Irrlicht 3D Engine
Tutorial 9: Mesh Viewer

This tutorial show how to create a more complex application with the engine. We construct a simple mesh viewer using the user interface API and the scene management of Irrlicht. The tutorial show how to create and use Buttons, Windows, Toolbars, Menus, ComboBoxes, Tabcontrols, Editboxes, Images, MessageBoxes, SkyBoxes, and how to parse XML files with the integrated XML reader of the engine.

We start like in most other tutorials: Include all necessary header files, add a comment to let the engine be linked with the right .lib file in Visual Studio, and declare some global variables. We also add two 'using namespace' statements, so we do not need to write the whole names of all classes. In this tutorial, we use a lot stuff from the gui namespace.

#include <irrlicht.h>
#include "driverChoice.h"
using namespace irr;
using namespace gui;
#ifdef _MSC_VER
#pragma comment(lib, "Irrlicht.lib")
#endif
Main header file of the irrlicht, the only file needed to include.
Everything in the Irrlicht Engine can be found in this namespace.
Definition: aabbox3d.h:13

Some global variables used later on

IrrlichtDevice *Device = 0;
core::stringc StartUpModelFile;
core::stringw MessageText;
core::stringw Caption;
scene::ISceneNode* Model = 0;
scene::ISceneNode* SkyBox = 0;
bool Octree=false;
bool UseLight=false;
scene::ICameraSceneNode* Camera[2] = {0, 0};
// Values used to identify individual GUI elements
enum
{
GUI_ID_DIALOG_ROOT_WINDOW = 0x10000,
GUI_ID_X_SCALE,
GUI_ID_Y_SCALE,
GUI_ID_Z_SCALE,
GUI_ID_OPEN_MODEL,
GUI_ID_SET_MODEL_ARCHIVE,
GUI_ID_LOAD_AS_OCTREE,
GUI_ID_SKY_BOX_VISIBLE,
GUI_ID_TOGGLE_DEBUG_INFO,
GUI_ID_DEBUG_OFF,
GUI_ID_DEBUG_BOUNDING_BOX,
GUI_ID_DEBUG_NORMALS,
GUI_ID_DEBUG_SKELETON,
GUI_ID_DEBUG_WIRE_OVERLAY,
GUI_ID_DEBUG_HALF_TRANSPARENT,
GUI_ID_DEBUG_BUFFERS_BOUNDING_BOXES,
GUI_ID_DEBUG_ALL,
GUI_ID_MODEL_MATERIAL_SOLID,
GUI_ID_MODEL_MATERIAL_TRANSPARENT,
GUI_ID_MODEL_MATERIAL_REFLECTION,
GUI_ID_CAMERA_MAYA,
GUI_ID_CAMERA_FIRST_PERSON,
GUI_ID_POSITION_TEXT,
GUI_ID_ABOUT,
GUI_ID_QUIT,
GUI_ID_TEXTUREFILTER,
GUI_ID_SKIN_TRANSPARENCY,
GUI_ID_SKIN_ANIMATION_FPS,
GUI_ID_BUTTON_SET_SCALE,
GUI_ID_BUTTON_SCALE_MUL10,
GUI_ID_BUTTON_SCALE_DIV10,
GUI_ID_BUTTON_OPEN_MODEL,
GUI_ID_BUTTON_SHOW_ABOUT,
GUI_ID_BUTTON_SHOW_TOOLBOX,
GUI_ID_BUTTON_SELECT_ARCHIVE,
GUI_ID_ANIMATION_INFO,
// And some magic numbers
MAX_FRAMERATE = 80,
DEFAULT_FRAMERATE = 30
};
string< c8 > stringc
Typedef for character strings.
Definition: irrString.h:1358
string< wchar_t > stringw
Typedef for wide character strings.
Definition: irrString.h:1361

