Started adjusting all the implementations to the new API's formal definition. There's bugs in uiAttributedString...

darwin/drawtext.m

@@ -421,10 +421,20 @@ void uiDrawTextLayoutHitTest(uiDrawTextLayout *tl, double x, double y, size_t *p
 
 double uiDrawTextLayoutByteLocationInLine(uiDrawTextLayout *tl, size_t pos, int line)
 {
-	CTLineRef ln;
+	CTLineRef lr;
+	CFRange range;
 
-	ln = (CTLineRef) CFArrayGetValueAtIndex(tl->lines, line);
+printf("= %zd %zd ", pos, tl->nUTF8);
-	// TODO what happens if the byte location is not in this line? a return of 0?
+	pos = tl->u8tou16[pos];
-	// TODO check return? see if this can return 0, anyway, and if so make a note I guess
+printf("-> %zd %zd\n", pos, tl->nUTF16);
-	return CTLineGetOffsetForStringIndex(ln, tl->u8tou16[pos], NULL);
+	if (line < 0 || line >= tl->nLines)
+		return -1;
+	lr = (CTLineRef) CFArrayGetValueAtIndex(tl->lines, line);
+	range = CTLineGetStringRange(lr);
+	// note: >, not >=, because the position at end is valid!
+printf("%zd %zd\n", pos, (size_t)(range.location+range.length));
+	if (pos < range.location || pos > (range.location + range.length))
+		return -1;
+	// no point in checking the return; we already validated everything and 0 is a valid return for the first index :/
+	return CTLineGetOffsetForStringIndex(lr, pos, NULL);
 }

examples/drawtext/hittest.c

@@ -113,6 +113,7 @@ static void draw(uiAreaDrawParams *p)
 	}
 	caretX = uiDrawTextLayoutByteLocationInLine(layout,
 		caretPos, caretLine);
+printf("%g\n", caretX);
 	uiDrawTextLayoutLineGetMetrics(layout, caretLine, &m);
 	path = uiDrawNewPath(uiDrawFillModeWinding);
 	uiDrawPathNewFigure(path, margins + caretX, margins + m.Y);
@@ -146,12 +147,6 @@ static void draw(uiAreaDrawParams *p)
 	uiDrawFreeTextLayout(layout);
 }
 
-static const char *positions[] = {
-	[uiDrawTextLayoutHitTestPositionBefore] = "before",
-	[uiDrawTextLayoutHitTestPositionInside] = "inside",
-	[uiDrawTextLayoutHitTestPositionAfter] = "after",
-};
-
 static void mouse(uiAreaMouseEvent *e)
 {
 	uiDrawTextLayout *layout;

ui_attrstr.h

@@ -87,8 +87,6 @@ struct uiDrawFontDescriptor {
 
 typedef struct uiDrawTextLayout uiDrawTextLayout;
 typedef struct uiDrawTextLayoutLineMetrics uiDrawTextLayoutLineMetrics;
-typedef struct uiDrawTextLayoutHitTestResult uiDrawTextLayoutHitTestResult;
-typedef struct uiDrawTextLayoutByteRangeRectangle uiDrawTextLayoutByteRangeRectangle;
 
 struct uiDrawTextLayoutLineMetrics {
 	// This describes the overall bounding box of the line.
@@ -121,30 +119,6 @@ struct uiDrawTextLayoutLineMetrics {
 	// TODO trailing whitespace?
 };
 
-struct uiDrawTextLayoutHitTestResult {
-	// The byte position of the character at the given point.
-	size_t Pos;
-	// Line is the line at the given point. If the point is on the space
-	// after the end of a line, Pos will be Line's end index. In this case,
-	// the rectangle for that character will actually be on the *next*
-	// line. This disparity is only relevant for caret positioning when
-	// using the mouse; in that case, to ensure proper behavior, use
-	// the Caret fields below. In all other cases (including keyboard
-	// caret movement), use the actual rectangle for the grapheme
-	// at Pos (via uiDrawTextLayoutByteRangeToRectangle()).
-	int Line;
-	uiDrawTextLayoutHitTestPosition XPosition;
-	uiDrawTextLayoutHitTestPosition YPosition;
-
-// TODO?
-//	int InTrailingWhitespace;
-// TODO?
-//	double XFraction;
-// extra TODO?
-//	double YFraction;
-// or just have offsets instead? in addition?
-};
-
 // TODO
 // - allow creating a layout out of a substring
 // - allow marking compositon strings
@@ -185,4 +159,5 @@ _UI_EXTERN void uiDrawTextLayoutHitTest(uiDrawTextLayout *tl, double x, double y
 // the correct offset, even if pos is at the end of the line. If pos is not
 // in the range [start, end], a negative value will be returned,
 // indicating you need to move the cursor to another line.
+// TODO make sure this works right for right-aligned and center-aligned lines and justified lines and RTL text
 _UI_EXTERN double uiDrawTextLayoutByteLocationInLine(uiDrawTextLayout *tl, size_t pos, int line);