/* Hello, Emacs, this is -*-C-*- */

/* GNUPLOT - block.trm */

/*

Copyright (c) 2020-2022 Bastian Maerkisch. 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.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT HOLDER 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 "driver.h"

#ifdef TERM_REGISTER
register_term(block)
#endif

#ifdef TERM_PROTO
TERM_PUBLIC void BLOCK_options(void);
TERM_PUBLIC void BLOCK_init(void);
TERM_PUBLIC void BLOCK_reset(void);
TERM_PUBLIC void BLOCK_text(void);
TERM_PUBLIC void BLOCK_graphics(void);
TERM_PUBLIC void BLOCK_put_text(unsigned int x, unsigned int y, const char *str);
TERM_PUBLIC void BLOCK_point(unsigned int x, unsigned int y, int point);
TERM_PUBLIC void BLOCK_arrow(unsigned int sx, unsigned int sy, unsigned int ex, unsigned int ey, int head);
TERM_PUBLIC void BLOCK_linetype(int linetype);
TERM_PUBLIC void BLOCK_set_color(t_colorspec *color);
#endif

#ifndef TERM_PROTO_ONLY
#ifdef TERM_BODY

#ifdef HAVE_ICONV
# include <iconv.h>
#endif

// default values for quadrants, the default mode
#define BLOCK_XMAX  (DUMB_XMAX)
#define BLOCK_YMAX  (DUMB_YMAX)
#define BLOCK_VCHAR (2)
#define BLOCK_HCHAR (2)
// We want really small tics. Approximate aspect ratio.
#define BLOCK_VTIC  (1)
#define BLOCK_HTIC  (2)

enum BLOCK_modes {
    BLOCK_MODE_DOT, BLOCK_MODE_HALF,
    BLOCK_MODE_QUAD,
    BLOCK_MODE_SEXT, BLOCK_MODE_SEXT_PUA,
    BLOCK_MODE_OCT, BLOCK_MODE_OCT_PUA,
    BLOCK_MODE_BRAILLE
};

typedef struct {
    short mode;
    short cellx;
    short celly;
} BLOCK_modeinfo_entry;

#define USQR(a) (((unsigned)a)*((unsigned)a))

/* internal functions for color mapping */
static void to_rgb255(int v, rgb255_color * rgb255);
static unsigned to_ansi256(rgb255_color *c);
static const char * ansi_bg_colorstring(t_colorspec * color);

#if defined(OS2) || defined(MSDOS)
static int BLOCK_mode = BLOCK_MODE_HALF;
#else
static int BLOCK_mode = BLOCK_MODE_QUAD;
#endif
static TBOOLEAN BLOCK_animate = FALSE;
static int BLOCK_xchars = BLOCK_XMAX;
static int BLOCK_ychars = BLOCK_YMAX;
static TBOOLEAN BLOCK_optimize = TRUE;

enum BLOCK_pointtypes {
    BLOCK_POINT_CHAR, BLOCK_POINT_NUM, BLOCK_POINT_GP
};
#if defined(OS2) || defined(MSDOS)
static int BLOCK_pointtype = BLOCK_POINT_CHAR;
#else
static int BLOCK_pointtype = BLOCK_POINT_NUM;
#endif

#define BLOCK_BGTRANSPARENT 0xffffffff
static uint32_t BLOCK_background = BLOCK_BGTRANSPARENT;
static BLOCK_modeinfo_entry BLOCK_modeinfo[] = {
    { BLOCK_MODE_DOT,     1, 1 },
    { BLOCK_MODE_HALF,    1, 2 },
    { BLOCK_MODE_QUAD,    2, 2 },
    { BLOCK_MODE_SEXT,    2, 3 },
    { BLOCK_MODE_SEXT_PUA,2, 3 },
    { BLOCK_MODE_OCT,     2, 4 },
    { BLOCK_MODE_OCT_PUA, 2, 4 },
    { BLOCK_MODE_BRAILLE, 2, 4 }
};

enum BLOCK_id {
    BLOCK_ENH, BLOCK_NOENH,
    // The code relies on those having the same order as the modes.
    BLOCK_DOT, BLOCK_HALF, BLOCK_QUADRANTS,
      BLOCK_SEXTANTS, BLOCK_SEXTANTS_PUA,
      BLOCK_OCTANTS, BLOCK_OCTANTS_PUA,
      BLOCK_BRAILLE,
    BLOCK_ANSI, BLOCK_ANSI256, BLOCK_ANSIRGB, BLOCK_NOCOLOR,
    BLOCK_OPTIMIZE, BLOCK_NOOPTIMIZE,
    BLOCK_CHARPOINTS, BLOCK_GPPOINTS, BLOCK_NUMPOINTS,
    BLOCK_ATTRIBUTES, BLOCK_NOATTRIBUTES,
    BLOCK_SIZE, BLOCK_BACKGROUND, BLOCK_TRANSPARENT,
    BLOCK_ANIMATE, BLOCK_NOANIMATE,
    BLOCK_OTHER
};

static struct gen_table BLOCK_opts[] =
{
    { "enh$anced", BLOCK_ENH },
    { "noe$nhanced", BLOCK_NOENH },
    { "dot", BLOCK_DOT },
    { "half", BLOCK_HALF },
    { "quad$rants", BLOCK_QUADRANTS },
    { "sext$ants", BLOCK_SEXTANTS },
    { "sextpua", BLOCK_SEXTANTS_PUA },
    { "sextantspua", BLOCK_SEXTANTS_PUA },
    { "oct$ants", BLOCK_OCTANTS },
    { "octpua", BLOCK_OCTANTS_PUA },
    { "octantspua", BLOCK_OCTANTS_PUA },
    { "br$aille", BLOCK_BRAILLE },
    { "mono", BLOCK_NOCOLOR },
    { "ansi", BLOCK_ANSI },
    { "ansi256", BLOCK_ANSI256 },
    { "pal$ette", BLOCK_ANSI256 },
    { "ansirgb", BLOCK_ANSIRGB },
    { "tru$ecolor", BLOCK_ANSIRGB },
    { "opt$imize", BLOCK_OPTIMIZE },
    { "noopt$imize", BLOCK_NOOPTIMIZE },
    { "charp$oints", BLOCK_CHARPOINTS },
    { "nump$oints", BLOCK_NUMPOINTS },
    { "gpp$oints", BLOCK_GPPOINTS },
    { "siz$e", BLOCK_SIZE },
    { "attr$ibutes", BLOCK_ATTRIBUTES },
    { "noattr$ibutes", BLOCK_NOATTRIBUTES },
    { "back$ground", BLOCK_BACKGROUND },
    { "transp$arent", BLOCK_TRANSPARENT },
    { "anim$ate", BLOCK_ANIMATE },
    { "noanim$ate", BLOCK_NOANIMATE },
    { NULL, BLOCK_OTHER }
};


