From ddfc707b4efdb777425233c8a6806719631c5266 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Branimir=20Karad=C5=BEi=C4=87?= <branimirkaradzic@gmail.com>
Date: Mon, 8 Jun 2026 21:07:05 -0700
Subject: [PATCH] D3D11: Re-implement RGBA4/RGB5A1/R5G6B5 swizzle in
 TextureD3D11::update. Closes #2953. (#3742)

---
 src/renderer_d3d11.cpp | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/src/renderer_d3d11.cpp b/src/renderer_d3d11.cpp
index 89df80d1e..4e0fe65e2 100644
--- a/src/renderer_d3d11.cpp
+++ b/src/renderer_d3d11.cpp
@@ -4830,6 +4830,32 @@ namespace bgfx { namespace d3d11
 			box.right  = bx::max(1u, m_width  >> _mip);
 			box.bottom = bx::max(1u, m_height >> _mip);
 		}
+		else
+		{
+			switch (m_textureFormat)
+			{
+			case TextureFormat::R5G6B5:
+				temp = (uint8_t*)bx::alloc(g_allocator, slicepitch);
+				bimg::imageConvert(temp, 16, bx::packB5G6R5, data, bx::unpackR5G6B5, slicepitch);
+				data = temp;
+				break;
+
+			case TextureFormat::RGBA4:
+				temp = (uint8_t*)bx::alloc(g_allocator, slicepitch);
+				bimg::imageConvert(temp, 16, bx::packBgra4, data, bx::unpackRgba4, slicepitch);
+				data = temp;
+				break;
+
+			case TextureFormat::RGB5A1:
+				temp = (uint8_t*)bx::alloc(g_allocator, slicepitch);
+				bimg::imageConvert(temp, 16, bx::packBgr5a1, data, bx::unpackRgb5a1, slicepitch);
+				data = temp;
+				break;
+
+			default:
+				break;
+			}
+		}
 
 		deviceCtx->UpdateSubresource(
 			  m_ptr