From 1fae5a8b06eb70bcd00fd266434c17c40a0f367d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Branimir=20Karad=C5=BEi=C4=87?= <branimirkaradzic@gmail.com>
Date: Sun, 12 Jul 2026 18:43:24 -0700
Subject: [PATCH] D3D11/D3D12/VK/WebGPU: Fixed blend-state, and blend factor
 for MRT. (#3825)

---
 src/renderer_d3d11.cpp  | 12 ++++++++++--
 src/renderer_d3d12.cpp  | 12 ++++++++++--
 src/renderer_vk.cpp     |  8 ++++++++
 src/renderer_webgpu.cpp |  8 ++++++++
 4 files changed, 36 insertions(+), 4 deletions(-)

diff --git a/src/renderer_d3d11.cpp b/src/renderer_d3d11.cpp
index 154146f4a..7587cbd87 100644
--- a/src/renderer_d3d11.cpp
+++ b/src/renderer_d3d11.cpp
@@ -2924,7 +2924,7 @@ namespace bgfx { namespace d3d11
 
 				if (desc.IndependentBlendEnable)
 				{
-					for (uint32_t ii = 1, rgba = _rgba; ii < BGFX_CONFIG_MAX_FRAME_BUFFER_ATTACHMENTS; ++ii, rgba >>= 11)
+					for (uint32_t ii = 1, rgba = _rgba; ii < BX_COUNTOF(desc.RenderTarget); ++ii, rgba >>= 11)
 					{
 						drt = &desc.RenderTarget[ii];
 						drt->BlendEnable = 0 != (rgba & 0x7ff);
@@ -2946,7 +2946,7 @@ namespace bgfx { namespace d3d11
 				}
 				else
 				{
-					for (uint32_t ii = 1; ii < BGFX_CONFIG_MAX_FRAME_BUFFER_ATTACHMENTS; ++ii)
+					for (uint32_t ii = 1; ii < BX_COUNTOF(desc.RenderTarget); ++ii)
 					{
 						bx::memCopy(&desc.RenderTarget[ii], drt, sizeof(D3D11_RENDER_TARGET_BLEND_DESC) );
 					}
@@ -2961,11 +2961,19 @@ namespace bgfx { namespace d3d11
 			const uint64_t f1 = BGFX_STATE_BLEND_INV_FACTOR;
 			const uint64_t f2 = BGFX_STATE_BLEND_FACTOR<<4;
 			const uint64_t f3 = BGFX_STATE_BLEND_INV_FACTOR<<4;
+			const uint64_t f4 = BGFX_STATE_BLEND_FACTOR<<8;
+			const uint64_t f5 = BGFX_STATE_BLEND_INV_FACTOR<<8;
+			const uint64_t f6 = BGFX_STATE_BLEND_FACTOR<<12;
+			const uint64_t f7 = BGFX_STATE_BLEND_INV_FACTOR<<12;
 			bool hasFactor = 0
 				|| f0 == (_state & f0)
 				|| f1 == (_state & f1)
 				|| f2 == (_state & f2)
 				|| f3 == (_state & f3)
+				|| f4 == (_state & f4)
+				|| f5 == (_state & f5)
+				|| f6 == (_state & f6)
+				|| f7 == (_state & f7)
 				;
 
 			float blendFactor[4] = { 1.0f, 1.0f, 1.0f, 1.0f };
diff --git a/src/renderer_d3d12.cpp b/src/renderer_d3d12.cpp
index 8fa73d446..1bbb2fa81 100644
--- a/src/renderer_d3d12.cpp
+++ b/src/renderer_d3d12.cpp
@@ -3200,7 +3200,7 @@ namespace bgfx { namespace d3d12
 
 			if (_desc.IndependentBlendEnable)
 			{
-				for (uint32_t ii = 1, rgba = _rgba; ii < BGFX_CONFIG_MAX_FRAME_BUFFER_ATTACHMENTS; ++ii, rgba >>= 11)
+				for (uint32_t ii = 1, rgba = _rgba; ii < BX_COUNTOF(_desc.RenderTarget); ++ii, rgba >>= 11)
 				{
 					drt = &_desc.RenderTarget[ii];
 					drt->BlendEnable = 0 != (rgba & 0x7ff);
@@ -3224,7 +3224,7 @@ namespace bgfx { namespace d3d12
 			}
 			else
 			{
-				for (uint32_t ii = 1; ii < BGFX_CONFIG_MAX_FRAME_BUFFER_ATTACHMENTS; ++ii)
+				for (uint32_t ii = 1; ii < BX_COUNTOF(_desc.RenderTarget); ++ii)
 				{
 					bx::memCopy(&_desc.RenderTarget[ii], drt, sizeof(D3D12_RENDER_TARGET_BLEND_DESC) );
 				}
@@ -7565,6 +7565,10 @@ namespace bgfx { namespace d3d12
 		const uint64_t f1 = BGFX_STATE_BLEND_INV_FACTOR;
 		const uint64_t f2 = BGFX_STATE_BLEND_FACTOR<<4;
 		const uint64_t f3 = BGFX_STATE_BLEND_INV_FACTOR<<4;
+		const uint64_t f4 = BGFX_STATE_BLEND_FACTOR<<8;
+		const uint64_t f5 = BGFX_STATE_BLEND_INV_FACTOR<<8;
+		const uint64_t f6 = BGFX_STATE_BLEND_FACTOR<<12;
+		const uint64_t f7 = BGFX_STATE_BLEND_INV_FACTOR<<12;
 