TERM_PUBLIC void
BLOCK_options()
{
    int cmd;

    while (!END_OF_COMMAND) {
	switch (cmd = lookup_table(&BLOCK_opts[0], c_token)) {
#ifndef NO_DUMB_ENHANCED_SUPPORT
	case BLOCK_ENH:
	    c_token++;
	    term->flags |= TERM_ENHANCED_TEXT;
	    break;
	case BLOCK_NOENH:
	    c_token++;
	    term->flags &= ~TERM_ENHANCED_TEXT;
	    break;
#endif
	case BLOCK_DOT:
	case BLOCK_HALF:
	case BLOCK_QUADRANTS:
	case BLOCK_SEXTANTS:
	case BLOCK_SEXTANTS_PUA:
	case BLOCK_OCTANTS:
	case BLOCK_OCTANTS_PUA:
	case BLOCK_BRAILLE:
	    BLOCK_mode = BLOCK_MODE_DOT + cmd - BLOCK_DOT;
	    c_token++;
	    break;
	case BLOCK_ANSI:
	case BLOCK_ANSI256:
	case BLOCK_ANSIRGB:
#ifndef NO_DUMB_COLOR_SUPPORT
	    if (cmd == BLOCK_ANSI)
		dumb_colormode = DUMB_ANSI;
	    else if (cmd == BLOCK_ANSI256)
		dumb_colormode = DUMB_ANSI256;
	    else
		dumb_colormode = DUMB_ANSIRGB;
	    term->make_palette = DUMB_make_palette;
	    term->flags &= ~TERM_MONOCHROME;
#else
	    int_warn(c_token, "block terminal built without color support");
#endif
	    c_token++;
	    break;
	case BLOCK_NOCOLOR:
	    c_token++;
	    dumb_colormode = 0;
	    term->make_palette = NULL;
	    term->flags |= TERM_MONOCHROME;
	    break;
	case BLOCK_ATTRIBUTES:
	    c_token++;
	    dumb_text_attributes = TRUE;
	    break;
	case BLOCK_NOATTRIBUTES:
	    c_token++;
	    dumb_text_attributes = FALSE;
	    break;
	case BLOCK_OPTIMIZE:
	    c_token++;
	    BLOCK_optimize = TRUE;
	    break;
	case BLOCK_NOOPTIMIZE:
	    c_token++;
	    BLOCK_optimize = FALSE;
	    break;
	case BLOCK_CHARPOINTS:
	    c_token++;
	    BLOCK_pointtype = BLOCK_POINT_CHAR;
	    break;
	case BLOCK_NUMPOINTS:
	    c_token++;
	    BLOCK_pointtype = BLOCK_POINT_NUM;
	    break;
	case BLOCK_GPPOINTS:
	    c_token++;
	    BLOCK_pointtype = BLOCK_POINT_GP;
	    break;
	case BLOCK_SIZE: {
	    float width, height;

	    c_token++;
	    parse_term_size(&width, &height, PIXELS);
	    BLOCK_xchars = width;
	    BLOCK_ychars = height;
	    break;
	}
	case BLOCK_BACKGROUND:
	    c_token++;
	    BLOCK_background = parse_color_name();
	    break;
	case BLOCK_TRANSPARENT:
	    c_token++;
	    BLOCK_background = BLOCK_BGTRANSPARENT;
	    break;
	case BLOCK_ANIMATE:
	    c_token++;
	    BLOCK_animate = TRUE;
	    break;
	case BLOCK_NOANIMATE:
	    c_token++;
	    BLOCK_animate = FALSE;
	    break;
	case BLOCK_OTHER:
	default:
	    int_error(c_token, "unknown option");
	}
    }

    // initialize terminal canvas size
    term->xmax = BLOCK_modeinfo[BLOCK_mode].cellx * BLOCK_xchars - 1;
    term->ymax = BLOCK_modeinfo[BLOCK_mode].celly * BLOCK_ychars - 1;

    // init options string
    {
	//Note: These need to be in the same order as the corresponding definitions.
	const char * mode_strings[] =
	    { "dot", "half", "quadrants", "sextants", "sextpua", "octants", "octpua", "braille" };
	const char * color_strings[] =
	    {"mono", "ansi", "ansi256", "ansirgb"};
	const char * pointtype_strings[] =
	    {"char", "num", "gp"};
	char bg_str[32];

	if (BLOCK_background == BLOCK_BGTRANSPARENT)
	    strcpy(bg_str, "transparent");
	else
	    sprintf(bg_str, "background rgb \"0x%06X\"", BLOCK_background);
	sprintf(term_options, "%s %s %s %soptimize %senhanced %sattributes %spoints size %d,%d %s",
	    mode_strings[BLOCK_mode],
	    color_strings[dumb_colormode == 0 ? 0 : dumb_colormode - DUMB_ANSI + 1],
	    bg_str,
	    (BLOCK_optimize && (BLOCK_mode != BLOCK_MODE_BRAILLE) ? "" : "no"),
	    (term->flags & TERM_ENHANCED_TEXT) ? "" : "no",
	    (dumb_text_attributes ? "" : "no"),
	    pointtype_strings[BLOCK_pointtype],
	    BLOCK_xchars, BLOCK_ychars,
	    BLOCK_animate ? "animate" : "");
    }
}


TERM_PUBLIC void
BLOCK_init()
{
    /* LSB is "opacity" */
    switch (dumb_colormode) {
    case 0:
	b_makebitmap(term->xmax + 1, term->ymax + 1, 1);
	break;
    case DUMB_ANSI:
	b_makebitmap(term->xmax + 1, term->ymax + 1, 5);
	break;
    case DUMB_ANSI256:
	b_makebitmap(term->xmax + 1, term->ymax + 1, 9);
#ifdef BLOCK_DEBUG_256
	for (int i = 16; i <= 255; i++) {
	    rgb255_color c;
	    unsigned v;
	    to_rgb255(i, &c);
	    v = to_ansi256(&c);
	    if (i != v)
	    printf("i=%i -> %02x,%02x,%02x -> %i\n", i, c.r, c.g, c.b, v);
	}
#endif
	break;
    case DUMB_ANSIRGB:
	b_makebitmap(term->xmax + 1, term->ymax + 1, 25);
	break;
    }

    term->h_char = BLOCK_modeinfo[BLOCK_mode].cellx;
    term->v_char = BLOCK_modeinfo[BLOCK_mode].celly;
    dumb_xmax = BLOCK_xchars - 1;
    dumb_ymax = BLOCK_ychars - 1;

    // guide the aspect ratio calculation in the core layer
    if (BLOCK_mode == BLOCK_MODE_QUAD || BLOCK_mode == BLOCK_MODE_DOT) {
	term->h_tic = BLOCK_HTIC;
	term->v_tic = BLOCK_VTIC;
    } else if (BLOCK_mode == BLOCK_MODE_SEXT || BLOCK_mode == BLOCK_MODE_SEXT_PUA) {
	term->h_tic = BLOCK_HTIC * 3 / 2;
	term->v_tic = BLOCK_VTIC * 2;
    } else { // BLOCK_MODE_HALF, BLOCK_MODE_OCT, BLOCK_MODE_OCT_PUA, BLOCK_MODE_BRAILLE
	term->h_tic = BLOCK_HTIC / 2;
	term->v_tic = BLOCK_VTIC;
    }

    DUMB_init();
}


TERM_PUBLIC void
BLOCK_reset()
{
    b_freebitmap();
    DUMB_reset();
}


/*
  Halfblocks, vertical:
*/
static uint32_t block_half_map[4] = {
    0x00A0, 0x2580, 0x2584, 0x2588
};

/*
  ZX-81 like box drawing map:
    1 2
    3 4
*/
static uint32_t block_quadrant_map[16] = {
    0x00A0, 0x2598, 0x259D, 0x2580, //  0,   1,   2,   12
    0x2596, 0x258C, 0x259E, 0x259B, //  3,  13,  23,  123
    0x2597, 0x259A, 0x2590, 0x259C, //  4,  14,  24,  124
    0x2584, 0x2599, 0x259F, 0x2588  // 34, 134, 234, 1234
};

/*
  Sextant map. Unfortunately non-continuous.
    1 2
    3 4
    5 6
*/
static uint32_t block_sextant_map[64] = {
     0x00A0,  0x1FB00,  0x1FB01,  0x1FB02,  // *0* (empty), 1, 2, 12
    0x1FB03,  0x1FB04,  0x1FB05,  0x1FB06,  // 3, 13, 23, 123
    0x1FB07,  0x1FB08,  0x1FB09,  0x1FB0A,  // 4, 14, 24, 124
    0x1FB0B,  0x1FB0C,  0x1FB0D,  0x1FB0E,  // 34, 134, 234, 1234,

