From 3abf13106680aa161d5a3d5530de8d2f6a610f5c Mon Sep 17 00:00:00 2001
From: Mathias Agopian <mathias@google.com>
Date: Tue, 7 Jan 2025 11:43:39 -0800
Subject: [PATCH] Trivial clean-ups that shouldn't affect the behavior

We add an offset to the shadowmap viewport, but in this change
it is always set to (0,0)
---
 filament/src/ShadowMap.cpp        | 14 +++++++++-----
 filament/src/ShadowMap.h          |  4 +++-
 filament/src/ShadowMapManager.cpp | 16 ++++------------
 filament/src/ShadowMapManager.h   |  3 ++-
 4 files changed, 18 insertions(+), 19 deletions(-)

diff --git a/filament/src/ShadowMap.cpp b/filament/src/ShadowMap.cpp
index 35fa104dcdc..1115bbcba24 100644
--- a/filament/src/ShadowMap.cpp
+++ b/filament/src/ShadowMap.cpp
@@ -1296,6 +1296,10 @@ void ShadowMap::updateSceneInfoSpot(mat4f const& Mv, FScene const& scene,
             }
     );
 }
+void ShadowMap::setAllocation(uint8_t layer, backend::Viewport viewport) noexcept {
+    mLayer = layer;
+    mOffset = { viewport.left, viewport.bottom };
+}
 
 backend::Viewport ShadowMap::getViewport() const noexcept {
     // We set a viewport with a 1-texel border for when we index outside the texture.
@@ -1305,7 +1309,7 @@ backend::Viewport ShadowMap::getViewport() const noexcept {
     // can work properly if the shadowmap is in an atlas (and we can't rely on h/w clamp).
     const uint32_t dim = mOptions->mapSize;
     const uint16_t border = 1u;
-    return { border, border, dim - 2u * border, dim - 2u * border };
+    return { mOffset.x + border, mOffset.y + border, dim - 2u * border, dim - 2u * border };
 }
 
 backend::Viewport ShadowMap::getScissor() const noexcept {
@@ -1319,10 +1323,10 @@ backend::Viewport ShadowMap::getScissor() const noexcept {
     const uint16_t border = 1u;
     switch (mShadowType) {
         case ShadowType::DIRECTIONAL:
-            return { border, border, dim - 2u * border, dim - 2u * border };
+            return { mOffset.x + border, mOffset.y + border, dim - 2u * border, dim - 2u * border };
         case ShadowType::SPOT:
         case ShadowType::POINT:
-            return { 0, 0, dim, dim };
+            return { mOffset.x, mOffset.y, dim, dim };
     }
 }
 
@@ -1345,8 +1349,8 @@ math::float4 ShadowMap::getClampToEdgeCoords(ShadowMapInfo const& shadowMapInfo)
 
     float const texel = 1.0f / float(shadowMapInfo.atlasDimension);
     float const dim = float(mOptions->mapSize);
-    float const l = border;
-    float const b = border;
+    float const l = float(mOffset.x) + border;
+    float const b = float(mOffset.y) + border;
     float const w = dim - 2.0f * border;
     float const h = dim - 2.0f * border;
     float4 const v = float4{ l, b, l + w, b + h } * texel;
diff --git a/filament/src/ShadowMap.h b/filament/src/ShadowMap.h
index cf131d4f64d..1da8b10e2b1 100644
--- a/filament/src/ShadowMap.h
+++ b/filament/src/ShadowMap.h
@@ -179,7 +179,8 @@ class ShadowMap {
     LightManager::ShadowOptions const* getShadowOptions() const noexcept { return mOptions; }
     size_t getLightIndex() const { return mLightIndex; }
     uint16_t getShadowIndex() const { return mShadowIndex; }
-    void setLayer(uint8_t layer) noexcept { mLayer = layer; }
+    void setAllocation(uint8_t layer, backend::Viewport viewport) noexcept;
+
     uint8_t getLayer() const noexcept { return mLayer; }
     backend::Viewport getViewport() const noexcept;
     backend::Viewport getScissor() const noexcept;
@@ -353,6 +354,7 @@ class ShadowMap {
     ShadowType mShadowType  : 2;                                            // :2
     bool mHasVisibleShadows : 2;                                            // :2
     uint8_t mFace           : 3;                                            // :3
+    math::ushort2 mOffset{};                                                // 4
 };
 
 } // namespace filament
diff --git a/filament/src/ShadowMapManager.cpp b/filament/src/ShadowMapManager.cpp
index 158259bdcf3..25e8815280d 100644
--- a/filament/src/ShadowMapManager.cpp
+++ b/filament/src/ShadowMapManager.cpp
@@ -979,13 +979,13 @@ void ShadowMapManager::calculateTextureRequirements(FEngine& engine, FView& view
         auto const& options = shadowMap.getShadowOptions();
         maxDimension = std::max(maxDimension, options->mapSize);
         elvsm = elvsm || options->vsm.elvsm;
-        shadowMap.setLayer(layer++);
+        shadowMap.setAllocation(layer++, {});
     }
     for (ShadowMap& shadowMap : getSpotShadowMaps()) {
         auto const& options = shadowMap.getShadowOptions();
         maxDimension = std::max(maxDimension, options->mapSize);
         elvsm = elvsm || options->vsm.elvsm;
-        shadowMap.setLayer(layer++);
+        shadowMap.setAllocation(layer++, {});
     }
 
     const uint8_t layersNeeded = layer;
@@ -1003,17 +1003,9 @@ void ShadowMapManager::calculateTextureRequirements(FEngine& engine, FView& view
     TextureFormat format = TextureFormat::DEPTH16;
     if (view.hasVSM()) {
         if (vsmShadowOptions.highPrecision) {
-            if (elvsm) {
-                format = TextureFormat::RGBA32F;
-            } else {
-                format = TextureFormat::RG32F;
-            }
+            format = elvsm ? TextureFormat::RGBA32F : TextureFormat::RG32F;
         } else {
-            if (elvsm) {
-                format = TextureFormat::RGBA16F;
-            } else {
-                format = TextureFormat::RG16F;
-            }
+            format = elvsm ? TextureFormat::RGBA16F : TextureFormat::RG16F;
         }
     }
 
diff --git a/filament/src/ShadowMapManager.h b/filament/src/ShadowMapManager.h
index 28df0f73206..964be0d1593 100644
--- a/filament/src/ShadowMapManager.h
+++ b/filament/src/ShadowMapManager.h
@@ -17,12 +17,13 @@
 #ifndef TNT_FILAMENT_DETAILS_SHADOWMAPMANAGER_H
 #define TNT_FILAMENT_DETAILS_SHADOWMAPMANAGER_H
 
-#include "Culler.h"
+#include "AtlasAllocator.h"
 #include "ShadowMap.h"
 #include "ds/TypedBuffer.h"
 
 #include <filament/LightManager.h>
 #include <filament/Options.h>
+#include <filament/Viewport.h>
 
 #include <private/filament/EngineEnums.h>
 #include <private/filament/UibStructs.h>