa,0xb,0xe,0xd,0xe,0xf,
    0x0,0x1,0x3,0x3,0x7,0x5,0x7,0x7,0xb,0x9,0xb,0xb,0xf,0xd,0xf,0xf,
    0x0,0x1,0x2,0x3,0x4,0x4,0x6,0x7,0x8,0x9,0xa,0xb,0xc,0xd,0xe,0xf,
    0x0,0x1,0x3,0x3,0x5,0x5,0x7,0x7,0xd,0x9,0xb,0xb,0xd,0xd,0xf,0xf,
    0x0,0x1,0x2,0x3,0x4,0x5,0x6,0x7,0xe,0x9,0xa,0xb,0xe,0xd,0xe,0xf,
    0x0,0x1,0x7,0x3,0x7,0x5,0x7,0x7,0xf,0x9,0xb,0xb,0xf,0xd,0xf,0xf,
};

uint8_t video__dhires2[256] = {
    0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x8,0x8,0x0,0xb,0x8,0xd,0x0,0x0,
    0x1,0x1,0x1,0x1,0x0,0x5,0x1,0x1,0x0,0x9,0xb,0xb,0x0,0xd,0xf,0xf,
    0x0,0x1,0x2,0x2,0x2,0x5,0x2,0x2,0x0,0xa,0xa,0xa,0xe,0xd,0x2,0x2,
    0x3,0x3,0x3,0x3,0x7,0x5,0x7,0x7,0x0,0xb,0xb,0xb,0xf,0xd,0xf,0xf,
    0x0,0x0,0x4,0x0,0x4,0x4,0x4,0x4,0xc,0x8,0x4,0x8,0xc,0xd,0x4,0x4,
    0x5,0x5,0x5,0x5,0x5,0x5,0x5,0x5,0xd,0x4,0x4,0x4,0xd,0xd,0x4,0x4,
    0x6,0x6,0x6,0x2,0xe,0x6,0x6,0x6,0xe,0xe,0xa,0xa,0xe,0x6,0xe,0x6,
    0x7,0x7,0x7,0x7,0x7,0x7,0x7,0x7,0xf,0xf,0xb,0xb,0xf,0xf,0xf,0xf,
};


static void video_initialize_dhires_values(void) {
    for (unsigned int i = 0; i < 0x80; i++) {
        video__dhires1[i+0x80] = video__dhires1[i];
        video__dhires2[i+0x80] = video__dhires2[i];
    }
}

static void video_initialize_hires_values(void) {
    // precalculate colors for all the 256*8 bit combinations. */
    for (unsigned int value = 0x00; value <= 0xFF; value++) {
        for (unsigned int e = value*8, last_not_black=0, v=value, b=0; b < 7; b++, v >>= 1, e++) {
            if (v & 1) {
                if (last_not_black) {
                    video__hires_even[e] = COLOR_LIGHT_WHITE;
                    video__hires_odd[e] = COLOR_LIGHT_WHITE;
                    if (b > 0)
                    {
                        video__hires_even[e-1] = COLOR_LIGHT_WHITE,
                        video__hires_odd [e-1] = COLOR_LIGHT_WHITE;
                    }
                } else {
                    if (b & 1) {
                        if (value & 0x80) {
                            video__hires_even[e] = COLOR_LIGHT_RED;
                            video__hires_odd [e] = COLOR_LIGHT_BLUE;
                        } else {
                            video__hires_even[e] = COLOR_LIGHT_GREEN;
                            video__hires_odd [e] = COLOR_LIGHT_PURPLE;
                        }
                    } else {
                        if (value & 0x80) {
                            video__hires_even[e] = COLOR_LIGHT_BLUE;
                            video__hires_odd [e] = COLOR_LIGHT_RED;
                        } else {
                            video__hires_even[e] = COLOR_LIGHT_PURPLE;
                            video__hires_odd [e] = COLOR_LIGHT_GREEN;
                        }
                    }
                }
                last_not_black = 1;
            } else {
                video__hires_even[e] = COLOR_BLACK,
                video__hires_odd [e] = COLOR_BLACK,
                last_not_black = 0;
            }
        }
    }

    if (color_mode == COLOR_NONE) {
        for (unsigned int value = 0x00; value <= 0xFF; value++) {
            for (unsigned int b = 0, e = value * 8; b < 7; b++, e++) {
                if (video__hires_even[e] != COLOR_BLACK) {
                    video__hires_even[e] = COLOR_LIGHT_WHITE;
                }
                if (video__hires_odd[e] != COLOR_BLACK) {
                    video__hires_odd[e] = COLOR_LIGHT_WHITE;
                }
            }
        }
    } else if (color_mode == COLOR_INTERP) {
        for (unsigned int value = 0x00; value <= 0xFF; value++) {
            for (unsigned int b=1, e=value*8 + 1; b <= 5; b += 2, e += 2) {
                if (video__hires_even[e] == COLOR_BLACK) {
                    if (video__hires_even[e-1] != COLOR_BLACK &&
                        video__hires_even[e+1] != COLOR_BLACK &&
                        video__hires_even[e-1] != COLOR_LIGHT_WHITE &&
                        video__hires_even[e+1] != COLOR_LIGHT_WHITE)
                    {
                        video__hires_even[e] = video__hires_even[e-1];
                    }
                    else if (
                        video__hires_even[e-1] != COLOR_BLACK &&
                        video__hires_even[e+1] != COLOR_BLACK &&
                        video__hires_even[e-1] != COLOR_LIGHT_WHITE &&
                        video__hires_even[e+1] == COLOR_LIGHT_WHITE)
                    {
                        video__hires_even[e] = video__hires_even[e-1];
                    }
                    else if (
                        video__hires_even[e-1] != COLOR_BLACK &&
                        video__hires_even[e+1] != COLOR_BLACK &&
                        video__hires_even[e-1] == COLOR_LIGHT_WHITE &&
                        video__hires_even[e+1] != COLOR_LIGHT_WHITE)
                    {
                        video__hires_even[e] = video__hires_even[e+1];
                    }
                    else if (
                        video__hires_even[e-1] == COLOR_LIGHT_WHITE &&
                        video__hires_even[e+1] == COLOR_LIGHT_WHITE)
                    {
                        video__hires_even[e] = (value & 0x80) ? COLOR_LIGHT_BLUE : COLOR_LIGHT_PURPLE;
                    }
                }

