Apply boxdraw patch

4 files changed, 605 insertions, 1 deletions

diff --git a/Makefile b/Makefile
index ec2781d..6fdd0c6 100644
--- a/Makefile
+++ b/Makefile
@@ -4,7 +4,7 @@
 
 include config.mk
 
-SRC = st.c x.c
+SRC = st.c x.c boxdraw.c hb.c
 OBJ = $(SRC:.c=.o)
 
 all: options st
@@ -15,11 +15,15 @@ options:
 	@echo "LDFLAGS = $(STLDFLAGS)"
 	@echo "CC      = $(CC)"
 
+config.h:
+	cp config.def.h config.h
+
 .c.o:
 	$(CC) $(STCFLAGS) -c $<
 
 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..e69de29
--- /dev/null
+++ b/boxdraw.c
diff --git a/boxdraw_data.h b/boxdraw_data.h
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/boxdraw_data.h
diff --git a/patches/st-boxdraw_v2-0.8.3.diff b/patches/st-boxdraw_v2-0.8.3.diff
new file mode 100644
index 0000000..04a868c
--- /dev/null
+++ b/patches/st-boxdraw_v2-0.8.3.diff
@@ -0,0 +1,600 @@
+From 3f3b80b9966c60086f4ed80ce4de0cbf03468d36 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,
++	[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) */
++};
+diff --git a/config.def.h b/config.def.h
+index 0895a1f..bf6718b 100644
+--- a/config.def.h
++++ b/config.def.h
+@@ -58,6 +58,18 @@ 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
+diff --git a/st.c b/st.c
+index 0ce6ac2..c035e19 100644
+--- a/st.c
++++ b/st.c
+@@ -1230,6 +1230,9 @@ tsetchar(Rune u, Glyph *attr, int x, int y)
+ 	term.dirty[y] = 1;
+ 	term.line[y][x] = *attr;
+ 	term.line[y][x].u = u;
++
++	if (isboxdraw(u))
++		term.line[y][x].mode |= ATTR_BOXDRAW;
+ }
+ 
+ void
+diff --git a/st.h b/st.h
+index d978458..a6c382a 100644
+--- a/st.h
++++ b/st.h
+@@ -33,6 +33,7 @@ enum glyph_attribute {
+ 	ATTR_WRAP       = 1 << 8,
+ 	ATTR_WIDE       = 1 << 9,
+ 	ATTR_WDUMMY     = 1 << 10,
++	ATTR_BOXDRAW    = 1 << 11,
+ 	ATTR_BOLD_FAINT = ATTR_BOLD | ATTR_FAINT,
+ };
+ 
+@@ -111,6 +112,14 @@ void *xmalloc(size_t);
+ void *xrealloc(void *, size_t);
+ char *xstrdup(char *);
+ 
++int isboxdraw(Rune);
++ushort boxdrawindex(const Glyph *);
++#ifdef XFT_VERSION
++/* only exposed to x.c, otherwise we'll need Xft.h for the types */
++void boxdraw_xinit(Display *, Colormap, XftDraw *, Visual *);
++void drawboxes(int, int, int, int, XftColor *, XftColor *, const XftGlyphFontSpec *, int);
++#endif
++
+ /* config.h globals */
+ extern char *utmp;
+ extern char *scroll;
+@@ -122,3 +131,4 @@ extern char *termname;
+ extern unsigned int tabspaces;
+ extern unsigned int defaultfg;
+ extern unsigned int defaultbg;
++extern const int boxdraw, boxdraw_bold, boxdraw_braille;
+diff --git a/x.c b/x.c
+index e5f1737..6f7ea2c 100644
+--- a/x.c
++++ b/x.c
+@@ -1205,6 +1205,8 @@ xinit(int cols, int rows)
+ 	xsel.xtarget = XInternAtom(xw.dpy, "UTF8_STRING", 0);
+ 	if (xsel.xtarget == None)
+ 		xsel.xtarget = XA_STRING;
++
++	boxdraw_xinit(xw.dpy, xw.cmap, xw.draw, xw.vis);
+ }
+ 
+ int
+@@ -1251,8 +1253,13 @@ xmakeglyphfontspecs(XftGlyphFontSpec *specs, const Glyph *glyphs, int len, int x
+ 			yp = winy + font->ascent;
+ 		}
+ 
+-		/* Lookup character index with default font. */
+-		glyphidx = XftCharIndex(xw.dpy, font->match, rune);
++		if (mode & ATTR_BOXDRAW) {
++			/* minor shoehorning: boxdraw uses only this ushort */
++			glyphidx = boxdrawindex(&glyphs[i]);
++		} else {
++			/* Lookup character index with default font. */
++			glyphidx = XftCharIndex(xw.dpy, font->match, rune);
++		}
+ 		if (glyphidx) {
+ 			specs[numspecs].font = font->match;
+ 			specs[numspecs].glyph = glyphidx;
+@@ -1456,8 +1463,12 @@ xdrawglyphfontspecs(const XftGlyphFontSpec *specs, Glyph base, int len, int x, i
+ 	r.width = width;
+ 	XftDrawSetClipRectangles(xw.draw, winx, winy, &r, 1);
+ 
+-	/* Render the glyphs. */
+-	XftDrawGlyphFontSpec(xw.draw, fg, specs, len);
++	if (base.mode & ATTR_BOXDRAW) {
++		drawboxes(winx, winy, width / len, win.ch, fg, bg, specs, len);
++	} else {
++		/* Render the glyphs. */
++		XftDrawGlyphFontSpec(xw.draw, fg, specs, len);
++	}
+ 
+ 	/* Render underline and strikethrough. */
+ 	if (base.mode & ATTR_UNDERLINE) {
+@@ -1500,7 +1511,7 @@ xdrawcursor(int cx, int cy, Glyph g, int ox, int oy, Glyph og)
+ 	/*
+ 	 * Select the right color for the right mode.
+ 	 */
+-	g.mode &= ATTR_BOLD|ATTR_ITALIC|ATTR_UNDERLINE|ATTR_STRUCK|ATTR_WIDE;
++	g.mode &= ATTR_BOLD|ATTR_ITALIC|ATTR_UNDERLINE|ATTR_STRUCK|ATTR_WIDE|ATTR_BOXDRAW;
+ 
+ 	if (IS_SET(MODE_REVERSE)) {
+ 		g.mode |= ATTR_REVERSE;
+
+base-commit: 43a395ae91f7d67ce694e65edeaa7bbc720dd027
+-- 
+2.20.1
+