 		D3D12_GPU_DESCRIPTOR_HANDLE gpuHandle;
 		ScratchBufferD3D12& scratchBuffer = m_scratchBuffer[m_backBufferColorIdx];
@@ -8004,6 +8008,10 @@ namespace bgfx { namespace d3d12
 						|| f1 == (state & f1)
 						|| f2 == (state & f2)
 						|| f3 == (state & f3)
+						|| f4 == (state & f4)
+						|| f5 == (state & f5)
+						|| f6 == (state & f6)
+						|| f7 == (state & f7)
 						;
 
 					const VertexLayout* layouts[BGFX_CONFIG_MAX_VERTEX_STREAMS];
diff --git a/src/renderer_vk.cpp b/src/renderer_vk.cpp
index bcfb777c0..464ba6d26 100644
--- a/src/renderer_vk.cpp
+++ b/src/renderer_vk.cpp
@@ -9405,6 +9405,10 @@ VK_DESTROY
 		const uint64_t f1 = BGFX_STATE_BLEND_INV_FACTOR;
 		const uint64_t f2 = BGFX_STATE_BLEND_FACTOR<<4;
 		const uint64_t f3 = BGFX_STATE_BLEND_INV_FACTOR<<4;
+		const uint64_t f4 = BGFX_STATE_BLEND_FACTOR<<8;
+		const uint64_t f5 = BGFX_STATE_BLEND_INV_FACTOR<<8;
+		const uint64_t f6 = BGFX_STATE_BLEND_FACTOR<<12;
+		const uint64_t f7 = BGFX_STATE_BLEND_INV_FACTOR<<12;
 
 		const uint32_t descriptorFrame = m_cmd.m_currentFrameInFlight;
 		for (uint32_t ii = 0; ii < m_numDescriptorPools[descriptorFrame]; ++ii)
@@ -10008,6 +10012,10 @@ VK_DESTROY
 						|| f1 == (draw.m_stateFlags & f1)
 						|| f2 == (draw.m_stateFlags & f2)
 						|| f3 == (draw.m_stateFlags & f3)
+						|| f4 == (draw.m_stateFlags & f4)
+						|| f5 == (draw.m_stateFlags & f5)
+						|| f6 == (draw.m_stateFlags & f6)
+						|| f7 == (draw.m_stateFlags & f7)
 						;
 
 					if (hasFactor
diff --git a/src/renderer_webgpu.cpp b/src/renderer_webgpu.cpp
index 2a212c3ea..acc98f7a1 100644
--- a/src/renderer_webgpu.cpp
+++ b/src/renderer_webgpu.cpp
@@ -6301,11 +6301,19 @@ m_resolution.formatColor = TextureFormat::BGRA8;
 				constexpr uint64_t kF1 = BGFX_STATE_BLEND_INV_FACTOR;
 				constexpr uint64_t kF2 = BGFX_STATE_BLEND_FACTOR<<4;
 				constexpr uint64_t kF3 = BGFX_STATE_BLEND_INV_FACTOR<<4;
+				constexpr uint64_t kF4 = BGFX_STATE_BLEND_FACTOR<<8;
+				constexpr uint64_t kF5 = BGFX_STATE_BLEND_INV_FACTOR<<8;
+				constexpr uint64_t kF6 = BGFX_STATE_BLEND_FACTOR<<12;
+				constexpr uint64_t kF7 = BGFX_STATE_BLEND_INV_FACTOR<<12;
 				bool hasFactor = 0
 					|| kF0 == (state & kF0)
 					|| kF1 == (state & kF1)
 					|| kF2 == (state & kF2)
 					|| kF3 == (state & kF3)
+					|| kF4 == (state & kF4)
+					|| kF5 == (state & kF5)
+					|| kF6 == (state & kF6)
+					|| kF7 == (state & kF7)
 					;
 
 				if (hasFactor