                if (video__hires_odd[e] == COLOR_BLACK) {
                    if (video__hires_odd[e-1] != COLOR_BLACK &&
                        video__hires_odd[e+1] != COLOR_BLACK &&
                        video__hires_odd[e-1] != COLOR_LIGHT_WHITE &&
                        video__hires_odd[e+1] != COLOR_LIGHT_WHITE)
                    {
                        video__hires_odd[e] = video__hires_odd[e-1];
                    }
                    else if (
                        video__hires_odd[e-1] != COLOR_BLACK &&
                        video__hires_odd[e+1] != COLOR_BLACK &&
                        video__hires_odd[e-1] != COLOR_LIGHT_WHITE &&
                        video__hires_odd[e+1] == COLOR_LIGHT_WHITE)
                    {
                        video__hires_odd[e] = video__hires_odd[e-1];
                    }
                    else if (
                        video__hires_odd[e-1] != COLOR_BLACK &&
                        video__hires_odd[e+1] != COLOR_BLACK &&
                        video__hires_odd[e-1] == COLOR_LIGHT_WHITE &&
                        video__hires_odd[e+1] != COLOR_LIGHT_WHITE)
                    {
                        video__hires_odd[e] = video__hires_odd[e+1];
                    }
                    else if (
                        video__hires_odd[e-1] == COLOR_LIGHT_WHITE &&
                        video__hires_odd[e+1] == COLOR_LIGHT_WHITE)
                    {
                        video__hires_odd[e] = (value & 0x80) ? COLOR_LIGHT_RED : COLOR_LIGHT_GREEN;
                    }
                }
            }

            for (unsigned int b = 0, e = value * 8; b <= 6; b += 2, e += 2) {
                if (video__hires_even[ e ] == COLOR_BLACK) {
                    if (b > 0 && b < 6) {
                        if (video__hires_even[e-1] != COLOR_BLACK &&
                            video__hires_even[e+1] != COLOR_BLACK &&
                            video__hires_even[e-1] != COLOR_LIGHT_WHITE &&
                            video__hires_even[e+1] != COLOR_LIGHT_WHITE)
                        {
                            video__hires_even[e] = video__hires_even[e-1];
                        }
                        else if (
                            video__hires_even[e-1] != COLOR_BLACK &&
                            video__hires_even[e+1] != COLOR_BLACK &&
                            video__hires_even[e-1] != COLOR_LIGHT_WHITE &&
                            video__hires_even[e+1] == COLOR_LIGHT_WHITE)
                        {
                            video__hires_even[e] = video__hires_even[e-1];
                        }
                        else if (
                            video__hires_even[e-1] != COLOR_BLACK &&
                            video__hires_even[e+1] != COLOR_BLACK &&
                            video__hires_even[e-1] == COLOR_LIGHT_WHITE &&
                            video__hires_even[e+1] != COLOR_LIGHT_WHITE)
                        {
                            video__hires_even[e] = video__hires_even[e+1];
                        }
                        else if (
                            video__hires_even[e-1] == COLOR_LIGHT_WHITE &&
                            video__hires_even[e+1] == COLOR_LIGHT_WHITE)
                        {
                            video__hires_even[e] = (value & 0x80) ? COLOR_LIGHT_RED : COLOR_LIGHT_GREEN;
                        }
                    }
                }

                if (video__hires_odd[e] == COLOR_BLACK) {
                    if (b > 0 && b < 6) {
                        if (video__hires_odd[e-1] != COLOR_BLACK &&
                            video__hires_odd[e+1] != COLOR_BLACK &&
                            video__hires_odd[e-1] != COLOR_LIGHT_WHITE &&
                            video__hires_odd[e+1] != COLOR_LIGHT_WHITE)
                        {
                            video__hires_odd[e] = video__hires_odd[e-1];
                        }
                        else if (
                            video__hires_odd[e-1] != COLOR_BLACK &&
                            video__hires_odd[e+1] != COLOR_BLACK &&
                            video__hires_odd[e-1] != COLOR_LIGHT_WHITE &&
                            video__hires_odd[e+1] == COLOR_LIGHT_WHITE)
                        {
                            video__hires_odd[e] = video__hires_odd[e-1];
                        }
                        else if (
                            video__hires_odd[e-1] != COLOR_BLACK &&
                            video__hires_odd[e+1] != COLOR_BLACK &&
                            video__hires_odd[e-1] == COLOR_LIGHT_WHITE &&
                            video__hires_odd[e+1] != COLOR_LIGHT_WHITE)
                        {
                            video__hires_odd[e] = video__hires_odd[e+1];
                        }
                        else if (
                            video__hires_odd[e-1] == COLOR_LIGHT_WHITE &&
                            video__hires_odd[e+1] == COLOR_LIGHT_WHITE)
                        {
                            video__hires_odd[e] = (value & 0x80) ? COLOR_LIGHT_BLUE : COLOR_LIGHT_PURPLE;
                        }
                    }
                }
            }
        }
    }
}

