Add reverse Z implementation.

ShaderRecomp/shader_common.h

@@ -6,6 +6,7 @@
 #define SPEC_CONSTANT_BICUBIC_GI_FILTER (1 << 2)
 #define SPEC_CONSTANT_ALPHA_TEST        (1 << 3)
 #define SPEC_CONSTANT_ALPHA_TO_COVERAGE (1 << 4)
+#define SPEC_CONSTANT_REVERSE_Z         (1 << 5)
 
 #if !defined(__cplusplus) || defined(__INTELLISENSE__)
 

ShaderRecomp/shader_recompiler.cpp

@@ -253,8 +253,7 @@ void ShaderRecompiler::recompile(const TextureFetchInstruction& instr, bool bicu
     if (findResult != samplers.end())
     {
         constNamePtr = findResult->second;
-        subtractFromOne = strcmp(constNamePtr, "sampZBuffer") == 0 ||
+        subtractFromOne = hasMtxPrevInvViewProjection && strcmp(constNamePtr, "sampZBuffer") == 0;
-            strcmp(constNamePtr, "g_DepthSampler") == 0;
     }
     else
     {
@@ -448,8 +447,16 @@ void ShaderRecompiler::recompile(const AluInstruction& instr)
                     const char* constantName = reinterpret_cast<const char*>(constantTableData + findResult->second->name);
                     if (findResult->second->registerCount > 1)
                     {
-                        regFormatted = std::format("{}({}{})", constantName, 
+                        if (hasMtxProjection && strcmp(constantName, "g_MtxProjection") == 0)
-                            reg - findResult->second->registerIndex, instr.const0Relative ? (instr.constAddressRegisterRelative ? " + a0" : " + aL") : "");
+                        {
+                            regFormatted = std::format("(iterationIndex == 0 ? mtxProjectionReverseZ[{0}] : mtxProjection[{0}])",
+                                reg - findResult->second->registerIndex);
+                        }
+                        else
+                        {
+                            regFormatted = std::format("{}({}{})", constantName,
+                                reg - findResult->second->registerIndex, instr.const0Relative ? (instr.constAddressRegisterRelative ? " + a0" : " + aL") : "");
+                        }
                     }
                     else
                     {
@@ -552,6 +559,8 @@ void ShaderRecompiler::recompile(const AluInstruction& instr)
         break;
     }
 
+    bool closeIfBracket = false;
+
     std::string_view exportRegister;
     if (instr.exportData)
     {
@@ -582,6 +591,18 @@ void ShaderRecompiler::recompile(const AluInstruction& instr)
             {
             case ExportRegister::VSPosition:
                 exportRegister = "oPos";
+
+                if (hasMtxProjection)
+                {
+                    indent();
+                    out += "if ((g_SpecConstants() & SPEC_CONSTANT_REVERSE_Z) == 0 || iterationIndex == 0)\n";
+                    indent();
+                    out += "{\n";
+                    ++indentation;
+
+                    closeIfBracket = true;
+                }
+
                 break;
 
             default:
@@ -1044,6 +1065,13 @@ void ShaderRecompiler::recompile(const AluInstruction& instr)
         out += "clip(ps != 0.0 ? 1 : -1);\n";
     }
 
+    if (closeIfBracket)
+    {
+        --indentation;
+        indent();
+        out += "}\n";
+    }
+
     if (instr.isPredicated)
     {
         --indentation;
@@ -1081,11 +1109,18 @@ void ShaderRecompiler::recompile(const uint8_t* shaderData, const std::string_vi
 
         if (!isPixelShader)
         {
-            if (strcmp(constantName, "g_InstanceTypes") == 0)
+            if (strcmp(constantName, "g_MtxProjection") == 0)
+                hasMtxProjection = true;
+            else if (strcmp(constantName, "g_InstanceTypes") == 0)
                 isMetaInstancer = true;
             else if (strcmp(constantName, "g_IndexCount") == 0)
                 hasIndexCount = true;
         }
+        else
+        {
+            if (strcmp(constantName, "g_MtxPrevInvViewProjection") == 0)
+                hasMtxPrevInvViewProjection = true;
+        }
 
         switch (constantInfo->registerSet)
         {
@@ -1285,6 +1320,20 @@ void ShaderRecompiler::recompile(const uint8_t* shaderData, const std::string_vi
     out += ")\n";
     out += "{\n";
 
+
+    if (hasMtxProjection)
+    {
+        specConstantsMask |= SPEC_CONSTANT_REVERSE_Z;
+
+        out += "\toPos = 0.0;\n";
+
+        out += "\tfloat4x4 mtxProjection = float4x4(g_MtxProjection(0), g_MtxProjection(1), g_MtxProjection(2), g_MtxProjection(3));\n";
+        out += "\tfloat4x4 mtxProjectionReverseZ = mul(mtxProjection, float4x4(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, -1, 0, 0, 0, 1, 1));\n";
+
+        out += "\t[unroll] for (int iterationIndex = 0; iterationIndex < 2; iterationIndex++)\n";
+        out += "\t{\n";
+    }
+
     if (shaderContainer->definitionTableOffset != NULL)
     {
         auto definitionTable = reinterpret_cast<const DefinitionTable*>(shaderData + shaderContainer->definitionTableOffset);
@@ -1360,7 +1409,9 @@ void ShaderRecompiler::recompile(const uint8_t* shaderData, const std::string_vi
 
     if (!isPixelShader)
     {
-        out += "\toPos = 0.0;\n";
+        if (!hasMtxProjection)
+            out += "\toPos = 0.0;\n";
+
         for (auto& [usage, usageIndex] : INTERPOLATORS)
             println("\to{}{} = 0.0;", USAGE_VARIABLES[uint32_t(usage)], usageIndex);
 
@@ -1734,7 +1785,10 @@ void ShaderRecompiler::recompile(const uint8_t* shaderData, const std::string_vi
                 if (simpleControlFlow)
                 {
                     indent();
-                    out += "return;\n";
+                    if (hasMtxProjection)
+                        out += "continue;\n";
+                    else
+                        out += "return;\n";
                 }
                 else
                 {
@@ -1762,5 +1816,8 @@ void ShaderRecompiler::recompile(const uint8_t* shaderData, const std::string_vi
         out += "\t}\n";
     }
 
+    if (hasMtxProjection)
+        out += "\t}\n";
+
     out += "}";
 }

ShaderRecomp/shader_recompiler.h

@@ -33,6 +33,8 @@ struct ShaderRecompiler : StringBuffer
     std::unordered_map<uint32_t, const char*> samplers;
     std::unordered_map<uint32_t, uint32_t> ifEndLabels;
     uint32_t specConstantsMask = 0;
+    bool hasMtxProjection = false;
+    bool hasMtxPrevInvViewProjection = false;
 
     void indent()
     {