From c090ad6a5697f1ee58b08f744825d4d2d2fbb796 Mon Sep 17 00:00:00 2001
From: Chris Galvan <chgalvan@amazon.com>
Date: Thu, 20 Jan 2022 16:10:42 -0600
Subject: [PATCH] Account for the pixel size when computing the image data
 index

Signed-off-by: Chris Galvan <chgalvan@amazon.com>
---
 .../Source/RPI.Reflect/Image/StreamingImageAsset.cpp     | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/Gems/Atom/RPI/Code/Source/RPI.Reflect/Image/StreamingImageAsset.cpp b/Gems/Atom/RPI/Code/Source/RPI.Reflect/Image/StreamingImageAsset.cpp
index aaf232d4f0..e2268dbdd8 100644
--- a/Gems/Atom/RPI/Code/Source/RPI.Reflect/Image/StreamingImageAsset.cpp
+++ b/Gems/Atom/RPI/Code/Source/RPI.Reflect/Image/StreamingImageAsset.cpp
@@ -376,13 +376,14 @@ namespace AZ
             {
                 const AZ::RHI::ImageDescriptor imageDescriptor = GetImageDescriptor();
                 auto width = imageDescriptor.m_size.m_width;
+                const uint32_t pixelSize = AZ::RHI::GetFormatSize(imageDescriptor.m_format);
 
                 size_t outValuesIndex = 0;
                 for (uint32_t y = topLeft.second; y <= bottomRight.second; ++y)
                 {
                     for (uint32_t x = topLeft.first; x <= bottomRight.first; ++x)
                     {
-                        size_t imageDataIndex = (y * width) + x;
+                        size_t imageDataIndex = (y * width * pixelSize) + (x * pixelSize);
 
                         auto& outValue = const_cast<float&>(outValues[outValuesIndex++]);
                         outValue = Internal::RetrieveFloatValue(imageData.data(), imageDataIndex, imageDescriptor.m_format);
@@ -402,13 +403,14 @@ namespace AZ
             {
                 const AZ::RHI::ImageDescriptor imageDescriptor = GetImageDescriptor();
                 auto width = imageDescriptor.m_size.m_width;
+                const uint32_t pixelSize = AZ::RHI::GetFormatSize(imageDescriptor.m_format);
 
                 size_t outValuesIndex = 0;
                 for (uint32_t y = topLeft.second; y <= bottomRight.second; ++y)
                 {
                     for (uint32_t x = topLeft.first; x <= bottomRight.first; ++x)
                     {
-                        size_t imageDataIndex = (y * width) + x;
+                        size_t imageDataIndex = (y * width * pixelSize) + (x * pixelSize);
 
                         auto& outValue = const_cast<AZ::u32&>(outValues[outValuesIndex++]);
                         outValue = Internal::RetrieveUintValue(imageData.data(), imageDataIndex, imageDescriptor.m_format);
@@ -428,13 +430,14 @@ namespace AZ
             {
                 const AZ::RHI::ImageDescriptor imageDescriptor = GetImageDescriptor();
                 auto width = imageDescriptor.m_size.m_width;
+                const uint32_t pixelSize = AZ::RHI::GetFormatSize(imageDescriptor.m_format);
 
                 size_t outValuesIndex = 0;
                 for (uint32_t y = topLeft.second; y <= bottomRight.second; ++y)
                 {
                     for (uint32_t x = topLeft.first; x <= bottomRight.first; ++x)
                     {
-                        size_t imageDataIndex = (y * width) + x;
+                        size_t imageDataIndex = (y * width * pixelSize) + (x * pixelSize);
 
                         auto& outValue = const_cast<AZ::s32&>(outValues[outValuesIndex++]);
                         outValue = Internal::RetrieveIntValue(imageData.data(), imageDataIndex, imageDescriptor.m_format);