    0x1FB0F,  0x1FB10,  0x1FB11,  0x1FB12,  // 5, 15, 25, 125
    0x1FB13,   0x258C,  0x1FB14,  0x1FB15,  // 35, *135* (left half), 235, 1235
    0x1FB16,  0x1FB17,  0x1FB18,  0x1FB19,  // 45, 145, 245, 1245
    0x1FB1A,  0x1FB1B,  0x1FB1C,  0x1FB1D,  // 345, 1345, 2345, 12345

    0x1FB1E,  0x1FB1F,  0x1FB20,  0x1FB21,  // 6, 16, 26, 126
    0x1FB22,  0x1FB23,  0x1FB24,  0x1FB25,  // 36, 136, 236, 1236
    0x1FB26,  0x1FB27,   0x2590,  0x1FB28,  // 46, 146, *246* (right half), 1246
    0x1FB29,  0x1FB2A,  0x1FB2B,  0x1FB2C,  // 346, 1346, 2346, 12346,

    0x1FB2D,  0x1FB1E,  0x1FB2F,  0x1FB30,  // 56, 156, 256, 1256
    0x1FB31,  0x1FB32,  0x1FB33,  0x1FB34,  // 356, 1356, 2356, 12356
    0x1FB35,  0x1FB36,  0x1FB37,  0x1FB38,  // 456, 1456, 2456, 12456
    0x1FB39,  0x1FB3A,  0x1FB3B,   0x2588,  // 3456, 13456, 23456, *12345* (full)
};

/*
  Octant map. Non-continuous.
    1 2
    3 4
    5 6
    7 8
*/
static uint32_t block_octant_map[256] = {
    0x00A0,  0x1CEA8, 0x1CEAB, 0x1FB82, 0x1CD00, 0x2598,  0x1CD01, 0x1CD02,
    0x1CD03, 0x1CD04, 0x259D,  0x1CD05, 0x1CD06, 0x1CD07, 0x1CD08, 0x2580,
    0x1CD09, 0x1CD0A, 0x1CD0B, 0x1CD0C, 0x1FBE7, 0x1CD0D, 0x1CD0E, 0x1CD0F,
    0x1CD10, 0x1CD11, 0x1CD12, 0x1CD13, 0x1CD14, 0x1CD15, 0x1CD16, 0x1CD17,
    0x1CD18, 0x1CD19, 0x1CD1A, 0x1CD1B, 0x1CD1C, 0x1CD1D, 0x1CD1E, 0x1CD1F,
    0x1FBE6, 0x1CD20, 0x1CD21, 0x1CD22, 0x1CD23, 0x1CD24, 0x1CD25, 0x1CD26,
    0x1CD27, 0x1CD28, 0x1CD29, 0x1CD2A, 0x1CD2B, 0x1CD2C, 0x1CD2D, 0x1CD2E,
    0x1CD2F, 0x1CD30, 0x1CD31, 0x1CD32, 0x1CD33, 0x1CD34, 0x1CD35, 0x1FB85,
    0x1CEA3, 0x1CD36, 0x1CD37, 0x1CD38, 0x1CD39, 0x1CD3A, 0x1CD3B, 0x1CD3C,
    0x1CD3D, 0x1CD3E, 0x1CD3F, 0x1CD40, 0x1CD41, 0x1CD42, 0x1CD43, 0x1CD44,
    0x2596,  0x1CD45, 0x1CD46, 0x1CD47, 0x1CD48, 0x258C,  0x1CD49, 0x1CD4A,
    0x1CD4B, 0x1CD4C, 0x259E,  0x1CD4D, 0x1CD4E, 0x1CD4F, 0x1CD50, 0x259B,
    0x1CD51, 0x1CD52, 0x1CD53, 0x1CD54, 0x1CD55, 0x1CD56, 0x1CD57, 0x1CD58,
    0x1CD59, 0x1CD5A, 0x1CD5B, 0x1CD5C, 0x1CD5D, 0x1CD5E, 0x1CD5F, 0x1CD60,
    0x1CD61, 0x1CD62, 0x1CD63, 0x1CD64, 0x1CD65, 0x1CD66, 0x1CD67, 0x1CD68,
    0x1CD69, 0x1CD6A, 0x1CD6B, 0x1CD6C, 0x1CD6D, 0x1CD6E, 0x1CD6F, 0x1CD70,
    0x1CEA0, 0x1CD71, 0x1CD72, 0x1CD73, 0x1CD74, 0x1CD75, 0x1CD76, 0x1CD77,
    0x1CD78, 0x1CD79, 0x1CD7A, 0x1CD7B, 0x1CD7C, 0x1CD7D, 0x1CD7E, 0x1CD7F,
    0x1CD80, 0x1CD81, 0x1CD82, 0x1CD83, 0x1CD84, 0x1CD85, 0x1CD86, 0x1CD87,
    0x1CD88, 0x1CD89, 0x1CD8A, 0x1CD8B, 0x1CD8C, 0x1CD8D, 0x1CD8E, 0x1CD8F,
    0x2597,  0x1CD90, 0x1CD91, 0x1CD92, 0x1CD93, 0x259A,  0x1CD94, 0x1CD95,
    0x1CD96, 0x1CD97, 0x2590,  0x1CD98, 0x1CD99, 0x1CD9A, 0x1CD9B, 0x259C,
    0x1CD9C, 0x1CD9D, 0x1CD9E, 0x1CD9F, 0x1CDA0, 0x1CDA1, 0x1CDA2, 0x1CDA3,
    0x1CDA4, 0x1CDA5, 0x1CDA6, 0x1CDA7, 0x1CDA8, 0x1CDA9, 0x1CDAA, 0x1CDAB,
    0x2582,  0x1CDAC, 0x1CDAD, 0x1CDAE, 0x1CDAF, 0x1CDB0, 0x1CDB1, 0x1CDB2,
    0x1CDB3, 0x1CDB4, 0x1CDB5, 0x1CDB6, 0x1CDB7, 0x1CDB8, 0x1CDB9, 0x1CDBA,
    0x1CDBB, 0x1CDBC, 0x1CDBD, 0x1CDBE, 0x1CDBF, 0x1CDC0, 0x1CDC1, 0x1CDC2,
    0x1CDC3, 0x1CDC4, 0x1CDC5, 0x1CDC6, 0x1CDC7, 0x1CDC8, 0x1CDC9, 0x1CDCA,
    0x1CDCB, 0x1CDCC, 0x1CDCD, 0x1CDCE, 0x1CDCF, 0x1CDD0, 0x1CDD1, 0x1CDD2,
    0x1CDD3, 0x1CDD4, 0x1CDD5, 0x1CDD6, 0x1CDD7, 0x1CDD8, 0x1CDD9, 0x1CDDA,
    0x2584,  0x1CDDB, 0x1CDDC, 0x1CDDD, 0x1CDDE, 0x2599,  0x1CDDF, 0x1CDE0,
    0x1CDE1, 0x1CDE2, 0x259F,  0x1CDE3, 0x2586,  0x1CDE4, 0x1CDE5, 0x2588
};

