* st + patches and config
       
   URI git clone git://git.codevoid.de/st-sdk
   DIR Log
   DIR Files
   DIR Refs
   DIR README
   DIR LICENSE
       ---
   DIR commit 1ba04986ac35ac7e14dc46d3e85d59b16570492b
   DIR parent 7f8357954492f2039f30b4281519f64591802883
   URI Author: Stefan Hagen <sh+git[at]codevoid[dot]de>
       Date:   Wed, 28 Aug 2019 21:15:39 +0200
       
       Add and enable boxdraw patch
       
       Diffstat:
         M Makefile                            |       3 ++-
         A boxdraw.c                           |     194 ++++++++++++++++++++++++++++++
         A boxdraw_data.h                      |     214 +++++++++++++++++++++++++++++++
         M config.def.h                        |      12 ++++++++++++
         M config.h                            |      12 ++++++++++++
         A patches/st-boxdraw_v2-0.8.2.diff    |     598 +++++++++++++++++++++++++++++++
         M st.c                                |       3 +++
         M st.h                                |      10 ++++++++++
         M x.c                                 |      21 ++++++++++++++++-----
       
       9 files changed, 1061 insertions(+), 6 deletions(-)
       ---
   DIR diff --git a/Makefile b/Makefile
       @@ -4,7 +4,7 @@
        
        include config.mk
        
       -SRC = st.c x.c
       +SRC = st.c x.c boxdraw.c
        OBJ = $(SRC:.c=.o)
        
        all: options st
       @@ -23,6 +23,7 @@ config.h:
        
        st.o: config.h st.h win.h
        x.o: arg.h st.h win.h
       +boxdraw.o: config.h st.h boxdraw_data.h
        
        $(OBJ): config.h config.mk
        
   DIR diff --git a/boxdraw.c b/boxdraw.c
       @@ -0,0 +1,194 @@
       +/*
       + * Copyright 2018 Avi Halachmi (:avih) avihpit@yahoo.com https://github.com/avih
       + * MIT/X Consortium License
       + */
       +
       +#include <X11/Xft/Xft.h>
       +#include "st.h"
       +#include "boxdraw_data.h"
       +
       +/* Rounded non-negative integers division of n / d  */
       +#define DIV(n, d) (((n) + (d) / 2) / (d))
       +
       +static Display *xdpy;
       +static Colormap xcmap;
       +static XftDraw *xd;
       +static Visual *xvis;
       +
       +static void drawbox(int, int, int, int, XftColor *, XftColor *, ushort);
       +static void drawboxlines(int, int, int, int, XftColor *, ushort);
       +
       +/* public API */
       +
       +void
       +boxdraw_xinit(Display *dpy, Colormap cmap, XftDraw *draw, Visual *vis)
       +{
       +        xdpy = dpy; xcmap = cmap; xd = draw, xvis = vis;
       +}
       +
       +int
       +isboxdraw(Rune u)
       +{
       +        Rune block = u & ~0xff;
       +        return (boxdraw && block == 0x2500 && boxdata[(uint8_t)u]) ||
       +               (boxdraw_braille && block == 0x2800);
       +}
       +
       +/* the "index" is actually the entire shape data encoded as ushort */
       +ushort
       +boxdrawindex(const Glyph *g)
       +{
       +        if (boxdraw_braille && (g->u & ~0xff) == 0x2800)
       +                return BRL | (uint8_t)g->u;
       +        if (boxdraw_bold && (g->mode & ATTR_BOLD))
       +                return BDB | boxdata[(uint8_t)g->u];
       +        return boxdata[(uint8_t)g->u];
       +}
       +
       +void
       +drawboxes(int x, int y, int cw, int ch, XftColor *fg, XftColor *bg,
       +          const XftGlyphFontSpec *specs, int len)
       +{
       +        for ( ; len-- > 0; x += cw, specs++)
       +                drawbox(x, y, cw, ch, fg, bg, (ushort)specs->glyph);
       +}
       +
       +/* implementation */
       +
       +void
       +drawbox(int x, int y, int w, int h, XftColor *fg, XftColor *bg, ushort bd)
       +{
       +        ushort cat = bd & ~(BDB | 0xff);  /* mask out bold and data */
       +        if (bd & (BDL | BDA)) {
       +                /* lines (light/double/heavy/arcs) */
       +                drawboxlines(x, y, w, h, fg, bd);
       +
       +        } else if (cat == BBD) {
       +                /* lower (8-X)/8 block */
       +                int d = DIV((uint8_t)bd * h, 8);
       +                XftDrawRect(xd, fg, x, y + d, w, h - d);
       +
       +        } else if (cat == BBU) {
       +                /* upper X/8 block */
       +                XftDrawRect(xd, fg, x, y, w, DIV((uint8_t)bd * h, 8));
       +
       +        } else if (cat == BBL) {
       +                /* left X/8 block */
       +                XftDrawRect(xd, fg, x, y, DIV((uint8_t)bd * w, 8), h);
       +
       +        } else if (cat == BBR) {
       +                /* right (8-X)/8 block */
       +                int d = DIV((uint8_t)bd * w, 8);
       +                XftDrawRect(xd, fg, x + d, y, w - d, h);
       +
       +        } else if (cat == BBQ) {
       +                /* Quadrants */
