fix(freetype) fix underline calculation

Fixes: #2711 Based on: lvgl/lv_lib_freetype@aa85d97
lvgl · Oct 21, 2021 · 76c8ee6 · 76c8ee6
1 parent c2d93f7
commit 76c8ee6
Showing 1 changed file with 10 additions and 4 deletions.
diff --git a/src/extra/libs/freetype/lv_freetype.c b/src/extra/libs/freetype/lv_freetype.c
@@ -264,8 +264,11 @@ static bool lv_ft_font_init_cache(lv_ft_info_t * info)
     font->subpx = LV_FONT_SUBPX_NONE;
     font->line_height = (face_size->face->size->metrics.height >> 6);
     font->base_line = -(face_size->face->size->metrics.descender >> 6);
-    font->underline_position = face_size->face->underline_position;
-    font->underline_thickness = face_size->face->underline_thickness;
+
+    FT_Fixed scale = face_size->face->size->metrics.y_scale;
+    int8_t thickness = FT_MulFix(scale, face_size->face->underline_thickness) >> 6;
+    font->underline_position = FT_MulFix(scale, face_size->face->underline_position) >> 6;
+    font->underline_thickness = thickness < 1 ? 1 : thickness;
 
     /* return to user */
     info->font = font;
@@ -446,10 +449,13 @@ static bool lv_ft_font_init_nocache(lv_ft_info_t * info)
     font->get_glyph_bitmap = get_glyph_bitmap_cb_nocache;
     font->line_height = (face->size->metrics.height >> 6);
     font->base_line = -(face->size->metrics.descender >> 6);
-    font->underline_position = face->underline_position;
-    font->underline_thickness = face->underline_thickness;
     font->subpx = LV_FONT_SUBPX_NONE;
 
+    FT_Fixed scale = face->size->metrics.y_scale;
+    int8_t thickness = FT_MulFix(scale, face->underline_thickness) >> 6;
+    font->underline_position = FT_MulFix(scale, face->underline_position) >> 6;
+    font->underline_thickness = thickness < 1 ? 1 : thickness;
+
     info->font = font;
     return true;