/* optimization bit patterns */
// half blocks: 1
const int half_pat[] = { 0x01 };
const int nhalf_pats = 1;
// quadrants: 4!/3! + 4!/(2!+2!) = 4 + 6 = 10
const int quad_pat[] = {
    0x0e, 0x0d, 0x0b, 0x07,              // 3 bits
    0x0c, 0x0a, 0x09, 0x06, 0x05, 0x03   // 2 bits
};
const int nquad_pats = sizeof(quad_pat) / sizeof(int);
// sextants: 6!/5! + 6!/(4!*2!) + 6!/(3!*3!) = 6 + 15 + 20 = 41
const int sext_pat[] = {
    0x3e, 0x3d, 0x3b, 0x37, 0x2f, 0x1f,  // 5 bits
    0x3c, 0x3a, 0x39, 0x36, 0x35, 0x33,  // 4 bits
    0x2e, 0x2d, 0x2b, 0x27,
    0x1e, 0x1d, 0x1b, 0x17,
    0x0f,
    0x38, 0x34, 0x32, 0x31,              // 3 bits
    0x2c, 0x2a, 0x29, 0x26, 0x25, 0x23,
    0x1c, 0x1a, 0x19, 0x16, 0x15, 0x13,
    0x0e, 0x0d, 0x0b, 0x07
};
const int nsext_pats = sizeof(sext_pat) / sizeof(int);
// octants: 8!/7! + 8!/(6!*2!) + 8!/(5!*3!) + 8!/(4!*4!) =  8 + 28 + 56 + 70 = 162
const int oct_pat[] = {
    0xfe, 0xfd, 0xfb, 0xf7,              // 7 bits
    0xef, 0xdf, 0xbf, 0x7f,
    0xfc, 0xfa, 0xf9, 0xf6, 0xf5, 0xf3,  // 6 bits
    0xee, 0xed, 0xeb, 0xe7,
    0xde, 0xdd, 0xdb, 0xd7,
    0xbe, 0xbd, 0xbb, 0xb7,
    0x7e, 0x7d, 0x7b, 0x77,
    0xcf, 0xaf, 0x9f, 0x6f, 0x5f, 0x3f,
    0xf8, 0xf4, 0xf2, 0xf1,              // 5 bits
    0xec, 0xea, 0xe9, 0xe6, 0xe5, 0xe3,
    0xdc, 0xda, 0xd9, 0xd6, 0xd5, 0xd3,
    0xbc, 0xba, 0xb9, 0xb6, 0xb5, 0xb3,
    0x7c, 0x7a, 0x79, 0x76, 0x75, 0x73,
    0xce, 0xae, 0x9e, 0x6e, 0x5e, 0x3e,
    0xcd, 0xad, 0x9d, 0x6d, 0x5d, 0x3d,
    0xcb, 0xab, 0x9b, 0x6b, 0x5b, 0x3b,
    0xc7, 0xa7, 0x97, 0x67, 0x57, 0x37,
    0x8f, 0x4f, 0x2f, 0x1f,
    0xf0,                                // 4 bits
    0xe8, 0xe4, 0xe2, 0xe1,
    0xd8, 0xd4, 0xd2, 0xd1,
    0xb8, 0xb4, 0xb2, 0xb1,
    0x78, 0x74, 0x72, 0x71,
    0xcc, 0xca, 0xc9, 0xc6, 0xc5, 0xc3,
    0xac, 0xaa, 0xa9, 0xa6, 0xa5, 0xa3,
    0x9c, 0x9a, 0x99, 0x96, 0x95, 0x93,
    0x6c, 0x6a, 0x69, 0x66, 0x65, 0x63,
    0x5c, 0x5a, 0x59, 0x56, 0x55, 0x53,
    0x3c, 0x3a, 0x39, 0x36, 0x35, 0x33,
    0x8e, 0x8d, 0x8b, 0x87,
    0x4e, 0x4d, 0x4b, 0x47,
    0x2e, 0x2d, 0x2b, 0x27,
    0x1e, 0x1d, 0x1b, 0x17,
    0x0f
};
const int noct_pats = sizeof(oct_pat) / sizeof(int);


#ifndef NO_DUMB_COLOR_SUPPORT
static void
to_rgb255(int v, rgb255_color * rgb255)
{
    switch (dumb_colormode) {
    case DUMB_ANSIRGB:
	// direct RGB
	rgb255->r = (v >> 16) & 0xff;
	rgb255->g = (v >>  8) & 0xff;
	rgb255->b = (v >>  0) & 0xff;
	break;
    case DUMB_ANSI:
    case DUMB_ANSI256:
	if (v < 16) {
	    // "standard" colors
	    v = ansitab16[v];
	    rgb255->r = ((v >> 0) & 0x0f) << 4;
	    rgb255->g = ((v >> 4) & 0x0f) << 4;
	    rgb255->b = ((v >> 8) & 0x0f) << 4;
	} else if (v < 232) {
	    // 6x6x6 color cube
	    v -= 16;
#define MAPCUBE6(n) ((n) ? (n) * 40 + 55 : 0)
	    rgb255->r = MAPCUBE6((v / 36) % 6);
	    rgb255->g = MAPCUBE6((v /  6) % 6);
	    rgb255->b = MAPCUBE6((v     ) % 6);
	} else {
	    // gray scale
	    v = (v - 232) * 10 + 8;  // like Mintty
	    rgb255->r = rgb255->b = rgb255->g = v;
	}
	break;
    }
}


static const char *
ansi_bg_colorstring(t_colorspec * color)
{
    if (dumb_colormode == DUMB_ANSI) {
	// This needs special attention due to multiple attributes being used.
	rgb255_color rgb255;
	unsigned n;
	static char colorstring[32];

	rgb255.r = (color->lt >> 16) & 0xff;
	rgb255.g = (color->lt >>  8) & 0xff;
	rgb255.b = (color->lt >>  0) & 0xff;
	n = nearest_ansi(rgb255);
	if (n < 8) {
	    sprintf(colorstring, "\033[%im", 40 + (n % 8));
	} else {
	    // For color >= 8, we try to set both, the (dark) background color,
	    // and then the brighter color using the aixterm sequence. Unfortunately,
	    // that is not widely supported, so we likely get the right color, but
	    // it is too dark.
	    sprintf(colorstring, "\033[%i;%im", 40 + (n % 8), (n >= 8 ? 100: 40) + (n % 8));
	}
	return colorstring;
    } else {
	// Hack alert: We change foreground color commands to
	// background color commands by changing a single byte only.
	char * c = (char *) ansi_colorstring(color, NULL);
	if (c[0] != NUL && c[2] == '3')
	    c[2] = '4';
	return c;
    }
}
#endif


TERM_PUBLIC void
BLOCK_text()
{
    char *line;
    unsigned char *s;
    int x, y;
    uint32_t v;
    int cellx, celly; // number of pseudo-pixels per cell
    const int * idx;
    const int idx_dot[1]       = { 1 };
    const int idx_half[2]      = { 0x02, 0x01 };
    const int idx_quadrants[4] = { 0x04, 0x08, 0x01, 0x02 };
    const int idx_sextants[6]  = { 0x10, 0x20, 0x04, 0x08, 0x01, 0x02 };
    const int idx_octants[8]   = { 0x40, 0x80, 0x10, 0x20, 0x04, 0x08, 0x01, 0x02 };
    const int idx_braille[8]   = { 0x40, 0x80, 0x04, 0x20, 0x02, 0x10, 0x01, 0x08 };
    const int * idx_list[] = { idx_dot, idx_half, idx_quadrants,
			        idx_sextants, idx_sextants,
			        idx_octants, idx_octants, idx_braille };
    size_t bufsiz;
    text_attr prev_text_attr;
#ifndef NO_DUMB_COLOR_SUPPORT
    unsigned nsets, set;
    const int * pattern;
    char bg_str[32] = "";
#if defined(HAVE_ICONV) && !defined(_WIN32)
    iconv_t cd = (iconv_t) -1;

