From 2252feeef375e155f6bd301d430dabb1ba031144 Mon Sep 17 00:00:00 2001
From: Joshua Goins <josh@redstrate.com>
Date: Mon, 27 May 2024 13:15:40 -0400
Subject: [PATCH] MDLPart: Add render material cache

---
 parts/mdl/mdlpart.cpp         | 26 ++++++++++++++++++++++++--
 parts/mdl/mdlpart.h           |  3 +++
 renderer/include/drawobject.h |  2 +-
 3 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/parts/mdl/mdlpart.cpp b/parts/mdl/mdlpart.cpp
index 65f17ff..709e493 100644
--- a/parts/mdl/mdlpart.cpp
+++ b/parts/mdl/mdlpart.cpp
@@ -92,11 +92,11 @@ void MDLPart::addModel(physis_MDL mdl,
     model.skinned = skinned;
 
     std::transform(materials.begin(), materials.end(), std::back_inserter(model.materials), [this](const physis_Material &mat) {
-        return createMaterial(mat);
+        return createOrCacheMaterial(mat);
     });
 
     if (materials.empty()) {
-        model.materials.push_back(createMaterial(physis_Material{}));
+        model.materials.push_back(createOrCacheMaterial(physis_Material{}));
     }
 
     models.push_back(model);
@@ -335,6 +335,28 @@ RenderMaterial MDLPart::createMaterial(const physis_Material &material)
     return newMaterial;
 }
 
+RenderMaterial MDLPart::createOrCacheMaterial(const physis_Material &mat)
+{
+    auto hash = getMaterialHash(mat);
+    if (!renderMaterialCache.contains(hash)) {
+        renderMaterialCache[hash] = createMaterial(mat);
+    }
+
+    return renderMaterialCache[hash];
+}
+
+uint64_t MDLPart::getMaterialHash(const physis_Material &mat)
+{
+    // TODO: this hash is terrible
+    uint64_t hash = strlen(mat.shpk_name);
+    hash += mat.num_constants;
+    hash += mat.num_samplers;
+    hash += mat.num_shader_keys;
+    hash += mat.num_textures;
+
+    return hash;
+}
+
 void MDLPart::calculateBoneInversePose(physis_Skeleton &skeleton, physis_Bone &bone, physis_Bone *parent_bone)
 {
     const glm::mat4 parentMatrix = parent_bone == nullptr ? glm::mat4(1.0f) : boneData[parent_bone->index].inversePose;
diff --git a/parts/mdl/mdlpart.h b/parts/mdl/mdlpart.h
index 6268783..ca6d51f 100644
--- a/parts/mdl/mdlpart.h
+++ b/parts/mdl/mdlpart.h
@@ -89,6 +89,8 @@ protected:
 
 private:
     RenderMaterial createMaterial(const physis_Material &mat);
+    RenderMaterial createOrCacheMaterial(const physis_Material &mat);
+    uint64_t getMaterialHash(const physis_Material &mat);
 
     void calculateBoneInversePose(physis_Skeleton &skeleton, physis_Bone &bone, physis_Bone *parent_bone);
     void calculateBone(physis_Skeleton &skeleton, physis_Bone &bone, const physis_Bone *parent_bone);
@@ -97,6 +99,7 @@ private:
     FileCache &cache;
 
     std::vector<DrawObject> models;
+    std::unordered_map<uint64_t, RenderMaterial> renderMaterialCache;
 
     RenderManager *renderer = nullptr;
     VulkanWindow *vkWindow = nullptr;
diff --git a/renderer/include/drawobject.h b/renderer/include/drawobject.h
index b5d8cea..81c1ff6 100644
--- a/renderer/include/drawobject.h
+++ b/renderer/include/drawobject.h
@@ -18,7 +18,7 @@ enum class MaterialType { Object, Skin };
 struct RenderMaterial {
     physis_Material mat;
     MaterialType type = MaterialType::Object;
-    physis_SHPK shaderPackage;
+    physis_SHPK shaderPackage{};
 
     std::optional<Texture> diffuseTexture;
     std::optional<Texture> normalTexture;