Render on a temporary surface when needed
Some platforms draw directly to the screen, which means that updates
will flicker if we draw multiple layers. Prevent this by first
composing the update on a hidden surface.
diff --git a/tests/fbperf.cxx b/tests/fbperf.cxx
index 8c71d96..7f1e2c1 100644
--- a/tests/fbperf.cxx
+++ b/tests/fbperf.cxx
@@ -72,6 +72,7 @@
protected:
Surface* overlay;
+ Surface* offscreen;
};
TestWindow::TestWindow() :
@@ -202,7 +203,7 @@
}
OverlayTestWindow::OverlayTestWindow() :
- overlay(NULL)
+ overlay(NULL), offscreen(NULL)
{
}
@@ -212,12 +213,21 @@
overlay = new Surface(400, 200);
overlay->clear(0xff, 0x80, 0x00, 0xcc);
+
+ // X11 needs an off screen buffer for compositing to avoid flicker
+#if !defined(WIN32) && !defined(__APPLE__)
+ offscreen = new Surface(w(), h());
+#else
+ offscreen = NULL;
+#endif
}
void OverlayTestWindow::stop()
{
PartialTestWindow::stop();
+ delete offscreen;
+ offscreen = NULL;
delete overlay;
overlay = NULL;
}
@@ -227,13 +237,15 @@
int ox, oy, ow, oh;
int X, Y, W, H;
+ // We cannot update the damage region from inside the draw function,
+ // so delegate this to an idle function
+ Fl::add_idle(timer, this);
+
// Check what actually needs updating
fl_clip_box(0, 0, w(), h(), X, Y, W, H);
if ((W == 0) || (H == 0))
return;
- PartialTestWindow::draw();
-
// We might get a redraw before we are fully ready
if (!overlay)
return;
@@ -243,16 +255,33 @@
fl_push_no_clip();
fl_push_clip(X, Y, W, H);
+ if (offscreen)
+ fb->draw(offscreen, X, Y, X, Y, W, H);
+ else
+ fb->draw(X, Y, X, Y, W, H);
+
+ pixels += W*H;
+ frames++;
+
ox = (w() - overlay->width()) / 2;
oy = h() / 4 - overlay->height() / 2;
ow = overlay->width();
oh = overlay->height();
fl_clip_box(ox, oy, ow, oh, X, Y, W, H);
- if ((W != 0) && (H != 0))
- overlay->draw(X - ox, Y - oy, X, Y, W, H);
+ if ((W != 0) && (H != 0)) {
+ if (offscreen)
+ overlay->draw(offscreen, X - ox, Y - oy, X, Y, W, H);
+ else
+ overlay->draw(X - ox, Y - oy, X, Y, W, H);
+ }
fl_pop_clip();
fl_pop_clip();
+
+ if (offscreen) {
+ fl_clip_box(0, 0, w(), h(), X, Y, W, H);
+ offscreen->draw(X, Y, X, Y, W, H);
+ }
}
static void dosubtest(TestWindow* win, int width, int height,