From 247f36102b75f5bb273ef9163b9c86a6dda52ec2 Mon Sep 17 00:00:00 2001
From: Phillip Stephens <antidote.crk@gmail.com>
Date: Mon, 14 Apr 2025 18:36:21 -0700
Subject: [PATCH] Fix RGB5A3 alpha, we want to swap  before assigning the color
 or we stomp on alpha

---
 Runtime/Graphics/CTexture.cpp | 41 ++++++++++++++++++-----------------
 1 file changed, 21 insertions(+), 20 deletions(-)

diff --git a/Runtime/Graphics/CTexture.cpp b/Runtime/Graphics/CTexture.cpp
index ee7dcd3bb..0e17a9515 100644
--- a/Runtime/Graphics/CTexture.cpp
+++ b/Runtime/Graphics/CTexture.cpp
@@ -258,22 +258,22 @@ void CTexture::MangleMipmap(u32 mip) {
     return;
   }
 
-  const uint colors[4] = {
-    0x000000FF,
-    0x0000FF00,
-    0x00FF0000,
-    0x0000FFFF,
-};
+  constexpr uint colors[4] = {
+      0x000000FF,
+      0x0000FF00,
+      0x00FF0000,
+      0x0000FFFF,
+  };
   const uint color = colors[(mip - 1) & 3];
-  ushort rgb565Color = ((color >> 3) & 0x001F) | // B
-                       ((color >> 5) & 0x07E0) | // G
-                       ((color >> 8) & 0xF800);  // R
-  ushort rgb555Color = ((color >> 3) & 0x001F) | // B
-                       ((color >> 6) & 0x03E0) | // G
-                       ((color >> 9) & 0x7C00);  // R
-  ushort rgb4Color = ((color >> 4) & 0x000F) |   // B
-                     ((color >> 8) & 0x00F0) |   // G
-                     ((color >> 12) & 0x0F00);   // R
+  const ushort rgb565Color = ((color >> 3) & 0x001F) | // B
+                             ((color >> 5) & 0x07E0) | // G
+                             ((color >> 8) & 0xF800);  // R
+  const ushort rgb555Color = ((color >> 3) & 0x001F) | // B
+                             ((color >> 6) & 0x03E0) | // G
+                             ((color >> 9) & 0x7C00);  // R
+  const ushort rgb4Color = ((color >> 4) & 0x000F) |   // B
+                           ((color >> 8) & 0x00F0) |   // G
+                           ((color >> 12) & 0x0F00);   // R
 
   int width = GetWidth();
   int height = GetHeight();
@@ -287,7 +287,7 @@ void CTexture::MangleMipmap(u32 mip) {
 
   switch (GetTexelFormat()) {
   case ETexelFormat::RGB565: {
-    ushort* ptr = reinterpret_cast< ushort* >(x44_aramToken_x4_buff.get());//mARAMToken.GetMRAMSafe());
+    const auto ptr = reinterpret_cast<ushort*>(x44_aramToken_x4_buff.get()); // mARAMToken.GetMRAMSafe());
     for (int i = 0; i < width * height; ++i) {
       ptr[i + offset] = rgb565Color;
       CBasics::Swap2Bytes(reinterpret_cast<u8*>(&ptr[i + offset]));
@@ -295,7 +295,7 @@ void CTexture::MangleMipmap(u32 mip) {
     break;
   }
   case ETexelFormat::CMPR: {
-    ushort* ptr = reinterpret_cast< ushort* >(x44_aramToken_x4_buff.get()) + offset / 4;
+    auto ptr = reinterpret_cast<ushort*>(x44_aramToken_x4_buff.get()) + offset / 4;
     for (int i = 0; i < width * height / 16; ++i, ptr += 4) {
       ptr[0] = rgb565Color;
       CBasics::Swap2Bytes(reinterpret_cast<u8*>(&ptr[0]));
@@ -307,10 +307,11 @@ void CTexture::MangleMipmap(u32 mip) {
     break;
   }
   case ETexelFormat::RGB5A3: {
-    ushort* ptr = reinterpret_cast< ushort* >(x44_aramToken_x4_buff.get());
+    const auto ptr = reinterpret_cast<ushort*>(x44_aramToken_x4_buff.get());
     for (int i = 0; i < width * height; ++i) {
       ushort& val = ptr[i + offset];
-      if (val & 0x8000) {
+      CBasics::Swap2Bytes(reinterpret_cast<u8*>(&val));
+      if ((val & 0x8000) != 0) {
         val = rgb555Color | 0x8000;
       } else {
         val = (val & 0xF000) | rgb4Color;
@@ -346,7 +347,7 @@ u32 CTexture::TexelFormatBitsPerPixel(ETexelFormat fmt) {
   }
 }
 
-bool CTexture::sMangleMips = false;
+bool CTexture::sMangleMips = true;
 u32 CTexture::sCurrentFrameCount = 0;
 u32 CTexture::sTotalAllocatedMemory = 0;