4 files changed, 55 insertions, 0 deletions
diff --git a/src/Fl_Graphics_Driver.cxx b/src/Fl_Graphics_Driver.cxx
index 2f687e151..00eaf5a15 100644
--- a/src/Fl_Graphics_Driver.cxx
+++ b/src/Fl_Graphics_Driver.cxx
@@ -626,6 +626,9 @@ void Fl_Graphics_Driver::overlay_rect(int x, int y, int w , int h) {
   loop(x, y, x+w-1, y, x+w-1, y+h-1, x, y+h-1);
 }
 
+float Fl_Graphics_Driver::remove_scale() { return 1.f;}
+
+void Fl_Graphics_Driver::restore_scale(float) { }
 
 /**
  \}
@@ -976,4 +979,20 @@ void Fl_Scalable_Graphics_Driver::draw_image_mono_unscaled(Fl_Draw_Image_Cb cb,
 
 void Fl_Scalable_Graphics_Driver::transformed_vertex0(float x, float y) {}
 
+float Fl_Scalable_Graphics_Driver::remove_scale() {
+  float s = scale();
+  if (s != 1.f) {
+    push_no_clip();
+    scale(1.f);
+  }
+  return s;
+}
+
+void Fl_Scalable_Graphics_Driver::restore_scale(float s) {
+  if (s != 1.f) {
+    scale(s);
+    pop_clip();
+  }
+}
+
 #endif
diff --git a/src/drivers/Quartz/Fl_Quartz_Graphics_Driver.H b/src/drivers/Quartz/Fl_Quartz_Graphics_Driver.H
index b61761d6f..7e4aab962 100644
--- a/src/drivers/Quartz/Fl_Quartz_Graphics_Driver.H
+++ b/src/drivers/Quartz/Fl_Quartz_Graphics_Driver.H
@@ -188,6 +188,8 @@ protected:
   void descriptor_init(const char* name, Fl_Fontsize Size, Fl_Quartz_Font_Descriptor *d);
 #endif
   virtual void overlay_rect(int x, int y, int w , int h);
+  virtual float remove_scale();
+  virtual void restore_scale(float);
 };
 
 class Fl_Quartz_Printer_Graphics_Driver : public Fl_Quartz_Graphics_Driver {
diff --git a/src/drivers/Quartz/Fl_Quartz_Graphics_Driver.cxx b/src/drivers/Quartz/Fl_Quartz_Graphics_Driver.cxx
index 9d82d5c73..acabf6e73 100644
--- a/src/drivers/Quartz/Fl_Quartz_Graphics_Driver.cxx
+++ b/src/drivers/Quartz/Fl_Quartz_Graphics_Driver.cxx
@@ -17,6 +17,7 @@
 #include <config.h>
 #include "Fl_Quartz_Graphics_Driver.H"
 #include "../Darwin/Fl_Darwin_System_Driver.H"
+#include "../../Fl_Screen_Driver.H"
 #include <FL/platform.H>
 #include <FL/fl_draw.H>
 #include <FL/Fl_Image_Surface.H>
@@ -158,3 +159,19 @@ void Fl_Quartz_Graphics_Driver::cache_size(Fl_Image *img, int &width, int &heigh
   width *= 2 * scale();
   height *= 2 * scale();
 }
+
+float Fl_Quartz_Graphics_Driver::remove_scale() {
+  float s = scale();
+  if (s != 1.f && Fl_Display_Device::display_device()->is_current()) {
+    Fl::screen_driver()->scale(0, 1.f);
+    CGContextScaleCTM(gc_, 1/s, 1/s);
+  }
+  return s;
+}
+
+void Fl_Quartz_Graphics_Driver::restore_scale(float s) {
+  if (s != 1.f && Fl_Display_Device::display_device()->is_current()) {
+    Fl::screen_driver()->scale(0, s);
+    CGContextScaleCTM(gc_, s, s);
+  }
+}
diff --git a/src/fl_draw.cxx b/src/fl_draw.cxx
index 72a117df0..538e63f2a 100644
--- a/src/fl_draw.cxx
+++ b/src/fl_draw.cxx
@@ -458,3 +458,20 @@ int fl_height(int font, int size) {
     fl_font(tf,ts);                       // restore
     return(height);
 }
+
+/** Removes any GUI scaling factor in subsequent drawing operations.
+ This must be matched by a later call to fl_restore_scale().
+ This function can be used to transiently perform drawing operations
+ that are not rescaled by the current value of the GUI scaling factor.
+ The resulting drawing context has no clipping region.
+ \return The GUI scaling factor value that was applied when the function started.
+ */
+float fl_remove_scale() {
+  return fl_graphics_driver->remove_scale();
+}
+
+/** Restores the GUI scaling factor and the clipping region in subsequent drawing operations.
+ \param s Value returned by a previous call to fl_remove_scale(). */
+void fl_restore_scale(float s) {
+  fl_graphics_driver->restore_scale(s);
+}