static void video_initialize_row_col_tables(void) {
    for (unsigned int i = 0; i < 8192; i++) {
        video__screen_addresses[i] = -1;
    }

    for (unsigned int y = 0; y < TEXT_ROWS; y++) {
        for (unsigned int off = 0; off < 8; off++) {
            for (unsigned int x = 0; x < 40; x++) {
                video__screen_addresses[video__line_offset[y] + (0x400*off) + x] = (y*16 + 2*off /* + 8*/) * SCANWIDTH + x*14 + 4;
                video__columns         [video__line_offset[y] + (0x400*off) + x] = (uint8_t)x;
            }
        }
    }
}

static void video_initialize_tables_video(void) {
    // initialize text/lores & hires graphics routines
    for (unsigned int y = 0; y < TEXT_ROWS; y++) {
        for (unsigned int x = 0; x < TEXT_COLS; x++) {
            unsigned int idx = video__line_offset[y] + x + 0x400;
            // text/lores pages
            if (y < 20) {
                cpu65_vmem_w[idx      ] = video__write_2e_text0;
                cpu65_vmem_w[idx+0x400] = video__write_2e_text1;
            } else {
                cpu65_vmem_w[idx      ] = video__write_2e_text0_mixed;
                cpu65_vmem_w[idx+0x400] = video__write_2e_text1_mixed;
            }

            // hires/dhires pages
            for (unsigned int i = 0; i < 8; i++) {
                idx = 0x2000 + video__line_offset[ y ] + (0x400*i) + x;
                if (y < 20) {
                    if (x & 1) {
                        cpu65_vmem_w[idx       ] = video__write_2e_odd0;
                        cpu65_vmem_w[idx+0x2000] = video__write_2e_odd1;
                    } else {
                        cpu65_vmem_w[idx       ] = video__write_2e_even0;
                        cpu65_vmem_w[idx+0x2000] = video__write_2e_even1;
                    }
                } else {
                    if (x & 1) {
                        cpu65_vmem_w[idx       ] = video__write_2e_odd0_mixed;
                        cpu65_vmem_w[idx+0x2000] = video__write_2e_odd1_mixed;
                    } else {
                        cpu65_vmem_w[idx       ] = video__write_2e_even0_mixed;
                        cpu65_vmem_w[idx+0x2000] = video__write_2e_even1_mixed;
                    }
                }
            }
        }
    }
}

static void video_initialize_color() {
    unsigned char col2[ 3 ] = { 255,255,255 };

    /* align the palette for hires graphics */
    for (unsigned int i = 0; i < 8; i++) {
        for (unsigned int j = 0; j < 3; j++) {
            unsigned int c = 0;
            c = (i & 1) ? col2[ j ] : 0;
            colormap[ j+i*3+32].red = c;
            c = (i & 2) ? col2[ j ] : 0;
            colormap[ j+i*3+32].green = c;
            c = (i & 4) ? col2[ j ] : 0;
            colormap[ j+i*3+32].blue = c;
        }
    }

    colormap[ COLOR_FLASHING_BLACK].red = 0;
    colormap[ COLOR_FLASHING_BLACK].green = 0;
    colormap[ COLOR_FLASHING_BLACK].blue = 0;

    colormap[ COLOR_LIGHT_WHITE].red   = (255<<8)|255;
    colormap[ COLOR_LIGHT_WHITE].green = (255<<8)|255;
    colormap[ COLOR_LIGHT_WHITE].blue  = (255<<8)|255;

    colormap[ COLOR_FLASHING_WHITE].red   = (255<<8)|255;
    colormap[ COLOR_FLASHING_WHITE].green = (255<<8)|255;
    colormap[ COLOR_FLASHING_WHITE].blue  = (255<<8)|255;

    colormap[0x00].red = 0; colormap[0x00].green = 0;
    colormap[0x00].blue = 0;   /* Black */
    colormap[0x10].red = 195; colormap[0x10].green = 0;
    colormap[0x10].blue = 48;  /* Magenta */
    colormap[0x20].red = 0; colormap[0x20].green = 0;
    colormap[0x20].blue = 130; /* Dark Blue */
    colormap[0x30].red = 166; colormap[0x30].green = 52;
    colormap[0x30].blue = 170; /* Purple */
    colormap[0x40].red = 0; colormap[0x40].green = 146;
    colormap[0x40].blue = 0;   /* Dark Green */
    colormap[0x50].red = 105; colormap[0x50].green = 105;
    colormap[0x50].blue = 105; /* Dark Grey*/
    colormap[0x60].red = 113; colormap[0x60].green = 24;
    colormap[0x60].blue = 255; /* Medium Blue */
    colormap[0x70].red = 12; colormap[0x70].green = 190;
    colormap[0x70].blue = 235; /* Light Blue */
    colormap[0x80].red = 150; colormap[0x80].green = 85;
    colormap[0x80].blue = 40; /* Brown */
    colormap[0x90].red = 255; colormap[0xa0].green = 24;
    colormap[0x90].blue = 44; /* Orange */
    colormap[0xa0].red = 150; colormap[0xa0].green = 170;
    colormap[0xa0].blue = 170; /* Light Gray */
    colormap[0xb0].red = 255; colormap[0xb0].green = 158;
    colormap[0xb0].blue = 150; /* Pink */
    colormap[0xc0].red = 0; colormap[0xc0].green = 255;
    colormap[0xc0].blue = 0; /* Green */
    colormap[0xd0].red = 255; colormap[0xd0].green = 255;
    colormap[0xd0].blue = 0; /* Yellow */
    colormap[0xe0].red = 130; colormap[0xe0].green = 255;
    colormap[0xe0].blue = 130; /* Aqua */
    colormap[0xf0].red = 255; colormap[0xf0].green = 255;
    colormap[0xf0].blue = 255; /* White */

