partially implement external display clipping
we perform external display clipping only on the GL
side (ie: not done on the h/w composer side, which is
harder and would be too risky). in practice this means
that WFD will be clipped properly, while HDMI *may* or
may not depending on how hwc is used.
Bug: 7149437
Change-Id: I92d4d04220db72b6ffb134c7fa7a93af569723a5
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 26e9c60..7ee6e5e 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -1500,6 +1500,28 @@
drawWormhole(hw, region);
}
}
+
+ if (hw->getDisplayType() >= DisplayDevice::DISPLAY_EXTERNAL) {
+ // TODO: just to be on the safe side, we don't set the
+ // scissor on the main display. It should never be needed
+ // anyways (though in theory it could since the API allows it).
+ const Rect& bounds(hw->getBounds());
+ const Transform& tr(hw->getTransform());
+ const Rect scissor(tr.transform(hw->getViewport()));
+ if (scissor != bounds) {
+ // scissor doesn't match the screen's dimensions, so we
+ // need to clear everything outside of it and enable
+ // the GL scissor so we don't draw anything where we shouldn't
+ const GLint height = hw->getHeight();
+ glScissor(scissor.left, height - scissor.bottom,
+ scissor.getWidth(), scissor.getHeight());
+ // clear everything unscissored
+ glClearColor(0, 0, 0, 0);
+ glClear(GL_COLOR_BUFFER_BIT);
+ // enable scissor for this frame
+ glEnable(GL_SCISSOR_TEST);
+ }
+ }
}
/*
@@ -1552,6 +1574,9 @@
}
}
}
+
+ // disable scissor at the end of the frame
+ glDisable(GL_SCISSOR_TEST);
}
void SurfaceFlinger::drawWormhole(const sp<const DisplayDevice>& hw,
