Fixed bug 2976767 on corrupted char glyphs.

After unfinished translation of the game, several inaccessible characters
have been left in the game files.  Since the font does not contain all 256
characters, trying to draw them brings them random jump.  I now properly
skip these characters.

svn-id: r48462

1 files changed, 15 insertions, 10 deletions

diff --git a/engines/draci/font.cpp b/engines/draci/font.cpp
index b9231bb237..688458f3d4 100644
--- a/engines/draci/font.cpp
+++ b/engines/draci/font.cpp
@@ -108,7 +108,12 @@ void Font::freeFont() {
 }
 
 uint8 Font::getCharWidth(uint8 chr) const {
-	return _charWidths[chr - kCharIndexOffset];
+	// Safe-guard against incorrect strings containing localized characters
+	// with inaccessible codes.  These strings do not exist in the original
+	// Czech version, but they do in the (never properly reviewed) English
+	// version.
+	return chr >= kCharIndexOffset && chr < kCharIndexOffset + kCharNum
+		? _charWidths[chr - kCharIndexOffset] : 0;
 }
 
 /**
@@ -126,9 +131,13 @@ void Font::drawChar(Surface *dst, uint8 chr, int tx, int ty, int with_colour) co
 	assert(ty >= 0);
 
 	byte *ptr = (byte *)dst->getBasePtr(tx, ty);
-	uint8 charIndex = chr - kCharIndexOffset;
-	int charOffset = charIndex * _fontHeight * _maxCharWidth;
-	uint8 currentWidth = _charWidths[charIndex];
+	const uint8 currentWidth = getCharWidth(chr);
+	if (currentWidth == 0) {
+		return;
+	}
+
+	const uint8 charIndex = chr - kCharIndexOffset;
+	const int charOffset = charIndex * _fontHeight * _maxCharWidth;
 
 	// Determine how many pixels to draw horizontally (to prevent overflow)
 	int xSpaceLeft = dst->w - tx - 1;
@@ -256,9 +265,7 @@ uint Font::getStringWidth(const Common::String &str, int spacing) const {
 	for (uint i = 0, tmp = 0; i < len; ++i) {
 
 		if (str[i] != '|') {
-			uint8 charIndex = str[i] - kCharIndexOffset;
-			tmp += _charWidths[charIndex];
-			tmp += spacing;
+			tmp += getCharWidth(str[i]) + spacing;
 		}
 
 		// Newline char encountered, skip it and store the new length if it is greater.
@@ -291,9 +298,7 @@ uint Font::getLineWidth(const Common::String &str, uint startIndex, int spacing)
 			break;
 
 		// Add width of the current char
-		uint8 charIndex = str[i] - kCharIndexOffset;
-		width += _charWidths[charIndex];
-		width += spacing;
+		width += getCharWidth(str[i]) + spacing;
 	}
 
 	return width;