New context_changed() function for OpenGL windows allowing efficient texture loading (str #1372)

git-svn-id: file:///fltk/svn/fltk/branches/branch-1.1@5322 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

CHANGES

@@ -1,5 +1,7 @@
 CHANGES IN FLTK 1.1.8
 
+	- Added "context_changed()" function for OpenGL windows
+	  which allows efficent texture loading (STR #1372)
 	- Added missing "const" to GLUT call (STR #1371)
 	- Fixed stray FL_RELEASE events after clicking system
 	  areas on OS X (STR #1376)

FL/Fl_Gl_Window.H

@@ -41,7 +41,7 @@ class FL_EXPORT Fl_Gl_Window : public Fl_Window {
   const int *alist;
   Fl_Gl_Choice *g;
   GLContext context_;
-  char valid_;
+  char valid_f_;
   char damage1_; // damage() of back buffer
   virtual void draw_overlay();
   void init();
@@ -61,10 +61,13 @@ public:
   void hide();
   void resize(int,int,int,int);
 
-  char valid() const {return valid_;}
-  void valid(char v) {valid_ = v;}
+  char valid() const {return valid_f_ & 1;}
+  void valid(char v) {if (v) valid_f_ |= 1; else valid_f_ &= 0xfe;}
   void invalidate();
 
+  char context_valid() const {return valid_f_ & 2;}
+  void context_valid(char v) {if (v) valid_f_ |= 2; else valid_f_ &= 0xfd;}
+
   static int can_do(int m) {return can_do(m,0);}
   static int can_do(const int *m) {return can_do(0, m);}
   int can_do() {return can_do(mode_,alist);}

documentation/Fl_Gl_Window.html

@@ -58,6 +58,7 @@ unless those Widgets are modified to draw using OpenGL calls.</P>
 </TD><TD align=left valign=top>
 <UL>
 <LI><A href=#Fl_Gl_Window.context>context</A></LI>
+<LI><A href=#Fl_Gl_Window.context_valid>context_valid</A></LI>
 <LI><A href=#Fl_Gl_Window.draw>draw</A></LI>
 <LI><A href=#Fl_Gl_Window.draw_overlay>draw_overlay</A></LI>
 </UL>
@@ -164,9 +165,11 @@ void mywindow::draw() {
   if (!valid()) {
     glViewport(0,0,w(),h());
     glFrustum(...);
-    glLight(...);
     ...other initialization...
   }
+  if (!context_valid()) {
+    ...load textures, etc. ...
+  }
   ... draw your geometry here ...
 }
 </PRE></UL>
@@ -178,6 +181,14 @@ draw()</TT> returns.
 <H4><A name=Fl_Gl_Window.invalidate>void Fl_Gl_Window::invalidate()</A></H4>
  The <TT>invalidate()</TT> method turns off <TT>valid()</TT> and is
 equivalent to calling <TT>value(0)</TT>.
+
+<H4><A name=Fl_Gl_Window.context_valid>char Fl_Gl_Window::context_valid() const
+<BR> void Fl_Gl_Window::context_valid(char i)</A></H4>
+<TT>Fl_Gl_Window::context_valid()</TT> will only be set if the 
+OpenGL context is created or recreated. It differs from
+<TT>Fl_Gl_Window::valid()</TT> which is also set whenever the context
+changes size.
+
 <H4><A name=Fl_Gl_Window.ortho>void Fl_Gl_Window::ortho()</A></H4>
  Set the projection so 0,0 is in the lower left of the window and each
 pixel is 1 unit wide/tall.  If you are drawing 2D images, your <TT>

src/Fl_Gl_Window.cxx

@@ -88,8 +88,12 @@ void Fl_Gl_Window::show() {
 
 void Fl_Gl_Window::invalidate() {
   valid(0);
+  context_valid(0);
 #ifndef WIN32
-  if (overlay) ((Fl_Gl_Window*)overlay)->valid(0);
+  if (overlay) {
+    ((Fl_Gl_Window*)overlay)->valid(0);
+    ((Fl_Gl_Window*)overlay)->context_valid(0);
+  }
 #endif
 }
 
@@ -137,6 +141,7 @@ void Fl_Gl_Window::make_current() {
     mode_ &= ~NON_LOCAL_CONTEXT;
     context_ = fl_create_gl_context(this, g);
     valid(0);
+    context_valid(0);
   }
   fl_set_gl_context(this, context_);
 
@@ -215,7 +220,10 @@ int fl_overlay_depth = 0;
 #endif
 
 void Fl_Gl_Window::flush() {
-  uchar save_valid = valid_;
+  uchar save_valid = valid_f_ & 1;
+#if HAVE_GL_OVERLAY && defined(WIN32)
+  uchar save_valid_f = valid_f_;
+#endif
 
 #ifdef __APPLE_QD__
   //: clear previous clipping in this shared port
@@ -256,7 +264,7 @@ void Fl_Gl_Window::flush() {
     fl_overlay = 1;
     draw_overlay();
     fl_overlay = 0;
-    valid(save_valid);
+    valid_f_ = save_valid_f;
     wglSwapLayerBuffers(Fl_X::i(this)->private_dc, WGL_SWAP_OVERLAY1);
     // if only the overlay was damaged we are done, leave main layer alone:
     if (damage() == FL_DAMAGE_OVERLAY) {
@@ -357,6 +365,7 @@ void Fl_Gl_Window::flush() {
   if (fixcursor) SetCursor(Fl_X::i(this)->cursor);
 #endif
   valid(1);
+  context_valid(1);
 }
 
 void Fl_Gl_Window::resize(int X,int Y,int W,int H) {
@@ -408,7 +417,7 @@ void Fl_Gl_Window::init() {
   context_ = 0;
   g        = 0;
   overlay  = 0;
-  valid_   = 0;
+  valid_f_ = 0;
   damage1_ = 0;
 
 #if 0 // This breaks resizing on Linux/X11

test/CubeView.cxx

@@ -40,8 +40,8 @@ CubeView::CubeView(int x,int y,int w,int h,const char *l)
     vAng = 0.0;
     hAng=0.0;
     size=10.0;
-	xshift=0.0;
-	yshift=0.0;
+    xshift=0.0;
+    yshift=0.0;
     
     /* The cube definition. These are the vertices of a unit cube
      * centered on the origin.*/

test/CubeViewUI.fl

@@ -1,5 +1,5 @@
 # data file for the Fltk User Interface Designer (fluid)
-version 1.0100 
+version 1.0108 
 header_name {.h} 
 code_name {.cxx}
 class CubeViewUI {open
@@ -7,7 +7,7 @@ class CubeViewUI {open
   Function {CubeViewUI()} {open
   } {
     Fl_Window mainWindow {
-      label CubeView open selected
+      label CubeView open
       private xywh {428 124 415 405} type Double box UP_BOX labelsize 12 resizable visible
     } {
       Fl_Group {} {open
@@ -47,14 +47,14 @@ cube->redraw();}
           }
         }
         Fl_Group MainView {open
-          xywh {46 27 333 333}
+          xywh {46 27 333 333} resizable
         } {
           Fl_Box cframe {
             xywh {46 27 333 333} box DOWN_FRAME color 4 selection_color 69
           }
           Fl_Box cube {
-            label {This is the cube_view}
-            xywh {48 29 329 329} align 16
+            label {This is the cube_view} selected
+            xywh {48 29 329 329} align 16 resizable
             code0 {\#include "CubeView.h"}
             class CubeView
           }