STR 1373: adds vsync control to OpenGL contexts on macOS

Windows and X11 to follow, no idea about Wayland.

2 files changed, 17 insertions, 0 deletions

diff --git a/src/drivers/Cocoa/Fl_Cocoa_Gl_Window_Driver.H b/src/drivers/Cocoa/Fl_Cocoa_Gl_Window_Driver.H
index 79b93e6df..21a3a4589 100644
--- a/src/drivers/Cocoa/Fl_Cocoa_Gl_Window_Driver.H
+++ b/src/drivers/Cocoa/Fl_Cocoa_Gl_Window_Driver.H
@@ -38,6 +38,8 @@ class Fl_Cocoa_Gl_Window_Driver : public Fl_Gl_Window_Driver {
   void swap_buffers() FL_OVERRIDE;
   void resize(int is_a_resize, int w, int h) FL_OVERRIDE;
   char swap_type() FL_OVERRIDE;
+  void swap_interval(int) FL_OVERRIDE;
+  int swap_interval() FL_OVERRIDE;
   Fl_Gl_Choice *find(int m, const int *alistp) FL_OVERRIDE;
   GLContext create_gl_context(Fl_Window* window, const Fl_Gl_Choice* g) FL_OVERRIDE;
   void set_gl_context(Fl_Window* w, GLContext context) FL_OVERRIDE;
diff --git a/src/drivers/Cocoa/Fl_Cocoa_Gl_Window_Driver.mm b/src/drivers/Cocoa/Fl_Cocoa_Gl_Window_Driver.mm
index a2c8e7578..43bc2d480 100644
--- a/src/drivers/Cocoa/Fl_Cocoa_Gl_Window_Driver.mm
+++ b/src/drivers/Cocoa/Fl_Cocoa_Gl_Window_Driver.mm
@@ -355,6 +355,21 @@ void Fl_Cocoa_Gl_Window_Driver::swap_buffers() {
 
 char Fl_Cocoa_Gl_Window_Driver::swap_type() {return copy;}
 
+void Fl_Cocoa_Gl_Window_Driver::swap_interval(int n) {
+  GLint interval = (GLint)n;
+  NSOpenGLContext* ctx = (NSOpenGLContext*)pWindow->context();
+  if (ctx)
+    [ctx setValues:&interval forParameter:NSOpenGLContextParameterSwapInterval];
+}
+
+int Fl_Cocoa_Gl_Window_Driver::swap_interval() {
+  GLint interval = (GLint)-1;
+  NSOpenGLContext* ctx = (NSOpenGLContext*)pWindow->context();
+  if (ctx)
+    [ctx getValues:&interval forParameter:NSOpenGLContextParameterSwapInterval];
+  return interval;
+}
+
 void Fl_Cocoa_Gl_Window_Driver::resize(int is_a_resize, int w, int h) {
   if (pWindow->shown()) apply_scissor();
   [(NSOpenGLContext*)pWindow->context() update];