FLTK widgets in OpenGL 3 windows: rewrite for driver system.

1 files changed, 20 insertions, 0 deletions

diff --git a/src/drivers/WinAPI/Fl_WinAPI_Gl_Window_Driver.cxx b/src/drivers/WinAPI/Fl_WinAPI_Gl_Window_Driver.cxx
index 7952dfdc1..ca72d3e92 100644
--- a/src/drivers/WinAPI/Fl_WinAPI_Gl_Window_Driver.cxx
+++ b/src/drivers/WinAPI/Fl_WinAPI_Gl_Window_Driver.cxx
@@ -25,6 +25,10 @@
 #include "../GDI/Fl_Font.H"
 extern void fl_save_dc(HWND, HDC);
 
+#ifndef GL_CURRENT_PROGRAM
+#  define GL_CURRENT_PROGRAM 0x8B8D // from glew.h
+#endif
+
 // STR #3119: select pixel format with composition support
 // ... and no more than 32 color bits (8 bits/color)
 // Ref: PixelFormatDescriptor Object
@@ -368,6 +372,22 @@ void Fl_WinAPI_Gl_Window_Driver::get_list(Fl_Font_Descriptor *fd, int r) {
 }
 
 
+typedef void (WINAPI *glUseProgram_type)(GLint);
+static glUseProgram_type glUseProgram_f = NULL;
+
+void Fl_WinAPI_Gl_Window_Driver::switch_to_GL1() {
+  if (!glUseProgram_f) {
+    glUseProgram_f = (glUseProgram_type)GetProcAddress("glUseProgram");
+  }
+  glGetIntegerv(GL_CURRENT_PROGRAM, &current_prog);
+  if (current_prog) glUseProgram_f(0);
+}
+
+void Fl_WinAPI_Gl_Window_Driver::switch_back() {
+  if (current_prog) glUseProgram_f((GLuint)current_prog);
+}
+
+
 FL_EXPORT HGLRC fl_win32_glcontext(GLContext rc) { return (HGLRC)rc; }
 
 #endif // HAVE_GL