Toggle between various cameras

void setActiveCamera(scene::ICameraSceneNode* newActive)
{
if (0 == Device)
return;
scene::ICameraSceneNode * active = Device->getSceneManager()->getActiveCamera();
active->setInputReceiverEnabled(false);
newActive->setInputReceiverEnabled(true);
Device->getSceneManager()->setActiveCamera(newActive);
}

Set the skin transparency by changing the alpha values of all skin-colors

void setSkinTransparency(s32 alpha, irr::gui::IGUISkin * skin)
{
for (s32 i=0; i<irr::gui::EGDC_COUNT ; ++i)
{
video::SColor col = skin->getColor((EGUI_DEFAULT_COLOR)i);
col.setAlpha(alpha);
skin->setColor((EGUI_DEFAULT_COLOR)i, col);
}
}
A skin modifies the look of the GUI elements.
Definition: IGUISkin.h:379
virtual void setColor(EGUI_DEFAULT_COLOR which, video::SColor newColor)=0
sets a default color
virtual video::SColor getColor(EGUI_DEFAULT_COLOR color) const =0
returns default color
void setAlpha(u32 a)
Sets the alpha component of the Color.
Definition: SColor.h:259
EGUI_DEFAULT_COLOR
Enumeration for skin colors.
Definition: IGUISkin.h:61
@ EGDC_COUNT
Definition: IGUISkin.h:115
signed int s32
32 bit signed variable.
Definition: irrTypes.h:66

Update the display of the model scaling

void updateScaleInfo(scene::ISceneNode* model)
{
IGUIElement* toolboxWnd = Device->getGUIEnvironment()->getRootGUIElement()->getElementFromId(GUI_ID_DIALOG_ROOT_WINDOW, true);
if (!toolboxWnd)
return;
if (!model)
{
toolboxWnd->getElementFromId(GUI_ID_X_SCALE, true)->setText( L"-" );
toolboxWnd->getElementFromId(GUI_ID_Y_SCALE, true)->setText( L"-" );
toolboxWnd->getElementFromId(GUI_ID_Z_SCALE, true)->setText( L"-" );
}
else
{
core::vector3df scale = model->getScale();
toolboxWnd->getElementFromId(GUI_ID_X_SCALE, true)->setText( core::stringw(scale.X).c_str() );
toolboxWnd->getElementFromId(GUI_ID_Y_SCALE, true)->setText( core::stringw(scale.Y).c_str() );
toolboxWnd->getElementFromId(GUI_ID_Z_SCALE, true)->setText( core::stringw(scale.Z).c_str() );
}
}
vector3d< f32 > vector3df
Typedef for a f32 3d vector.
Definition: vector3d.h:445

Function showAboutText() displays a messagebox with a caption and a message text. The texts will be stored in the MessageText and Caption variables at startup.

void showAboutText()
{
// create modal message box with the text
// loaded from the xml file.
Device->getGUIEnvironment()->addMessageBox(
Caption.c_str(), MessageText.c_str());
}

Function loadModel() loads a model and displays it using an addAnimatedMeshSceneNode and the scene manager. Nothing difficult. It also displays a short message box, if the model could not be loaded.