    /* mirror of lores colormap optimized for dhires code */
    colormap[0x00].red = 0; colormap[0x00].green = 0;
    colormap[0x00].blue = 0;   /* Black */
    colormap[0x08].red = 195; colormap[0x08].green = 0;
    colormap[0x08].blue = 48;  /* Magenta */
    colormap[0x01].red = 0; colormap[0x01].green = 0;
    colormap[0x01].blue = 130; /* Dark Blue */
    colormap[0x09].red = 166; colormap[0x09].green = 52;
    colormap[0x09].blue = 170; /* Purple */
    colormap[0x02].red = 0; colormap[0x02].green = 146;
    colormap[0x02].blue = 0;   /* Dark Green */
    colormap[0x0a].red = 105; colormap[0x0A].green = 105;
    colormap[0x0a].blue = 105; /* Dark Grey*/
    colormap[0x03].red = 113; colormap[0x03].green = 24;
    colormap[0x03].blue = 255; /* Medium Blue */
    colormap[0x0b].red = 12; colormap[0x0b].green = 190;
    colormap[0x0b].blue = 235; /* Light Blue */
    colormap[0x04].red = 150; colormap[0x04].green = 85;
    colormap[0x04].blue = 40; /* Brown */
    colormap[0x0c].red = 255; colormap[0x0c].green = 24;
    colormap[0x0c].blue = 44; /* Orange */
    colormap[0x05].red = 150; colormap[0x05].green = 170;
    colormap[0x05].blue = 170; /* Light Gray */
    colormap[0x0d].red = 255; colormap[0x0d].green = 158;
    colormap[0x0d].blue = 150; /* Pink */
    colormap[0x06].red = 0; colormap[0x06].green = 255;
    colormap[0x06].blue = 0; /* Green */
    colormap[0x0e].red = 255; colormap[0x0e].green = 255;
    colormap[0x0e].blue = 0; /* Yellow */
    colormap[0x07].red = 130; colormap[0x07].green = 255;
    colormap[0x07].blue = 130; /* Aqua */
    colormap[0x0f].red = 255; colormap[0x0f].green = 255;
    colormap[0x0f].blue = 255; /* White */

    for (unsigned int i=0; i<16; i++) {
        colormap[i].red      = (colormap[i].red<<8)      | colormap[i].red;
        colormap[i].green    = (colormap[i].green<<8)    | colormap[i].green;
        colormap[i].blue     = (colormap[i].blue<<8)     | colormap[i].blue;
        colormap[i<<4].red   = (colormap[i<<4].red<<8)   | colormap[i<<4].red;
        colormap[i<<4].green = (colormap[i<<4].green<<8) | colormap[i<<4].green;
        colormap[i<<4].blue  = (colormap[i<<4].blue<<8)  | colormap[i<<4].blue;
    }
}

void video_set(int flags) {
    video__strictcolors = (color_mode == COLOR_INTERP) ? 2 : 1;
    video_initialize_hires_values();
    video_initialize_row_col_tables();
    video_initialize_tables_video();
    video_initialize_dhires_values();
}

void video_loadfont_int(int first, int quantity, const uint8_t *data) {
    unsigned int i = quantity * 8;
    while (i--) {
        unsigned int j = 8;
        uint8_t x = data[i];
        while (j--) {
            unsigned int y = (first << 6) + (i << 3) + j;
            if (x & 128) {
                video__int_font[0][y] = video__int_font[1][y] = COLOR_LIGHT_GREEN;
                video__int_font[2][y] = COLOR_LIGHT_RED;
            } else {
                video__int_font[0][y] = video__int_font[2][y] = COLOR_BLACK;
                video__int_font[1][y] = COLOR_MEDIUM_BLUE;
            }
            x <<= 1;
        }
    }
}

// ----------------------------------------------------------------------------
// Plotting routines

static inline void _plot_char40(uint8_t **d, uint8_t **s) {
    *((uint32_t *)(*d)) = *((uint32_t *)(*s));
    *d += 4, *s += 4;
    *((uint32_t *)(*d)) = *((uint32_t *)(*s));
    *d += 4, *s += 4;
    *((uint32_t *)(*d)) = *((uint32_t *)(*s));
    *d += 4, *s += 4;
    *((uint16_t *)(*d)) = *((uint16_t *)(*s));
    *d += SCANSTEP, *s -= 12;
    *((uint32_t *)(*d)) = *((uint32_t *)(*s));
    *d += 4, *s += 4;
    *((uint32_t *)(*d)) = *((uint32_t *)(*s));
    *d += 4, *s += 4;
    *((uint32_t *)(*d)) = *((uint32_t *)(*s));
    *d += 4, *s += 4;
    *((uint16_t *)(*d)) = *((uint16_t *)(*s));
    *d += SCANSTEP, *s += 4;
}

