boxdraw.c (6194B)
1 /* 2 * Copyright 2018 Avi Halachmi (:avih) avihpit@yahoo.com https://github.com/avih 3 * MIT/X Consortium License 4 */ 5 6 #include <X11/Xft/Xft.h> 7 8 /* Rounded non-negative integers division of n / d */ 9 #define DIV(n, d) (((n) + (d) / 2) / (d)) 10 11 static Display *xdpy; 12 static Colormap xcmap; 13 static XftDraw *xd; 14 static Visual *xvis; 15 16 static void drawbox(int, int, int, int, XftColor *, XftColor *, ushort); 17 static void drawboxlines(int, int, int, int, XftColor *, ushort); 18 19 /* public API */ 20 21 void 22 boxdraw_xinit(Display *dpy, Colormap cmap, XftDraw *draw, Visual *vis) 23 { 24 xdpy = dpy; xcmap = cmap; xd = draw, xvis = vis; 25 } 26 27 int 28 isboxdraw(Rune u) 29 { 30 Rune block = u & ~0xff; 31 return (boxdraw && block == 0x2500 && boxdata[(uint8_t)u]) || 32 (boxdraw_braille && block == 0x2800); 33 } 34 35 /* the "index" is actually the entire shape data encoded as ushort */ 36 ushort 37 boxdrawindex(const Glyph *g) 38 { 39 if (boxdraw_braille && (g->u & ~0xff) == 0x2800) 40 return BRL | (uint8_t)g->u; 41 if (boxdraw_bold && (g->mode & ATTR_BOLD)) 42 return BDB | boxdata[(uint8_t)g->u]; 43 return boxdata[(uint8_t)g->u]; 44 } 45 46 void 47 drawboxes(int x, int y, int cw, int ch, XftColor *fg, XftColor *bg, 48 const XftGlyphFontSpec *specs, int len) 49 { 50 for ( ; len-- > 0; x += cw, specs++) 51 drawbox(x, y, cw, ch, fg, bg, (ushort)specs->glyph); 52 } 53 54 /* implementation */ 55 56 void 57 drawbox(int x, int y, int w, int h, XftColor *fg, XftColor *bg, ushort bd) 58 { 59 ushort cat = bd & ~(BDB | 0xff); /* mask out bold and data */ 60 if (bd & (BDL | BDA)) { 61 /* lines (light/double/heavy/arcs) */ 62 drawboxlines(x, y, w, h, fg, bd); 63 64 } else if (cat == BBD) { 65 /* lower (8-X)/8 block */ 66 int d = DIV((uint8_t)bd * h, 8); 67 XftDrawRect(xd, fg, x, y + d, w, h - d); 68 69 } else if (cat == BBU) { 70 /* upper X/8 block */ 71 XftDrawRect(xd, fg, x, y, w, DIV((uint8_t)bd * h, 8)); 72 73 } else if (cat == BBL) { 74 /* left X/8 block */ 75 XftDrawRect(xd, fg, x, y, DIV((uint8_t)bd * w, 8), h); 76 77 } else if (cat == BBR) { 78 /* right (8-X)/8 block */ 79 int d = DIV((uint8_t)bd * w, 8); 80 XftDrawRect(xd, fg, x + d, y, w - d, h); 81 82 } else if (cat == BBQ) { 83 /* Quadrants */ 84 int w2 = DIV(w, 2), h2 = DIV(h, 2); 85 if (bd & TL) 86 XftDrawRect(xd, fg, x, y, w2, h2); 87 if (bd & TR) 88 XftDrawRect(xd, fg, x + w2, y, w - w2, h2); 89 if (bd & BL) 90 XftDrawRect(xd, fg, x, y + h2, w2, h - h2); 91 if (bd & BR) 92 XftDrawRect(xd, fg, x + w2, y + h2, w - w2, h - h2); 93 94 } else if (bd & BBS) { 95 /* Shades - data is 1/2/3 for 25%/50%/75% alpha, respectively */ 96 int d = (uint8_t)bd; 97 XftColor xfc; 98 XRenderColor xrc = { .alpha = 0xffff }; 99 100 xrc.red = DIV(fg->color.red * d + bg->color.red * (4 - d), 4); 101 xrc.green = DIV(fg->color.green * d + bg->color.green * (4 - d), 4); 102 xrc.blue = DIV(fg->color.blue * d + bg->color.blue * (4 - d), 4); 103 104 XftColorAllocValue(xdpy, xvis, xcmap, &xrc, &xfc); 105 XftDrawRect(xd, &xfc, x, y, w, h); 106 XftColorFree(xdpy, xvis, xcmap, &xfc); 107 108 } else if (cat == BRL) { 109 /* braille, each data bit corresponds to one dot at 2x4 grid */ 110 int w1 = DIV(w, 2); 111 int h1 = DIV(h, 4), h2 = DIV(h, 2), h3 = DIV(3 * h, 4); 