       +                int w2 = DIV(w, 2), h2 = DIV(h, 2);
       +                if (bd & TL)
       +                        XftDrawRect(xd, fg, x, y, w2, h2);
       +                if (bd & TR)
       +                        XftDrawRect(xd, fg, x + w2, y, w - w2, h2);
       +                if (bd & BL)
       +                        XftDrawRect(xd, fg, x, y + h2, w2, h - h2);
       +                if (bd & BR)
       +                        XftDrawRect(xd, fg, x + w2, y + h2, w - w2, h - h2);
       +
       +        } else if (bd & BBS) {
       +                /* Shades - data is 1/2/3 for 25%/50%/75% alpha, respectively */
       +                int d = (uint8_t)bd;
       +                XftColor xfc;
       +                XRenderColor xrc = { .alpha = 0xffff };
       +
       +                xrc.red = DIV(fg->color.red * d + bg->color.red * (4 - d), 4);
       +                xrc.green = DIV(fg->color.green * d + bg->color.green * (4 - d), 4);
       +                xrc.blue = DIV(fg->color.blue * d + bg->color.blue * (4 - d), 4);
       +
       +                XftColorAllocValue(xdpy, xvis, xcmap, &xrc, &xfc);
       +                XftDrawRect(xd, &xfc, x, y, w, h);
       +                XftColorFree(xdpy, xvis, xcmap, &xfc);
       +
       +        } else if (cat == BRL) {
       +                /* braille, each data bit corresponds to one dot at 2x4 grid */
       +                int w1 = DIV(w, 2);
       +                int h1 = DIV(h, 4), h2 = DIV(h, 2), h3 = DIV(3 * h, 4);
       +
       +                if (bd & 1)   XftDrawRect(xd, fg, x, y, w1, h1);
       +                if (bd & 2)   XftDrawRect(xd, fg, x, y + h1, w1, h2 - h1);
       +                if (bd & 4)   XftDrawRect(xd, fg, x, y + h2, w1, h3 - h2);
       +                if (bd & 8)   XftDrawRect(xd, fg, x + w1, y, w - w1, h1);
       +                if (bd & 16)  XftDrawRect(xd, fg, x + w1, y + h1, w - w1, h2 - h1);
       +                if (bd & 32)  XftDrawRect(xd, fg, x + w1, y + h2, w - w1, h3 - h2);
       +                if (bd & 64)  XftDrawRect(xd, fg, x, y + h3, w1, h - h3);
       +                if (bd & 128) XftDrawRect(xd, fg, x + w1, y + h3, w - w1, h - h3);
       +
       +        }
       +}
       +
       +void
       +drawboxlines(int x, int y, int w, int h, XftColor *fg, ushort bd)
       +{
       +        /* s: stem thickness. width/8 roughly matches underscore thickness. */
       +        /* We draw bold as 1.5 * normal-stem and at least 1px thicker.      */
       +        /* doubles draw at least 3px, even when w or h < 3. bold needs 6px. */
       +        int mwh = MIN(w, h);
       +        int base_s = MAX(1, DIV(mwh, 8));
       +        int bold = (bd & BDB) && mwh >= 6;  /* possibly ignore boldness */
       +        int s = bold ? MAX(base_s + 1, DIV(3 * base_s, 2)) : base_s;
       +        int w2 = DIV(w - s, 2), h2 = DIV(h - s, 2);
       +        /* the s-by-s square (x + w2, y + h2, s, s) is the center texel.    */
       +        /* The base length (per direction till edge) includes this square.  */
       +
       +        int light = bd & (LL | LU | LR | LD);
       +        int double_ = bd & (DL | DU | DR | DD);
       +
       +        if (light) {
       +                /* d: additional (negative) length to not-draw the center   */
       +                /* texel - at arcs and avoid drawing inside (some) doubles  */
       +                int arc = bd & BDA;
       +                int multi_light = light & (light - 1);
       +                int multi_double = double_ & (double_ - 1);
       +                /* light crosses double only at DH+LV, DV+LH (ref. shapes)  */
       +                int d = arc || (multi_double && !multi_light) ? -s : 0;
       +
       +                if (bd & LL)
       +                        XftDrawRect(xd, fg, x, y + h2, w2 + s + d, s);
       +                if (bd & LU)
       +                        XftDrawRect(xd, fg, x + w2, y, s, h2 + s + d);
       +                if (bd & LR)
       +                        XftDrawRect(xd, fg, x + w2 - d, y + h2, w - w2 + d, s);
       +                if (bd & LD)
       +                        XftDrawRect(xd, fg, x + w2, y + h2 - d, s, h - h2 + d);
       +        }
       +
       +        /* double lines - also align with light to form heavy when combined */
       +        if (double_) {
       +                /*
       +                * going clockwise, for each double-ray: p is additional length
       +                * to the single-ray nearer to the previous direction, and n to
       +                * the next. p and n adjust from the base length to lengths
       +                * which consider other doubles - shorter to avoid intersections
       +                * (p, n), or longer to draw the far-corner texel (n).