void loadModel(const c8* fn)
{
// modify the name if it a .pk3 file
io::path filename(fn);
io::path extension;
core::getFileNameExtension(extension, filename);
extension.make_lower();
// if a texture is loaded apply it to the current model..
if (extension == ".jpg" || extension == ".pcx" ||
extension == ".png" || extension == ".ppm" ||
extension == ".pgm" || extension == ".pbm" ||
extension == ".psd" || extension == ".tga" ||
extension == ".bmp" || extension == ".wal" ||
extension == ".rgb" || extension == ".rgba")
{
video::ITexture * texture =
Device->getVideoDriver()->getTexture( filename );
if ( texture && Model )
{
// always reload texture
Device->getVideoDriver()->removeTexture(texture);
texture = Device->getVideoDriver()->getTexture( filename );
Model->setMaterialTexture(0, texture);
}
return;
}
// if a archive is loaded add it to the FileArchive..
else if (extension == ".pk3" || extension == ".zip" || extension == ".pak" || extension == ".npk")
{
Device->getFileSystem()->addFileArchive(filename.c_str());
return;
}
// load a model into the engine
if (Model)
Model->remove();
Model = 0;
if (extension==".irr")
{
core::array<scene::ISceneNode*> outNodes;
Device->getSceneManager()->loadScene(filename);
Device->getSceneManager()->getSceneNodesFromType(scene::ESNT_ANIMATED_MESH, outNodes);
if (outNodes.size())
Model = outNodes[0];
return;
}
scene::IAnimatedMesh* m = Device->getSceneManager()->getMesh( filename.c_str() );
if (!m)
{
// model could not be loaded
if (StartUpModelFile != filename)
Device->getGUIEnvironment()->addMessageBox(
Caption.c_str(), L"The model could not be loaded. " \
L"Maybe it is not a supported file format.");
return;
}
// set default material properties
if (Octree)
Model = Device->getSceneManager()->addOctreeSceneNode(m->getMesh(0));
else
{
scene::IAnimatedMeshSceneNode* animModel = Device->getSceneManager()->addAnimatedMeshSceneNode(m);
animModel->setAnimationSpeed(30);
Model = animModel;
}
Model->setMaterialFlag(video::EMF_LIGHTING, UseLight);
Model->setMaterialFlag(video::EMF_NORMALIZE_NORMALS, UseLight);
// Model->setMaterialFlag(video::EMF_BACK_FACE_CULLING, false);
Model->setDebugDataVisible(scene::EDS_OFF);
// we need to uncheck the menu entries. would be cool to fake a menu event, but
// that's not so simple. so we do it brute force
gui::IGUIContextMenu* menu = (gui::IGUIContextMenu*)Device->getGUIEnvironment()->getRootGUIElement()->getElementFromId(GUI_ID_TOGGLE_DEBUG_INFO, true);
if (menu)
for(int item = 1; item < 6; ++item)
menu->setItemChecked(item, false);
updateScaleInfo(Model);
}
io::path & getFileNameExtension(io::path &dest, const io::path &source)
get the filename extension from a file path
Definition: coreutil.h:57
core::string< fschar_t > path
Type used for all file system related strings.
Definition: path.h:17
@ EDS_OFF
No Debug Data ( Default )
@ ESNT_ANIMATED_MESH
Animated Mesh Scene Node.
@ EMF_NORMALIZE_NORMALS
Normalizes normals. Default: false.
@ EMF_LIGHTING
Will this material be lighted? Default: true.
char c8
8 bit character variable.
Definition: irrTypes.h:31

Function createToolBox() creates a toolbox window. In this simple mesh viewer, this toolbox only contains a tab control with three edit boxes for changing the scale of the displayed model.