    {
	enum set_encoding_id encoding = encoding_from_locale();
	if (isatty(fileno(gpoutfile)) &&  /* only convert if output to terminal */
	    encoding != S_ENC_UTF8 && encoding != S_ENC_DEFAULT &&
	    iconv_encoding_name(encoding) != NULL) {
	    char tocode [128];

	    strcpy(tocode, iconv_encoding_name(encoding));
# ifndef OS2
	    strcat(tocode, "//TRANSLIT//IGNORE");
# endif
	    if ((cd = iconv_open(tocode, "UTF-8")) == (iconv_t) -1)
		int_warn(NO_CARET, "iconv_open failed");
	}
    }
#endif

    if (dumb_colormode > 0) {
#if defined(OS2) || defined(MSDOS)
	fputs("\033[0;37m", gpoutfile); /* reset foreground color to white */
#else
	fputs("\033[0;39m", gpoutfile); /* reset foreground color to default */
#endif
	memset(&dumb_prev_color, 0, sizeof(t_colorspec));
    }
#endif

    // Initialize variable for loop below.
    cellx = BLOCK_modeinfo[BLOCK_mode].cellx;
    celly = BLOCK_modeinfo[BLOCK_mode].celly;
    idx = idx_list[BLOCK_mode];
#ifndef NO_DUMB_COLOR_SUPPORT
    switch (BLOCK_mode) {
    default:
	nsets = 0;
	pattern = NULL;
	break;
    case BLOCK_MODE_HALF:
	nsets = nhalf_pats;
	pattern = half_pat;
	break;
    case BLOCK_MODE_QUAD:
	nsets = nquad_pats;
	pattern = quad_pat;
	break;
    case BLOCK_MODE_SEXT:
    case BLOCK_MODE_SEXT_PUA:
	nsets = nsext_pats;
	pattern = sext_pat;
	break;
    case BLOCK_MODE_OCT:
    case BLOCK_MODE_OCT_PUA:
	nsets = noct_pats;
	pattern = oct_pat;
	break;
    }

    // Generate background string once
    if (BLOCK_background != BLOCK_BGTRANSPARENT) {
	t_colorspec color;
	color.type = TC_RGB,
	color.lt = BLOCK_background;
	strcpy(bg_str, ansi_bg_colorstring(&color));
    }
#endif

    // convert bitmap to Unicode characters
    // printf("vvvvvvvvvvvvvvvvvvvvvvvvvvvv\n");
    // FIXME: last row and column not handled properly!
    bufsiz = (term->xmax + 1) * 8;
    line = gp_alloc(bufsiz, "line buffer");
    if (dumb_text_attributes)
	memset(&prev_text_attr, 0, sizeof(text_attr));

    for (y = term->ymax - celly + 1; y >= 0; y -= celly) {
	int yd = y / celly; // character cell coordinate

	s = (unsigned char *) line;

#ifndef NO_DUMB_COLOR_SUPPORT
	// Set background color.
	if (bg_str[0] != NUL) {
	    strcpy((char *) s, bg_str);
	    s += strlen(bg_str);
	}
#endif

	for (x = 0; x <= term->xmax; x += cellx) {
	    int xd = x / cellx;  // character cell coordinate
	    int i = 0;  // index to character map
	    TBOOLEAN resetbg = FALSE;
	    const char * c;
	    t_colorspec color;

	    // increase buffer size if necessary, assuming a maximum of 100 bytes per cell
	    if (((char *)s - line) > (bufsiz - 100)) {
		char * l;
		bufsiz += (term->xmax + 1) * 8;
		l = realloc(line, bufsiz);
		s = (unsigned char *)(l + ((char *)s - line));
		line = l;
	    }

	    if (*(char *)(&DUMB_PIXEL(xd, yd)) != ' ') {
		//
		// There is a character in the charcell.
		//
#ifndef NO_DUMB_COLOR_SUPPORT
		// Handle the character's color first.
		t_colorspec * color;
		int n = 0; // number of set pixels in charcell
		int r = 0, g = 0, b = 0;  // color components
		int k;
		rgb255_color col;

		// Text "transparency": if all pixels are set, we average over
		// the cell to set the background color.
		if ((dumb_colormode > 0) && BLOCK_optimize && (BLOCK_mode != BLOCK_MODE_BRAILLE)) {
		    // get all pixels within charcell
		    for (k = 0; k < (cellx * celly); k++) {
			v = b_getpixel(x + (k % cellx), y + (k / cellx));
			// Is the pixel set? (first plane is "opacity")
			if (v & 1) {
			    // sum up RGB colors
			    to_rgb255(v >> 1, &col);
			    r += USQR(col.r);
			    g += USQR(col.g);
			    b += USQR(col.b);
			    n++;
			}
		    }
		    if (n == cellx * celly) {
			t_colorspec color;
			color.type = TC_RGB;
			color.lt = ((unsigned) sqrt(r / n) << 16) +
				   ((unsigned) sqrt(g / n) <<  8) +
				   ((unsigned) sqrt(b / n));
			c = ansi_bg_colorstring(&color);
			if (c != NULL && strcmp(bg_str, c) != 0) {
			    strcpy((char *) s, c);
			    s += strlen(c);
			    resetbg = TRUE;
			}
		    }
		}

		// Set color _after_ the background color.
		color = &dumb_colors[dumb_xmax * yd + xd];
		c = ansi_colorstring(color, &dumb_prev_color);
		if (c[0] != NUL) {
		    strcpy((char *) s, c);
		    s += strlen(c);
		}
		memcpy(&dumb_prev_color, color, sizeof(t_colorspec));
#endif

		// Copy the character.
		c = (char *)(&DUMB_PIXEL(xd, yd));
		if (*c != NUL) { /* Do not print cells occupied by wide characters. */
		    /* character attributes */
		    if (dumb_text_attributes) {
			text_attr * attr = &dumb_attributes[dumb_xmax*yd + xd];
			const char * attrstring = dumb_attrstring(attr, &prev_text_attr);
			if (attrstring[0] != NUL) {
			    strcpy((char *) s, attrstring);
			    s += strlen(attrstring);
			    memcpy(&prev_text_attr, attr, sizeof(text_attr));
			}
		    }
		    for (i = 0; i < sizeof(charcell) && *c != NUL; i++, c++, s++)
			*s = *c;
		}
	    } else {
		//
		// No character. Print graphics.
		//
		int k;
		int n = 0; // number of set pixels in charcell
		unsigned cell[8]; // array of all pixels in charcell
#ifndef NO_DUMB_COLOR_SUPPORT
		int r = 0, g = 0, b = 0;  // color components
		rgb255_color col[8];
#endif

		// get all pixels within charcell
		i = 0;
		for (k = 0; k < (cellx * celly); k++) {
		    cell[k] = v = b_getpixel(x + (k % cellx), y + (k / cellx));
		    // Is the pixel set? (first plane is "opacity")
		    if (v & 1) {
			// update character index
			i += idx[k];
#ifndef NO_DUMB_COLOR_SUPPORT
			// sum up RGB colors
			to_rgb255(v >> 1, col + k);
			r += USQR(col[k].r);
			g += USQR(col[k].g);
			b += USQR(col[k].b);
			n++;
#endif
		    }
		}

#ifndef NO_DUMB_COLOR_SUPPORT
		// In case all pixels of the charcell are set, we do try to optimize
		// changing both, fore- and background colors. This always
		// works for half-blocks, mostly for quadrants, but is increasingly
		// difficult for sextants and octants. We cannot do that for Braille symbols.
		if ((dumb_colormode > 0) && BLOCK_optimize &&
		    (((BLOCK_mode == BLOCK_MODE_HALF) && (n == 2) &&
		       !(cell[0] == cell[1])) ||
		     ((BLOCK_mode == BLOCK_MODE_QUAD) && (n == 4) &&
		      !(cell[0] == cell[1] && cell[1] == cell[2] && cell[2] == cell[3])) ||
		     ((BLOCK_mode == BLOCK_MODE_SEXT || BLOCK_mode == BLOCK_MODE_SEXT_PUA) && (n == 6) &&
		      !(cell[0] == cell[1] && cell[1] == cell[2] && cell[2] == cell[3] &&
		        cell[3] == cell[4] && cell[4] == cell[5])) ||
		     ((BLOCK_mode == BLOCK_MODE_OCT || BLOCK_mode == BLOCK_MODE_OCT_PUA) && (n == 8) &&
		      !(cell[0] == cell[1] && cell[1] == cell[2] && cell[2] == cell[3] &&
		        cell[3] == cell[4] && cell[4] == cell[5] && cell[5] == cell[6] &&
		        cell[6] == cell[7])) )) {
		    int wmin = INT_MAX;
		    int r2, g2, b2, m;
		    int ropt = 0, gopt = 0, bopt = 0;
		    int r2opt = 0, g2opt = 0, b2opt = 0;
		    int nopt = 0, mopt = 0, iopt = 0;