       +                */
       +                int dl = bd & DL, du = bd & DU, dr = bd & DR, dd = bd & DD;
       +                if (dl) {
       +                        int p = dd ? -s : 0, n = du ? -s : dd ? s : 0;
       +                        XftDrawRect(xd, fg, x, y + h2 + s, w2 + s + p, s);
       +                        XftDrawRect(xd, fg, x, y + h2 - s, w2 + s + n, s);
       +                }
       +                if (du) {
       +                        int p = dl ? -s : 0, n = dr ? -s : dl ? s : 0;
       +                        XftDrawRect(xd, fg, x + w2 - s, y, s, h2 + s + p);
       +                        XftDrawRect(xd, fg, x + w2 + s, y, s, h2 + s + n);
       +                }
       +                if (dr) {
       +                        int p = du ? -s : 0, n = dd ? -s : du ? s : 0;
       +                        XftDrawRect(xd, fg, x + w2 - p, y + h2 - s, w - w2 + p, s);
       +                        XftDrawRect(xd, fg, x + w2 - n, y + h2 + s, w - w2 + n, s);
       +                }
       +                if (dd) {
       +                        int p = dr ? -s : 0, n = dl ? -s : dr ? s : 0;
       +                        XftDrawRect(xd, fg, x + w2 + s, y + h2 - p, s, h - h2 + p);
       +                        XftDrawRect(xd, fg, x + w2 - s, y + h2 - n, s, h - h2 + n);
       +                }
       +        }
       +}
   DIR diff --git a/boxdraw_data.h b/boxdraw_data.h
       @@ -0,0 +1,214 @@
       +/*
       + * Copyright 2018 Avi Halachmi (:avih) avihpit@yahoo.com https://github.com/avih
       + * MIT/X Consortium License
       + */
       +
       +/*
       + * U+25XX codepoints data
       + *
       + * References:
       + *   http://www.unicode.org/charts/PDF/U2500.pdf
       + *   http://www.unicode.org/charts/PDF/U2580.pdf
       + *
       + * Test page:
       + *   https://github.com/GNOME/vte/blob/master/doc/boxes.txt
       + */
       +
       +/* Each shape is encoded as 16-bits. Higher bits are category, lower are data */
       +/* Categories (mutually exclusive except BDB): */
       +/* For convenience, BDL/BDA/BBS/BDB are 1 bit each, the rest are enums */
       +#define BDL (1<<8)   /* Box Draw Lines (light/double/heavy) */
       +#define BDA (1<<9)   /* Box Draw Arc (light) */
       +
       +#define BBD (1<<10)  /* Box Block Down (lower) X/8 */
       +#define BBL (2<<10)  /* Box Block Left X/8 */
       +#define BBU (3<<10)  /* Box Block Upper X/8 */
       +#define BBR (4<<10)  /* Box Block Right X/8 */
       +#define BBQ (5<<10)  /* Box Block Quadrants */
       +#define BRL (6<<10)  /* Box Braille (data is lower byte of U28XX) */
       +
       +#define BBS (1<<14)  /* Box Block Shades */
       +#define BDB (1<<15)  /* Box Draw is Bold */
       +
       +/* (BDL/BDA) Light/Double/Heavy x Left/Up/Right/Down/Horizontal/Vertical      */
       +/* Heavy is light+double (literally drawing light+double align to form heavy) */
       +#define LL (1<<0)
       +#define LU (1<<1)
       +#define LR (1<<2)
       +#define LD (1<<3)
       +#define LH (LL+LR)
       +#define LV (LU+LD)
       +
       +#define DL (1<<4)
       +#define DU (1<<5)
       +#define DR (1<<6)
       +#define DD (1<<7)
       +#define DH (DL+DR)
       +#define DV (DU+DD)
       +
       +#define HL (LL+DL)
       +#define HU (LU+DU)
       +#define HR (LR+DR)
       +#define HD (LD+DD)
       +#define HH (HL+HR)
       +#define HV (HU+HD)
       +
       +/* (BBQ) Quadrants Top/Bottom x Left/Right */
       +#define TL (1<<0)
       +#define TR (1<<1)
       +#define BL (1<<2)
       +#define BR (1<<3)
       +
       +/* Data for U+2500 - U+259F except dashes/diagonals */
       +static const unsigned short boxdata[256] = {
       +        /* light lines */
       +        [0x00] = BDL + LH,       /* light horizontal */
       +        [0x02] = BDL + LV,       /* light vertical */
       +        [0x0c] = BDL + LD + LR,  /* light down and right */
       +        [0x10] = BDL + LD + LL,  /* light down and left */
       +        [0x14] = BDL + LU + LR,  /* light up and right */
       +        [0x18] = BDL + LU + LL,  /* light up and left */
       +        [0x1c] = BDL + LV + LR,  /* light vertical and right */
       +        [0x24] = BDL + LV + LL,  /* light vertical and left */
