Fixed bugs in calculating text size (#3864)

Fixed bugs in calculating text size
python-pillow · Jun 19, 2019 · 26182dd · 26182dd
2 parents be1b551 + ea0f1c6
commit 26182dd
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Showing 6 changed files with 33 additions and 21 deletions.
diff --git a/Tests/fonts/ArefRuqaa-Regular.ttf b/Tests/fonts/ArefRuqaa-Regular.ttf
diff --git a/Tests/fonts/LICENSE.txt b/Tests/fonts/LICENSE.txt
@@ -3,6 +3,7 @@ NotoNastaliqUrdu-Regular.ttf, from https://github.com/googlei18n/noto-fonts
 NotoSansJP-Thin.otf, from https://www.google.com/get/noto/help/cjk/
 AdobeVFPrototype.ttf, from https://github.com/adobe-fonts/adobe-variable-font-prototype
 TINY5x3GX.ttf, from http://velvetyne.fr/fonts/tiny
+ArefRuqaa-Regular.ttf, from https://github.com/google/fonts/tree/master/ofl/arefruqaa
 
 All of the above fonts are published under the SIL Open Font License (OFL) v1.1 (http://scripts.sil.org/cms/scripts/page.php?site_id=nrsi&id=OFL), which allows you to copy, modify, and redistribute them if you need to.
 

diff --git a/Tests/images/test_x_max_and_y_offset.png b/Tests/images/test_x_max_and_y_offset.png
diff --git a/Tests/images/test_y_offset.png b/Tests/images/test_y_offset.png
diff --git a/Tests/test_imagefontctl.py b/Tests/test_imagefontctl.py
@@ -159,6 +159,18 @@ def test_arabictext_features(self):
 
         self.assert_image_similar(im, target_img, .5)
 
+    def test_x_max_and_y_offset(self):
+        ttf = ImageFont.truetype("Tests/fonts/ArefRuqaa-Regular.ttf", 40)
+
+        im = Image.new(mode='RGB', size=(50, 100))
+        draw = ImageDraw.Draw(im)
+        draw.text((0, 0), 'لح', font=ttf, fill=500)
+
+        target = 'Tests/images/test_x_max_and_y_offset.png'
+        target_img = Image.open(target)
+
+        self.assert_image_similar(im, target_img, .5)
+
     def test_language(self):
         ttf = ImageFont.truetype(FONT_PATH, FONT_SIZE)
 

diff --git a/src/_imagingft.c b/src/_imagingft.c
@@ -618,7 +618,7 @@ text_layout(PyObject* string, FontObject* self, const char* dir, PyObject *featu
 static PyObject*
 font_getsize(FontObject* self, PyObject* args)
 {
-    int x_max, x_min, y_max, y_min;
+    int x_position, x_max, x_min, y_max, y_min;
     FT_Face face;
     int xoffset, yoffset;
     int horizontal_dir;
@@ -634,18 +634,18 @@ font_getsize(FontObject* self, PyObject* args)
     if (!PyArg_ParseTuple(args, "O|zOz:getsize", &string, &dir, &features, &lang))
         return NULL;
 
-    face = NULL;
-    xoffset = yoffset = 0;
-    x_max = x_min = y_max = y_min = 0;
-
     count = text_layout(string, self, dir, features, lang, &glyph_info, 0);
     if (PyErr_Occurred()) {
         return NULL;
     }
 
+    face = NULL;
+    xoffset = yoffset = 0;
+    x_position = x_max = x_min = y_max = y_min = 0;
+
     horizontal_dir = dir && strcmp(dir, "ttb") == 0 ? 0 : 1;
     for (i = 0; i < count; i++) {
-        int index, error;
+        int index, error, offset, x_advanced;
         FT_BBox bbox;
         FT_Glyph glyph;
         face = self->face;
@@ -661,7 +661,7 @@ font_getsize(FontObject* self, PyObject* args)
             if (horizontal_dir) {
                 if (face->glyph->metrics.horiBearingX < 0) {
                     xoffset = face->glyph->metrics.horiBearingX;
-                    x_max -= xoffset;
+                    x_position -= xoffset;
                 }
             } else {
                 if (face->glyph->metrics.vertBearingY < 0) {
@@ -674,20 +674,19 @@ font_getsize(FontObject* self, PyObject* args)
         FT_Get_Glyph(face->glyph, &glyph);
         FT_Glyph_Get_CBox(glyph, FT_GLYPH_BBOX_SUBPIXELS, &bbox);
         if (horizontal_dir) {
-            x_max += glyph_info[i].x_advance;
-
-            if (i == count - 1) {
-                // trim end gap from final glyph
-                int offset;
-                offset = glyph_info[i].x_advance -
-                        face->glyph->metrics.width -
-                        face->glyph->metrics.horiBearingX;
-                if (offset < 0)
-                    x_max -= offset;
-            }
-
-            bbox.yMax -= glyph_info[i].y_offset;
-            bbox.yMin -= glyph_info[i].y_offset;
+            x_position += glyph_info[i].x_advance;
+
+            x_advanced = x_position;
+            offset = glyph_info[i].x_advance -
+                    face->glyph->metrics.width -
+                    face->glyph->metrics.horiBearingX;
+            if (offset < 0)
+                x_advanced -= offset;
+            if (x_advanced > x_max)
+                x_max = x_advanced;
+
+            bbox.yMax += glyph_info[i].y_offset;
+            bbox.yMin += glyph_info[i].y_offset;
             if (bbox.yMax > y_max)
                 y_max = bbox.yMax;
             if (bbox.yMin < y_min)