static inline void _plot_char80(uint8_t **d, uint8_t **s) {
    *((uint32_t *)(*d)) = *((uint32_t *)(*s));
    *d += 4, *s += 4;
    *((uint16_t *)(*d)) = *((uint16_t *)(*s));
    *d += 2, *s += 2;
    *((uint8_t *)(*d)) = *((uint8_t *)(*s));
    *d += SCANWIDTH-6, *s -= 6;
    *((uint32_t *)(*d)) = *((uint32_t *)(*s));
    *d += 4, *s += 4;
    *((uint16_t *)(*d)) = *((uint16_t *)(*s));
    *d += 2, *s += 2;
    *((uint8_t *)(*d)) = *((uint8_t *)(*s));
    *d += SCANWIDTH-6, *s += 2;
}

static inline void _plot_lores(uint8_t **d, const uint32_t val) {
    *((uint32_t *)(*d)) = val;
    *d += 4;
    *((uint32_t *)(*d)) = val;
    *d += 4;
    *((uint32_t *)(*d)) = val;
    *d += 4;
    *((uint16_t *)(*d)) = (uint16_t)(val & 0xffff);
    *d += (SCANWIDTH-12);
    *((uint32_t *)(*d)) = val;
    *d += 4;
    *((uint32_t *)(*d)) = val;
    *d += 4;
    *((uint32_t *)(*d)) = val;
    *d += 4;
    *((uint16_t *)(*d)) = (uint16_t)(val & 0xffff);
}

void video_plotchar( int x, int y, int scheme, uint8_t c ) {
    uint8_t *d;
    uint8_t *s;

    unsigned int off = y * SCANWIDTH * 16 + x * 7 + 4;
    s = video__int_font[scheme] + c * 64;
    d = video__fb1 + off;

    _plot_char80(&d,&s);
    _plot_char80(&d,&s);
    _plot_char80(&d,&s);
    _plot_char80(&d,&s);
    _plot_char80(&d,&s);
    _plot_char80(&d,&s);
    _plot_char80(&d,&s);
    _plot_char80(&d,&s);
}

#if !HEADLESS
extern void video_driver_init();
extern void video_driver_shutdown();
#endif
void video_init() {

    video__fb1 = vga_mem_page_0;
    video__fb2 = vga_mem_page_1;

    // reset Apple2 softframebuffers
    memset(video__fb1,0,SCANWIDTH*SCANHEIGHT);
    memset(video__fb2,0,SCANWIDTH*SCANHEIGHT);

    video_initialize_color();
#if !HEADLESS
    if (!is_headless) {
        video_driver_init();
    }
#endif
}

void video_shutdown(void)
{
#if !HEADLESS
    if (!is_headless) {
        video_driver_shutdown();
    }
#endif
}

/* -------------------------------------------------------------------------
    video_setpage(p):    Switch to screen page p
   ------------------------------------------------------------------------- */
void video_setpage(int p)
{
    video__current_page = p;
}

const uint8_t * const video_current_framebuffer() {
    return !video__current_page ? video__fb1 : video__fb2;
}


// ----------------------------------------------------------------------------

static inline void _plot_character(const unsigned int font_off, uint8_t *fb_ptr) {
    uint8_t *font_ptr = video__wider_font+font_off;
    _plot_char40(/*dst*/&fb_ptr, /*src*/&font_ptr);
    _plot_char40(/*dst*/&fb_ptr, /*src*/&font_ptr);
    _plot_char40(/*dst*/&fb_ptr, /*src*/&font_ptr);
    _plot_char40(/*dst*/&fb_ptr, /*src*/&font_ptr);
    _plot_char40(/*dst*/&fb_ptr, /*src*/&font_ptr);
    _plot_char40(/*dst*/&fb_ptr, /*src*/&font_ptr);
    _plot_char40(/*dst*/&fb_ptr, /*src*/&font_ptr);
    _plot_char40(/*dst*/&fb_ptr, /*src*/&font_ptr);
}

static inline void _plot_character0(uint16_t ea, uint8_t b)
{
    _plot_character(b<<7/* *128 */, video__fb1+video__screen_addresses[ea-0x0400]);
}

static inline void _plot_character1(uint16_t ea, uint8_t b)
{
    _plot_character(b<<7/* *128 */, video__fb2+video__screen_addresses[ea-0x0800]);
}

static inline void _plot_80character(const unsigned int font_off, uint8_t *fb_ptr) {
    uint8_t *font_ptr = video__font+font_off;
    _plot_char80(/*dst*/&fb_ptr, /*src*/&font_ptr);
    _plot_char80(/*dst*/&fb_ptr, /*src*/&font_ptr);
    _plot_char80(/*dst*/&fb_ptr, /*src*/&font_ptr);
    _plot_char80(/*dst*/&fb_ptr, /*src*/&font_ptr);
    _plot_char80(/*dst*/&fb_ptr, /*src*/&font_ptr);
    _plot_char80(/*dst*/&fb_ptr, /*src*/&font_ptr);
    _plot_char80(/*dst*/&fb_ptr, /*src*/&font_ptr);
    _plot_char80(/*dst*/&fb_ptr, /*src*/&font_ptr);
}

