From 970be9d2c567a904f0527c304ae893d2aa5ca053 Mon Sep 17 00:00:00 2001
From: Ryan Huffman <ryanhuffman@gmail.com>
Date: Fri, 21 Apr 2017 01:10:54 -0700
Subject: [PATCH] Add check for canPopulate to gpu backend

---
 libraries/gpu-gl/src/gpu/gl/GLTexture.cpp   | 6 ++++--
 libraries/gpu-gl/src/gpu/gl/GLTexture.h     | 4 ++--
 libraries/gpu-gl/src/gpu/gl41/GL41Backend.h | 2 +-
 3 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/libraries/gpu-gl/src/gpu/gl/GLTexture.cpp b/libraries/gpu-gl/src/gpu/gl/GLTexture.cpp
index 1179403bff..f1bf76b39d 100644
--- a/libraries/gpu-gl/src/gpu/gl/GLTexture.cpp
+++ b/libraries/gpu-gl/src/gpu/gl/GLTexture.cpp
@@ -437,6 +437,7 @@ void GLVariableAllocationSupport::updateMemoryPressure() {
     size_t idealMemoryAllocation = 0;
     bool canDemote = false;
     bool canPromote = false;
+    bool canPopulate = false;
     bool hasTransfers = false;
     for (const auto& texture : strongTextures) {
         // Race conditions can still leave nulls in the list, so we need to check
@@ -450,7 +451,8 @@ void GLVariableAllocationSupport::updateMemoryPressure() {
         // Track how much we're actually using
         totalVariableMemoryAllocation += gltexture->size();
         canDemote |= vartexture->canDemote();
-        canPromote |= vartexture->canPromote() || (texture->minAvailableMipLevel() < vartexture->_allocatedMip);
+        canPromote |= vartexture->canPromote();
+        canPopulate |= vartexture->canPopulate();
         hasTransfers |= vartexture->hasPendingTransfers();
     }
 
@@ -464,7 +466,7 @@ void GLVariableAllocationSupport::updateMemoryPressure() {
     } else if (pressure > OVERSUBSCRIBED_PRESSURE_VALUE && canDemote) {
         qDebug() << "Demoting";
         newState = MemoryPressureState::Oversubscribed;
-    } else if (pressure < UNDERSUBSCRIBED_PRESSURE_VALUE && unallocated != 0 && canPromote) {
+    } else if (pressure < UNDERSUBSCRIBED_PRESSURE_VALUE && ((unallocated != 0 && canPromote) || canPopulate)) {
         qDebug() << "Promoting";
         newState = MemoryPressureState::Undersubscribed;
     }
diff --git a/libraries/gpu-gl/src/gpu/gl/GLTexture.h b/libraries/gpu-gl/src/gpu/gl/GLTexture.h
index bc8467b808..9aad49546e 100644
--- a/libraries/gpu-gl/src/gpu/gl/GLTexture.h
+++ b/libraries/gpu-gl/src/gpu/gl/GLTexture.h
@@ -112,11 +112,11 @@ protected:
     static void manageMemory();
 
     //bool canPromoteNoAllocate() const { return _allocatedMip < _populatedMip; }
-    bool canPromote() const { return _allocatedMip > 0 || _populatedMip > 0; }
+    virtual bool canPopulate() const = 0;
+    bool canPromote() const { return _allocatedMip > 0; }
     bool canDemote() const { return _allocatedMip < _maxAllocatedMip; }
     bool hasPendingTransfers() const { return _pendingTransfers.size() > 0; }
     void executeNextTransfer(const TexturePointer& currentTexture);
-    virtual bool canPopulate() const = 0;
     virtual void populateTransferQueue() = 0;
     virtual void promote() = 0;
     virtual void demote() = 0;
diff --git a/libraries/gpu-gl/src/gpu/gl41/GL41Backend.h b/libraries/gpu-gl/src/gpu/gl41/GL41Backend.h
index c0b9ea0e45..dc6d2b3aa7 100644
--- a/libraries/gpu-gl/src/gpu/gl41/GL41Backend.h
+++ b/libraries/gpu-gl/src/gpu/gl41/GL41Backend.h
@@ -100,7 +100,7 @@ public:
         GL41VariableAllocationTexture(const std::weak_ptr<GLBackend>& backend, const Texture& texture);
         ~GL41VariableAllocationTexture();
 
-        bool canPopulate() const override { return _gpuObject.isStoredMipFaceAvailable(_populatedMip - 1, 0); }
+        bool canPopulate() const override { return _populatedMip > _allocatedMip && _gpuObject.isStoredMipFaceAvailable(_populatedMip - 1, 0); }
         void allocateStorage(uint16 allocatedMip);
         void syncSampler() const override;
         void promote() override;