Modernize fl_symbol hashing to C++11 code (#1417) (#1418)

* Replace hand rolles symbol hashing with C++11 code
* Update symbol drawing functions, add fl_remove_symbol()
* Refactored some of fl_draw_symbol.
* Using clang format for symbol code and test
* Circumvent Doxygen bug https://github.com/doxygen/doxygen/issues/11190

Co-authored-by: Copilot <copilot@github.com>
Co-authored-by: Albrecht Schlosser <albrechts.fltk@online.de>

.clang-format

@@ -1,7 +1,7 @@
 #
 # clang-format control file for the FLTK project.
 #
-# Copyright 2017-2022 by Bill Spitzak and others.
+# Copyright 2017-2026 by Bill Spitzak and others.
 #
 # This library is free software. Distribution and use rights are outlined in
 # the file "COPYING" which should have been included with this file.  If this
@@ -112,7 +112,9 @@ SortIncludes:                                   false
 # Multiple constructor initializers must be on consecutive lines.
 # Note: this is NOT (always) true in current FLTK code!
 
-BreakConstructorInitializersBeforeComma:        true
+BreakConstructorInitializers:                   BeforeColon
+# or: BeforeColon, BeforeComma, AfterColon, AfterComma
+# was: BreakConstructorInitializersBeforeComma:        true
 
 # Constructor initializers will be indented by 2 spaces.
 # LLVM default: 4
@@ -125,6 +127,20 @@ ConstructorInitializerIndentWidth:              2
 # LLVM default: 4
 # ContinuationIndentWidth:                      2
 
+# If a control statement (if-clause, etc.) spans multiple lines, the opening
+# brace can get visibly lost and it is hard to see when the condition ends and
+# the statements start. MultiLine puts the brace on the next line in this case.
+#
+# AfterFunction: true would be a change in style and is up for debate.
+# I like it because it separates the declaration from the body. I wish there
+# was a MultiLine option here as well.
+
+BreakBeforeBraces: Custom
+BraceWrapping:
+  AfterControlStatement:                        MultiLine
+  AfterFunction:                                true
+  SplitEmptyFunction:                           false
+
 # Most of FLTK's code uses 'void *p' as opposed to 'void* p'.
 # This is particularly useful in combined declarations like:
 # int var, var2, *pv, **pp;
@@ -136,4 +152,4 @@ ConstructorInitializerIndentWidth:              2
 # in function parameter lists.
 
 DerivePointerAlignment:                         false
-PointerAlignment:                               Right
+PointerAlignment:                               Left

FL/fl_draw.H

@@ -1,7 +1,7 @@
 //
 // Portable drawing function header file for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 1998-2025 by Bill Spitzak and others.
+// Copyright 1998-2026 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -1251,9 +1251,11 @@ FL_EXPORT void fl_set_spot(int font, int size, int X, int Y, int W, int H, Fl_Wi
 FL_EXPORT void fl_reset_spot(void);
 
 
-// XForms symbols:
+// Symbols (originally from XForms):
 FL_EXPORT int fl_draw_symbol(const char *label, int x, int y, int w, int h, Fl_Color);
-FL_EXPORT int fl_add_symbol(const char *name, void (*drawit)(Fl_Color), int scalable);
+FL_EXPORT int fl_add_symbol(const char *name, void (*drawit)(Fl_Color c), int scalable);
+FL_EXPORT int fl_add_symbol(const char *name, void (*draw_in_rect)(int x, int y, int w, int h, Fl_Color c), int scalable);
+FL_EXPORT int fl_remove_symbol(const char *name);
 /** @} */
 
 #endif

test/symbols.cxx

@@ -30,29 +30,38 @@ int N = 0;
 #define ROWS 6
 #define COLS 7
 
-Fl_Double_Window *window;
+Fl_Double_Window* window;
-Fl_Value_Slider *orientation;
+Fl_Value_Slider* orientation;
-Fl_Value_Slider *size;
+Fl_Value_Slider* size;
 
-void slider_cb(Fl_Widget *, void *) {
+void slider_cb(Fl_Widget*, void*)
+{
   static char buf[80];
   int val = (int)orientation->value();
   int sze = (int)size->value();
-  for (int i = window->children(); i--; ) {          // all window children
+  for (int i = window->children(); i--;) { // all window children
-    Fl_Widget *wc = window->child(i);
+    Fl_Widget* wc = window->child(i);
-    const char *l = (const char *)(wc->user_data());
+    const char* l = (const char*)(wc->user_data());
-    if ( l && *l == '@' ) {                       // all children with '@'
+    if (l && *l == '@') { // all children with '@'
-      l ++;
+      l++;
-      if ( wc->box() == FL_NO_BOX ) {             // ascii legend?
+      if (wc->box() == FL_NO_BOX) { // ascii legend?
-        if (val&&sze) snprintf(buf, sizeof(buf), "@@%+d%d%s", sze, val, l);
+        if (val && sze)
-        else if (val) snprintf(buf, sizeof(buf), "@@%d%s", val, l);
+          snprintf(buf, sizeof(buf), "@@%+d%d%s", sze, val, l);
-        else if (sze) snprintf(buf, sizeof(buf), "@@%+d%s", sze, l);
+        else if (val)
-        else          snprintf(buf, sizeof(buf), "@@%s", l);
+          snprintf(buf, sizeof(buf), "@@%d%s", val, l);
-      } else {                                    // box with symbol
+        else if (sze)
-        if (val&&sze) snprintf(buf, sizeof(buf), "@%+d%d%s", sze, val, l);
+          snprintf(buf, sizeof(buf), "@@%+d%s", sze, l);
-        else if (val) snprintf(buf, sizeof(buf), "@%d%s", val, l);
+        else
-        else if (sze) snprintf(buf, sizeof(buf), "@%+d%s", sze, l);
+          snprintf(buf, sizeof(buf), "@@%s", l);
-        else          snprintf(buf, sizeof(buf), "@%s", l);
+      } else { // box with symbol
+        if (val && sze)
+          snprintf(buf, sizeof(buf), "@%+d%d%s", sze, val, l);
+        else if (val)
+          snprintf(buf, sizeof(buf), "@%d%s", val, l);
+        else if (sze)
+          snprintf(buf, sizeof(buf), "@%+d%s", sze, l);
+        else
+          snprintf(buf, sizeof(buf), "@%s", l);
       }
       wc->copy_label(buf);
     }
@@ -60,80 +69,80 @@ void slider_cb(Fl_Widget *, void *) {
   window->redraw();
 }
 
