Fix glyph positioning for multibyte characters.

Author: s4y

src/MacVim/MMCoreTextView.m

@@ -706,26 +706,34 @@ - (void)drawRect:(NSRect)rect
 
         __block NSMutableString *lineString = nil;
         __block CGFloat lineStringStart = 0;
+        __block CFRange lineStringRange;
         __block GridCell lastStringCell;
         void (^flushLineString)() = ^{
             if (!lineString.length)
                 return;
-            CTLineRef line = [self lineForCharacterString:lineString textFlags:lastStringCell.textFlags];
-            CGFloat width = cellSize.width * (lastStringCell.textFlags & DRAW_WIDE ? 2 : 1);
+            CGPoint positionsByIndex[lineString.length];
+            for (size_t i = 0, stringIndex = 0; i < lineStringRange.length; i++) {
+                GridCell cell = *grid_cell(&grid, r, lineStringRange.location + i);
+                size_t cell_length = cell.string.length;
+                for (size_t j = 0; j < cell_length; j++)
+                    positionsByIndex[stringIndex++] = CGPointMake(i * cellSize.width, 0);
+                if (cell.textFlags & DRAW_WIDE)
+                    i++;
+            }
             CGContextSetFillColor(ctx, COMPONENTS(lastStringCell.fg));
             CGContextSetTextPosition(ctx, lineStringStart, rowRect.origin.y + fontDescent);
             CGContextSetBlendMode(ctx, kCGBlendModeNormal);
+            CTLineRef line = [self lineForCharacterString:lineString textFlags:lastStringCell.textFlags];
             for (id obj in (NSArray*)CTLineGetGlyphRuns(line)) {
                 CTRunRef run = (CTRunRef)obj;
                 CFIndex glyphCount = CTRunGetGlyphCount(run);
                 CFIndex indices[glyphCount];
                 CGPoint positions[glyphCount];
                 CGGlyph glyphs[glyphCount];
                 CTRunGetStringIndices(run, CFRangeMake(0, 0), indices);
-                CTRunGetPositions(run, CFRangeMake(0, 0), positions);
                 CTRunGetGlyphs(run, CFRangeMake(0, 0), glyphs);
                 for (CFIndex i = 0; i < glyphCount; i++)
-                    positions[i].x = indices[i] * width;
+                    positions[i] = positionsByIndex[indices[i]];
                 CTFontRef font = CFDictionaryGetValue(CTRunGetAttributes(run), kCTFontAttributeName);
                 CTFontDrawGlyphs(font, glyphs, positions, glyphCount, ctx);
             }
@@ -735,10 +743,8 @@ - (void)drawRect:(NSRect)rect
         for (size_t c = 0; c < grid.cols; c++) {
             GridCell cell = *grid_cell(&grid, r, c);
             CGRect cellRect = {{rowRect.origin.x + cellSize.width * c, rowRect.origin.y}, cellSize};
-            if (cell.textFlags & DRAW_WIDE) {
+            if (cell.textFlags & DRAW_WIDE)
                 cellRect.size.width *= 2;
-                c++;
-            }
             if (cell.inverted) {
                 cell.bg ^= 0xFFFFFF;
                 cell.fg ^= 0xFFFFFF;
@@ -793,13 +799,18 @@ - (void)drawRect:(NSRect)rect
                     flushLineString();
                 if (!lineString)
                     lineString = [[NSMutableString alloc] init];
-                if (!lineString.length)
+                if (!lineString.length) {
                     lineStringStart = cellRect.origin.x;
+                    lineStringRange = CFRangeMake(c, 1);
+                }
                 [lineString appendString:cell.string];
+                lineStringRange.length = c - lineStringRange.location + 1;
                 lastStringCell = cell;
             } else {
                 flushLineString();
             }
+            if (cell.textFlags & DRAW_WIDE)
+                c++;
         }
         flushLineString();
         [lineString release];