		    // Find optimum average color combination for fore- and background.
		    i = 0;
		    // Loop over all pixel patterns.
		    for (set = 0; set < nsets; set++) {
			unsigned mask;
			int rm, gm, bm;
			int rm2, gm2, bm2;
			int w;

			// Determine color averages for fore- and background.
			r = g = b = 0;
			r2 = g2 = b2 = 0;
			n = m = i = 0;
			mask = pattern[set];
			for (k = 0; k < cellx*celly; k++) {
			    if (mask & 1) {
				r += USQR(col[k].r);
				g += USQR(col[k].g);
				b += USQR(col[k].b);
				i += idx[k];
				n++;
			    } else {
				r2 += USQR(col[k].r);
				g2 += USQR(col[k].g);
				b2 += USQR(col[k].b);
				m++;
			    }
			    mask >>= 1;
			}
			rm = sqrt(r / n); gm = sqrt(g / n); bm = sqrt(b / n);
			rm2 = sqrt(r2 / m); gm2 = sqrt(g2 / m); bm2 = sqrt(b2 / m);

			// Determine weight of this combination.
			mask = pattern[set];
			w = 0;
			for (k = 0; k < cellx * celly; k++) {
			    if (mask & 1) {
				w += USQR(col[k].r - rm);
				w += USQR(col[k].g - gm);
				w += USQR(col[k].b - bm);
			    } else {
				w += USQR(col[k].r - rm2);
				w += USQR(col[k].g - gm2);
				w += USQR(col[k].b - bm2);
			    }
			    mask >>= 1;
			}

			// Did we find a new optimum?
			if (w < wmin) {
			    wmin = w;
			    nopt = n;
			    ropt = r; gopt = g; bopt = b;
			    mopt = m;
			    r2opt = r2; g2opt = g2; b2opt = b2;
			    iopt = i;
			}
		    }

		    // Use optimum values.
		    n = nopt;
		    r = ropt; g = gopt; b = bopt;
		    m = mopt;
		    r2 = r2opt; g2 = g2opt; b2 = b2opt;
		    i = iopt;

		    // Set background color.
		    color.type = TC_RGB;
		    color.lt = ((unsigned) sqrt(r2 / m) << 16) +
			       ((unsigned) sqrt(g2 / m) <<  8) +
			       ((unsigned) sqrt(b2 / m));
		    c = ansi_bg_colorstring(&color);
		    if (c != NULL && strcmp(bg_str, c) != 0) {
			strcpy((char *) s, c);
			s += strlen(c);
			resetbg = TRUE;
		    }
		}

		// Any pixel set within this charcell?
		// Then average over the color over the charcell.
		if (n != 0) {
		    // first, reset text attributes
		    if (dumb_text_attributes &&
			(prev_text_attr.italic || prev_text_attr.bold)) {
			const char tmp[] = "\033[22;23m"; /* reset attributes */
			strcpy((char *) s, tmp);
			s += strlen(tmp);
			memset(&prev_text_attr, 0, sizeof(text_attr));
		    }

		    // average charcell color
		    color.type = TC_RGB;
		    color.lt = ((unsigned) sqrt(r / n) << 16) +
		               ((unsigned) sqrt(g / n) <<  8) +
		               ((unsigned) sqrt(b / n));
		    c = ansi_colorstring(&color, &dumb_prev_color);
		    if (c[0] != NUL) {
			strcpy((char *) s, c);
			s += strlen(c);
		    }
		    memcpy(&dumb_prev_color, &color, sizeof(t_colorspec));
		}
#endif

		switch (BLOCK_mode) {
		case BLOCK_MODE_DOT:
		    // v = (n > 0 ? '*' : ' ');
		    v = (n > 0 ? 0x25cf : 0x00a0);
		    break;
		case BLOCK_MODE_HALF:
		    v = block_half_map[i];
		    break;
		case BLOCK_MODE_QUAD:
		    v = block_quadrant_map[i];
		    break;
		case BLOCK_MODE_SEXT:
		    v = block_sextant_map[i];
		    break;
		case BLOCK_MODE_SEXT_PUA:
		    // Sextants in the KreativeKorp PUA are ordered and complete,
		    // so no need for a mapping table.
		    v = 0xf2c0 + i;
		    break;
		case BLOCK_MODE_OCT:
		    v = block_octant_map[i];
		    break;
		case BLOCK_MODE_OCT_PUA:
		    // Octants in the KreativeKorp PUA are ordered and complete,
		    // so no need for a mapping table.
		    v = 0xf300 + i;
		    break;
		case BLOCK_MODE_BRAILLE:
		    // Braille characters are well-ordered,
		    // so we don't need a mapping.
		    v = 0x2800 + i;
		    break;
		default:
		    v = 0x0020;
		}

		s += ucs4toutf8(v, s);
	    }

#ifndef NO_DUMB_COLOR_SUPPORT
	    // turn bg color off again
	    if (resetbg) {
		if (bg_str[0] != NUL) {
		    strcpy((char *) s, bg_str);
		    s += strlen(bg_str);
		} else {
#if defined(OS2) || defined(MSDOS)
		    strcpy((char *) s, "\033[40m"); s += 5; /* reset background color to black */
#else
		    strcpy((char *) s, "\033[49m"); s += 5; /* reset background color to default */
#endif
		}
	    }
#endif
	}

#ifndef NO_DUMB_COLOR_SUPPORT
	// turn bg color off again
	if (bg_str[0] != NUL) {
#if defined(OS2) || defined(MSDOS)
	    strcpy((char *) s, "\033[40m"); s += 5; /* reset background color to black */
#else
	    strcpy((char *) s, "\033[49m"); s += 5; /* reset background color to default */
#endif
	}
#endif

	*s++ = '\n';
	*s = NUL;

#if defined(HAVE_ICONV) && !defined(_WIN32)
	/* If the current screen encoding is not UTF-8, we attempt to convert.
	   This is useful for half mode with CP850 or CP437. */
	if (cd != (iconv_t) -1) {
	    char * str_start = line;
	    size_t len1 = strlen(line) + 1;
	    size_t len2 = len1;
	    char * iconv_string = gp_alloc(len2, "iconv string");
	    char * stmp = iconv_string;

	    if (iconv(cd, (void *)&str_start, &len1, &stmp, &len2) == (size_t) -1)
		int_warn(NO_CARET, "iconv failed");
	    else
	       fputs(iconv_string, gpoutfile);
	    free(iconv_string);
	} else
#elif defined _WIN32
	if (isatty(fileno(gpoutfile)) && GetConsoleOutputCP() != 65001) {
	    LPWSTR wline = UnicodeText(line, S_ENC_UTF8);
	    HANDLE h = GetStdHandle(STD_OUTPUT_HANDLE);
	    WriteConsoleW(h, wline, wcslen(wline), NULL, NULL);
	    free(wline);
	} else
#endif
	fputs(line, gpoutfile);
    }
    // printf("^^^^^^^^^^^^^^^^^^^^^^^^^^^^\n");

    if (dumb_text_attributes)
	fputs("\033[22;23m", gpoutfile); /* reset attributes */
#ifndef NO_DUMB_COLOR_SUPPORT
    if (dumb_colormode > 0) {
#if defined(OS2) || defined(MSDOS)
	fputs("\033[0;37;40m", gpoutfile); /* reset colors to white on black */
#else
	fputs("\033[0;39;49m", gpoutfile); /* reset colors to default */
#endif
    }
#endif

