optimize rendering

vi.c

@@ -31,12 +31,24 @@ static struct {
 	{L'Y', {L'Ý', L'Ỳ', L'Ỷ', L'Ỹ', L'Ỵ'}},
 };
 
-static int tonetab[128] = {
-	['s'] = 1, ['f'] = 2, ['r'] = 3, ['x'] = 4, ['j'] = 5,
-};
+static int
+istone(Rune c)
+{
+	return c == 's' || c == 'f' || c == 'r' || c == 'x' || c == 'j';
+}
 
-#define Istone(c)	((c) < 128 && tonetab[(c)] > 0)
-#define Toneidx(c)	(tonetab[(c)] - 1)
+static int
+toneidx(Rune c)
+{
+	switch(c){
+	case 's': return 0;
+	case 'f': return 1;
+	case 'r': return 2;
+	case 'x': return 3;
+	case 'j': return 4;
+	}
+	return -1;
+}
 
 static int
 isvowel(Rune c)
@@ -85,7 +97,7 @@ transvi(Im *im, Rune c)
 	int i, tidx, vi, last, penult;
 	Rune v, b1, b2;
 
-	if(!Istone(c) && c != 'z')
+	if(!istone(c) && c != 'z')
 		return transmap(im, c);
 
 	memset(&e, 0, sizeof e);
@@ -139,7 +151,7 @@ transvi(Im *im, Rune c)
 	if(c == 'z')
 		mapped.r[vi] = removetone(mapped.r[vi]);
 	else{
-		tidx = Toneidx(c);
+		tidx = toneidx(c);
 		mapped.r[vi] = applytone(mapped.r[vi], tidx);
 	}
 	e.eat = 1;