IMGuiService Class Reference

#include <imguiservice.h>

Public Member Functions
	IMGuiService (ServiceConfiguration *configuration)
void	draw ()
void	selectWindow (nap::ResourcePtr< RenderWindow > window)
ImGuiContext *	getContext (nap::ResourcePtr< RenderWindow > window)
ImGuiContext *	findContext (int windowID)
float	getScale () const
float	getScale (const ImGuiContext *context) const
const gui::ColorPalette &	getPalette () const
ImGuiContext *	processInputEvent (const InputEvent &event)
bool	isCapturingKeyboard (ImGuiContext *context)
bool	isCapturingMouse (ImGuiContext *context)
ImTextureID	getTextureHandle (const nap::Texture2D &texture) const
nap::Icon &	getIcon (std::string &&name)
bool	loadIcon (const std::string &name, const nap::Module &module, utility::ErrorState &error)
Public Member Functions inherited from Service
UNPREFIXED_MODULE_NAME_INPUTCASE	Service (ServiceConfiguration *configuration)
	Service (ServiceConfiguration *configuration)
virtual	~Service ()
Core &	getCore ()
const Core &	getCore () const
std::string	getTypeName () const
const Module &	getModule () const
	Service (Service &)=delete
Service &	operator= (const Service &)=delete
	Service (Service &&)=delete
Service &	operator= (Service &&)=delete

Protected Member Functions
virtual bool	init (utility::ErrorState &error) override
virtual void	getDependentServices (std::vector< rtti::TypeInfo > &dependencies) override
virtual void	update (double deltaTime) override
virtual void	postUpdate (double deltaTime) override
virtual void	preShutdown () override
virtual void	shutdown () override
virtual void	registerObjectCreators (rtti::Factory &factory) override
Protected Member Functions inherited from Service
virtual void	created ()
virtual void	preUpdate (double deltaTime)
virtual void	preResourcesLoaded ()
virtual void	postResourcesLoaded ()
template<typename SERVICE_CONFIG >
SERVICE_CONFIG *	getConfiguration ()
template<typename SERVICE_CONFIG >
const SERVICE_CONFIG *	getConfiguration () const
std::string	getIniFilePath () const
std::string	getIniFilePath (const std::string &appendix) const

Description

This service manages the global ImGui state. Call draw() inside a window render pass to draw the GUI to screen. Call selectWindow() to select the window subsequent ImGUI calls apply to. Explicit window selection is only necessary when there is more than 1 window.

Only call selectWindow() on application update, not when rendering the GUI to screen. The service automatically creates a new GUI frame before application update.

Inheritance diagram for IMGuiService:

Collaboration diagram for IMGuiService:

Constructor & Destructor Documentation

IMGuiService()

IMGuiService

(

ServiceConfiguration *

configuration

)

Default constructor

Member Function Documentation

draw()

void draw

(

)

Draws the GUI elements for the currently active window to screen.

// Draw gui window 1
mRenderService->beginFrame();
if (mRenderService->beginRecording(*mRenderWindowOne))
{
   mRenderWindowOne->beginRendering();
   mGuiService->draw();
   mRenderWindowOne->endRendering();
   mRenderService->endRecording();
}
 
// Draw gui window 2
if (mRenderService->beginRecording(*mRenderWindowTwo))
{
   mRenderWindowTwo->beginRendering();
   mGuiService->draw();
   mRenderWindowTwo->endRendering();
   mRenderService->endRecording();
}
mRenderService->endFrame();

findContext()

ImGuiContext* findContext

(

int

windowID

)

Returns the ImGUI context associated with the given window id.

Parameters

windowID

the render window id

Returns

ImGUI context for the given window, nullptr if it doesn't exist.

getContext()

ImGuiContext* getContext

(

nap::ResourcePtr< RenderWindow >

window

)

Returns the ImGUI context associated with the given window.

Parameters

window

the render window

Returns

ImGUI context for the given window, asserts if it doesn't exist.

getDependentServices()

virtual void getDependentServices ( std::vector< rtti::TypeInfo > &  dependencies )

overrideprotectedvirtual

ImGui depends on the renderer

Parameters

dependencies

the type of services this service depends on

Reimplemented from Service.

getIcon()

nap::Icon& getIcon

(

std::string &&

name

)

Returns an icon with the given name and extension. Note that the icon must exist. Only ask for icons with their names explicitly declared in code, for example: 'icon::save'

if (ImGui::ImageButton(gui_service.getIcon(icon::ok)))
{
   ...
}

Parameters

name	the name, including extension, of the icon to load

Returns

icon with the given name

getPalette()

const gui::ColorPalette& getPalette

(

)

const

Returns the GUI color palette.