    // Move cursor up to start over.
    if (BLOCK_animate)
	fprintf(gpoutfile, "\033[%iA", BLOCK_ychars);

    free(line);
    (void) fflush(gpoutfile);	/* finish the graphics */
#if defined(HAVE_ICONV) && !defined(_WIN32)
    if (cd != (iconv_t) -1)
	iconv_close(cd);
#endif
}


TERM_PUBLIC void
BLOCK_graphics()
{
    b_boxfill(FS_EMPTY, 0, 0, term->xmax, term->ymax);
    DUMB_graphics();

    /* kludge: fix keybox size */
    if (keyT.width_fix == 0) keyT.width_fix = 1;
    if (keyT.height_fix == 0) keyT.height_fix = 1;
}


TERM_PUBLIC void
BLOCK_put_text(unsigned int x, unsigned int y, const char *str)
{
    int xd = x / BLOCK_modeinfo[BLOCK_mode].cellx;
    int yd = y / BLOCK_modeinfo[BLOCK_mode].celly;

#ifndef NO_DUMB_ENHANCED_SUPPORT
    if (term->flags & TERM_ENHANCED_TEXT)
	ENHdumb_put_text(xd, yd, str);
    else
#endif
	DUMB_put_text(xd, yd, str);
}


TERM_PUBLIC void
BLOCK_point(unsigned int x, unsigned int y, int point)
{
    if ((signed) x < 0 || (signed) y < 0)
	return;

    // Draw the smallest bitmap point symbols possible.
    //
    // These symbols are still too large and maybe only useful in combination
    // with error bars.
    //
    if (BLOCK_pointtype == BLOCK_POINT_GP) {
	if (point < 0) { // dot
	    b_putpixel(x, y);
	} else {
	    const int point_pat[] = {
		0x0ba, /* + */
		0x155, /* X */
		0x0aa, /* diamond */
		0x1ef, /* square */
		0x0af, /* triangle */
		0x1ea  /* downward triangle */
	    };
	    const int npat = sizeof(point_pat) / sizeof(int);
	    int pat = point_pat[point % npat];
	    int dx, dy;
	    for (dy = -1; dy <= 1; dy ++) {
		for (dx = -1; dx <= 1; dx ++) {
		    if (pat & 1) b_putpixel(x + dx, y + dy);
		    pat >>= 1;
		}
	    }
	}
	return;
    }

    // Draw point symbols using Unicode characters.
    //
    // The original idea was to use the corresponding character representations
    // listed below. The drawback is that they are not well-aligned with the
    // bitmap graph, as the cell-box resolution is smaller.
    // Instead, we now use super- or subscript numerals 1-9 as point symbols.
    // This results in double the resolution in vertical direction, but still
    // only matches the bitmap resolution in "half" mode. Note that we still
    // cannot overlay two characters in the same cell-box.
    //
    if (point >= 0) {
	// character position
	int xd = x / BLOCK_modeinfo[BLOCK_mode].cellx;
	int yd = y / BLOCK_modeinfo[BLOCK_mode].celly;

	DUMB_PIXEL(xd, yd) = 0;
	if (BLOCK_pointtype == BLOCK_POINT_CHAR) {
	    // correct character point symbols
	    const uint32_t pointtypes[] = {
		    '+', 'x' /* cross */, '*',
#if defined(OS2) || defined(MSDOS)
		    0x25a0, 0x25b2, 0x25bc
#else
		    0x25a1, 0x25a0, /* empty/full square */
		    0x25cb, 0x25cf, /* empty/full circle */
		    0x25b3, 0x25b2, /* empty/full upward triangle */
		    0x25bd, 0x25bc, /* empty/full downward triangle */
		    0x25c7, 0x25c6, /* empty/full diamond */
		    0x2b20, 0x2b1f, /* empty/full pentagon */
#endif
		};
	    const int npointtypes = sizeof(pointtypes) / sizeof(uint32_t);

	    ucs4toutf8(pointtypes[point % npointtypes], (unsigned char *) &DUMB_PIXEL(xd, yd));
	} else {
	    // super-/subscript numerals
	    // Some superscripts numerals are defined in latin-1, so we use a mapping table.
	    // Subscripts numerals have continuous code-points.
	    const uint32_t upoints[9] = {
		0x00B9, 0x00B2, 0x00B3, 0x2074, 0x2075,
		0x2076, 0x2077, 0x2078, 0x2079
	    };

	    unsigned ypos = (y % BLOCK_modeinfo[BLOCK_mode].celly);
	    if (((BLOCK_mode == BLOCK_MODE_SEXT || BLOCK_mode == BLOCK_MODE_SEXT_PUA) && ypos == 1) ||
	        (BLOCK_mode == BLOCK_MODE_DOT)) {
		// special case: vertical center
		ucs4toutf8(('1' + (point % 9)), (unsigned char *) &DUMB_PIXEL(xd, yd));
	    } else {
		// y-position in upper half of the character box?
		bool upper = (ypos >= (BLOCK_modeinfo[BLOCK_mode].celly / 2));
		ucs4toutf8(upper ? upoints[point % 9] : (0x2081 + (point % 9)), (unsigned char *) &DUMB_PIXEL(xd, yd));
	    }
	}
#ifndef NO_DUMB_COLOR_SUPPORT
	memcpy(&dumb_colors[dumb_xmax * yd + xd], &dumb_color, sizeof(t_colorspec));
#endif
    } else {
	// Draw dots on the bitmap
	b_putpixel(x, y);
    }
}


TERM_PUBLIC void
BLOCK_arrow(unsigned int sx, unsigned int sy,
	    unsigned int ex, unsigned int ey,
	    int head)
{
    // Enforce minimally sized arrows, but take three head variants into account:
    if (curr_arrow_headlength <= 0 || curr_arrow_headangle <= 80) {
	curr_arrow_headangle = 45;
	curr_arrow_headlength = 2;
    } else if (curr_arrow_headangle <= 100) {
	curr_arrow_headangle = 90;
	curr_arrow_headlength = (sx == ex) || (sy == ey) ? 1 : 2;
    } else {
	curr_arrow_headangle = 135;
	curr_arrow_headlength = 2;
    }
    curr_arrow_headbackangle = 90;
    curr_arrow_headfilled = AS_NOFILL;

    do_arrow(sx, sy, ex, ey, head);
}


TERM_PUBLIC void
BLOCK_linetype(int linetype)
{
    t_colorspec color;

    // set dash pattern
    if (linetype != LT_AXIS)
	b_setlinetype(LT_SOLID);  // always solid
    else
	b_setlinetype(LT_AXIS);

    // set line color
    color.type = TC_LT;
    color.lt = linetype;
    BLOCK_set_color(&color);