// FIXME TODO NOTE : dup'ing work here?
static inline void _plot_80character0(uint16_t ea, uint8_t b)
{
    b = apple_ii_64k[1][ea];
    _plot_80character(b<<6/* *64 */, video__fb1+video__screen_addresses[ea-0x0400]);
    b = apple_ii_64k[0][ea];
    _plot_80character(b<<6/* *64 */, video__fb1+video__screen_addresses[ea-0x0400]+7);
}

static inline void _plot_80character1(uint16_t ea, uint8_t b)
{
    b = apple_ii_64k[1][ea];
    _plot_80character(b<<6/* *64 */, video__fb2+video__screen_addresses[ea-0x0800]);
    b = apple_ii_64k[0][ea];
    _plot_80character(b<<6/* *64 */, video__fb2+video__screen_addresses[ea-0x0800]+7);
}

static inline void _plot_block(const uint32_t val, uint8_t *fb_ptr) {
    uint8_t color = (val & 0x0F) << 4;
    uint32_t val32 = (color << 24) | (color << 16) | (color << 8) | color;

    _plot_lores(/*dst*/&fb_ptr, val32);
    fb_ptr += SCANSTEP;
    _plot_lores(/*dst*/&fb_ptr, val32);
    fb_ptr += SCANSTEP;
    _plot_lores(/*dst*/&fb_ptr, val32);
    fb_ptr += SCANSTEP;
    _plot_lores(/*dst*/&fb_ptr, val32);

    fb_ptr += SCANSTEP;
    color = val & 0xF0;
    val32 = (color << 24) | (color << 16) | (color << 8) | color;

    _plot_lores(/*dst*/&fb_ptr, val32);
    fb_ptr += SCANSTEP;
    _plot_lores(/*dst*/&fb_ptr, val32);
    fb_ptr += SCANSTEP;
    _plot_lores(/*dst*/&fb_ptr, val32);
    fb_ptr += SCANSTEP;
    _plot_lores(/*dst*/&fb_ptr, val32);
}

/* plot lores block first page */
static inline void _plot_block0(uint16_t ea, uint8_t b)
{
    _plot_block(b, video__fb1+video__screen_addresses[ea-0x0400]);
}

static inline void _plot_block1(uint16_t ea, uint8_t b)
{
    _plot_block(b, video__fb2+video__screen_addresses[ea-0x0800]);
}

#define DRAW_TEXT(PAGE, SW) \
    do { \
        if (softswitches & SS_TEXT) { \
            if (softswitches & SS_80COL) { \
                _plot_80character##PAGE(ea, b); \
            } else if (softswitches & SW) { \
                /* ??? */ \
            } else { \
                _plot_character##PAGE(ea, b); \
            } \
        } else { \
            if (softswitches & (SS_HIRES|SW)) { \
                /* ??? */ \
            } else { \
                _plot_block##PAGE(ea, b); \
            } \
        } \
    } while(0)


#define DRAW_MIXED(PAGE, SW) \
    do { \
        if (softswitches & (SS_TEXT|SS_MIXED)) { \
            if (softswitches & SS_80COL) { \
                _plot_80character##PAGE(ea, b); \
            } else if (softswitches & SW) { \
                /* ??? */ \
            } else { \
                _plot_character##PAGE(ea, b); \
            } \
        } else { \
            if (softswitches & (SS_HIRES|SW)) { \
                /* ??? */ \
            } else { \
                _plot_block##PAGE(ea, b); \
            } \
        } \
    } while(0)

GLUE_C_WRITE(video__write_2e_text0)
{
    base_textwrt[ea] = b;
    DRAW_TEXT(0, SS_TEXTWRT);
}

GLUE_C_WRITE(video__write_2e_text0_mixed)
{
    base_textwrt[ea] = b;
    DRAW_MIXED(0, SS_TEXTWRT);
}

GLUE_C_WRITE(video__write_2e_text1)
{
    base_ramwrt[ea] = b;
    DRAW_TEXT(1, SS_RAMWRT);
}

GLUE_C_WRITE(video__write_2e_text1_mixed)
{
    base_ramwrt[ea] = b;
    DRAW_MIXED(1, SS_RAMWRT);
}

// ----------------------------------------------------------------------------
// Double-Hires GRaphics

// PlotDHiresByte
static inline void _plot_dhires_pixels(uint8_t idx, uint8_t *fb_ptr) {
    uint8_t b1 = video__dhires1[idx];
    uint8_t b2 = video__dhires2[idx];
    uint32_t b = (b2<<24) | (b1<<8);
    *((uint32_t *)fb_ptr) = b;
    *((uint32_t *)(fb_ptr+SCANWIDTH)) = b;
}

// PlotDHires
static inline void _plot_dhires(uint16_t base, uint16_t ea, uint8_t *fb_base) {
    ea &= ~0x1;

    uint16_t memoff = ea - base;
    uint8_t *fb_ptr = fb_base+video__screen_addresses[memoff];
    uint8_t col = video__columns[memoff];

    uint8_t b0 = 0x0;
    uint8_t b1 = 0x0;
    uint32_t b = 0x0;

    if (col) {
        b0 = apple_ii_64k[0][ea-1];
        b1 = apple_ii_64k[1][ea];

        b0 &= ~0x80;
        b0 = (b1<<4)|(b0>>3);

        _plot_dhires_pixels(b0, fb_ptr-4);
    }

    b1 = apple_ii_64k[1][ea+2];
    b = (b1<<28);

    b0 = apple_ii_64k[0][ea+1];
    b0 &= ~0x80;
    b |= (b0<<21);

    b1 = apple_ii_64k[1][ea+1];
    b1 &= ~0x80;
    b |= (b1<<14);

    b0 = apple_ii_64k[0][ea];
    b0 &= ~0x80;
    b |= (b0<<7);

    b1 = apple_ii_64k[1][ea];
    b1 &= ~0x80;
    b |= b1;

