Expand ligature presentation forms into their individual characters when extracting text.

1 files changed, 60 insertions, 6 deletions

diff --git a/fitz/dev_text.c b/fitz/dev_text.c
index 02ee9687..0753fe31 100644
--- a/fitz/dev_text.c
+++ b/fitz/dev_text.c
@@ -29,6 +29,7 @@ typedef struct fz_textdevice_s fz_textdevice;
 struct fz_textdevice_s
 {
 	fz_point point;
+	fz_textspan *head;
 	fz_textspan *span;
 };
 
@@ -59,6 +60,28 @@ fz_freetextspan(fz_textspan *span)
 }
 
 static void
+fz_addtextcharimp(fz_textspan *span, int c, fz_bbox bbox)
+{
+	if (span->len + 1 >= span->cap)
+	{
+		span->cap = span->cap ? (span->cap * 3) / 2 : 80;
+		span->text = fz_realloc(span->text, sizeof(fz_textchar) * span->cap);
+	}
+	span->text[span->len].c = c;
+	span->text[span->len].bbox = bbox;
+	span->len ++;
+}
+
+static fz_bbox
+fz_splitbbox(fz_bbox bbox, int i, int n)
+{
+	int w = bbox.x1 - bbox.x0;
+	bbox.x0 = bbox.x0 + w * i / n;
+	bbox.x1 = bbox.x0 + w * (i + 1) / n;
+	return bbox;
+}
+
+static void
 fz_addtextchar(fz_textspan **last, fz_font *font, float size, int c, fz_bbox bbox)
 {
 	fz_textspan *span = *last;
@@ -78,14 +101,39 @@ fz_addtextchar(fz_textspan **last, fz_font *font, float size, int c, fz_bbox bbo
 		*last = span;
 	}
 
-	if (span->len + 1 >= span->cap)
+	switch (c)
 	{
-		span->cap = span->cap ? (span->cap * 3) / 2 : 80;
-		span->text = fz_realloc(span->text, sizeof(fz_textchar) * span->cap);
+	case 0xFB00: /* ff */
+		fz_addtextcharimp(span, 'f', fz_splitbbox(bbox, 0, 2));
+		fz_addtextcharimp(span, 'f', fz_splitbbox(bbox, 1, 2));
+		break;
+	case 0xFB01: /* fi */
+		fz_addtextcharimp(span, 'f', fz_splitbbox(bbox, 0, 2));
+		fz_addtextcharimp(span, 'i', fz_splitbbox(bbox, 1, 2));
+		break;
+	case 0xFB02: /* fl */
+		fz_addtextcharimp(span, 'f', fz_splitbbox(bbox, 0, 2));
+		fz_addtextcharimp(span, 'l', fz_splitbbox(bbox, 1, 2));
+		break;
+	case 0xFB03: /* ffi */
+		fz_addtextcharimp(span, 'f', fz_splitbbox(bbox, 0, 3));
+		fz_addtextcharimp(span, 'f', fz_splitbbox(bbox, 1, 3));
+		fz_addtextcharimp(span, 'i', fz_splitbbox(bbox, 2, 3));
+		break;
+	case 0xFB04: /* ffl */
+		fz_addtextcharimp(span, 'f', fz_splitbbox(bbox, 0, 3));
+		fz_addtextcharimp(span, 'f', fz_splitbbox(bbox, 1, 3));
+		fz_addtextcharimp(span, 'l', fz_splitbbox(bbox, 2, 3));
+		break;
+	case 0xFB05: /* long st */
+	case 0xFB06: /* st */
+		fz_addtextcharimp(span, 's', fz_splitbbox(bbox, 0, 2));
+		fz_addtextcharimp(span, 't', fz_splitbbox(bbox, 1, 2));
+		break;
+	default:
+		fz_addtextcharimp(span, c, bbox);
+		break;
 	}
-	span->text[span->len].c = c;
-	span->text[span->len].bbox = bbox;
-	span->len ++;
 }
 
 static void
@@ -286,7 +334,12 @@ static void
 fz_textfreeuser(void *user)
 {
 	fz_textdevice *tdev = user;
+
 	tdev->span->eol = 1;
+
+	/* TODO: unicode NFC normalization */
+	/* TODO: bidi logical reordering */
+
 	fz_free(tdev);
 }
 
@@ -295,6 +348,7 @@ fz_newtextdevice(fz_textspan *root)
 {
 	fz_device *dev;
 	fz_textdevice *tdev = fz_malloc(sizeof(fz_textdevice));
+	tdev->head = root;
 	tdev->span = root;
 	tdev->point.x = -1;
 	tdev->point.y = -1;