Returns

the GUI color palette.

getScale() [1/2]

float getScale

(

)

const

Returns the scaling factor of the current active context. The scaling factor is calculated using the display DPI (if high DPI rendering is enabled) and the global GUI scale.

Returns

the scaling factor for the current active context, -1.0 if no context is active

getScale() [2/2]

float getScale

(

const ImGuiContext *

context

)

const

Returns the scaling factor for the given context. The scaling factor is calculated using the display DPI (if high DPI rendering is enabled) and the global GUI scale.

Parameters

context

the ImGUI context

Returns

the scaling factor for the given context

getTextureHandle()

ImTextureID getTextureHandle

(

const nap::Texture2D &

texture

)

const

Returns a texture handle that can be used to display a Vulkan texture inside ImGUI. Alternatively, use the ImGUI::Image(nap::Texture2D&, ...) utility function, to immediately display a texture instead. Internally the handles are cached, it is therefore fine to call this function every frame. Keep in mind that a handle (descriptor set) is created for every unique texture.

ImGui::Begin("Texture");
ImGui::Image(mGuiService.getTextureHandle(texture), ...);
ImGui::End();

Returns

Vulkan texture handle, used to display a texture in ImGUI

init()

virtual bool init ( utility::ErrorState &  error )

overrideprotectedvirtual

Initializes the IMGui library. This will also create all associated gui devices objects Note that a GUI can only be associated with the primary window (for now).

Parameters

error

contains the error message if the lib could not be initialized correctly

Returns

if the lib was initialized successfully

Reimplemented from Service.

isCapturingKeyboard()

bool isCapturingKeyboard

(

ImGuiContext *

context

)

Returns

if the GUI is capturing keyboard events

isCapturingMouse()

bool isCapturingMouse

(

ImGuiContext *

context

)

Returns

if the GUI is capturing mouse events

loadIcon()

bool loadIcon	(	const std::string &	name,
		const nap::Module &	module,
		utility::ErrorState &	error
	)

Create and add an icon to the default set of icons. The system looks for the icon in the data search paths of the module. On success call getIcon() to retrieve and draw the icon.

Call this function on initialization of your service and make sure your icon names are unique. Duplicates are not allowed!

const auto& icon_names = icon::sequencer::get();
for (const auto& icon_name : icon_names)
{
   if (!mGuiService->loadIcon(icon_name, this->getModule(), errorState))
       return false;
}

Parameters

name	the name of the icon, including extension
module	the module that points to the icon
error	contains the error message if the load operations fails

Returns

if the icon is loaded and added to system defaults

postUpdate()

virtual void postUpdate ( double  deltaTime )

overrideprotectedvirtual

Ends frame operation for all contexts.

Reimplemented from Service.

preShutdown()

virtual void preShutdown ( )

overrideprotectedvirtual

Saves all gui .ini files

Reimplemented from Service.

processInputEvent()

ImGuiContext* processInputEvent

(

const InputEvent &

event

)

Forwards window input events to the GUI, called from GUIAppEventHandler.

Returns

context that belongs to the event, nullptr if the event is not related to a window.

registerObjectCreators()

virtual void registerObjectCreators ( rtti::Factory &  factory )

overrideprotectedvirtual

Registers all gui object creation objects

Reimplemented from Service.

selectWindow()

void selectWindow

(

nap::ResourcePtr< RenderWindow >

window

)

Select the window all subsequent ImGUI calls apply to. Explicit selection is only necessary when there is more than 1 window. Only call selectWindow() on application update, not when rendering the GUI to screen.

mGuiService->selectWindow(mRenderWindowOne);
ImGui::Begin("GUI Window One");
...
ImGui::End();
 
mGuiService->selectWindow(mRenderWindowTwo);
ImGui::Begin("GUI Window Two");
...
ImGui::End();

Parameters

window

the window to select

shutdown()

virtual void shutdown ( )

overrideprotectedvirtual

Deletes all GUI related resources

Reimplemented from Service.

update()

virtual void update ( double  deltaTime )

overrideprotectedvirtual

Allows IMGUI to draw a new frame. This is called automatically by core in the app loop

Parameters

deltaTime

the time in seconds between ticks

Reimplemented from Service.