From cb45bdaadce76af1c344c311ed2ef8e968dc11dd Mon Sep 17 00:00:00 2001
From: Jan <jan@laupetin.net>
Date: Sat, 16 Apr 2022 15:41:45 +0200
Subject: [PATCH] Progress on reversing technique flags

---
 src/Common/Game/IW4/IW4_Assets.h              | 27 +++++++++++++++++++
 .../AssetLoaders/AssetLoaderTechniqueSet.cpp  | 17 ++++++++++--
 2 files changed, 42 insertions(+), 2 deletions(-)

diff --git a/src/Common/Game/IW4/IW4_Assets.h b/src/Common/Game/IW4/IW4_Assets.h
index 75f4c755..1f8bc360 100644
--- a/src/Common/Game/IW4/IW4_Assets.h
+++ b/src/Common/Game/IW4/IW4_Assets.h
@@ -968,6 +968,18 @@ namespace IW4
         int arrayStride;
     };
 
+    enum
+    {
+        MTL_TYPE_DEFAULT = 0x0,
+        MTL_TYPE_MODEL = 0x1, // m_
+        MTL_TYPE_MODEL_VERTCOL = 0x2, // mc_
+        MTL_TYPE_MODEL_VERTCOL_GREY = 0x3, // ?
+        MTL_TYPE_WORLD = 0x4, // w_
+        MTL_TYPE_WORLD_VERTCOL = 0x5, // wc_
+
+        MTL_TYPE_COUNT,
+    };
+
     enum MaterialConstantSource
     {
         CONST_SRC_CODE_MAYBE_DIRTY_PS_BEGIN = 0x0,
@@ -1202,6 +1214,21 @@ namespace IW4
         MaterialShaderArgument* args;
     };
 
+    enum TechniqueFlags
+    {
+        // Guesses purely based on data analysis:
+        TECHNIQUE_FLAG_1 = 0x1, // uses resolvedPostSun code sampler
+        TECHNIQUE_FLAG_2 = 0x2, // uses resolvedScene code sampler
+        TECHNIQUE_FLAG_4 = 0x4, // zprepass only
+        TECHNIQUE_FLAG_8 = 0x8, // build_floatz only
+        TECHNIQUE_FLAG_10 = 0x10, // build_shadowmap_depth + build_shadowmap_model only
+        TECHNIQUE_FLAG_20 = 0x20, // techniques with _i_ in its name (all use texcoord[1] in decl -> other optional stream sources are not used at all so might be any optional)
+        TECHNIQUE_FLAG_40 = 0x40, // uses code constant light.spotDir or light.spotFactors
+        TECHNIQUE_FLAG_80 = 0x80, // uses floatZ sampler and does not have 0x100 flag
+        TECHNIQUE_FLAG_100 = 0x100, // distortion_scale_zfeather_dtex + distortion_scale_ua_zfeather
+        TECHNIQUE_FLAG_200 = 0x200, // ?
+    };
+
     struct MaterialTechnique
     {
         const char* name;
diff --git a/src/ObjLoading/Game/IW4/AssetLoaders/AssetLoaderTechniqueSet.cpp b/src/ObjLoading/Game/IW4/AssetLoaders/AssetLoaderTechniqueSet.cpp
index 3f99238a..86767813 100644
--- a/src/ObjLoading/Game/IW4/AssetLoaders/AssetLoaderTechniqueSet.cpp
+++ b/src/ObjLoading/Game/IW4/AssetLoaders/AssetLoaderTechniqueSet.cpp
@@ -20,6 +20,7 @@
 #include "Utils/Alignment.h"
 
 using namespace IW4;
+using namespace std::string_literals;
 
 namespace IW4
 {
@@ -992,6 +993,13 @@ namespace IW4
             return ss.str();
         }
 
+        static void UpdateTechniqueFlags(MaterialTechnique& technique)
+        {
+            // This is stupid but that's what the game does
+            if("zprepass"s == technique.name)
+                technique.flags |= 4u;
+        }
+
         static void UpdateTechniqueFlagsForArgument(uint16_t& techniqueFlags, const TechniqueCreator::PassShaderArgument& arg)
         {
             if(arg.m_arg.type == MTL_ARG_CODE_PIXEL_SAMPLER)
@@ -999,10 +1007,10 @@ namespace IW4
                 switch(arg.m_arg.u.codeSampler)
                 {
                 case TEXTURE_SRC_CODE_RESOLVED_POST_SUN:
-                    techniqueFlags |= 1u;
+                    techniqueFlags |= TECHNIQUE_FLAG_1;
                     break;
                 case TEXTURE_SRC_CODE_RESOLVED_SCENE:
-                    techniqueFlags |= 2u;
+                    techniqueFlags |= TECHNIQUE_FLAG_2;
                     break;
                 default:
                     break;
@@ -1065,6 +1073,8 @@ namespace IW4
             out.perPrimArgCount = static_cast<unsigned char>(perPrimArgCount);
             out.stableArgCount = static_cast<unsigned char>(stableArgCount);
 
+            UpdateTechniqueFlags(technique);
+
             if (in.m_vertex_shader)
                 dependencies.push_back(in.m_vertex_shader);
             if (in.m_pixel_shader)
@@ -1170,6 +1180,9 @@ bool AssetLoaderTechniqueSet::CreateTechsetFromDefinition(const std::string& ass
         }
     }
 
+    const auto* disAsset = GlobalAssetPool<MaterialTechniqueSet>::GetAssetByName("distortion_scale");
+    const auto* dis = disAsset ? disAsset->Asset() : nullptr;
+
     manager->AddAsset(ASSET_TYPE_TECHNIQUE_SET, assetName, techset, std::vector(dependencies.begin(), dependencies.end()), std::vector<scr_string_t>());
 
     return true;