112 113 if (bd & 1) XftDrawRect(xd, fg, x, y, w1, h1); 114 if (bd & 2) XftDrawRect(xd, fg, x, y + h1, w1, h2 - h1); 115 if (bd & 4) XftDrawRect(xd, fg, x, y + h2, w1, h3 - h2); 116 if (bd & 8) XftDrawRect(xd, fg, x + w1, y, w - w1, h1); 117 if (bd & 16) XftDrawRect(xd, fg, x + w1, y + h1, w - w1, h2 - h1); 118 if (bd & 32) XftDrawRect(xd, fg, x + w1, y + h2, w - w1, h3 - h2); 119 if (bd & 64) XftDrawRect(xd, fg, x, y + h3, w1, h - h3); 120 if (bd & 128) XftDrawRect(xd, fg, x + w1, y + h3, w - w1, h - h3); 121 122 } 123 } 124 125 void 126 drawboxlines(int x, int y, int w, int h, XftColor *fg, ushort bd) 127 { 128 /* s: stem thickness. width/8 roughly matches underscore thickness. */ 129 /* We draw bold as 1.5 * normal-stem and at least 1px thicker. */ 130 /* doubles draw at least 3px, even when w or h < 3. bold needs 6px. */ 131 int mwh = MIN(w, h); 132 int base_s = MAX(1, DIV(mwh, 8)); 133 int bold = (bd & BDB) && mwh >= 6; /* possibly ignore boldness */ 134 int s = bold ? MAX(base_s + 1, DIV(3 * base_s, 2)) : base_s; 135 int w2 = DIV(w - s, 2), h2 = DIV(h - s, 2); 136 /* the s-by-s square (x + w2, y + h2, s, s) is the center texel. */ 137 /* The base length (per direction till edge) includes this square. */ 138 139 int light = bd & (LL | LU | LR | LD); 140 int double_ = bd & (DL | DU | DR | DD); 141 142 if (light) { 143 /* d: additional (negative) length to not-draw the center */ 144 /* texel - at arcs and avoid drawing inside (some) doubles */ 145 int arc = bd & BDA; 146 int multi_light = light & (light - 1); 147 int multi_double = double_ & (double_ - 1); 148 /* light crosses double only at DH+LV, DV+LH (ref. shapes) */ 149 int d = arc || (multi_double && !multi_light) ? -s : 0; 150 151 if (bd & LL) 152 XftDrawRect(xd, fg, x, y + h2, w2 + s + d, s); 153 if (bd & LU) 154 XftDrawRect(xd, fg, x + w2, y, s, h2 + s + d); 155 if (bd & LR) 156 XftDrawRect(xd, fg, x + w2 - d, y + h2, w - w2 + d, s); 157 if (bd & LD) 158 XftDrawRect(xd, fg, x + w2, y + h2 - d, s, h - h2 + d); 159 } 160 161 /* double lines - also align with light to form heavy when combined */ 162 if (double_) { 163 /* 164 * going clockwise, for each double-ray: p is additional length 165 * to the single-ray nearer to the previous direction, and n to 166 * the next. p and n adjust from the base length to lengths 167 * which consider other doubles - shorter to avoid intersections 168 * (p, n), or longer to draw the far-corner texel (n). 169 */ 170 int dl = bd & DL, du = bd & DU, dr = bd & DR, dd = bd & DD; 171 if (dl) { 172 int p = dd ? -s : 0, n = du ? -s : dd ? s : 0; 173 XftDrawRect(xd, fg, x, y + h2 + s, w2 + s + p, s); 174 XftDrawRect(xd, fg, x, y + h2 - s, w2 + s + n, s); 175 } 176 if (du) { 177 int p = dl ? -s : 0, n = dr ? -s : dl ? s : 0; 178 XftDrawRect(xd, fg, x + w2 - s, y, s, h2 + s + p); 179 XftDrawRect(xd, fg, x + w2 + s, y, s, h2 + s + n); 180 } 181 if (dr) { 182 int p = du ? -s : 0, n = dd ? -s : du ? s : 0; 183 XftDrawRect(xd, fg, x + w2 - p, y + h2 - s, w - w2 + p, s); 184 XftDrawRect(xd, fg, x + w2 - n, y + h2 + s, w - w2 + n, s); 185 } 186 if (dd) { 187 int p = dr ? -s : 0, n = dl ? -s : dr ? s : 0; 188 XftDrawRect(xd, fg, x + w2 + s, y + h2 - p, s, h - h2 + p); 189 XftDrawRect(xd, fg, x + w2 - s, y + h2 - n, s, h - h2 + n); 190 } 191 } 192 }