-void bt(const char *name) {
+void bt(const char* name)
-  int x = N%COLS;
+{
-  int y = N/COLS;
+  int x = N % COLS;
+  int y = N / COLS;
   char buf[255];
   N++;
-  x = x*W+10;
+  x = x * W + 10;
-  y = y*H+10;
+  y = y * H + 10;
   snprintf(buf, sizeof(buf), "@%s", name);
-  Fl_Box *a = new Fl_Box(x,y,W-20,H-20);
+  Fl_Box* a = new Fl_Box(x, y, W - 20, H - 20);
   a->box(FL_NO_BOX);
   a->copy_label(buf);
   a->align(FL_ALIGN_BOTTOM);
   a->labelsize(11);
-  a->user_data((void *)name);
+  a->user_data((void*)name);
-  Fl_Box *b = new Fl_Box(x,y,W-20,H-20);
+  Fl_Box* b = new Fl_Box(x, y, W - 20, H - 20);
   b->box(FL_UP_BOX);
   b->copy_label(name);
   b->labelcolor(FL_DARK3);
-  b->user_data((void *)name);
+  b->user_data((void*)name);
 }
 
-int main(int argc, char ** argv) {
+int main(int argc, char** argv)
-  window = new Fl_Double_Window(COLS*W,ROWS*H+60);
+{
-bt("@->");
+  window = new Fl_Double_Window(COLS * W, ROWS * H + 60);
-bt("@>");
+  bt("@->");
-bt("@>>");
+  bt("@>");
-bt("@>|");
+  bt("@>>");
-bt("@>[]");
+  bt("@>|");
-bt("@|>");
+  bt("@>[]");
-bt("@<-");
+  bt("@|>");
-bt("@<");
+  bt("@<-");
-bt("@<<");
+  bt("@<");
-bt("@|<");
+  bt("@<<");
-bt("@[]<");
+  bt("@|<");
-bt("@<|");
+  bt("@[]<");
-bt("@<->");
+  bt("@<|");
-bt("@-->");
+  bt("@<->");
-bt("@+");
+  bt("@-->");
-bt("@->|");
+  bt("@+");
-bt("@||");
+  bt("@->|");
-bt("@arrow");
+  bt("@||");
-bt("@returnarrow");
+  bt("@arrow");
-bt("@square");
+  bt("@returnarrow");
-bt("@circle");
+  bt("@square");
-bt("@line");
+  bt("@circle");
-bt("@menu");
+  bt("@line");
-bt("@UpArrow");
+  bt("@menu");
-bt("@DnArrow");
+  bt("@UpArrow");
-bt("@search");
+  bt("@DnArrow");
-bt("@FLTK");
+  bt("@search");
-bt("@filenew");
+  bt("@FLTK");
-bt("@fileopen");
+  bt("@filenew");
-bt("@filesave");
+  bt("@fileopen");
-bt("@filesaveas");
+  bt("@filesave");
-bt("@fileprint");
+  bt("@filesaveas");
-bt("@refresh");
+  bt("@fileprint");
-bt("@reload");
+  bt("@refresh");
-bt("@undo");
+  bt("@reload");
-bt("@redo");
+  bt("@undo");
-bt("@import");
+  bt("@redo");
-bt("@export");
+  bt("@import");
+  bt("@export");
 
-  orientation = new Fl_Value_Slider(
+  orientation = new Fl_Value_Slider((int)(window->w() * .05 + .5), window->h() - 40,
-    (int)(window->w()*.05+.5), window->h()-40,
+                                    (int)(window->w() * .42 + .5), 16, "Orientation");
-    (int)(window->w()*.42+.5), 16, "Orientation");
   orientation->type(FL_HORIZONTAL);
   orientation->range(0.0, 9.0);
   orientation->value(0.0);
   orientation->step(1);
   orientation->callback(slider_cb, 0);
 
-  size = new Fl_Value_Slider(
+  size = new Fl_Value_Slider((int)(window->w() * .53 + .5), window->h() - 40,
-    (int)(window->w()*.53+.5), window->h()-40,
+                             (int)(window->w() * .42 + .5), 16, "Size");
-    (int)(window->w()*.42+.5), 16, "Size");
   size->type(FL_HORIZONTAL);
   size->range(-3.0, 9.0);
   size->value(0.0);
@@ -141,6 +150,6 @@ bt("@export");
   size->callback(slider_cb, 0);
 
   window->resizable(window);
-  window->show(argc,argv);
+  window->show(argc, argv);
   return Fl::run();
 }