Ensure correct blending function for transparent window

3 files changed, 12 insertions, 1 deletions

diff --git a/depends/mgl b/depends/mgl
-Subproject 470dac0e891c1ec59dfe52e77861cf068837976
+Subproject f2da59054cedd1c07779e72537da4d7b14616b4
diff --git a/include/mglpp/window/Window.hpp b/include/mglpp/window/Window.hpp
index 7d3f90b..6e4e485 100644
--- a/include/mglpp/window/Window.hpp
+++ b/include/mglpp/window/Window.hpp
@@ -44,7 +44,7 @@ namespace mgl {
             WindowHandle parent_window = 0; /* 0 = root window */
             bool hidden = false;
             bool override_redirect = false;
-            bool support_alpha = false; /* support alpha for the window */
+            bool support_alpha = false; /* support alpha for the window. If this is set to true then you need to call window.set_texture_blend_func before rendering textures and call window.set_render_blend_func afterwards to ensure correct alpha blending */
             bool hide_decorations = false; /* this is a hint, it may be ignored by the window manager */
             Color background_color = {0, 0, 0, 0};
             const char *class_name = nullptr;
@@ -107,6 +107,9 @@ namespace mgl {
         bool get_clipboard(ClipboardCallback callback);
         std::string get_clipboard_string();
 
+        void set_texture_blend_func();
+        void set_render_blend_func();
+
         WindowHandle get_system_handle() const;
 
         mgl_window* internal_window();
diff --git a/src/window/Window.cpp b/src/window/Window.cpp
index 339df71..0e80456 100644
--- a/src/window/Window.cpp
+++ b/src/window/Window.cpp
@@ -182,6 +182,14 @@ namespace mgl {
         return result;
     }
 
+    void Window::set_texture_blend_func() {
+        mgl_window_set_texture_blend_func(&window);
+    }
+
+    void Window::set_render_blend_func() {
+        mgl_window_set_render_blend_func(&window);
+    }
+
     WindowHandle Window::get_system_handle() const {
         return window.window;
     }