    // 00000001 11111122 22222333 3333xxxx

    _plot_dhires_pixels(b, fb_ptr);

    b >>= 4;
    fb_ptr += 4;
    _plot_dhires_pixels(b, fb_ptr);

    b >>= 4;
    fb_ptr += 4;
    _plot_dhires_pixels(b, fb_ptr);

    b >>= 4;
    fb_ptr += 4;
    _plot_dhires_pixels(b, fb_ptr);

    b >>= 4;
    fb_ptr += 4;
    _plot_dhires_pixels(b, fb_ptr);

    b >>= 4;
    fb_ptr += 4;
    _plot_dhires_pixels(b, fb_ptr);

    b >>= 4;
    fb_ptr += 4;
    _plot_dhires_pixels(b, fb_ptr);
}

static inline void iie_plot_dhires0(uint16_t ea) {
    _plot_dhires(0x2000, ea, video__fb1);
}

static inline void iie_plot_dhires1(uint16_t ea) {
    _plot_dhires(0x4000, ea, video__fb2);
}

// ----------------------------------------------------------------------------
// Hires GRaphics

// CalculateInterpColor
static inline void _calculate_interp_color(uint8_t *color_buf, const unsigned int idx, const uint8_t *interp_base, const uint16_t ea) {
    if (color_buf[idx] != 0x0) {
        return;
    }
    uint8_t pixR = color_buf[idx+1];
    if (pixR == 0x0) {
        return;
    }
    uint8_t pixL = color_buf[idx-1];
    if (pixL == 0x0) {
        return;
    }

    // Calculates the color at the edge of interpolated bytes: called 4 times in little endian order (...7 0...7 0...)
    if (pixL == COLOR_LIGHT_WHITE) {
        if (pixR == COLOR_LIGHT_WHITE) {
            pixL = apple_ii_64k[0][ea];
            color_buf[idx] = interp_base[pixL>>7];
        } else {
            color_buf[idx] = pixR;
        }
    } else {
        color_buf[idx] = pixL;
    }
}

// PlotPixelsExtra
static inline void _plot_hires_pixels(uint8_t *dst, const uint8_t *src) {
    for (unsigned int i=2; i; i--) {
        for (unsigned int j=DYNAMIC_SZ-1; j; j--) {
            uint16_t pix = *src;
            pix = ((pix<<8) | pix);
            *((uint16_t *)dst) = pix;
            ++src;
            dst+=2;
        }

        dst += (SCANWIDTH-18);
        src -= DYNAMIC_SZ-2;
    }
}

// PlotByte
static inline void _plot_hires(uint16_t ea, uint8_t b, bool is_even, uint8_t *fb_ptr) {
    uint8_t _buf[DYNAMIC_SZ];
    uint8_t *color_buf = (uint8_t *)_buf; // <--- work around for -Wstrict-aliasing
    uint8_t *apple2_vmem = (uint8_t *)apple_ii_64k[0];

    uint8_t *hires_ptr = NULL;
    if (is_even) {
        hires_ptr = (uint8_t *)&video__hires_even[b<<3];
    } else {
        hires_ptr = (uint8_t *)&video__hires_odd[b<<3];
    }
    *((uint32_t *)&color_buf[2]) = *((uint32_t *)(hires_ptr+0));
    *((uint16_t *)&color_buf[6]) = *((uint16_t *)(hires_ptr+4));
    *((uint8_t  *)&color_buf[8]) = *((uint8_t  *)(hires_ptr+6));
    hires_ptr = NULL;

    // copy adjacent pixel bytes
    *((uint16_t *)&color_buf[0]) = *((uint16_t *)(fb_ptr-3));
    *((uint16_t *)&color_buf[DYNAMIC_SZ-2]) = *((uint16_t *)(fb_ptr+15));

    // %eax = +8
    if (color_mode != COLOR_NONE) {
        uint8_t *hires_altbase = NULL;
        if (is_even) {
            hires_altbase = (uint8_t *)&video__hires_odd[0];
        } else {
            hires_altbase = (uint8_t *)&video__hires_even[0];
        }

        // if right-side color is not black, re-calculate edge values
        if (color_buf[DYNAMIC_SZ-2] & 0xff) {
            uint16_t pix16 = *((uint16_t *)(apple2_vmem+ea));
            if ((pix16 & 0x100) && (pix16 & 0x40)) {
                *((uint16_t *)&color_buf[DYNAMIC_SZ-3]) = (uint16_t)0x3737;// COLOR_LIGHT_WHITE
            } else {
                // PB_black0:
                pix16 >>= 8;
                color_buf[DYNAMIC_SZ-2] = hires_altbase[pix16<<3];
            }
        }

        // if left-side color is not black, re-calculate edge values
        if (color_buf[1] & 0xff) {
            uint16_t pix16 = *((uint16_t *)(apple2_vmem+ea-1));
            if ((pix16 & 0x100) && (pix16 & 0x40)) {
                *((uint16_t *)&color_buf[1]) = (uint16_t)0x3737;// COLOR_LIGHT_WHITE
            } else {
                // PB_black1:
                pix16 &= 0xFF;
                color_buf[1] = hires_altbase[(pix16<<3)+6];
            }
        }

        if (color_mode == COLOR_INTERP) {
            uint8_t *interp_base = NULL;
            uint8_t *interp_altbase = NULL;
            if (is_even) {
                interp_base = (uint8_t *)&video__even_colors[0];
                interp_altbase = (uint8_t *)&video__odd_colors[0];
            } else {
                interp_base = (uint8_t *)&video__odd_colors[0];
                interp_altbase = (uint8_t *)&video__even_colors[0];
            }