void createToolBox()
{
// remove tool box if already there
IGUIEnvironment* env = Device->getGUIEnvironment();
IGUIElement* root = env->getRootGUIElement();
IGUIElement* e = root->getElementFromId(GUI_ID_DIALOG_ROOT_WINDOW, true);
if (e)
e->remove();
// create the toolbox window
IGUIWindow* wnd = env->addWindow(core::rect<s32>(600,45,800,480),
false, L"Toolset", 0, GUI_ID_DIALOG_ROOT_WINDOW);
// create tab control and tabs
IGUITabControl* tab = env->addTabControl(
core::rect<s32>(2,20,800-602,480-7), wnd, true, true);
IGUITab* t1 = tab->addTab(L"Config");
// add some edit boxes and a button to tab one
env->addStaticText(L"Scale:",
core::rect<s32>(10,20,60,45), false, false, t1);
env->addStaticText(L"X:", core::rect<s32>(22,48,40,66), false, false, t1);
env->addEditBox(L"1.0", core::rect<s32>(40,46,130,66), true, t1, GUI_ID_X_SCALE);
env->addStaticText(L"Y:", core::rect<s32>(22,82,40,96), false, false, t1);
env->addEditBox(L"1.0", core::rect<s32>(40,76,130,96), true, t1, GUI_ID_Y_SCALE);
env->addStaticText(L"Z:", core::rect<s32>(22,108,40,126), false, false, t1);
env->addEditBox(L"1.0", core::rect<s32>(40,106,130,126), true, t1, GUI_ID_Z_SCALE);
env->addButton(core::rect<s32>(10,134,85,165), t1, GUI_ID_BUTTON_SET_SCALE, L"Set");
// quick scale buttons
env->addButton(core::rect<s32>(65,20,95,40), t1, GUI_ID_BUTTON_SCALE_MUL10, L"* 10");
env->addButton(core::rect<s32>(100,20,130,40), t1, GUI_ID_BUTTON_SCALE_DIV10, L"* 0.1");
updateScaleInfo(Model);
// add transparency control
env->addStaticText(L"GUI Transparency Control:",
core::rect<s32>(10,200,150,225), true, false, t1);
IGUIScrollBar* scrollbar = env->addScrollBar(true,
core::rect<s32>(10,225,150,240), t1, GUI_ID_SKIN_TRANSPARENCY);
scrollbar->setMax(255);
scrollbar->setPos(255);
// add framerate control
env->addStaticText(L":", core::rect<s32>(10,240,150,265), true, false, t1);
env->addStaticText(L"Framerate:",
core::rect<s32>(12,240,75,265), false, false, t1);
// current frame info
env->addStaticText(L"", core::rect<s32>(75,240,200,265), false, false, t1,
GUI_ID_ANIMATION_INFO);
scrollbar = env->addScrollBar(true,
core::rect<s32>(10,265,150,280), t1, GUI_ID_SKIN_ANIMATION_FPS);
scrollbar->setMax(MAX_FRAMERATE);
scrollbar->setMin(-MAX_FRAMERATE);
scrollbar->setPos(DEFAULT_FRAMERATE);
scrollbar->setSmallStep(1);
}

Function updateToolBox() is called each frame to update dynamic information in the toolbox.

void updateToolBox()
{
IGUIEnvironment* env = Device->getGUIEnvironment();
IGUIElement* root = env->getRootGUIElement();
IGUIElement* dlg = root->getElementFromId(GUI_ID_DIALOG_ROOT_WINDOW, true);
if (!dlg )
return;
// update the info we have about the animation of the model
IGUIStaticText * aniInfo = (IGUIStaticText *)(dlg->getElementFromId(GUI_ID_ANIMATION_INFO, true));
if (aniInfo)
{
if ( Model && scene::ESNT_ANIMATED_MESH == Model->getType() )
{
scene::IAnimatedMeshSceneNode* animatedModel = (scene::IAnimatedMeshSceneNode*)Model;
core::stringw str( (s32)core::round_(animatedModel->getAnimationSpeed()) );
str += L" Frame: ";
str += core::stringw((s32)animatedModel->getFrameNr());
aniInfo->setText(str.c_str());
}
else
aniInfo->setText(L"");
}
}
void onKillFocus()
{
// Avoid that the FPS-camera continues moving when the user presses alt-tab while
// moving the camera.
const core::list<scene::ISceneNodeAnimator*>& animators = Camera[1]->getAnimators();
core::list<irr::scene::ISceneNodeAnimator*>::ConstIterator iter = animators.begin();
while ( iter != animators.end() )
{
if ( (*iter)->getType() == scene::ESNAT_CAMERA_FPS )
{
// we send a key-down event for all keys used by this animator
scene::ISceneNodeAnimatorCameraFPS * fpsAnimator = static_cast<scene::ISceneNodeAnimatorCameraFPS*>(*iter);
const core::array<SKeyMap>& keyMap = fpsAnimator->getKeyMap();
for ( irr::u32 i=0; i< keyMap.size(); ++i )
{
irr::SEvent event;
event.KeyInput.Key = keyMap[i].KeyCode;
event.KeyInput.PressedDown = false;
fpsAnimator->OnEvent(event);
}
}
++iter;
}
}
f32 round_(f32 x)
Definition: irrMath.h:449
@ ESNAT_CAMERA_FPS
FPS camera animator.
unsigned int u32
32 bit unsigned variable.
Definition: irrTypes.h:58
@ EET_KEY_INPUT_EVENT
A key input event.
SEvents hold information about an event. See irr::IEventReceiver for details on event handling.
EEVENT_TYPE EventType

