Initial refactoring for remote DebugGUI (#28)

Author: luigifusco

DebugGUI/src/DebugGUI.cxx

@@ -9,6 +9,7 @@
 #include <GLFW/glfw3.h>
 #include <cstdio>
 #include <functional>
+#include <ostream>
 
 static void default_error_callback(int error, const char* description)
 {
@@ -54,31 +55,187 @@ void* initGUI(const char* name, void(*error_callback)(int, char const*descriptio
   return window;
 }
 
-/// @return true if we do not need to exit, false if we do.
-bool pollGUI(void* context, std::function<void(void)> guiCallback)
+// fills a stream with drawing data in JSON format
+// the JSON is composed of a list of draw commands
+/// FIXME: document the actual schema of the format.
+void getFrameJSON(void *data, std::ostream& json_data)
+{
+  ImDrawData* draw_data = (ImDrawData*)data;
+
+  json_data << "[";
+
+  for (int cmd_id = 0; cmd_id < draw_data->CmdListsCount; ++cmd_id) {
+    const auto cmd_list = draw_data->CmdLists[cmd_id];
+    const auto vtx_buffer = cmd_list->VtxBuffer;
+    const auto idx_buffer = cmd_list->IdxBuffer;
+    const auto cmd_buffer = cmd_list->CmdBuffer;
+
+    json_data << "{\"vtx\":[";
+    for (int i = 0; i < vtx_buffer.size(); ++i) {
+      auto v = vtx_buffer[i];
+      json_data << "[" << v.pos.x << "," << v.pos.y << "," << v.col << ',' << v.uv.x << "," << v.uv.y << "]";
+      if (i < vtx_buffer.size() - 1) json_data << ",";
+    }
+
+    json_data << "],\"idx\":[";
+    for (int i = 0; i < idx_buffer.size(); ++i) {
+      auto id = idx_buffer[i];
+      json_data << id;
+      if (i < idx_buffer.size() - 1) json_data << ",";
+    }
+
+    json_data << "],\"cmd\":[";
+    for (int i = 0; i < cmd_buffer.size(); ++i) {
+      auto cmd = cmd_buffer[i];
+      json_data << "{\"cnt\":" << cmd.ElemCount << ", \"clp\":[" << cmd.ClipRect.x << "," << cmd.ClipRect.y << "," << cmd.ClipRect.z << "," << cmd.ClipRect.w << "]}";
+      if (i < cmd_buffer.size() - 1) json_data << ",";
+    }
+    json_data << "]}";
+    if (cmd_id < draw_data->CmdListsCount - 1) json_data << ",";
+  }
+
+  json_data << "]";
+}
+
+
+struct vtxContainer {
+  float posX, posY, uvX, uvY;
+  int col;
+};
+
+struct cmdContainer {
+  int count;
+  float rectX, rectY, rectZ, rectW;
+};
+
+// given draw data, returns a mallocd buffer containing formatted frame data
+// ready to be sent and its size.
+// the returned buffer must be freed by the caller.
+/// FIXME: document actual schema of the format
+void getFrameRaw(void *data, void **raw_data, int *size)
+{
+  ImDrawData* draw_data = (ImDrawData*)data;
+
+  // compute sizes
+  int buffer_size = sizeof(int)*3,
+      vtx_count = 0,
+      idx_count = 0,
+      cmd_count = 0;
+  for (int cmd_id = 0; cmd_id < draw_data->CmdListsCount; ++cmd_id) {
+    const auto cmd_list = draw_data->CmdLists[cmd_id];
+
+    vtx_count += cmd_list->VtxBuffer.size();
+    buffer_size += cmd_list->VtxBuffer.size() * (sizeof(vtxContainer));
+
+    idx_count += cmd_list->IdxBuffer.size();
+    buffer_size += cmd_list->IdxBuffer.size() * (sizeof(short));
+
+    cmd_count += cmd_list->CmdBuffer.size();
+    buffer_size += cmd_list->CmdBuffer.size() * (sizeof(cmdContainer));
+  }
+
+  void *local_data_base = malloc(buffer_size);
+
+  int *data_header_ptr = (int*) local_data_base;
+  *data_header_ptr = vtx_count; data_header_ptr++;
+  *data_header_ptr = idx_count; data_header_ptr++;
+  *data_header_ptr = cmd_count; data_header_ptr++;
+
+  vtxContainer* data_vtx_ptr = (vtxContainer*) data_header_ptr;
+  for (int cmd_id = 0; cmd_id < draw_data->CmdListsCount; ++cmd_id) {
+    const auto cmd_list = draw_data->CmdLists[cmd_id];
+
+    for (auto const& vtx : cmd_list->VtxBuffer) {
+      data_vtx_ptr->posX = vtx.pos.x;
+      data_vtx_ptr->posY = vtx.pos.y;
+      data_vtx_ptr->uvX = vtx.uv.x;
+      data_vtx_ptr->uvY = vtx.uv.y;
+      data_vtx_ptr->col = vtx.col;
+      data_vtx_ptr++;
+    }
+  }
+
+  int idx_offset = 0;
+  short* data_idx_ptr = (short*) data_vtx_ptr;
+  for (int cmd_id = 0; cmd_id < draw_data->CmdListsCount; ++cmd_id) {
+    const auto cmd_list = draw_data->CmdLists[cmd_id];
+
+    for (auto const& idx : cmd_list->IdxBuffer) {
+      *data_idx_ptr = idx + (short)idx_offset;
+      data_idx_ptr++;
+    }
+
+    idx_offset += cmd_list->VtxBuffer.size();
+  }
+
+  cmdContainer* data_cmd_ptr = (cmdContainer*) data_idx_ptr;
+  for (int cmd_id = 0; cmd_id < draw_data->CmdListsCount; ++cmd_id) {
+    const auto cmd_list = draw_data->CmdLists[cmd_id];
+
+    for (auto const& cmd : cmd_list->CmdBuffer) {
+      data_cmd_ptr->count = cmd.ElemCount;
+      data_cmd_ptr->rectX = cmd.ClipRect.x;
+      data_cmd_ptr->rectY = cmd.ClipRect.y;
+      data_cmd_ptr->rectZ = cmd.ClipRect.z;
+      data_cmd_ptr->rectW = cmd.ClipRect.w;
+      data_cmd_ptr++;
+    }
+  }
+
+  *size = buffer_size;
+  *raw_data = local_data_base;
+}
+
+bool pollGUIPreRender(void* context)
 {
   GLFWwindow* window = reinterpret_cast<GLFWwindow*>(context);
+
   if (glfwWindowShouldClose(window)) {
     return false;
   }
   glfwPollEvents();
   ImGui_ImplGlfwGL3_NewFrame();
 