       +        [0x2c] = BDL + LH + LD,  /* light horizontal and down */
       +        [0x34] = BDL + LH + LU,  /* light horizontal and up */
       +        [0x3c] = BDL + LV + LH,  /* light vertical and horizontal */
       +        [0x74] = BDL + LL,       /* light left */
       +        [0x75] = BDL + LU,       /* light up */
       +        [0x76] = BDL + LR,       /* light right */
       +        [0x77] = BDL + LD,       /* light down */
       +
       +        /* heavy [+light] lines */
       +        [0x01] = BDL + HH,
       +        [0x03] = BDL + HV,
       +        [0x0d] = BDL + HR + LD,
       +        [0x0e] = BDL + HD + LR,
       +        [0x0f] = BDL + HD + HR,
       +        [0x11] = BDL + HL + LD,
       +        [0x12] = BDL + HD + LL,
       +        [0x13] = BDL + HD + HL,
       +        [0x15] = BDL + HR + LU,
       +        [0x16] = BDL + HU + LR,
       +        [0x17] = BDL + HU + HR,
       +        [0x19] = BDL + HL + LU,
       +        [0x1a] = BDL + HU + LL,
       +        [0x1b] = BDL + HU + HL,
       +        [0x1d] = BDL + HR + LV,
       +        [0x1e] = BDL + HU + LD + LR,
       +        [0x1f] = BDL + HD + LR + LU,
       +        [0x20] = BDL + HV + LR,
       +        [0x21] = BDL + HU + HR + LD,
       +        [0x22] = BDL + HD + HR + LU,
       +        [0x23] = BDL + HV + HR,
       +        [0x25] = BDL + HL + LV,
       +        [0x26] = BDL + HU + LD + LL,
       +        [0x27] = BDL + HD + LU + LL,
       +        [0x28] = BDL + HV + LL,
       +        [0x29] = BDL + HU + HL + LD,
       +        [0x2a] = BDL + HD + HL + LU,
       +        [0x2b] = BDL + HV + HL,
       +        [0x2d] = BDL + HL + LD + LR,
       +        [0x2e] = BDL + HR + LL + LD,
       +        [0x2f] = BDL + HH + LD,
       +        [0x30] = BDL + HD + LH,
       +        [0x31] = BDL + HD + HL + LR,
       +        [0x32] = BDL + HR + HD + LL,
       +        [0x33] = BDL + HH + HD,
       +        [0x35] = BDL + HL + LU + LR,
       +        [0x36] = BDL + HR + LU + LL,
       +        [0x37] = BDL + HH + LU,
       +        [0x38] = BDL + HU + LH,
       +        [0x39] = BDL + HU + HL + LR,
       +        [0x3a] = BDL + HU + HR + LL,
       +        [0x3b] = BDL + HH + HU,
       +        [0x3d] = BDL + HL + LV + LR,
       +        [0x3e] = BDL + HR + LV + LL,
       +        [0x3f] = BDL + HH + LV,
       +        [0x40] = BDL + HU + LH + LD,
       +        [0x41] = BDL + HD + LH + LU,
       +        [0x42] = BDL + HV + LH,
       +        [0x43] = BDL + HU + HL + LD + LR,
       +        [0x44] = BDL + HU + HR + LD + LL,
       +        [0x45] = BDL + HD + HL + LU + LR,
       +        [0x46] = BDL + HD + HR + LU + LL,
       +        [0x47] = BDL + HH + HU + LD,
       +        [0x48] = BDL + HH + HD + LU,
       +        [0x49] = BDL + HV + HL + LR,
       +        [0x4a] = BDL + HV + HR + LL,
       +        [0x4b] = BDL + HV + HH,
       +        [0x78] = BDL + HL,
       +        [0x79] = BDL + HU,
       +        [0x7a] = BDL + HR,
       +        [0x7b] = BDL + HD,
       +        [0x7c] = BDL + HR + LL,
       +        [0x7d] = BDL + HD + LU,
       +        [0x7e] = BDL + HL + LR,
       +        [0x7f] = BDL + HU + LD,
       +
       +        /* double [+light] lines */
       +        [0x50] = BDL + DH,
       +        [0x51] = BDL + DV,
       +        [0x52] = BDL + DR + LD,
       +        [0x53] = BDL + DD + LR,
       +        [0x54] = BDL + DR + DD,
       +        [0x55] = BDL + DL + LD,
       +        [0x56] = BDL + DD + LL,
       +        [0x57] = BDL + DL + DD,
       +        [0x58] = BDL + DR + LU,
       +        [0x59] = BDL + DU + LR,
       +        [0x5a] = BDL + DU + DR,
       +        [0x5b] = BDL + DL + LU,
       +        [0x5c] = BDL + DU + LL,
       +        [0x5d] = BDL + DL + DU,
       +        [0x5e] = BDL + DR + LV,
       +        [0x5f] = BDL + DV + LR,
       +        [0x60] = BDL + DV + DR,
       +        [0x61] = BDL + DL + LV,
       +        [0x62] = BDL + DV + LL,
       +        [0x63] = BDL + DV + DL,
       +        [0x64] = BDL + DH + LD,
       +        [0x65] = BDL + DD + LH,
       +        [0x66] = BDL + DD + DH,
       +        [0x67] = BDL + DH + LU,
       +        [0x68] = BDL + DU + LH,
       +        [0x69] = BDL + DH + DU,
       +        [0x6a] = BDL + DH + LV,
