From d7bc037c0164de1431e24bc470f45e0242dce1a0 Mon Sep 17 00:00:00 2001
From: assiduous <assiduous@diligentgraphics.com>
Date: Mon, 14 Oct 2024 17:46:55 -0700
Subject: [PATCH] DynamicTextureAtlas: added growth factor parameter

---
 Graphics/GraphicsTools/interface/DynamicTextureAtlas.h | 9 ++++++---
 Graphics/GraphicsTools/src/DynamicTextureAtlas.cpp     | 6 ++++--
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/Graphics/GraphicsTools/interface/DynamicTextureAtlas.h b/Graphics/GraphicsTools/interface/DynamicTextureAtlas.h
index f1e805c16..7b88b0ee3 100644
--- a/Graphics/GraphicsTools/interface/DynamicTextureAtlas.h
+++ b/Graphics/GraphicsTools/interface/DynamicTextureAtlas.h
@@ -1,5 +1,5 @@
 /*
- *  Copyright 2019-2023 Diligent Graphics LLC
+ *  Copyright 2019-2024 Diligent Graphics LLC
  *  Copyright 2015-2019 Egor Yusov
  *
  *  Licensed under the Apache License, Version 2.0 (the "License");
@@ -224,10 +224,13 @@ struct DynamicTextureAtlasCreateInfo
     /// The number of extra slices.
 
     /// When non-zero, the array will be expanded by the specified number of slices every time
-    /// there is insufficient space. If zero, the array size will be doubled when
-    /// more space is needed.
+    /// there is insufficient space. If zero, the array size will be expanded by the growth factor.
     Uint32 ExtraSliceCount = 0;
 
+    /// Growth factor.
+
+    /// If ExtraSliceCount is zero, defines the factor by which the array size will be expanded.
+    float GrowthFactor = 2.0f;
 
     /// Maximum number of slices in texture array.
     Uint32 MaxSliceCount = 2048;
diff --git a/Graphics/GraphicsTools/src/DynamicTextureAtlas.cpp b/Graphics/GraphicsTools/src/DynamicTextureAtlas.cpp
index 075e776da..313e5fbeb 100644
--- a/Graphics/GraphicsTools/src/DynamicTextureAtlas.cpp
+++ b/Graphics/GraphicsTools/src/DynamicTextureAtlas.cpp
@@ -1,5 +1,5 @@
 /*
- *  Copyright 2019-2023 Diligent Graphics LLC
+ *  Copyright 2019-2024 Diligent Graphics LLC
  *  Copyright 2015-2019 Egor Yusov
  *
  *  Licensed under the Apache License, Version 2.0 (the "License");
@@ -384,6 +384,7 @@ class DynamicTextureAtlasImpl final : public ObjectBase<IDynamicTextureAtlas>
         // clang-format off
         m_MinAlignment    {CreateInfo.MinAlignment},
         m_ExtraSliceCount {CreateInfo.ExtraSliceCount},
+        m_GrowthFactor    {clamp(CreateInfo.GrowthFactor, 1.f, 2.f)},
         m_MaxSliceCount   {CreateInfo.Desc.Type == RESOURCE_DIM_TEX_2D_ARRAY ? std::min(CreateInfo.MaxSliceCount, Uint32{2048}) : 1},
         m_Silent          {CreateInfo.Silent},
         m_SuballocationsAllocator
@@ -688,7 +689,7 @@ class DynamicTextureAtlasImpl final : public ObjectBase<IDynamicTextureAtlas>
         {
             const auto ExtraSliceCount = m_ExtraSliceCount != 0 ?
                 m_ExtraSliceCount :
-                std::max(m_TexArraySize.load(), 1u);
+                std::max(static_cast<Uint32>(static_cast<float>(m_TexArraySize.load()) * m_GrowthFactor), 1u);
 
             m_TexArraySize.store(std::min(m_TexArraySize + ExtraSliceCount, m_MaxSliceCount));
         }
@@ -721,6 +722,7 @@ class DynamicTextureAtlasImpl final : public ObjectBase<IDynamicTextureAtlas>
 
     const Uint32 m_MinAlignment;
     const Uint32 m_ExtraSliceCount;
+    const float  m_GrowthFactor;
     const Uint32 m_MaxSliceCount;
     const bool   m_Silent;