From 4a28361e058ed2ef6f827111b179bf7be41710ae Mon Sep 17 00:00:00 2001
From: Brad Davis <bdavis@saintandreas.org>
Date: Thu, 3 Sep 2015 22:12:21 -0700
Subject: [PATCH] Fix mirror to display on Oculus

---
 .../oculus/OculusDisplayPlugin.cpp            | 52 +++++--------------
 1 file changed, 12 insertions(+), 40 deletions(-)

diff --git a/libraries/display-plugins/src/display-plugins/oculus/OculusDisplayPlugin.cpp b/libraries/display-plugins/src/display-plugins/oculus/OculusDisplayPlugin.cpp
index 2ed5e69fe7..c8d9993e5a 100644
--- a/libraries/display-plugins/src/display-plugins/oculus/OculusDisplayPlugin.cpp
+++ b/libraries/display-plugins/src/display-plugins/oculus/OculusDisplayPlugin.cpp
@@ -310,8 +310,6 @@ void OculusDisplayPlugin::activate() {
     // not needed since the structure was zeroed on init, but explicit
     sceneLayer.ColorTexture[1] = nullptr;
 
-    PerformanceTimer::setActive(true);
-
     if (!OVR_SUCCESS(ovr_ConfigureTracking(_hmd,
         ovrTrackingCap_Orientation | ovrTrackingCap_Position | ovrTrackingCap_MagYawCorrection, 0))) {
         qFatal("Could not attach to sensor device");
@@ -322,15 +320,12 @@ void OculusDisplayPlugin::activate() {
 void OculusDisplayPlugin::customizeContext() {
     WindowOpenGLDisplayPlugin::customizeContext();
 #if (OVR_MAJOR_VERSION >= 6)
-    //_texture = DependencyManager::get<TextureCache>()->
-    //    getImageTexture(PathUtils::resourcesPath() + "/images/cube_texture.png");
-    uvec2 mirrorSize = toGlm(_window->geometry().size());
-
     _sceneFbo = SwapFboPtr(new SwapFramebufferWrapper(_hmd));
     _sceneFbo->Init(getRecommendedRenderSize());
 #endif
     enableVsync(false);
-    isVsyncEnabled();
+    // Only enable mirroring if we know vsync is disabled
+    _enableMirror = !isVsyncEnabled();
 }
 
 void OculusDisplayPlugin::deactivate() {
@@ -338,7 +333,6 @@ void OculusDisplayPlugin::deactivate() {
     makeCurrent();
     _sceneFbo.reset();
     doneCurrent();
-    PerformanceTimer::setActive(false);
 
     WindowOpenGLDisplayPlugin::deactivate();
 
@@ -355,6 +349,16 @@ void OculusDisplayPlugin::display(GLuint finalTexture, const glm::uvec2& sceneSi
     // controlling vsync
     wglSwapIntervalEXT(0);
 
+    // screen mirroring
+    if (_enableMirror) {
+        auto windowSize = toGlm(_window->size());
+        Context::Viewport(windowSize.x, windowSize.y);
+        glBindTexture(GL_TEXTURE_2D, finalTexture);
+        GLenum err = glGetError();
+        Q_ASSERT(0 == err);
+        drawUnitQuad();
+    }
+
     _sceneFbo->Bound([&] {
         auto size = _sceneFbo->size;
         Context::Viewport(size.x, size.y);
@@ -369,25 +373,7 @@ void OculusDisplayPlugin::display(GLuint finalTexture, const glm::uvec2& sceneSi
     });
 
     auto windowSize = toGlm(_window->size());
-
-    /* 
-       Two alternatives for mirroring to the screen, the first is to copy our own composited
-       scene to the window framebuffer, before distortion.  Note this only works if we're doing
-       ui compositing ourselves, and not relying on the Oculus SDK compositor (or we don't want 
-       the UI visible in the output window (unlikely).  This should be done before 
-       _sceneFbo->Increment or we're be using the wrong texture
-    */
-    if (_enableMirror) {
-        _sceneFbo->Bound(Framebuffer::Target::Read, [&] {
-            glBlitFramebuffer(
-                0, 0, _sceneFbo->size.x, _sceneFbo->size.y,
-                0, 0, windowSize.x, windowSize.y,
-                GL_COLOR_BUFFER_BIT, GL_NEAREST);
-        });
-    }
-
     {
-        PerformanceTimer("OculusSubmit");
         ovrViewScaleDesc viewScaleDesc;
         viewScaleDesc.HmdSpaceToWorldScaleInMeters = 1.0f;
         viewScaleDesc.HmdToEyeViewOffset[0] = _eyeOffsets[0];
@@ -401,20 +387,6 @@ void OculusDisplayPlugin::display(GLuint finalTexture, const glm::uvec2& sceneSi
     }
     _sceneFbo->Increment();
 
-    /* 
-        The other alternative for mirroring is to use the Oculus mirror texture support, which 
-        will contain the post-distorted and fully composited scene regardless of how many layers 
-        we send.
-        Currently generates an error.
-    */
-    //auto mirrorSize = _mirrorFbo->size;
-    //_mirrorFbo->Bound(Framebuffer::Target::Read, [&] {
-    //    Context::BlitFramebuffer(
-    //        0, mirrorSize.y, mirrorSize.x, 0,
-    //        0, 0, windowSize.x, windowSize.y,
-    //        BufferSelectBit::ColorBuffer, BlitFilter::Nearest);
-    //});
-
     ++_frameIndex;
 #endif
 }