From 601b30f0628aaa2466e59984ecd91ec3c875d654 Mon Sep 17 00:00:00 2001
From: SamGondelman <samuel_gondelman@alumni.brown.edu>
Date: Thu, 5 Oct 2017 15:31:45 -0700
Subject: [PATCH] fix flash when switching display modes

---
 .../display-plugins/OpenGLDisplayPlugin.cpp   | 22 ++++++++++---------
 .../display-plugins/hmd/HmdDisplayPlugin.cpp  |  2 +-
 2 files changed, 13 insertions(+), 11 deletions(-)

diff --git a/libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.cpp b/libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.cpp
index 93e648f441..13abcbadc6 100644
--- a/libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.cpp
+++ b/libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.cpp
@@ -564,17 +564,19 @@ void OpenGLDisplayPlugin::updateFrameData() {
 
 std::function<void(gpu::Batch&, const gpu::TexturePointer&)> OpenGLDisplayPlugin::getHUDOperator() {
     return [this](gpu::Batch& batch, const gpu::TexturePointer& hudTexture) {
-        batch.enableStereo(false);
-        batch.setPipeline(_hudPipeline);
-        batch.setResourceTexture(0, hudTexture);
-        if (isStereo()) {
-            for_each_eye([&](Eye eye) {
-                batch.setViewportTransform(eyeViewport(eye, getRecommendedRenderSize()));
+        if (_hudPipeline) {
+            batch.enableStereo(false);
+            batch.setPipeline(_hudPipeline);
+            batch.setResourceTexture(0, hudTexture);
+            if (isStereo()) {
+                for_each_eye([&](Eye eye) {
+                    batch.setViewportTransform(eyeViewport(eye, getRecommendedRenderSize()));
+                    batch.draw(gpu::TRIANGLE_STRIP, 4);
+                });
+            } else {
+                batch.setViewportTransform(ivec4(uvec2(0), getRecommendedRenderSize()));
                 batch.draw(gpu::TRIANGLE_STRIP, 4);
-            });
-        } else {
-            batch.setViewportTransform(ivec4(uvec2(0), getRecommendedRenderSize()));
-            batch.draw(gpu::TRIANGLE_STRIP, 4);
+            }
         }
     };
 }
diff --git a/libraries/display-plugins/src/display-plugins/hmd/HmdDisplayPlugin.cpp b/libraries/display-plugins/src/display-plugins/hmd/HmdDisplayPlugin.cpp
index e5e1295786..053f3171be 100644
--- a/libraries/display-plugins/src/display-plugins/hmd/HmdDisplayPlugin.cpp
+++ b/libraries/display-plugins/src/display-plugins/hmd/HmdDisplayPlugin.cpp
@@ -431,8 +431,8 @@ std::function<void(gpu::Batch&, const gpu::TexturePointer&)> HmdDisplayPlugin::H
     updatePipeline();
     return [this](gpu::Batch& batch, const gpu::TexturePointer& hudTexture) {
         if (pipeline) {
-
             batch.setPipeline(pipeline);
+
             batch.setInputFormat(format);
             gpu::BufferView posView(vertices, VERTEX_OFFSET, vertices->getSize(), VERTEX_STRIDE, format->getAttributes().at(gpu::Stream::POSITION)._element);
             gpu::BufferView uvView(vertices, TEXTURE_OFFSET, vertices->getSize(), VERTEX_STRIDE, format->getAttributes().at(gpu::Stream::TEXCOORD)._element);