diff options
Diffstat (limited to 'boxdraw.c')
| -rw-r--r-- | boxdraw.c | 194 |
1 files changed, 194 insertions, 0 deletions
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); + } + } +} |