VideoCommon: add action to create a camera that is relative to the game view

Source/Core/VideoCommon/GraphicsModSystem/Runtime/Actions/RelativeCameraAction.cpp

@@ -0,0 +1,111 @@
+// Copyright 2025 Dolphin Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "VideoCommon/GraphicsModSystem/Runtime/Actions/RelativeCameraAction.h"
+
+#include <array>
+#include <memory>
+#include <ranges>
+#include <string_view>
+
+#include <fmt/format.h>
+#include <imgui.h>
+
+#include "Core/System.h"
+
+#include "VideoCommon/AbstractTexture.h"
+#include "VideoCommon/FreeLookCamera.h"
+#include "VideoCommon/GraphicsModEditor/Controls/AssetDisplay.h"
+#include "VideoCommon/GraphicsModEditor/EditorEvents.h"
+#include "VideoCommon/GraphicsModEditor/EditorMain.h"
+#include "VideoCommon/GraphicsModEditor/EditorState.h"
+#include "VideoCommon/Resources/CustomResourceManager.h"
+
+std::unique_ptr<RelativeCameraAction>
+RelativeCameraAction::Create(const picojson::value& json_data,
+                             std::shared_ptr<VideoCommon::CustomAssetLibrary> library)
+{
+  if (!json_data.is<picojson::object>())
+    return nullptr;
+
+  // const auto& obj = json_data.get<picojson::object>();
+
+  return std::make_unique<RelativeCameraAction>(std::move(library));
+}
+
+RelativeCameraAction::RelativeCameraAction(std::shared_ptr<VideoCommon::CustomAssetLibrary> library)
+    : m_library(std::move(library))
+{
+}
+
+RelativeCameraAction::RelativeCameraAction(std::shared_ptr<VideoCommon::CustomAssetLibrary> library,
+                                           GraphicsModSystem::Camera camera)
+    : m_library(std::move(library)), m_camera(std::move(camera))
+{
+}
+
+void RelativeCameraAction::OnDrawStarted(GraphicsModActionData::DrawStarted* draw_started)
+{
+  if (!draw_started) [[unlikely]]
+    return;
+
+  if (!draw_started->camera) [[unlikely]]
+    return;
+
+  auto& resource_manager = Core::System::GetInstance().GetCustomResourceManager();
+  const auto resource = resource_manager.GetRenderTargetFromAsset(m_color_rt_asset_id, m_library);
+  if (resource)
+  {
+    // resource->GetData();
+    *draw_started->camera = m_camera;
+  }
+}
+
+void RelativeCameraAction::DrawImGui()
+{
+  auto& editor = Core::System::GetInstance().GetGraphicsModEditor();
+  if (ImGui::CollapsingHeader("Camera Data", ImGuiTreeNodeFlags_DefaultOpen))
+  {
+    if (ImGui::BeginTable("Camera Form", 2))
+    {
+      ImGui::TableNextRow();
+      ImGui::TableNextColumn();
+      ImGui::Text("Transform");
+      ImGui::TableNextColumn();
+      for (std::size_t i = 0; i < 4; i++)
+      {
+        const std::span<float> vec4 = m_camera.transform.data | std::views::take(4);
+        ImGui::InputFloat4(fmt::format("##CameraTransform{}", i).c_str(), vec4.data());
+      }
+      if (ImGui::Button("Set to current Freelook view"))
+      {
+        m_camera.transform = g_freelook_camera.GetView();
+      }
+      ImGui::TableNextRow();
+      ImGui::TableNextColumn();
+      ImGui::Text("Custom render taget");
+      ImGui::TableNextColumn();
+      if (GraphicsModEditor::Controls::AssetDisplay("Render target", editor.GetEditorState(),
+                                                    &m_color_rt_asset_id,
+                                                    GraphicsModEditor::RenderTarget))
+      {
+        GraphicsModEditor::EditorEvents::AssetReloadEvent::Trigger(m_camera.asset_id);
+      }
+      ImGui::EndTable();
+    }
+  }
+}
+
+void RelativeCameraAction::SerializeToConfig(picojson::object* obj)
+{
+  if (!obj) [[unlikely]]
+    return;
+
+  auto& json_obj = *obj;
+  json_obj["color_rt_asset"] = picojson::value{m_color_rt_asset_id};
+}
+
+std::string RelativeCameraAction::GetFactoryName() const
+{
+  return std::string{factory_name};
+}

Source/Core/VideoCommon/GraphicsModSystem/Runtime/Actions/RelativeCameraAction.h

@@ -0,0 +1,30 @@
+// Copyright 2025 Dolphin Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include <picojson.h>
+
+#include "VideoCommon/GraphicsModSystem/Runtime/GraphicsModAction.h"
+
+class RelativeCameraAction final : public GraphicsModAction
+{
+public:
+  static constexpr std::string_view factory_name = "relative_camera";
+  static std::unique_ptr<RelativeCameraAction>
+  Create(const picojson::value& json_data,
+         std::shared_ptr<VideoCommon::CustomAssetLibrary> library);
+  explicit RelativeCameraAction(std::shared_ptr<VideoCommon::CustomAssetLibrary> library);
+  RelativeCameraAction(std::shared_ptr<VideoCommon::CustomAssetLibrary> library,
+                       GraphicsModSystem::Camera camera);
+  void OnDrawStarted(GraphicsModActionData::DrawStarted*) override;
+
+  void DrawImGui() override;
+  void SerializeToConfig(picojson::object* obj) override;
+  std::string GetFactoryName() const override;
+
+private:
+  std::shared_ptr<VideoCommon::CustomAssetLibrary> m_library;
+  VideoCommon::CustomAssetLibrary::AssetID m_color_rt_asset_id;
+  GraphicsModSystem::Camera m_camera;
+};