       +        [0x6b] = BDL + DV + LH,
       +        [0x6c] = BDL + DH + DV,
       +
       +        /* (light) arcs */
       +        [0x6d] = BDA + LD + LR,
       +        [0x6e] = BDA + LD + LL,
       +        [0x6f] = BDA + LU + LL,
       +        [0x70] = BDA + LU + LR,
       +
       +        /* Lower (Down) X/8 block (data is 8 - X) */
       +        [0x81] = BBD + 7, [0x82] = BBD + 6, [0x83] = BBD + 5, [0x84] = BBD + 4,
       +        [0x85] = BBD + 3, [0x86] = BBD + 2, [0x87] = BBD + 1, [0x88] = BBD + 0,
       +
       +        /* Left X/8 block (data is X) */
       +        [0x89] = BBL + 7, [0x8a] = BBL + 6, [0x8b] = BBL + 5, [0x8c] = BBL + 4,
       +        [0x8d] = BBL + 3, [0x8e] = BBL + 2, [0x8f] = BBL + 1,
       +
       +        /* upper 1/2 (4/8), 1/8 block (X), right 1/2, 1/8 block (8-X) */
       +        [0x80] = BBU + 4, [0x94] = BBU + 1,
       +        [0x90] = BBR + 4, [0x95] = BBR + 7,
       +
       +        /* Quadrants */
       +        [0x96] = BBQ + BL,
       +        [0x97] = BBQ + BR,
       +        [0x98] = BBQ + TL,
       +        [0x99] = BBQ + TL + BL + BR,
       +        [0x9a] = BBQ + TL + BR,
       +        [0x9b] = BBQ + TL + TR + BL,
       +        [0x9c] = BBQ + TL + TR + BR,
       +        [0x9d] = BBQ + TR,
       +        [0x9e] = BBQ + BL + TR,
       +        [0x9f] = BBQ + BL + TR + BR,
       +
       +        /* Shades, data is an alpha value in 25% units (1/4, 1/2, 3/4) */
       +        [0x91] = BBS + 1, [0x92] = BBS + 2, [0x93] = BBS + 3,
       +
       +        /* U+2504 - U+250B, U+254C - U+254F: unsupported (dashes) */
       +        /* U+2571 - U+2573: unsupported (diagonals) */
       +};
   DIR diff --git a/config.def.h b/config.def.h
       @@ -57,6 +57,18 @@ static unsigned int blinktimeout = 800;
        static unsigned int cursorthickness = 2;
        
        /*
       + * 1: render most of the lines/blocks characters without using the font for
       + *    perfect alignment between cells (U2500 - U259F except dashes/diagonals).
       + *    Bold affects lines thickness if boxdraw_bold is not 0. Italic is ignored.
       + * 0: disable (render all U25XX glyphs normally from the font).
       + */
       +const int boxdraw = 0;
       +const int boxdraw_bold = 0;
       +
       +/* braille (U28XX):  1: render as adjacent "pixels",  0: use font */
       +const int boxdraw_braille = 0;
       +
       +/*
         * bell volume. It must be a value between -100 and 100. Use 0 for disabling
         * it
         */
   DIR diff --git a/config.h b/config.h
       @@ -64,6 +64,18 @@ static unsigned int blinktimeout = 0;
        static unsigned int cursorthickness = 2;
        
        /*
       + * 1: render most of the lines/blocks characters without using the font for
       + *    perfect alignment between cells (U2500 - U259F except dashes/diagonals).
       + *    Bold affects lines thickness if boxdraw_bold is not 0. Italic is ignored.
       + * 0: disable (render all U25XX glyphs normally from the font).
       + */
       +const int boxdraw = 1;
       +const int boxdraw_bold = 0;
       +
       +/* braille (U28XX):  1: render as adjacent "pixels",  0: use font */
       +const int boxdraw_braille = 1;
       +
       +/*
         * bell volume. It must be a value between -100 and 100. Use 0 for disabling
         * it
         */
   DIR diff --git a/patches/st-boxdraw_v2-0.8.2.diff b/patches/st-boxdraw_v2-0.8.2.diff
       @@ -0,0 +1,598 @@
       +From 318ae7fe1bd614cb937c8f43d855a1c2e8e93fd4 Mon Sep 17 00:00:00 2001
       +From: "Avi Halachmi (:avih)" <avihpit@yahoo.com>
       +Date: Wed, 26 Dec 2018 14:51:45 +0200
       +Subject: [PATCH] boxdraw_v2: custom render lines/blocks/braille for perfect
       + alignment
       +
       +It seems impossible to ensure that blocks and line drawing glyphs
       +align without visible gaps for all combinations of arbitrary font,
       +size and width/height scale factor.
       +
       +This commit adds options to render most of the lines/blocks and
       +braille codepoints without using the font such that they align
       +perfectly regardless of font, size or other configuration values.
       +
       +Supported codepoints are U+2500 - U+259F except dashes/diagonals,
       +and U28XX.