-
   // Rendering
   int display_w, display_h;
   glfwGetFramebufferSize(window, &display_w, &display_h);
   glViewport(0, 0, display_w, display_h);
   ImVec4 clear_color = ImColor(114, 144, 154);
   glClearColor(clear_color.x, clear_color.y, clear_color.z, clear_color.w);
   glClear(GL_COLOR_BUFFER_BIT);
+
+  return true;
+}
+
+/// @return draw data as void* to avoid dependencies
+void *pollGUIRender(std::function<void(void)> guiCallback)
+{
   // This is where the magic actually happens...
   if (guiCallback) {
     guiCallback();
   }
   ImGui::Render();
-  ImGui_ImplGlfwGL3_RenderDrawLists(ImGui::GetDrawData());
+
+  return ImGui::GetDrawData();
+}
+
+void pollGUIPostRender(void* context, void *draw_data)
+{
+  GLFWwindow* window = reinterpret_cast<GLFWwindow*>(context);
+
+  ImGui_ImplGlfwGL3_RenderDrawLists((ImDrawData*)draw_data);
   glfwSwapBuffers(window);
+}
+
+/// @return true if we do not need to exit, false if we do.
+bool pollGUI(void* context, std::function<void(void)> guiCallback)
+{
+  if (!pollGUIPreRender(context)) {
+    return false;
+  }
+  void *draw_data = pollGUIRender(guiCallback);
+  pollGUIPostRender(context, draw_data);
+  
   return true;
 }
 

DebugGUI/src/DebugGUI.h

@@ -11,6 +11,7 @@
 #define FRAMEWORK_DEBUGGUI_H
 
 #include <functional>
+#include <iosfwd>
 
 namespace o2::framework {
 
@@ -19,6 +20,11 @@ void default_error_callback(int, const char*);
 
 void* initGUI(const char* name, decltype(default_error_callback) = nullptr);
 bool pollGUI(void* context, std::function<void(void)> guiCallback);
+void getFrameJSON(void *data, std::ostream& json_data);
+void getFrameRaw(void *data, void **raw_data, int *size);
+bool pollGUIPreRender(void* context);
+void* pollGUIRender(std::function<void(void)> guiCallback);
+void pollGUIPostRender(void* context, void* draw_data);
 void disposeGUI();
 
 } // namespace o2::framework