From bcd4b65f7d72ac388d2f50ca6ebf2a072b1f8397 Mon Sep 17 00:00:00 2001
From: Mathias Agopian <mathias@google.com>
Date: Fri, 23 Apr 2021 15:08:24 -0700
Subject: [PATCH] fix a memory corruption introduced recently

fixes #3844
---
 filament/include/filament/RenderTarget.h | 2 --
 filament/src/RenderTarget.cpp            | 4 ++--
 filament/src/details/RenderTarget.h      | 3 ++-
 3 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/filament/include/filament/RenderTarget.h b/filament/include/filament/RenderTarget.h
index dd4c4f688f..fd2d207b9d 100644
--- a/filament/include/filament/RenderTarget.h
+++ b/filament/include/filament/RenderTarget.h
@@ -59,8 +59,6 @@ public:
         COLOR  = COLOR0,     //!< identifies the 1st color attachment
     };
 
-    static constexpr size_t ATTACHMENT_COUNT = backend::MRT::MAX_SUPPORTED_RENDER_TARGET_COUNT + 1;
-
     //! Use Builder to construct a RenderTarget object instance
     class Builder : public BuilderBase<BuilderDetails> {
         friend struct BuilderDetails;
diff --git a/filament/src/RenderTarget.cpp b/filament/src/RenderTarget.cpp
index de4dc4513f..2abc74f710 100644
--- a/filament/src/RenderTarget.cpp
+++ b/filament/src/RenderTarget.cpp
@@ -28,7 +28,7 @@ namespace filament {
 using namespace backend;
 
 struct RenderTarget::BuilderDetails {
-    FRenderTarget::Attachment mAttachments[RenderTarget::ATTACHMENT_COUNT] = {};
+    FRenderTarget::Attachment mAttachments[FRenderTarget::ATTACHMENT_COUNT] = {};
     uint32_t mWidth{};
     uint32_t mHeight{};
     uint8_t mSamples = 1;   // currently not settable in the public facing API
@@ -127,7 +127,7 @@ FRenderTarget::FRenderTarget(FEngine& engine, const RenderTarget::Builder& build
         }
     };
 
-    for (size_t i = 0; i < ATTACHMENT_COUNT; i++) {
+    for (size_t i = 0; i < MRT::MAX_SUPPORTED_RENDER_TARGET_COUNT; i++) {
         if (mAttachments[i].texture) {
             mAttachmentMask |= getMRTColorFlag(i);
             setAttachment(mrt[i], (AttachmentPoint)i);
diff --git a/filament/src/details/RenderTarget.h b/filament/src/details/RenderTarget.h
index 6b07bf69e7..2992c950c6 100644
--- a/filament/src/details/RenderTarget.h
+++ b/filament/src/details/RenderTarget.h
@@ -57,7 +57,8 @@ public:
 
 private:
     friend class RenderTarget;
-    Attachment mAttachments[RenderTarget::ATTACHMENT_COUNT];
+    static constexpr size_t ATTACHMENT_COUNT = backend::MRT::MAX_SUPPORTED_RENDER_TARGET_COUNT + 1;
+    Attachment mAttachments[ATTACHMENT_COUNT];
     HwHandle mHandle{};
     backend::TargetBufferFlags mAttachmentMask = {};
 };