       +
       +The lines/blocks data is stored as 16-bit values at boxdraw_data.h
       +
       +boxdraw/braille are independent, disabled by default at config[.def].h
       +---
       + Makefile       |   3 +-
       + boxdraw.c      | 194 ++++++++++++++++++++++++++++++++++++++++++++
       + boxdraw_data.h | 214 +++++++++++++++++++++++++++++++++++++++++++++++++
       + config.def.h   |  12 +++
       + st.c           |   3 +
       + st.h           |  10 +++
       + x.c            |  21 +++--
       + 7 files changed, 451 insertions(+), 6 deletions(-)
       + create mode 100644 boxdraw.c
       + create mode 100644 boxdraw_data.h
       +
       +diff --git a/Makefile b/Makefile
       +index 470ac86..6dfa212 100644
       +--- a/Makefile
       ++++ b/Makefile
       +@@ -4,7 +4,7 @@
       + 
       + include config.mk
       + 
       +-SRC = st.c x.c
       ++SRC = st.c x.c boxdraw.c
       + OBJ = $(SRC:.c=.o)
       + 
       + all: options st
       +@@ -23,6 +23,7 @@ config.h:
       + 
       + st.o: config.h st.h win.h
       + x.o: arg.h config.h st.h win.h
       ++boxdraw.o: config.h st.h boxdraw_data.h
       + 
       + $(OBJ): config.h config.mk
       + 
       +diff --git a/boxdraw.c b/boxdraw.c
       +new file mode 100644
       +index 0000000..28a92d0
       +--- /dev/null
       ++++ b/boxdraw.c
       +@@ -0,0 +1,194 @@
       ++/*
       ++ * Copyright 2018 Avi Halachmi (:avih) avihpit@yahoo.com https://github.com/avih
       ++ * MIT/X Consortium License
       ++ */
       ++
       ++#include <X11/Xft/Xft.h>
       ++#include "st.h"
       ++#include "boxdraw_data.h"
       ++
       ++/* Rounded non-negative integers division of n / d  */
       ++#define DIV(n, d) (((n) + (d) / 2) / (d))
       ++
       ++static Display *xdpy;
       ++static Colormap xcmap;
       ++static XftDraw *xd;
       ++static Visual *xvis;
       ++
       ++static void drawbox(int, int, int, int, XftColor *, XftColor *, ushort);
       ++static void drawboxlines(int, int, int, int, XftColor *, ushort);
       ++
       ++/* public API */
       ++
       ++void
       ++boxdraw_xinit(Display *dpy, Colormap cmap, XftDraw *draw, Visual *vis)
       ++{
       ++        xdpy = dpy; xcmap = cmap; xd = draw, xvis = vis;
       ++}
       ++
       ++int
       ++isboxdraw(Rune u)
       ++{
       ++        Rune block = u & ~0xff;
       ++        return (boxdraw && block == 0x2500 && boxdata[(uint8_t)u]) ||
       ++               (boxdraw_braille && block == 0x2800);
       ++}
       ++
       ++/* the "index" is actually the entire shape data encoded as ushort */
       ++ushort
       ++boxdrawindex(const Glyph *g)
       ++{
       ++        if (boxdraw_braille && (g->u & ~0xff) == 0x2800)
       ++                return BRL | (uint8_t)g->u;
       ++        if (boxdraw_bold && (g->mode & ATTR_BOLD))
       ++                return BDB | boxdata[(uint8_t)g->u];
       ++        return boxdata[(uint8_t)g->u];
       ++}
       ++
       ++void
       ++drawboxes(int x, int y, int cw, int ch, XftColor *fg, XftColor *bg,
       ++          const XftGlyphFontSpec *specs, int len)
       ++{
       ++        for ( ; len-- > 0; x += cw, specs++)
       ++                drawbox(x, y, cw, ch, fg, bg, (ushort)specs->glyph);
       ++}
       ++
       ++/* implementation */
       ++
       ++void
       ++drawbox(int x, int y, int w, int h, XftColor *fg, XftColor *bg, ushort bd)
       ++{
       ++        ushort cat = bd & ~(BDB | 0xff);  /* mask out bold and data */
       ++        if (bd & (BDL | BDA)) {
       ++                /* lines (light/double/heavy/arcs) */
       ++                drawboxlines(x, y, w, h, fg, bd);
       ++
       ++        } else if (cat == BBD) {
       ++                /* lower (8-X)/8 block */
       ++                int d = DIV((uint8_t)bd * h, 8);
       ++                XftDrawRect(xd, fg, x, y + d, w, h - d);
       ++
       ++        } else if (cat == BBU) {
       ++                /* upper X/8 block */
       ++                XftDrawRect(xd, fg, x, y, w, DIV((uint8_t)bd * h, 8));
       ++
       ++        } else if (cat == BBL) {
       ++                /* left X/8 block */
       ++                XftDrawRect(xd, fg, x, y, DIV((uint8_t)bd * w, 8), h);
       ++
       ++        } else if (cat == BBR) {
       ++                /* right (8-X)/8 block */
       ++                int d = DIV((uint8_t)bd * w, 8);
       ++                XftDrawRect(xd, fg, x + d, y, w - d, h);
       ++
       ++        } else if (cat == BBQ) {
       ++                /* Quadrants */
       ++                int w2 = DIV(w, 2), h2 = DIV(h, 2);
       ++                if (bd & TL)
       ++                        XftDrawRect(xd, fg, x, y, w2, h2);
