2 files changed, 80 insertions, 1 deletions

diff --git a/src/drivers/Quartz/Fl_Quartz_Image_Surface_Driver.H b/src/drivers/Quartz/Fl_Quartz_Image_Surface_Driver.H
index b6f58ec8f..69e00dfd0 100644
--- a/src/drivers/Quartz/Fl_Quartz_Image_Surface_Driver.H
+++ b/src/drivers/Quartz/Fl_Quartz_Image_Surface_Driver.H
@@ -21,6 +21,11 @@
 #include <FL/platform.H>
 
 class Fl_Quartz_Image_Surface_Driver : public Fl_Image_Surface_Driver {
+private:
+# if MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_4
+  CGImageRef mask_;
+  void mask(const Fl_RGB_Image *) FL_OVERRIDE;
+#endif
   void end_current() FL_OVERRIDE;
 public:
   FLWindow *pre_window;
diff --git a/src/drivers/Quartz/Fl_Quartz_Image_Surface_Driver.cxx b/src/drivers/Quartz/Fl_Quartz_Image_Surface_Driver.cxx
index 451078484..fb522745a 100644
--- a/src/drivers/Quartz/Fl_Quartz_Image_Surface_Driver.cxx
+++ b/src/drivers/Quartz/Fl_Quartz_Image_Surface_Driver.cxx
@@ -1,7 +1,7 @@
 //
 // Draw-to-image code for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 1998-2018 by Bill Spitzak and others.
+// Copyright 1998-2023 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
@@ -23,6 +23,9 @@
 
 
 Fl_Quartz_Image_Surface_Driver::Fl_Quartz_Image_Surface_Driver(int w, int h, int high_res, Fl_Offscreen off) : Fl_Image_Surface_Driver(w, h, high_res, off) {
+# if MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_4
+  mask_ = NULL;
+#endif
   int W = w, H = h;
   float s = 1;
   if (high_res) {
@@ -49,6 +52,12 @@ Fl_Quartz_Image_Surface_Driver::Fl_Quartz_Image_Surface_Driver(int w, int h, int
 }
 
 Fl_Quartz_Image_Surface_Driver::~Fl_Quartz_Image_Surface_Driver() {
+# if MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_4
+  if (mask_) {
+    CGImageRelease(mask_);
+  }
+#endif
+  if (offscreen) CGContextRestoreGState((CGContextRef)offscreen);
   if (offscreen && !external_offscreen) {
     void *data = CGBitmapContextGetData((CGContextRef)offscreen);
     free(data);
@@ -56,6 +65,7 @@ Fl_Quartz_Image_Surface_Driver::~Fl_Quartz_Image_Surface_Driver() {
   }
   delete driver();
 }
+ 
 
 void Fl_Quartz_Image_Surface_Driver::set_current() {
   Fl_Surface_Device::set_current();
@@ -63,6 +73,15 @@ void Fl_Quartz_Image_Surface_Driver::set_current() {
   driver()->gc((CGContextRef)offscreen);
   fl_window = 0;
   ((Fl_Quartz_Graphics_Driver*)driver())->high_resolution( CGBitmapContextGetWidth((CGContextRef)offscreen) > (size_t)width );
+# if MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_4
+  if (mask_) {
+    int W, H;
+    printable_rect(&W, &H);
+    CGContextSaveGState((CGContextRef)offscreen);
+    CGContextClipToMask((CGContextRef)offscreen, CGRectMake(0,0,W,H), mask_); // 10.4
+    CGContextSaveGState((CGContextRef)offscreen);
+  }
+# endif
 }
 
 void Fl_Quartz_Image_Surface_Driver::translate(int x, int y) {
@@ -79,6 +98,13 @@ void Fl_Quartz_Image_Surface_Driver::untranslate() {
 Fl_RGB_Image* Fl_Quartz_Image_Surface_Driver::image()
 {
   CGContextFlush((CGContextRef)offscreen);
+# if MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_4
+  if (mask_) {
+    CGContextRestoreGState((CGContextRef)offscreen);
+    CGImageRelease(mask_);
+    mask_ = NULL;
+  }
+#endif
   int W = (int)CGBitmapContextGetWidth((CGContextRef)offscreen);
   int H = (int)CGBitmapContextGetHeight((CGContextRef)offscreen);
   int bpr = (int)CGBitmapContextGetBytesPerRow((CGContextRef)offscreen);
@@ -101,6 +127,54 @@ Fl_RGB_Image* Fl_Quartz_Image_Surface_Driver::image()
 
 void Fl_Quartz_Image_Surface_Driver::end_current()
 {
+# if MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_4
+  if (mask_) {
+    CGContextRestoreGState((CGContextRef)offscreen);
+    CGContextRestoreGState((CGContextRef)offscreen);
+  }
+# endif
   fl_window = pre_window;
   Fl_Surface_Device::end_current();
 }
+
+
+# if MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_4
+
+static void MyProviderReleaseData (void *info, const void *data, size_t size) {
+  delete[] (uchar*)data;
+}
+
+
+void Fl_Quartz_Image_Surface_Driver::mask(const Fl_RGB_Image *img) {
+  if (!&CGContextClipToMask) return;
+  int W = (int)CGBitmapContextGetWidth((CGContextRef)offscreen);
+  int H = (int)CGBitmapContextGetHeight((CGContextRef)offscreen);
+  bool using_copy = false;
+  if (W != img->data_w() || H != img->data_h()) {
+    Fl_RGB_Image *copy = (Fl_RGB_Image*)img->copy(W, H);
+    img = copy;
+    using_copy = true;
+  }
+  
+  int i, d = img->d(), w = img->data_w(), h = img->data_h();
+  // reverse top and bottom and convert to gray scale if img->d() == 3 and complement bits
+  int bytes_per_row = (img->ld() ? img->ld() : w * d);
+  uchar *from = new uchar[w * h];
+  for ( i = 0; i < h; i++) {
+    const uchar *p = img->array + bytes_per_row * i;
+    const uchar *last = p + bytes_per_row;
+    uchar *q = from + (h - 1 - i) * w;
+    while (p < last) {
+      unsigned u = *p++;
+      u += *p++;
+      u += *p++;
+      *q++ = ~(u/3);
+    }
+  }
+  CGDataProviderRef provider = CGDataProviderCreateWithData(NULL, from, w * h, MyProviderReleaseData);
+  mask_ = CGImageMaskCreate(w, h, 8, 8, w, provider, NULL, false);
+  CFRelease(provider);
+  if (using_copy) delete img;
+}
+
+#endif