AnimTestbed/src/AnimGraphEditor.cc

//
// Created by martin on 11.02.22.
//

#include "AnimGraphEditor.h"

#include "AnimGraphResource.h"
#include "imnodes.h"

static AnimGraphResource gGraphResource;

constexpr int NodeInputAttributeFlag = 2 << 16;
constexpr int NodeOutputAttributeFlag = 2 << 17;

void AnimGraphEditorUpdate() {
  ImGui::BeginMenuBar();
  if (ImGui::Button("Save")) {
    gGraphResource.saveToFile("editor_graph.json");
  }
  if (ImGui::Button("Load")) {
    gGraphResource.loadFromFile("editor_graph.json");

    for (size_t i = 1, n = gGraphResource.m_nodes.size(); i < n; i++) {
      const AnimNodeResource& node_resource = gGraphResource.m_nodes[i];
      ImNodes::SetNodeGridSpacePos(
          i,
          ImVec2(node_resource.m_position[0], node_resource.m_position[1]));
    }
  }
  if (ImGui::Button("Clear")) {
    gGraphResource.clear();
  }
  char graph_name_buffer[256];
  memset(graph_name_buffer, 0, sizeof(graph_name_buffer));
  strncpy(
      graph_name_buffer,
      gGraphResource.m_name.c_str(),
      sizeof(graph_name_buffer));
  if (ImGui::InputText("Name", graph_name_buffer, sizeof(graph_name_buffer))) {
    gGraphResource.m_name = graph_name_buffer;
  }

  ImGui::EndMenuBar();

  ImNodes::BeginNodeEditor();

  // Popup menu
  {
    const bool open_popup =
        ImGui::IsWindowFocused(ImGuiFocusedFlags_RootAndChildWindows)
        && ImNodes::IsEditorHovered()
        && ImGui::IsMouseReleased(ImGuiMouseButton_Right);

    ImGui::PushStyleVar(ImGuiStyleVar_WindowPadding, ImVec2(8.f, 8.f));
    if (!ImGui::IsAnyItemHovered() && open_popup) {
      ImGui::OpenPopup("add node");
    }

    if (ImGui::BeginPopup("add node")) {
      const ImVec2 click_pos = ImGui::GetMousePosOnOpeningCurrentPopup();
      std::string node_type_name = "";
      if (ImGui::MenuItem("AnimSampler")) {
        node_type_name = "AnimSampler";
      }

      if (ImGui::MenuItem("Blend2")) {
        node_type_name = "Blend2";
      }

      if (ImGui::MenuItem("SpeedScale")) {
        node_type_name = "SpeedScale";
      }

      if (node_type_name != "") {
        AnimNodeResource node_resource =
            AnimNodeResourceFactory(node_type_name);
        size_t node_id = gGraphResource.m_nodes.size();
        ImNodes::SetNodeScreenSpacePos(node_id, ImGui::GetMousePos());
        gGraphResource.m_nodes.push_back(node_resource);
      }

      ImGui::EndPopup();
    }

    ImGui::PopStyleVar(ImGuiStyleVar_WindowPadding);
  }

  for (size_t i = 1, n = gGraphResource.m_nodes.size(); i < n; i++) {
    AnimNodeResource& node_resource = gGraphResource.m_nodes[i];

    ImNodes::BeginNode(i);

    // Header
    ImNodes::BeginNodeTitleBar();
    ImGui::TextUnformatted(node_resource.m_type_name.c_str());
    ImNodes::EndNodeTitleBar();

    // Inputs
    const std::vector<Socket>& node_inputs =
        node_resource.m_socket_accessor->m_inputs;
    for (size_t j = 0, ni = node_inputs.size(); j < ni; j++) {
      const Socket& socket = node_inputs[j];
      ImNodes::BeginInputAttribute(GenerateInputAttributeId(i, j));
      ImGui::Text(socket.m_name.c_str());
      ImNodes::EndInputAttribute();
    }

    // Outputs
    const std::vector<Socket>& node_outputs =
        node_resource.m_socket_accessor->m_outputs;
    for (size_t j = 0, ni = node_outputs.size(); j < ni; j++) {
      const Socket& socket = node_outputs[j];
      ImNodes::BeginOutputAttribute(GenerateOutputAttributeId(i, j));
      ImGui::Text(socket.m_name.c_str());
      ImNodes::EndInputAttribute();
    }

    // Save state in node resource
    ImVec2 node_pos = ImNodes::GetNodeGridSpacePos(i);
    node_resource.m_position[0] = node_pos[0];
    node_resource.m_position[1] = node_pos[1];
    ImNodes::EndNode();
  }

  for (size_t i = 0, n = gGraphResource.m_connections.size(); i < n; i++) {
    const AnimGraphConnection& connection = gGraphResource.m_connections[i];
    int start_attr, end_attr;
    start_attr = GenerateOutputAttributeId(
        connection.m_source_node_index,
        connection.m_source_socket_index);
    end_attr = GenerateInputAttributeId(
        connection.m_target_node_index,
        connection.m_target_socket_index);
    ImNodes::Link(i, start_attr, end_attr);
  }

  ImNodes::EndNodeEditor();

  int start_attr, end_attr;
  if (ImNodes::IsLinkCreated(&start_attr, &end_attr)) {
    int node_start_id;
    int node_start_output_index;
    SplitOutputAttributeId(
        start_attr,
        &node_start_id,
        &node_start_output_index);

    int node_end_id;
    int node_end_input_index;
    SplitInputAttributeId(end_attr, &node_end_id, &node_end_input_index);

    std::cout << "Link created: " << node_start_id << ", "
              << node_start_output_index << " -> " << node_end_id << ", "
              << node_end_input_index << std::endl;

    AnimGraphConnection connection;
    connection.m_source_node_index = node_start_id;
    connection.m_source_socket_index = node_start_output_index;

    connection.m_target_node_index = node_end_id;
    connection.m_target_socket_index = node_end_input_index;
    gGraphResource.m_connections.push_back(connection);
  }
}