       ++                if (bd & TR)
       ++                        XftDrawRect(xd, fg, x + w2, y, w - w2, h2);
       ++                if (bd & BL)
       ++                        XftDrawRect(xd, fg, x, y + h2, w2, h - h2);
       ++                if (bd & BR)
       ++                        XftDrawRect(xd, fg, x + w2, y + h2, w - w2, h - h2);
       ++
       ++        } else if (bd & BBS) {
       ++                /* Shades - data is 1/2/3 for 25%/50%/75% alpha, respectively */
       ++                int d = (uint8_t)bd;
       ++                XftColor xfc;
       ++                XRenderColor xrc = { .alpha = 0xffff };
       ++
       ++                xrc.red = DIV(fg->color.red * d + bg->color.red * (4 - d), 4);
       ++                xrc.green = DIV(fg->color.green * d + bg->color.green * (4 - d), 4);
       ++                xrc.blue = DIV(fg->color.blue * d + bg->color.blue * (4 - d), 4);
       ++
       ++                XftColorAllocValue(xdpy, xvis, xcmap, &xrc, &xfc);
       ++                XftDrawRect(xd, &xfc, x, y, w, h);
       ++                XftColorFree(xdpy, xvis, xcmap, &xfc);
       ++
       ++        } else if (cat == BRL) {
       ++                /* braille, each data bit corresponds to one dot at 2x4 grid */
       ++                int w1 = DIV(w, 2);
       ++                int h1 = DIV(h, 4), h2 = DIV(h, 2), h3 = DIV(3 * h, 4);
       ++
       ++                if (bd & 1)   XftDrawRect(xd, fg, x, y, w1, h1);
       ++                if (bd & 2)   XftDrawRect(xd, fg, x, y + h1, w1, h2 - h1);
       ++                if (bd & 4)   XftDrawRect(xd, fg, x, y + h2, w1, h3 - h2);
       ++                if (bd & 8)   XftDrawRect(xd, fg, x + w1, y, w - w1, h1);
       ++                if (bd & 16)  XftDrawRect(xd, fg, x + w1, y + h1, w - w1, h2 - h1);
       ++                if (bd & 32)  XftDrawRect(xd, fg, x + w1, y + h2, w - w1, h3 - h2);
       ++                if (bd & 64)  XftDrawRect(xd, fg, x, y + h3, w1, h - h3);
       ++                if (bd & 128) XftDrawRect(xd, fg, x + w1, y + h3, w - w1, h - h3);
       ++
       ++        }
       ++}
       ++
       ++void
       ++drawboxlines(int x, int y, int w, int h, XftColor *fg, ushort bd)
       ++{
       ++        /* s: stem thickness. width/8 roughly matches underscore thickness. */
       ++        /* We draw bold as 1.5 * normal-stem and at least 1px thicker.      */
       ++        /* doubles draw at least 3px, even when w or h < 3. bold needs 6px. */
       ++        int mwh = MIN(w, h);
       ++        int base_s = MAX(1, DIV(mwh, 8));
       ++        int bold = (bd & BDB) && mwh >= 6;  /* possibly ignore boldness */
       ++        int s = bold ? MAX(base_s + 1, DIV(3 * base_s, 2)) : base_s;
       ++        int w2 = DIV(w - s, 2), h2 = DIV(h - s, 2);
       ++        /* the s-by-s square (x + w2, y + h2, s, s) is the center texel.    */
       ++        /* The base length (per direction till edge) includes this square.  */
       ++
       ++        int light = bd & (LL | LU | LR | LD);
       ++        int double_ = bd & (DL | DU | DR | DD);
       ++
       ++        if (light) {
       ++                /* d: additional (negative) length to not-draw the center   */
       ++                /* texel - at arcs and avoid drawing inside (some) doubles  */
       ++                int arc = bd & BDA;
       ++                int multi_light = light & (light - 1);
       ++                int multi_double = double_ & (double_ - 1);
       ++                /* light crosses double only at DH+LV, DV+LH (ref. shapes)  */
       ++                int d = arc || (multi_double && !multi_light) ? -s : 0;
       ++
       ++                if (bd & LL)
       ++                        XftDrawRect(xd, fg, x, y + h2, w2 + s + d, s);
       ++                if (bd & LU)
       ++                        XftDrawRect(xd, fg, x + w2, y, s, h2 + s + d);
       ++                if (bd & LR)
       ++                        XftDrawRect(xd, fg, x + w2 - d, y + h2, w - w2 + d, s);
       ++                if (bd & LD)
       ++                        XftDrawRect(xd, fg, x + w2, y + h2 - d, s, h - h2 + d);
       ++        }
       ++
       ++        /* double lines - also align with light to form heavy when combined */
       ++        if (double_) {
       ++                /*
       ++                * going clockwise, for each double-ray: p is additional length
       ++                * to the single-ray nearer to the previous direction, and n to
       ++                * the next. p and n adjust from the base length to lengths
       ++                * which consider other doubles - shorter to avoid intersections
       ++                * (p, n), or longer to draw the far-corner texel (n).
