From 404c984f9c42dc1e946921b1fd14bef8128ab56c Mon Sep 17 00:00:00 2001
From: Alpyne <alpyne.dreams@gmail.com>
Date: Thu, 27 Apr 2023 18:01:46 -0700
Subject: [PATCH] [dxso] Implement bem instruction

---
 src/dxso/dxso_compiler.cpp | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/src/dxso/dxso_compiler.cpp b/src/dxso/dxso_compiler.cpp
index be0344e0..4cc8a3dd 100644
--- a/src/dxso/dxso_compiler.cpp
+++ b/src/dxso/dxso_compiler.cpp
@@ -128,6 +128,7 @@ namespace dxvk {
     case DxsoOpcode::Lrp:
     case DxsoOpcode::Frc:
     case DxsoOpcode::Cmp:
+    case DxsoOpcode::Bem:
     case DxsoOpcode::Cnd:
     case DxsoOpcode::Dp2Add:
     case DxsoOpcode::DsX:
@@ -2196,6 +2197,41 @@ namespace dxvk {
           emitRegisterLoad(src[2], mask).id);
         break;
       }
+      case DxsoOpcode::Bem: {
+        DxsoRegisterValue src0 = emitRegisterLoad(src[0], mask);
+        DxsoRegisterValue src1 = emitRegisterLoad(src[1], mask);
+
+        // dst.x = src0.x + [bm00(m) * src1.x + bm10(m) * src1.y]
+        // dst.y = src0.y + [bm01(m) * src1.x + bm11(m) * src1.y]
+        
+        // But we flipped the bm indices so we can use dot here...
+
+        // dst.x = src0.x + dot(bm0, src1)
+        // dst.y = src0.y + dot(bm1, src1)
+
+        std::array<uint32_t, 2> values = { m_module.constf32(0.0f), m_module.constf32(0.0f) };
+
+        for (uint32_t i = 0; i < 2; i++) {
+          uint32_t fl_t   = getScalarTypeId(DxsoScalarType::Float32);
+          uint32_t vec2_t = getVectorTypeId({ DxsoScalarType::Float32, 2 });
+          std::array<uint32_t, 4> indices = { 0, 1, 2, 3 };
+
+          uint32_t tc_m_n = m_module.opCompositeExtract(fl_t, src0.id, 1, &i);
+
+          uint32_t offset = m_module.constu32(D3D9SharedPSStages_Count * ctx.dst.id.num + D3D9SharedPSStages_BumpEnvMat0 + i);
+          uint32_t bm     = m_module.opAccessChain(m_module.defPointerType(vec2_t, spv::StorageClassUniform),
+                                                  m_ps.sharedState, 1, &offset);
+                   bm     = m_module.opLoad(vec2_t, bm);
+
+          uint32_t t      = m_module.opVectorShuffle(vec2_t, src1.id, src1.id, 2, indices.data());
+
+          uint32_t dot    = m_module.opDot(fl_t, bm, t);
+
+          values[i]       = m_module.opFAdd(fl_t, tc_m_n, dot);
+        }
+        result.id = m_module.opCompositeConstruct(typeId, values.size(), values.data());
+        break;
+      }
       case DxsoOpcode::Cnd: {
         const uint32_t boolTypeId =
           getVectorTypeId({ DxsoScalarType::Bool, result.type.ccount });