drw.c

@@ -9,40 +9,54 @@
 #include "util.h"
 
 #define UTF_INVALID 0xFFFD
+#define UTF_SIZ     4
 
-static int
-utf8decode(const char *s_in, long *u, int *err)
+static const unsigned char utfbyte[UTF_SIZ + 1] = {0x80,    0, 0xC0, 0xE0, 0xF0};
+static const unsigned char utfmask[UTF_SIZ + 1] = {0xC0, 0x80, 0xE0, 0xF0, 0xF8};
+static const long utfmin[UTF_SIZ + 1] = {       0,    0,  0x80,  0x800,  0x10000};
+static const long utfmax[UTF_SIZ + 1] = {0x10FFFF, 0x7F, 0x7FF, 0xFFFF, 0x10FFFF};
+
+static long
+utf8decodebyte(const char c, size_t *i)
 {
-	static const unsigned char lens[] = {
-		/* 0XXXX */ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
-		/* 10XXX */ 0, 0, 0, 0, 0, 0, 0, 0,  /* invalid */
-		/* 110XX */ 2, 2, 2, 2,
-		/* 1110X */ 3, 3,
-		/* 11110 */ 4,
-		/* 11111 */ 0,  /* invalid */
-	};
-	static const unsigned char leading_mask[] = { 0x7F, 0x1F, 0x0F, 0x07 };
-	static const unsigned int overlong[] = { 0x0, 0x80, 0x0800, 0x10000 };
-
-	const unsigned char *s = (const unsigned char *)s_in;
-	int len = lens[*s >> 3];
-	*u = UTF_INVALID;
-	*err = 1;
-	if (len == 0)
-		return 1;
-
-	long cp = s[0] & leading_mask[len - 1];
-	for (int i = 1; i < len; ++i) {
-		if (s[i] == '\0' || (s[i] & 0xC0) != 0x80)
-			return i;
-		cp = (cp << 6) | (s[i] & 0x3F);
+	for (*i = 0; *i < (UTF_SIZ + 1); ++(*i))
+		if (((unsigned char)c & utfmask[*i]) == utfbyte[*i])
+			return (unsigned char)c & ~utfmask[*i];
+	return 0;
 }
-	/* out of range, surrogate, overlong encoding */
-	if (cp > 0x10FFFF || (cp >> 11) == 0x1B || cp < overlong[len - 1])
-		return len;
 
-	*err = 0;
-	*u = cp;
+static size_t
+utf8validate(long *u, size_t i)
+{
+	if (!BETWEEN(*u, utfmin[i], utfmax[i]) || BETWEEN(*u, 0xD800, 0xDFFF))
+		*u = UTF_INVALID;
+	for (i = 1; *u > utfmax[i]; ++i)
+		;
+	return i;
+}
+
+static size_t
+utf8decode(const char *c, long *u, size_t clen)
+{
+	size_t i, j, len, type;
+	long udecoded;
+
+	*u = UTF_INVALID;
+	if (!clen)
+		return 0;
+	udecoded = utf8decodebyte(c[0], &len);
+	if (!BETWEEN(len, 1, UTF_SIZ))
+		return 1;
+	for (i = 1, j = 1; i < clen && j < len; ++i, ++j) {
+		udecoded = (udecoded << 6) | utf8decodebyte(c[i], &type);
+		if (type)
+			return j;
+	}
+	if (j < len)
+		return 0;
+	*u = udecoded;
+	utf8validate(u, len);
+
 	return len;
 }
 
@@ -228,7 +242,7 @@ drw_text(Drw *drw, int x, int y, unsigned int w, unsigned int h, unsigned int lp
 	unsigned int tmpw, ew, ellipsis_w = 0, ellipsis_len, hash, h0, h1;
 	XftDraw *d = NULL;
 	Fnt *usedfont, *curfont, *nextfont;
-	int utf8strlen, utf8charlen, utf8err, render = x || y || w || h;
+	int utf8strlen, utf8charlen, render = x || y || w || h;
 	long utf8codepoint = 0;
 	const char *utf8str;
 	FcCharSet *fccharset;
@@ -237,8 +251,7 @@ drw_text(Drw *drw, int x, int y, unsigned int w, unsigned int h, unsigned int lp
 	XftResult result;
 	int charexists = 0, overflow = 0;
 	/* keep track of a couple codepoints for which we have no match. */
-	static unsigned int nomatches[128], ellipsis_width, invalid_width;
-	static const char invalid[] = "<EFBFBD>";
+	static unsigned int nomatches[128], ellipsis_width;
 
 	if (!drw || (render && (!drw->scheme || !w)) || !text || !drw->fonts)
 		return 0;
@@ -258,14 +271,12 @@ drw_text(Drw *drw, int x, int y, unsigned int w, unsigned int h, unsigned int lp
 	usedfont = drw->fonts;
 	if (!ellipsis_width && render)
 		ellipsis_width = drw_fontset_getwidth(drw, "...");
-	if (!invalid_width && render)
-		invalid_width = drw_fontset_getwidth(drw, invalid);
 	while (1) {
-		ew = ellipsis_len = utf8err = utf8charlen = utf8strlen = 0;
+		ew = ellipsis_len = utf8strlen = 0;
 		utf8str = text;
 		nextfont = NULL;
 		while (*text) {
-			utf8charlen = utf8decode(text, &utf8codepoint, &utf8err);
+			utf8charlen = utf8decode(text, &utf8codepoint, UTF_SIZ);
 			for (curfont = drw->fonts; curfont; curfont = curfont->next) {
 				charexists = charexists || XftCharExists(drw->dpy, curfont->xfont, utf8codepoint);
 				if (charexists) {
@@ -287,9 +298,9 @@ drw_text(Drw *drw, int x, int y, unsigned int w, unsigned int h, unsigned int lp
 						else
 							utf8strlen = ellipsis_len;
 					} else if (curfont == usedfont) {
+						utf8strlen += utf8charlen;
 						text += utf8charlen;
-						utf8strlen += utf8err ? 0 : utf8charlen;
-						ew += utf8err ? 0 : tmpw;
+						ew += tmpw;
 					} else {
 						nextfont = curfont;
 					}
@@ -297,7 +308,7 @@ drw_text(Drw *drw, int x, int y, unsigned int w, unsigned int h, unsigned int lp
 				}
 			}
 
-			if (overflow || !charexists || nextfont || utf8err)
+			if (overflow || !charexists || nextfont)
 				break;
 			else
 				charexists = 0;
@@ -312,12 +323,6 @@ drw_text(Drw *drw, int x, int y, unsigned int w, unsigned int h, unsigned int lp
 			x += ew;
 			w -= ew;
 		}
-		if (utf8err && (!render || invalid_width < w)) {
-			if (render)
-				drw_text(drw, x, y, w, h, 0, invalid, invert);
-			x += invalid_width;
-			w -= invalid_width;
-		}
 		if (render && overflow)
 			drw_text(drw, ellipsis_x, y, ellipsis_w, h, 0, "...", invert);