BLF: Refactor of blf_font_boundbox_foreach_glyph

Refactor of `BLF_boundbox_foreach_glyph` and simplification of its
usage by only passing translated glyph bounds to callbacks.

See D15765 for more details.

Differential Revision: https://developer.blender.org/D15765

Reviewed by Campbell Barton

2 files changed, 15 insertions, 82 deletions

diff --git a/source/blender/editors/interface/interface_handlers.c b/source/blender/editors/interface/interface_handlers.c
index a6c700bdc2f..56b550995be 100644
--- a/source/blender/editors/interface/interface_handlers.c
+++ b/source/blender/editors/interface/interface_handlers.c
@@ -3017,23 +3017,6 @@ static bool ui_textedit_delete_selection(uiBut *but, uiHandleButtonData *data)
   return changed;
 }
 
-static bool ui_textedit_set_cursor_pos_foreach_glyph(const char *UNUSED(str),
-                                                     const size_t str_step_ofs,
-                                                     const rcti *glyph_step_bounds,
-                                                     const int UNUSED(glyph_advance_x),
-                                                     const rcti *glyph_bounds,
-                                                     const int UNUSED(glyph_bearing[2]),
-                                                     void *user_data)
-{
-  int *cursor_data = user_data;
-  const int center = glyph_step_bounds->xmin + (BLI_rcti_size_x(glyph_bounds) / 2.0f);
-  if (cursor_data[0] < center) {
-    cursor_data[1] = str_step_ofs;
-    return false;
-  }
-  return true;
-}
-
 /**
  * \param x: Screen space cursor location - #wmEvent.x
  *
@@ -3064,7 +3047,7 @@ static void ui_textedit_set_cursor_pos(uiBut *but, uiHandleButtonData *data, con
       startx += UI_DPI_ICON_SIZE / aspect;
     }
   }
-  startx += (UI_TEXT_MARGIN_X * U.widget_unit) / aspect;
+  startx += (UI_TEXT_MARGIN_X * U.widget_unit - U.pixelsize) / aspect;
 
   /* mouse dragged outside the widget to the left */
   if (x < startx) {
@@ -3088,23 +3071,8 @@ static void ui_textedit_set_cursor_pos(uiBut *but, uiHandleButtonData *data, con
   }
   /* mouse inside the widget, mouse coords mapped in widget space */
   else {
-    str_last = &str[but->ofs];
-    const int str_last_len = strlen(str_last);
-    const int x_pos = (int)(x - startx);
-    int glyph_data[2] = {
-        x_pos, /* horizontal position to test. */
-        -1,    /* Write the character offset here. */
-    };
-    BLF_boundbox_foreach_glyph(fstyle.uifont_id,
-                               str + but->ofs,
-                               INT_MAX,
-                               ui_textedit_set_cursor_pos_foreach_glyph,
-                               glyph_data);
-    /* If value untouched then we are to the right. */
-    if (glyph_data[1] == -1) {
-      glyph_data[1] = str_last_len;
-    }
-    but->pos = glyph_data[1] + but->ofs;
+    but->pos = but->ofs + BLF_str_offset_from_cursor_position(
+                              fstyle.uifont_id, str + but->ofs, INT_MAX, (int)(x - startx));
   }
 
   ui_but_text_password_hide(password_str, but, true);
diff --git a/source/blender/editors/interface/interface_widgets.c b/source/blender/editors/interface/interface_widgets.c
index 1b13632b131..6ba80e2e0d9 100644
--- a/source/blender/editors/interface/interface_widgets.c
+++ b/source/blender/editors/interface/interface_widgets.c
@@ -1858,33 +1858,6 @@ static void widget_draw_text_ime_underline(const uiFontStyle *fstyle,
 }
 #endif /* WITH_INPUT_IME */
 
-struct UnderlineData {
-  size_t str_offset;  /* The string offset of the underlined character. */
-  int width_px;       /* The underline width in pixels. */
-  int r_offset_px[2]; /* Write the X,Y offset here. */
-};
-
-static bool widget_draw_text_underline_calc_position(const char *UNUSED(str),
-                                                     const size_t str_step_ofs,
-                                                     const rcti *glyph_step_bounds,
-                                                     const int UNUSED(glyph_advance_x),
-                                                     const rcti *glyph_bounds,
-                                                     const int UNUSED(glyph_bearing[2]),
-                                                     void *user_data)
-{
-  struct UnderlineData *ul_data = user_data;
-  if (ul_data->str_offset == str_step_ofs) {
-    /* Full width of this glyph including both bearings. */
-    const int width = glyph_bounds->xmin + BLI_rcti_size_x(glyph_bounds) + glyph_bounds->xmin;
-    ul_data->r_offset_px[0] = glyph_step_bounds->xmin + ((width - ul_data->width_px) / 2);
-    /* One line-width below the lower glyph bounds. */
-    ul_data->r_offset_px[1] = glyph_bounds->ymin - U.pixelsize;
-    /* Early exit. */
-    return false;
-  }
-  return true;
-}
-
 static void widget_draw_text(const uiFontStyle *fstyle,
                              const uiWidgetColors *wcol,
                              uiBut *but,
@@ -2150,26 +2123,18 @@ static void widget_draw_text(const uiFontStyle *fstyle,
         }
 
         if (ul_index != -1) {
-          int ul_width = round_fl_to_int(BLF_width(fstyle->uifont_id, "_", 2));
-
-          struct UnderlineData ul_data = {
-              .str_offset = ul_index,
-              .width_px = ul_width,
-          };
-
-          BLF_boundbox_foreach_glyph(fstyle->uifont_id,
-                                     drawstr_ofs,
-                                     ul_index + 1,
-                                     widget_draw_text_underline_calc_position,
-                                     &ul_data);
-
-          const int pos_x = rect->xmin + font_xofs + ul_data.r_offset_px[0];
-          const int pos_y = rect->ymin + font_yofs + ul_data.r_offset_px[1];
-
-          /* Use text output because direct drawing doesn't always work. See T89246. */
-          BLF_position(fstyle->uifont_id, pos_x, pos_y, 0.0f);
-          BLF_color4ubv(fstyle->uifont_id, wcol->text);
-          BLF_draw(fstyle->uifont_id, "_", 2);
+          rcti bounds;
+          if (BLF_str_offset_to_glyph_bounds(fstyle->uifont_id, drawstr_ofs, ul_index, &bounds) &&
+              !BLI_rcti_is_empty(&bounds)) {
+            int ul_width = round_fl_to_int(BLF_width(fstyle->uifont_id, "_", 2));
+            int pos_x = rect->xmin + font_xofs + bounds.xmin +
+                        (bounds.xmax - bounds.xmin - ul_width) / 2;
+            int pos_y = rect->ymin + font_yofs + bounds.ymin - U.pixelsize;
+            /* Use text output because direct drawing doesn't always work. See T89246. */
+            BLF_position(fstyle->uifont_id, (float)pos_x, pos_y, 0.0f);
+            BLF_color4ubv(fstyle->uifont_id, wcol->text);
+            BLF_draw(fstyle->uifont_id, "_", 2);
+          }
         }
       }
     }