Text: Character hit test vs. clusters

When multiple codepoints are in the same cluster, the hit test should only consider the first codepoint of the cluster, or otherwise the cursor is positioned somewhere in the middle of the cluster and not at the start.

1 files changed, 6 insertions, 5 deletions

diff --git a/src/ui/text.c b/src/ui/text.c
index a499d293..006a4d0b 100644
--- a/src/ui/text.c
+++ b/src/ui/text.c
@@ -1433,7 +1433,6 @@ static iRect run_Font_(iFont *d, const iRunArgs *args) {
     iBool        isFirst            = iTrue;
     const iBool  checkHitPoint      = wrap && !isEqual_I2(wrap->hitPoint, zero_I2());
     const iBool  checkHitChar       = wrap && wrap->hitChar;
-    //iBool        wasCharHit         = iFalse;
     while (!isEmpty_Range(&wrapRuns)) {
         if (isFirst) {
             isFirst = iFalse;
@@ -1447,15 +1446,16 @@ static iRect run_Font_(iFont *d, const iRunArgs *args) {
         if (wrap && (wrap->maxWidth > 0 || checkHitPoint)) {
             const iBool isHitPointOnThisLine = (checkHitPoint && wrap->hitPoint.y >= orig.y + yCursor &&
                                                 wrap->hitPoint.y < orig.y + yCursor + d->height);
+            iBool wasCharHit = iFalse; /* on this line */
             float breakAdvance = -1.0f;
             iAssert(wrapPosRange.end == textLen);
             /* Determine ends of wrapRuns and wrapVisRange. */
             for (size_t runIndex = wrapRuns.start; runIndex < wrapRuns.end; runIndex++) {
                 const iAttributedRun *run = at_Array(&attrText.runs, runIndex);
                 if (run->flags.isLineBreak) {
-                    if (checkHitChar && wrap->hitChar == sourcePtr_AttributedText_(&attrText, run->logical.start)) {
+                    if (checkHitChar &&
+                        wrap->hitChar == sourcePtr_AttributedText_(&attrText, run->logical.start)) {
                         wrap->hitAdvance_out = init_I2(wrapAdvance, yCursor);
-//                        wasCharHit = iTrue;
                     }
                     wrapPosRange.end   = run->logical.start;
                     wrapResumePos      = run->logical.end;
@@ -1479,9 +1479,10 @@ static iRect run_Font_(iFont *d, const iRunArgs *args) {
                     if (logPos < wrapPosRange.start || logPos >= wrapPosRange.end) {
                         continue;
                     }
-                    if (checkHitChar && wrap->hitChar == sourcePtr_AttributedText_(&attrText, logPos)) {
+                    if (checkHitChar && !wasCharHit &&
+                        wrap->hitChar == sourcePtr_AttributedText_(&attrText, logPos)) {
                         wrap->hitAdvance_out = init_I2(wrapAdvance, yCursor);
-                        //wasCharHit = iTrue;
+                        wasCharHit = iTrue; /* variation selectors etc. have matching cluster */
                     }
                     /* Check if the hit point is on the left side of this line. */
                     if (isHitPointOnThisLine && !wrap->hitChar_out && wrap->hitPoint.x < orig.x) {