Initial revision

git-svn-id: file:///fltk/svn/fltk/trunk@2 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

1 files changed, 157 insertions, 0 deletions

diff --git a/src/Fl_Double_Window.cxx b/src/Fl_Double_Window.cxx
new file mode 100644
index 000000000..aa285a5d2
--- /dev/null
+++ b/src/Fl_Double_Window.cxx
@@ -0,0 +1,157 @@
+// Fl_Double_Window.C
+
+// A double-buffered window.  This is achieved by using the Xdbe extension,
+// or a pixmap if that is not available.
+
+// On systems that support double buffering "naturally" the base
+// Fl_Window class will probably do double-buffer and this subclass
+// does nothing.
+
+#include <config.h>
+#include <FL/Fl.H>
+#include <FL/Fl_Double_Window.H>
+#include <FL/x.H>
+#include <FL/fl_draw.H>
+
+#if USE_XDBE
+
+#include <X11/extensions/Xdbe.h>
+
+static int use_xdbe;
+
+static int can_xdbe() {
+  static int tried;
+  if (!tried) {
+    tried = 1;
+    int event_base, error_base;
+    if (!XdbeQueryExtension(fl_display, &event_base, &error_base)) return 0;
+    Drawable root = RootWindow(fl_display,fl_screen);
+    int numscreens = 1;
+    XdbeScreenVisualInfo *a = XdbeGetVisualInfo(fl_display,&root,&numscreens);
+    if (!a) return 0;
+    for (int j = 0; j < a->count; j++)
+      if (a->visinfo[j].visual == fl_visual->visualid
+	  /*&& a->visinfo[j].perflevel > 0*/) {use_xdbe = 1; break;}
+    XdbeFreeVisualInfo(a);
+  }
+  return use_xdbe;
+}
+#endif
+
+void Fl_Double_Window::show() {
+#ifndef WIN32
+  if (!shown()) { // don't set the background pixel
+    fl_open_display();
+    Fl_X::make_xid(this);
+    return;
+  }
+#endif
+  Fl_Window::show();
+}
+
+#ifdef WIN32
+
+// Code to switch output to an off-screen window:
+// this is lame, I allow two to exist...
+
+static HDC blt_gc[2];
+
+void fl_switch_offscreen(HBITMAP bitmap) {
+  if (!blt_gc[0]) for (int i = 0; i < 2; i++) {
+    blt_gc[i] = CreateCompatibleDC(fl_gc);
+    SetTextAlign(blt_gc[i], TA_BASELINE|TA_LEFT);
+    SetBkMode(blt_gc[i], TRANSPARENT);
+#if USE_COLORMAP
+    if (fl_palette) SelectPalette(blt_gc[i], fl_palette, FALSE);
+#endif
+  }
+  int which = 0; if (fl_gc == blt_gc[0]) which = 1;
+  SelectObject(blt_gc[which], bitmap);
+  fl_gc = blt_gc[which];
+}
+
+void fl_copy_offscreen(int x,int y,int w,int h,HBITMAP bitmap,int srcx,int srcy) {
+  int which = 0; if (fl_gc == blt_gc[0]) which = 1;
+  SelectObject(blt_gc[which], bitmap);
+  BitBlt(fl_gc, x, y, w, h, blt_gc[which], srcx, srcy, SRCCOPY);
+}
+
+#endif
+
+// protected method used by Fl_Overlay_Window to fake overlay:
+void Fl_Double_Window::_flush(int eraseoverlay) {
+  make_current(); // make sure fl_gc is non-zero
+  Fl_X *i = Fl_X::i(this);
+  if (!i->other_xid) {
+#if USE_XDBE
+    if (can_xdbe()) i->other_xid =
+      XdbeAllocateBackBufferName(fl_display, fl_xid(this), XdbeCopied);
+    else
+#endif
+      i->other_xid = fl_create_offscreen(w(), h());
+    clear_damage(~0);
+  }
+  XRectangle rect = {0,0,w(),h()};
+  if (damage()) {
+    if (i->region && !eraseoverlay) XClipBox(i->region, &rect);
+    if (	// don't draw if back buffer is ok
+#if USE_XDBE
+	use_xdbe ||
+#endif
+	damage() != 2) {
+#ifdef WIN32
+      fl_begin_offscreen(i->other_xid);
+      fl_clip_region(i->region); i->region = 0;
+      draw();
+      fl_end_offscreen();
+#else
+      fl_window = i->other_xid;
+      fl_clip_region(i->region); i->region = 0;
+      draw();
+      fl_window = i->xid;
+#endif
+    }
+  }
+  fl_clip_region(0);
+#if USE_XDBE
+  if (use_xdbe) {
+    XdbeSwapInfo s;
+    s.swap_window = fl_xid(this);
+    s.swap_action = XdbeCopied;
+    XdbeSwapBuffers(fl_display,&s,1);
+  } else
+#endif
+    fl_copy_offscreen(rect.x, rect.y, rect.width, rect.height,
+		      i->other_xid, rect.x, rect.y);
+}
+
+void Fl_Double_Window::flush() {_flush(0);}
+
+void Fl_Double_Window::resize(int X,int Y,int W,int H) {
+  int ow = w();
+  int oh = h();
+  Fl_Window::resize(X,Y,W,H);
+#if USE_XDBE
+  if (use_xdbe) return;
+#endif
+  Fl_X* i = Fl_X::i(this);
+  if (i && i->other_xid && (ow != w() || oh != h())) {
+    fl_delete_offscreen(i->other_xid);
+    i->other_xid = 0;
+  }
+}
+
+void Fl_Double_Window::hide() {
+  Fl_X* i = Fl_X::i(this);
+  if (i && i->other_xid) {
+#if USE_XDBE
+    if (!use_xdbe)
+#endif
+      fl_delete_offscreen(i->other_xid);
+  }
+  Fl_Window::hide();
+}
+
+Fl_Double_Window::~Fl_Double_Window() {
+  hide();
+}