From c67764d7fe956448cb170139d19db3ac1ff6bddf Mon Sep 17 00:00:00 2001
From: MaranBr <maranbr@outlook.com>
Date: Fri, 26 Dec 2025 12:40:00 -0400
Subject: [PATCH] Fix CONST_A for different component sizes in MaxwellDMA
 Launch

---
 src/video_core/engines/maxwell_dma.cpp | 35 +++++++++++++++++++-------
 1 file changed, 26 insertions(+), 9 deletions(-)

diff --git a/src/video_core/engines/maxwell_dma.cpp b/src/video_core/engines/maxwell_dma.cpp
index e2aa6c7e49..26aa2e10c8 100644
--- a/src/video_core/engines/maxwell_dma.cpp
+++ b/src/video_core/engines/maxwell_dma.cpp
@@ -96,15 +96,32 @@ void MaxwellDMA::Launch() {
         auto& accelerate = rasterizer->AccessAccelerateDMA();
         const bool is_const_a_dst = regs.remap_const.dst_x == RemapConst::Swizzle::CONST_A;
         if (regs.launch_dma.remap_enable != 0 && is_const_a_dst) {
-            ASSERT(regs.remap_const.component_size_minus_one == 3);
-            accelerate.BufferClear(regs.offset_out, regs.line_length_in,
-                                   regs.remap_const.remap_consta_value);
-            read_buffer.resize_destructive(regs.line_length_in * sizeof(u32));
-            std::span<u32> span(reinterpret_cast<u32*>(read_buffer.data()), regs.line_length_in);
-            std::ranges::fill(span, regs.remap_const.remap_consta_value);
-            memory_manager.WriteBlockUnsafe(regs.offset_out,
-                                            reinterpret_cast<u8*>(read_buffer.data()),
-                                            regs.line_length_in * sizeof(u32));
+            const u32 component_size = regs.remap_const.component_size_minus_one + 1;
+            const u32 line_length = regs.line_length_in;
+            read_buffer.resize_destructive(line_length * component_size);
+            u8* buf = read_buffer.data();
+            switch (component_size) {
+                case 1: {
+                    std::span<u8> span(buf, line_length);
+                    std::ranges::fill(span, static_cast<u8>(regs.remap_const.remap_consta_value & 0xFF));
+                    break;
+                }
+                case 2: {
+                    std::span<u16> span(reinterpret_cast<u16*>(buf), line_length);
+                    std::ranges::fill(span, static_cast<u16>(regs.remap_const.remap_consta_value & 0xFFFF));
+                    break;
+                }
+                case 4: {
+                    std::span<u32> span(reinterpret_cast<u32*>(buf), line_length);
+                    std::ranges::fill(span, regs.remap_const.remap_consta_value);
+                    break;
+                }
+                default:
+                    LOG_WARNING(Render_OpenGL, "Remap CONST_A with unsupported component size {} bytes", component_size);
+                    break;
+            }
+            memory_manager.WriteBlockUnsafe(regs.offset_out, buf, line_length * component_size);
+            accelerate.BufferClear(regs.offset_out, line_length, regs.remap_const.remap_consta_value);
         } else {
             memory_manager.FlushCaching();
             const auto convert_linear_2_blocklinear_addr = [](u64 address) {