            // calculate interpolated/bleed colors
            _calculate_interp_color(color_buf, 1, interp_altbase, ea-1);
            _calculate_interp_color(color_buf, 2, interp_base, ea);
            _calculate_interp_color(color_buf, 8, interp_base, ea);
            _calculate_interp_color(color_buf, 9, interp_altbase, ea+1);
        }
    }

    _plot_hires_pixels(fb_ptr-4, color_buf);
}

// DRAW_GRAPHICS
static inline void _draw_hires_graphics(uint16_t ea, uint8_t b, bool is_even, uint8_t page, unsigned int ss_textflags) {
    if (softswitches & ss_textflags) {
        return;
    }
    if (!(softswitches & SS_HIRES)) {
        return;
    }
    if ((softswitches & SS_80COL) && (softswitches & SS_DHIRES)) {
        if (page) {
            iie_plot_dhires1(ea);
        } else {
            iie_plot_dhires0(ea);
        }
        return;
    }
    if (softswitches & SS_HGRWRT) {
        return;
    }

    uint16_t off = ea - 0x2000;
    uint8_t *fb_base = NULL;
    if (page) {
        off -= 0x2000;
        fb_base = video__fb2;
    } else {
        fb_base = video__fb1;
    }
    _plot_hires(ea, b, is_even, fb_base+video__screen_addresses[off]);
}

GLUE_C_WRITE(video__write_2e_even0)
{
    base_hgrwrt[ea] = b;
    _draw_hires_graphics(ea, b, /*even*/true, 0, SS_TEXT);
}

GLUE_C_WRITE(video__write_2e_even0_mixed)
{
    base_hgrwrt[ea] = b;
    _draw_hires_graphics(ea, b, /*even*/true, 0, (SS_TEXT|SS_MIXED));
}

GLUE_C_WRITE(video__write_2e_odd0)
{
    base_hgrwrt[ea] = b;
    _draw_hires_graphics(ea, b, /*even*/false, 0, SS_TEXT);
}

GLUE_C_WRITE(video__write_2e_odd0_mixed)
{
    base_hgrwrt[ea] = b;
    _draw_hires_graphics(ea, b, /*even*/false, 0, (SS_TEXT|SS_MIXED));
}

GLUE_C_WRITE(video__write_2e_even1)
{
    base_ramwrt[ea] = b;
    _draw_hires_graphics(ea, b, /*even*/true, 1, SS_TEXT);
}

GLUE_C_WRITE(video__write_2e_even1_mixed)
{
    base_ramwrt[ea] = b;
    _draw_hires_graphics(ea, b, /*even*/true, 1, (SS_TEXT|SS_MIXED));
}

GLUE_C_WRITE(video__write_2e_odd1)
{
    base_ramwrt[ea] = b;
    _draw_hires_graphics(ea, b, /*even*/false, 1, SS_TEXT);
}

GLUE_C_WRITE(video__write_2e_odd1_mixed)
{
    base_ramwrt[ea] = b;
    _draw_hires_graphics(ea, b, /*even*/false, 1, (SS_TEXT|SS_MIXED));
}

void video_redraw(void) {

    // temporarily reset softswitches
    uint32_t softswitches_save = softswitches;
    softswitches &= ~(SS_TEXTWRT|SS_HGRWRT|SS_RAMWRT);

    for (unsigned int y = 0; y < TEXT_ROWS; y++) {
        for (unsigned int x = 0; x < TEXT_COLS; x++) {
            uint16_t ea = video__line_offset[y] + x + 0x400;
            uint8_t b = apple_ii_64k[0][ea];

            // text/lores pages
            if (y < 20) {
                DRAW_TEXT(0, SS_TEXTWRT);
                ea += 0x400;
                DRAW_TEXT(1, SS_RAMWRT);
            } else {
                DRAW_MIXED(0, SS_TEXTWRT);
                ea += 0x400;
                DRAW_MIXED(1, SS_RAMWRT);
            }

            // hires/dhires pages
            for (unsigned int i = 0; i < 8; i++) {
                ea = 0x2000 + video__line_offset[y] + (0x400*i) + x;
                uint8_t b = apple_ii_64k[0][ea];
                if (y < 20) {
                    if (x & 1) {
                        _draw_hires_graphics(ea,        b, /*even*/false, 0, SS_TEXT);
                        _draw_hires_graphics(ea+0x2000, b, /*even*/false, 1, SS_TEXT);
                    } else {
                        _draw_hires_graphics(ea,        b, /*even*/true,  0, SS_TEXT);
                        _draw_hires_graphics(ea+0x2000, b, /*even*/true,  1, SS_TEXT);
                    }
                } else {
                    if (x & 1) {
                        _draw_hires_graphics(ea,        b, /*even*/false, 0, (SS_TEXT|SS_MIXED));
                        _draw_hires_graphics(ea+0x2000, b, /*even*/false, 1, (SS_TEXT|SS_MIXED));
                    } else {
                        _draw_hires_graphics(ea,        b, /*even*/true,  0, (SS_TEXT|SS_MIXED));
                        _draw_hires_graphics(ea+0x2000, b, /*even*/true,  1, (SS_TEXT|SS_MIXED));
                    }
                }
            }
        }
    }

    softswitches = softswitches_save;
}