       ++                */
       ++                int dl = bd & DL, du = bd & DU, dr = bd & DR, dd = bd & DD;
       ++                if (dl) {
       ++                        int p = dd ? -s : 0, n = du ? -s : dd ? s : 0;
       ++                        XftDrawRect(xd, fg, x, y + h2 + s, w2 + s + p, s);
       ++                        XftDrawRect(xd, fg, x, y + h2 - s, w2 + s + n, s);
       ++                }
       ++                if (du) {
       ++                        int p = dl ? -s : 0, n = dr ? -s : dl ? s : 0;
       ++                        XftDrawRect(xd, fg, x + w2 - s, y, s, h2 + s + p);
       ++                        XftDrawRect(xd, fg, x + w2 + s, y, s, h2 + s + n);
       ++                }
       ++                if (dr) {
       ++                        int p = du ? -s : 0, n = dd ? -s : du ? s : 0;
       ++                        XftDrawRect(xd, fg, x + w2 - p, y + h2 - s, w - w2 + p, s);
       ++                        XftDrawRect(xd, fg, x + w2 - n, y + h2 + s, w - w2 + n, s);
       ++                }
       ++                if (dd) {
       ++                        int p = dr ? -s : 0, n = dl ? -s : dr ? s : 0;
       ++                        XftDrawRect(xd, fg, x + w2 + s, y + h2 - p, s, h - h2 + p);
       ++                        XftDrawRect(xd, fg, x + w2 - s, y + h2 - n, s, h - h2 + n);
       ++                }
       ++        }
       ++}
       +diff --git a/boxdraw_data.h b/boxdraw_data.h
       +new file mode 100644
       +index 0000000..7890500
       +--- /dev/null
       ++++ b/boxdraw_data.h
       +@@ -0,0 +1,214 @@
       ++/*
       ++ * Copyright 2018 Avi Halachmi (:avih) avihpit@yahoo.com https://github.com/avih
       ++ * MIT/X Consortium License
       ++ */
       ++
       ++/*
       ++ * U+25XX codepoints data
       ++ *
       ++ * References:
       ++ *   http://www.unicode.org/charts/PDF/U2500.pdf
       ++ *   http://www.unicode.org/charts/PDF/U2580.pdf
       ++ *
       ++ * Test page:
       ++ *   https://github.com/GNOME/vte/blob/master/doc/boxes.txt
       ++ */
       ++
       ++/* Each shape is encoded as 16-bits. Higher bits are category, lower are data */
       ++/* Categories (mutually exclusive except BDB): */
       ++/* For convenience, BDL/BDA/BBS/BDB are 1 bit each, the rest are enums */
       ++#define BDL (1<<8)   /* Box Draw Lines (light/double/heavy) */
       ++#define BDA (1<<9)   /* Box Draw Arc (light) */
       ++
       ++#define BBD (1<<10)  /* Box Block Down (lower) X/8 */
       ++#define BBL (2<<10)  /* Box Block Left X/8 */
       ++#define BBU (3<<10)  /* Box Block Upper X/8 */
       ++#define BBR (4<<10)  /* Box Block Right X/8 */
       ++#define BBQ (5<<10)  /* Box Block Quadrants */
       ++#define BRL (6<<10)  /* Box Braille (data is lower byte of U28XX) */
       ++
       ++#define BBS (1<<14)  /* Box Block Shades */
       ++#define BDB (1<<15)  /* Box Draw is Bold */
       ++
       ++/* (BDL/BDA) Light/Double/Heavy x Left/Up/Right/Down/Horizontal/Vertical      */
       ++/* Heavy is light+double (literally drawing light+double align to form heavy) */
       ++#define LL (1<<0)
       ++#define LU (1<<1)
       ++#define LR (1<<2)
       ++#define LD (1<<3)
       ++#define LH (LL+LR)
       ++#define LV (LU+LD)
       ++
       ++#define DL (1<<4)
       ++#define DU (1<<5)
       ++#define DR (1<<6)
       ++#define DD (1<<7)
       ++#define DH (DL+DR)
       ++#define DV (DU+DD)
       ++
       ++#define HL (LL+DL)
       ++#define HU (LU+DU)
       ++#define HR (LR+DR)
       ++#define HD (LD+DD)
       ++#define HH (HL+HR)
       ++#define HV (HU+HD)
       ++
       ++/* (BBQ) Quadrants Top/Bottom x Left/Right */
       ++#define TL (1<<0)
       ++#define TR (1<<1)
       ++#define BL (1<<2)
       ++#define BR (1<<3)
       ++
       ++/* Data for U+2500 - U+259F except dashes/diagonals */
       ++static const unsigned short boxdata[256] = {
       ++        /* light lines */
       ++        [0x00] = BDL + LH,       /* light horizontal */
       ++        [0x02] = BDL + LV,       /* light vertical */
       ++        [0x0c] = BDL + LD + LR,  /* light down and right */
       ++        [0x10] = BDL + LD + LL,  /* light down and left */
       ++        [0x14] = BDL + LU + LR,  /* light up and right */
       ++        [0x18] = BDL + LU + LL,  /* light up and left */
       ++        [0x1c] = BDL + LV + LR,  /* light vertical and right */
       ++        [0x24] = BDL + LV + LL,  /* light vertical and left */
       ++        [0x2c] = BDL + LH + LD,  /* light horizontal and down */
       ++        [0x34] = BDL + LH + LU,  /* light horizontal and up */
       ++        [0x3c] = BDL + LV + LH,  /* light vertical and horizontal */
       ++        [0x74] = BDL + LL,       /* light left */
       ++        [0x75] = BDL + LU,       /* light up */
       ++        [0x76] = BDL + LR,       /* light right */
       ++        [0x77] = BDL + LD,       /* light down */
       ++
       ++        /* heavy [+light] lines */
       ++        [0x01] = BDL + HH,
       ++        [0x03] = BDL + HV,
       ++        [0x0d] = BDL + HR + LD,
       ++        [0x0e] = BDL + HD + LR,
       ++        [0x0f] = BDL + HD + HR,
       ++        [0x11] = BDL + HL + LD,
       ++        [0x12] = BDL + HD + LL,
       ++        [0x13] = BDL + HD + HL,
       ++        [0x15] = BDL + HR + LU,
       ++        [0x16] = BDL + HU + LR,
       ++        [0x17] = BDL + HU + HR,
       ++        [0x19] = BDL + HL + LU,
       ++        [0x1a] = BDL + HU + LL,
       ++        [0x1b] = BDL + HU + HL,
       ++        [0x1d] = BDL + HR + LV,
       ++        [0x1e] = BDL + HU + LD + LR,
       ++        [