Function hasModalDialog() checks if we currently have a modal dialog open.

bool hasModalDialog()
{
if ( !Device )
return false;
IGUIEnvironment* env = Device->getGUIEnvironment();
IGUIElement * focused = env->getFocus();
while ( focused )
{
if ( focused->isVisible() && focused->hasType(EGUIET_MODAL_SCREEN) )
return true;
focused = focused->getParent();
}
return false;
}
@ EGUIET_MODAL_SCREEN
A modal screen.

To get all the events sent by the GUI Elements, we need to create an event receiver. This one is really simple. If an event occurs, it checks the id of the caller and the event type, and starts an action based on these values. For example, if a menu item with id GUI_ID_OPEN_MODEL was selected, it opens a file-open-dialog.

class MyEventReceiver : public IEventReceiver
{
public:
virtual bool OnEvent(const SEvent& event)
{
// Escape swaps Camera Input
if (event.EventType == EET_KEY_INPUT_EVENT &&
event.KeyInput.PressedDown == false)
{
if ( OnKeyUp(event.KeyInput.Key) )
return true;
}
if (event.EventType == EET_GUI_EVENT)
{
s32 id = event.GUIEvent.Caller->getID();
IGUIEnvironment* env = Device->getGUIEnvironment();
switch(event.GUIEvent.EventType)
{
// a menu item was clicked
OnMenuItemSelected( (IGUIContextMenu*)event.GUIEvent.Caller );
break;
{
// load the model file, selected in the file open dialog
IGUIFileOpenDialog* dialog =
(IGUIFileOpenDialog*)event.GUIEvent.Caller;
loadModel(core::stringc(dialog->getFileName()).c_str());
}
break;
// control skin transparency
if (id == GUI_ID_SKIN_TRANSPARENCY)
{
const s32 pos = ((IGUIScrollBar*)event.GUIEvent.Caller)->getPos();
setSkinTransparency(pos, env->getSkin());
}
// control animation speed
else if (id == GUI_ID_SKIN_ANIMATION_FPS)
{
const s32 pos = ((IGUIScrollBar*)event.GUIEvent.Caller)->getPos();
if (scene::ESNT_ANIMATED_MESH == Model->getType())
((scene::IAnimatedMeshSceneNode*)Model)->setAnimationSpeed((f32)pos);
}
break;
// control anti-aliasing/filtering
if (id == GUI_ID_TEXTUREFILTER)
{
OnTextureFilterSelected( (IGUIComboBox*)event.GUIEvent.Caller );
}
break;
switch(id)
{
case GUI_ID_BUTTON_SET_SCALE:
{
// set scale
gui::IGUIElement* root = env->getRootGUIElement();
s = root->getElementFromId(GUI_ID_X_SCALE, true)->getText();
scale.X = (f32)atof(s.c_str());
s = root->getElementFromId(GUI_ID_Y_SCALE, true)->getText();
scale.Y = (f32)atof(s.c_str());
s = root->getElementFromId(GUI_ID_Z_SCALE, true)->getText();
scale.Z = (f32)atof(s.c_str());
if (Model)
Model->setScale(scale);
updateScaleInfo(Model);
}
break;
case GUI_ID_BUTTON_SCALE_MUL10:
if (Model)
Model->setScale(Model->getScale()*10.f);
updateScaleInfo(Model);
break;
case GUI_ID_BUTTON_SCALE_DIV10:
if (Model)
Model->setScale(Model->getScale()*0.1f);
updateScaleInfo(Model);
break;
case GUI_ID_BUTTON_OPEN_MODEL:
env->addFileOpenDialog(L"Please select a model file to open");
break;
case GUI_ID_BUTTON_SHOW_ABOUT:
showAboutText();
break;
case GUI_ID_BUTTON_SHOW_TOOLBOX:
createToolBox();
break;
case GUI_ID_BUTTON_SELECT_ARCHIVE:
env->addFileOpenDialog(L"Please select your game archive/directory");
break;
}
break;
default:
break;
}
}
return false;
}
@ EGET_SCROLL_BAR_CHANGED
A scrollbar has changed its position.
@ EGET_BUTTON_CLICKED
A button was clicked.
@ EGET_FILE_SELECTED
A file has been selected in the file dialog.
@ EGET_MENU_ITEM_SELECTED
A menu item was selected in a (context) menu.
@ EGET_COMBO_BOX_CHANGED
The selection in a combo box has been changed.
float f32
32 bit floating point variable.
Definition: irrTypes.h:104
@ EET_GUI_EVENT
An event of the graphical user interface.

