Assimp: Fix loading out-of-folder textures

Hopefully no reversions with the blender plugin

Author: snailspeed3

source/librii/assimp/LRAssimp.cpp

@@ -122,6 +122,7 @@ std::vector<Mesh> ReadMeshes(const aiScene& scn,
 // Old code, taken from Material.hpp
 namespace {
 struct ImpSampler {
+  std::string name;
   std::string path;
   u32 uv_channel;
 };
@@ -160,7 +161,8 @@ ImpMaterial ReadImp(const aiMaterial& mat) {
       const auto [path, uvindex, mapmode] = GetTexture(&mat, t, j);
 
       ImpSampler impSamp{
-          .path = getFileShort(path.C_Str()),
+          .name = getFileShort(path.C_Str()),
+          .path = {path.C_Str()},
           .uv_channel = uvindex,
       };
       impMat.samplers.push_back(impSamp);
@@ -192,10 +194,12 @@ static inline glm::mat4 getMat4(const aiMatrix4x4& mtx) {
 } // namespace
 Material ReadMaterial(const aiMaterial& mat) {
   auto imp = ReadImp(mat);
-  std::string tex = imp.samplers.empty() ? "" : imp.samplers[0].path;
+  std::string tex = imp.samplers.empty() ? "" : imp.samplers[0].name;
+  std::string tex_path_hint = imp.samplers.empty() ? "" : imp.samplers[0].path;
   return {
       .name = const_cast<aiMaterial&>(mat).GetName().C_Str(),
       .texture = tex,
+	  .texture_path_hint = tex_path_hint,
   };
 }
 std::vector<Material> ReadMaterials(const aiScene& scn) {

source/librii/assimp/LRAssimp.hpp

@@ -109,6 +109,9 @@ struct Material {
 
   // Dramatic simplification
   std::string texture;
+
+  // (OPTIONAL) Full absolute/relative path on disk to a .png file typically
+  std::string texture_path_hint;
 };
 
 struct Node {

source/librii/assimp2rhst/Importer.cpp

@@ -205,6 +205,7 @@ Result<librii::rhst::SceneTree> AssImporter::Import(const Settings& settings) {
     mr.name = new_mats[i];
 
     mr.texture_name = pMat->texture;
+    mr.texture_path_hint = pMat->texture_path_hint;
   }
 
   // TODO: Handle material limitations for samplers..

source/librii/rhst/RHST.hpp

@@ -209,7 +209,19 @@ struct PixelEngine {
 };
 
 struct ProtoSampler {
+  // TODO(rii): I would rather see raw texture bytes referenced, to be honest.
+  //            (maybe a texture array with entries of each `std::vector<u8>
+  //            encoded_texture`, texture format, width, height, etc?)
+  //
+  // - The blender plugin handles texture encoding, and it wouldn't be too much
+  //   effort to make the assimp code do so too! RHST need not be general beyond
+  //   GC/Wii, and GC/Wii has consistent texture hardware support.
+  //
+  // - Encoding can be done with gctex fairly easily. There's some nuance for
+  //   mipmap encoding; this is handled by the `librii::texture` wrapper
+  //
   std::string texture_name = "";
+
   WrapMode wrap_u = WrapMode::Repeat;
   WrapMode wrap_v = WrapMode::Repeat;
 
@@ -463,8 +475,12 @@ struct ProtoMaterial {
 
   std::vector<ProtoSampler> samplers;
 
+  // TODO: Remove legacy support! Assimp should be swapped over to sampler
+  // config method.
+
   // Legacy support
   std::string texture_name = "";
+  std::string texture_path_hint = ""; // For Assimp route
   WrapMode wrap_u = WrapMode::Repeat;
   WrapMode wrap_v = WrapMode::Repeat;
   bool min_filter = true;

source/plugins/rhst/RHSTImporter.cpp

@@ -1073,7 +1073,8 @@ void import_texture(std::string tex, libcube::Texture* pdata,
       return;
     }
   }
-  rsl::error("Cannot find texture {}", tex.c_str());
+  auto path_ = file_path.string();
+  rsl::error("Cannot find texture {} (initial path: {})", tex.c_str(), path_);
   // 32x32 (32bpp)
   const auto dummy_width = 32;
   const auto dummy_height = 32;
@@ -1093,17 +1094,21 @@ bool CompileRHST(librii::rhst::SceneTree& rhst, libcube::Scene& scene,
                  std::function<void(std::string, std::string)> info,
                  std::function<void(std::string_view, float)> progress,
                  std::optional<MipGen> mips, bool tristrip, bool verbose) {
-  std::set<std::string> textures_needed;
+  std::map<std::string, std::string /*path_hint (OPTIONAL)*/> textures_needed;
 
   for (auto& mat : rhst.materials) {
     if (mat.samplers.empty()) {
+      // For Assimp importer
+      // TODO: Remove this and move to the sampler-only workflow
       if (!mat.texture_name.empty()) {
-        textures_needed.emplace(mat.texture_name);
+        textures_needed.emplace(mat.texture_name, mat.texture_path_hint);
       }
     } else {
       for (auto& sam : mat.samplers) {
+        // Asssimp importer won't specify samplers; this is only the Blender
+        // plugin route?
         if (!sam.texture_name.empty()) {
-          textures_needed.emplace(sam.texture_name);
+          textures_needed.emplace(sam.texture_name, "");
         }
       }
     }
@@ -1127,19 +1132,17 @@ bool CompileRHST(librii::rhst::SceneTree& rhst, libcube::Scene& scene,
   }
 
   for (auto& tex : textures_needed) {
-    rsl::info("Importing texture: {}", tex.c_str());
+    rsl::info("Importing texture: {}", tex.first.c_str());
 
     auto& data = scene.getTextures().add();
-    data.setName(getFileShort(tex));
+    data.setName(getFileShort(tex.first));
   }
-  // Favor PNG, and the current directory
-  auto file_path = std::filesystem::path(path);
 
   std::vector<std::future<void>> futures;
 
   for (int i = 0; i < scene.getTextures().size(); ++i) {
     libcube::Texture* data = &scene.getTextures()[i];
-
+    std::filesystem::path file_path = textures_needed[data->getName()];
     futures.push_back(std::async(std::launch::async, [=] {
       import_texture(data->getName(), data, file_path, mips);
     }));