1 files changed, 86 insertions, 0 deletions
diff --git a/Src/Wasabi/api/wnd/wndclass/backbufferwnd.cpp b/Src/Wasabi/api/wnd/wndclass/backbufferwnd.cpp
new file mode 100644
index 00000000..10e0a04a
--- /dev/null
+++ b/Src/Wasabi/api/wnd/wndclass/backbufferwnd.cpp
@@ -0,0 +1,86 @@
+#include <precomp.h>
+#include "backbufferwnd.h"
+#include <tataki/canvas/bltcanvas.h>
+#include <api/api.h>
+#include <tataki/region/region.h>
+
+// -----------------------------------------------------------------------
+BackBufferWnd::BackBufferWnd() {
+  backbuffer = 0;
+  canvas_w = -1;
+  canvas_h = -1;
+  back_buffer = NULL;
+}               
+
+// -----------------------------------------------------------------------
+BackBufferWnd::~BackBufferWnd() {
+  delete back_buffer;
+}
+
+//------------------------------------------------------------------------
+BltCanvas *BackBufferWnd::getBackBuffer() {
+  return back_buffer;
+}
+
+// -----------------------------------------------------------------------
+int BackBufferWnd::onPaint(Canvas *canvas) {
+
+  BBWND_PARENT::onPaint(canvas);
+
+  if (!canvas) return 1;
+
+  RECT r;
+  getClientRect(&r);
+
+  if (back_buffer && r.right-r.left > 0 && r.bottom -r.top > 0) {
+
+    int w = r.right-r.left;
+    int h = r.bottom-r.top;
+
+    if (canvas_w != w || canvas_h != h) {
+      delete back_buffer;
+      back_buffer = new BltCanvas(w, h, getOsWindowHandle());
+      canvas_w = w;
+      canvas_h = h;
+    }
+
+#ifdef _WIN32
+    RegionI reg;
+    canvas->getClipRgn(&reg);
+    back_buffer->selectClipRgn(&reg);
+#else
+#warning port me
+#endif
+    canvas->blit(r.left, r.top, back_buffer, 0, 0, w, h);
+    back_buffer->selectClipRgn(NULL);
+  }
+
+  return 1;
+}
+
+int BackBufferWnd::onSiblingInvalidateRgn(api_region *r, ifc_window *who, int who_idx, int my_idx) {
+  if (who_idx >= my_idx || !wantBackBuffer()) return 0;
+
+  RECT rr;
+  getClientRect(&rr);
+
+  api_region *_r = getRegion();
+  RegionI *__r=NULL;
+
+  if (!_r) {
+    __r = new RegionI();
+    _r = __r;
+    _r->setRect(&rr);
+  } else {
+    _r->offset(rr.left, rr.top);
+  }
+
+  int intersect = _r->doesIntersectRgn(r);
+  if (intersect)
+    r->addRegion(_r);
+
+  delete __r;
+
+  return intersect;
+}
+