FBX Debugger project

just a sandbox for trying some stuff out.

Migration from ImGui 1.55 to 1.6 (WIP)

So, a lot of things I ran into that isn't necessarily documented.

Things to note:

• This project uses GLEW and OpenGL.
  • There were a number of significant changes from my old renderer to the one provided with the latest ImGui.
• This project also uses the FBX sdk - this is outside of the scope of this section.

OpenGL and GLFW

Previously, I had my own GLFW-passthrough to handle (and trap) Mouse and Keyboard events and then pass them through to the ImGui handlers.

For example, in my previous codebase, I would register the following GLFW callback:

static void KeyCallback(GLFWwindow* window, int key, int scancode, int action, int mods)
{
	if (key == GLFW_KEY_ESCAPE && action == GLFW_PRESS)
	{
		glfwSetWindowShouldClose(window, GL_TRUE);
		gAppState->ShouldExit = true;
	}

	int wasCursorKey = -1;
	switch (key)
	{
	case GLFW_KEY_W:
		wasCursorKey = KEY_W;
		break;
	case GLFW_KEY_S:
		wasCursorKey = KEY_S;
		break;
	case GLFW_KEY_A:
		wasCursorKey = KEY_A;
		break;
	case GLFW_KEY_D:
		wasCursorKey = KEY_D;
		break;
	default:
		break;
	}

	if (wasCursorKey != -1)
	{
		gCurrentKeyState.key[wasCursorKey] = true;
		gCurrentKeyState.action[wasCursorKey] = action;		
	}
	gCurrentKeyState.mods = mods;

	// Pass calls on through to ImGui
	ImGui_ImplGlfwGL3_KeyCallback(window, key, scancode, action, mods);
}

Whereas now we have the inverse, where we get mouse and keyboard events from ImGui::GetIO and the GLFW ImGui Implementation (`imgui_impl_glfw.h/.cpp).

	// Don't update if the UI has the UI.
	ImGuiIO& io = ImGui::GetIO();

	if (io.WantCaptureKeyboard || io.WantCaptureMouse)
	{
		return;
	}

	UpdateMouse(io);

and UpdateMouse would look like this:

void UpdateMouse(ImGuiIO& io)
{
	gMouseInfo.lmb = ImGui::IsMouseDown(0); // 0 - lmb  1 - mmb  2 - rmb

	gMouseInfo.deltaX = io.MouseDelta.x;
	gMouseInfo.deltaY = io.MouseDelta.y;

	gLastMousePosition = io.MousePos;
}

This does not mean that we stop invoking glfwDestroyWindow/glfwTerminate ourselves, but it does mean we need to invoke other methods.

Multiple function signature changes, for example (but not limited to):

• ImGui_ImplGlfwGL3_NewFrame()/ImGui_ImplGlfw_NewFrame()
• ImGui_ImplGlfwGL3_Shutdown/ImGui_ImplGlfw_Shutdown

What feels like undocumented changes

I've seen a number of methods that have been deprecated and doesn't feel like it's been properly documented. I've made a number of assumtpions, but that is exactly what they are: assumptions.

• ImGuiContext - FocusedWindow feels like it's been changed to NavWindow
• ImGuiContext - OsImePosRequest feels like it's been changed to PlatformImePos
• ImGuiWindow - WindowRectClipped feels like it's been changed to OuterRectClipped
• On of the widgets I'm porting used IsItemHovered but it doesn't feel like there is an appropriate alternative, so I've had to pull in the replacement.

You can see the last point illustrated in lumix.h:

    // if (ImGui::GetIO().MouseWheel != 0 && ImGui::IsItemHovered())
    // This also does not work
    // if (ImGui::GetIO().MouseWheel != 0 && IsItemHovered(ImGuiHoveredFlags_AllowWhenBlockedByActiveItem))
    // And neither does this
    // if (ImGui::GetIO().MouseWheel != 0 && IsItemHovered())

lumix.h

The current curve editor was pulled from the Lumix engine (https://github.com/nem0/LumixEngine). There used to be a fair number of other functions in there, but as I'm not currently using them, I'd rather not maintain them.

Notes

This project used the FBX sdk - due to file size, you'll need to grab the FBX sdk yourself and put it into extern/fbx. I've placed that library here: https://drive.google.com/file/d/1e3wGSMajOVD42VWAPAWmcXdrEfkdcaKo/view?usp=sharing

Note that I've already got the includes here - you really only need the lib folder.