// This file is part of the 64k demo project.
// It implements the resource management logic for Renderer3D.

#include "3d/renderer.h"
#include "util/asset_manager_utils.h"

void Renderer3D::create_default_resources() {
  global_uniform_buffer_ =
      gpu_create_buffer(device_, sizeof(GlobalUniforms),
                        WGPUBufferUsage_Uniform | WGPUBufferUsage_CopyDst,
                        nullptr)
          .buffer;
  object_storage_buffer_ =
      gpu_create_buffer(device_, sizeof(ObjectData) * kMaxObjects,
                        WGPUBufferUsage_Storage | WGPUBufferUsage_CopyDst,
                        nullptr)
          .buffer;
  bvh_storage_buffer_ =
      gpu_create_buffer(
          device_,
          sizeof(BVHNode) * kMaxObjects * 2, // Capacity for a full tree
          WGPUBufferUsage_Storage | WGPUBufferUsage_CopyDst, nullptr)
          .buffer;
}

const Renderer3D::MeshGpuData*
Renderer3D::get_or_create_mesh(AssetId asset_id) {
  auto it = mesh_cache_.find(asset_id);
  if (it != mesh_cache_.end()) {
    return &it->second;
  }

  MeshAsset asset = GetMeshAsset(asset_id);
  if (!asset.vertices || asset.num_vertices == 0) {
    return nullptr;
  }

  MeshGpuData data;
  data.num_indices = asset.num_indices;

  data.vertex_buffer =
      gpu_create_buffer(device_, asset.num_vertices * sizeof(MeshVertex),
                        WGPUBufferUsage_Vertex | WGPUBufferUsage_CopyDst,
                        asset.vertices)
          .buffer;
  data.index_buffer =
      gpu_create_buffer(device_, asset.num_indices * sizeof(uint32_t),
                        WGPUBufferUsage_Index | WGPUBufferUsage_CopyDst,
                        asset.indices)
          .buffer;

  mesh_cache_[asset_id] = data;
  return &mesh_cache_[asset_id];
}