    // set text color
    DUMB_linetype(linetype);
}


TERM_PUBLIC void
BLOCK_set_color(t_colorspec *color)
{
    switch (color->type) {
    case TC_LT: {
	if (color->lt == LT_BACKGROUND)
	    b_setvalue(0);
	else {
	    /* map line type to colors */
	    int n = color->lt + 1;
	    if (n <= 0)
		n = 7;  // should be "default", but choose white instead
	    else
		if (n > 15) n = ((n - 1) % 15) + 1;
	    switch (dumb_colormode) {
	    case 0:
		b_setvalue(1);
		break;
#ifndef NO_DUMB_COLOR_SUPPORT
	    case DUMB_ANSI:
	    case DUMB_ANSI256:
		b_setvalue((n << 1) + 1);
		break;
	    case DUMB_ANSIRGB: {
		unsigned v = ansitab16[n];
		unsigned r = (v >> 0) & 0x0f;
		unsigned g = (v >> 4) & 0x0f;
		unsigned b = (v >> 8) & 0x0f;
		b_setvalue((((r << 20) + (g << 12) + (b << 4)) << 1) + 1);
		break;
	    }
#endif
	    }
	}
	break;
    }
#ifndef NO_DUMB_COLOR_SUPPORT
    case TC_RGB:
	if (dumb_colormode == DUMB_ANSIRGB) {
	    b_setvalue(((color->lt & 0xffffff) << 1) + 1);
	} else {
	    rgb255_color rgb255;
	    rgb255.r = (color->lt >> 16) & 0xff;
	    rgb255.g = (color->lt >>  8) & 0xff;
	    rgb255.b = (color->lt >>  0) & 0xff;
	    if (dumb_colormode == DUMB_ANSI256)
		b_setvalue((to_ansi256(&rgb255) << 1) + 1);
	    else
		b_setvalue((nearest_ansi(rgb255) << 1) + 1);
	}
	break;
    case TC_FRAC: {
	rgb255_color rgb255;
	rgb255maxcolors_from_gray(color->value, &rgb255);
	if (dumb_colormode == DUMB_ANSIRGB) {
	    unsigned color = (((unsigned) rgb255.r) << 16) |
	                     (((unsigned) rgb255.g) <<  8) |
	                      ((unsigned) rgb255.b);
	    b_setvalue(((color & 0xffffff) << 1) + 1);
	} else if (dumb_colormode == DUMB_ANSI256)
	    b_setvalue((to_ansi256(&rgb255) << 1) + 1);
	else
	    b_setvalue((nearest_ansi(rgb255) << 1) + 1);
	break;
    }
#endif
    default:
	// should never happen
	break;
    }
#ifndef NO_DUMB_COLOR_SUPPORT
    if (dumb_colormode > 0)
	DUMB_set_color(color);
#endif
}

#endif /* TERM_BODY */

#ifdef TERM_TABLE

TERM_TABLE_START(block_driver)
    "block", "Pseudo-graphics using Unicode block or Braille characters",
    BLOCK_XMAX, BLOCK_YMAX,
    BLOCK_VCHAR, BLOCK_HCHAR,
    BLOCK_VTIC, BLOCK_HTIC,
    BLOCK_options, BLOCK_init, BLOCK_reset,
    BLOCK_text, null_scale, BLOCK_graphics,
    b_move, b_vector, BLOCK_linetype,
    BLOCK_put_text, null_text_angle, null_justify_text,
    BLOCK_point, BLOCK_arrow, DUMB_set_font, 0,
#ifndef NO_DUMB_ENHANCED_SUPPORT
    TERM_MONOCHROME | TERM_ENHANCED_TEXT,
#else
    TERM_MONOCHROME,
#endif
    0, 0, b_boxfill, NULL,
#ifdef USE_MOUSE
    term_waitforinput, NULL, NULL, NULL, NULL,
#endif
    NULL, NULL, BLOCK_set_color,
    b_filled_polygon,
    NULL, /* image */
#ifndef NO_DUMB_ENHANCED_SUPPORT
    ENHdumb_OPEN, ENHdumb_FLUSH, do_enh_writec,
#else
    NULL, NULL, NULL,
#endif /* NO_DUMB_ENHANCED_SUPPORT */
    NULL,
    NULL,
    0.,
    NULL,
    NULL,
    NULL,
    b_dashtype
TERM_TABLE_END(block_driver)

#undef LAST_TERM
#define LAST_TERM block_driver

#endif /* TERM_TABLE */
#endif /* TERM_PROTO_ONLY */


#ifdef TERM_HELP
START_HELP(block)
"1 block",
"?set terminal block",
"?block",
" The `block` terminal generates pseudo-graphic output using Unicode block or",
" Braille characters to increase the resolution.  It is an alternative for",
" terminal graphics.  It requires a UTF-8 capable terminal or viewer.  Drawing",
" uses the internal bitmap code.  Text is printed on top of the graphics",
" using the `dumb` terminal's routines.",
"",
" Syntax:",
"         set term block",
"                 {dot | half | quadrants | sextants | octants | braille |",
"                   sextpua | octpua}",
"                 {{no}enhanced}",
"                 {size <x>, <y>}",
#ifndef NO_DUMB_COLOR_SUPPORT
"                 {mono | ansi | ansi256 | ansirgb}",
"                 {{no}optimize}",
#endif
"                 {[no]attributes}",
"                 {numpoints | charpoints | gppoints}",
"                 {[no]animate}",
"",
" `size` sets the terminal size in character cells.",
"",
" `dot`, `half`, `quadrants`, `sextants`, or `braille` select the character",
" set used for the creation of pseudo-graphics.  `dot` uses simple dots,",
" while `half` uses half-block characters.  `quadrants` uses block characters",
" which yield double resolution in both directions.  `sextants` uses 2x3 block",
" characters, and `braille` uses Braille characters which give a 2x4",
" pseudo-resolution.  `octants` uses the proposed 2x4 block characters.",
" `sextpua` and `octpua` use the sextants or octants, respectively, in the",
" CreativeKorp private-use-area (PUA) which might be only available with their",
" `FairfaxHD` and `KreativeSquare` fonts.",
"",
" Note that the 2x3 block characters ('sextants') have only been included in",
" Unicode 13.  Hence, font support is still limited.  Similarly for Braille.",
" Usable fonts include e.g. `unscii`, `IBM 3270`, `GNU Unifont`, `DejaVu Sans`,",
" and, `FairfaxHD`.  2x4 block characters ('octants') have only been accepted",
" for inclusion in a future Unicode standard in 2022 and are available in the",
" `FairfaxHD` font.",
#ifndef NO_DUMB_COLOR_SUPPORT
"",
" The `ansi`, `ansi256`, and `ansirgb` options will include escape sequences",
" in the output to output colors.  Note that these might not be handled by",
" your terminal.  Default is `mono`.  See `terminal dumb` for a list of",
" escape sequences.",
"",
" The `attributes` option enables bold and italic text on terminals or",
" emulators that support these escape sequences, see `terminal dumb`.",
"",
" Using block characters increases the pseudo-resolution of the bitmap.  But",
" this is not the case for the color.  Multiple 'pixels' necessarily share the",
" same color.  This is dealt with by averaging the color of all pixels in a",
" charcell.  With `optimize`, the terminal tries to improve by setting both,",
" the background and foreground colors.  This trick works perfectly for the",
" `half` mode, but is increasingly difficult for `quadrants`, `sextants`,",
" or `octants`. For `braille` this cannot be used.",
#endif
"",
" `gppoints` draws point symbols using graphics commands. Due to the low",
" resolution of the terminal, this is mostly viable for `braille` or",
" `octant` mode, and probably most useful for error bars.",
" `charpoints` uses Unicode symbol characters instead.  Note that these",
" are also always drawn on top of the graphics.",
" `numpoints` uses super- and subscript numerals to double the vertical",
" resolution. For `sextants`, points in the character cell's center position",
" have to be drawn using ordinary numerals, though. Note that the bitmap",
" resolution is still different and lines and symbols in general do not align",
" exactly when using `charpoints` or `numpoints`.",
"",
" The `animate` option resets the cursor position to the top left of the plot",
" after every plot so that successive plots overwrite the same area on the",
" screen rather than having earlier plots scroll off the top. This may be",
" desirable in order to create an in-place animation.",
""
END_HELP(block)
#endif