Handle key-up events

bool OnKeyUp(irr::EKEY_CODE keyCode)
{
// Don't handle keys if we have a modal dialog open as it would lead
// to unexpected application behaviour for the user.
if ( hasModalDialog() )
return false;
if (keyCode == irr::KEY_ESCAPE)
{
if (Device)
{
scene::ICameraSceneNode * camera =
Device->getSceneManager()->getActiveCamera();
if (camera)
{
camera->setInputReceiverEnabled( !camera->isInputReceiverEnabled() );
}
return true;
}
}
else if (keyCode == irr::KEY_F1)
{
if (Device)
{
IGUIElement* elem = Device->getGUIEnvironment()->getRootGUIElement()->getElementFromId(GUI_ID_POSITION_TEXT);
if (elem)
elem->setVisible(!elem->isVisible());
}
}
else if (keyCode == irr::KEY_KEY_M)
{
if (Device)
Device->minimizeWindow();
}
else if (keyCode == irr::KEY_KEY_L)
{
UseLight=!UseLight;
if (Model)
{
Model->setMaterialFlag(video::EMF_LIGHTING, UseLight);
Model->setMaterialFlag(video::EMF_NORMALIZE_NORMALS, UseLight);
}
}
return false;
}
EKEY_CODE
Definition: Keycodes.h:12
@ KEY_F1
Definition: Keycodes.h:112
@ KEY_KEY_M
Definition: Keycodes.h:78
@ KEY_ESCAPE
Definition: Keycodes.h:35
@ KEY_KEY_L
Definition: Keycodes.h:77

Handle "menu item clicked" events.

void OnMenuItemSelected( IGUIContextMenu* menu )
{
s32 id = menu->getItemCommandId(menu->getSelectedItem());
IGUIEnvironment* env = Device->getGUIEnvironment();
switch(id)
{
case GUI_ID_OPEN_MODEL: // FilOnButtonSetScalinge -> Open Model
env->addFileOpenDialog(L"Please select a model file to open");
break;
case GUI_ID_SET_MODEL_ARCHIVE: // File -> Set Model Archive
env->addFileOpenDialog(L"Please select your game archive/directory");
break;
case GUI_ID_LOAD_AS_OCTREE: // File -> LoadAsOctree
Octree = !Octree;
menu->setItemChecked(menu->getSelectedItem(), Octree);
break;
case GUI_ID_QUIT: // File -> Quit
Device->closeDevice();
break;
case GUI_ID_SKY_BOX_VISIBLE: // View -> Skybox
menu->setItemChecked(menu->getSelectedItem(), !menu->isItemChecked(menu->getSelectedItem()));
SkyBox->setVisible(!SkyBox->isVisible());
break;
case GUI_ID_DEBUG_OFF: // View -> Debug Information
menu->setItemChecked(menu->getSelectedItem()+1, false);
menu->setItemChecked(menu->getSelectedItem()+2, false);
menu->setItemChecked(menu->getSelectedItem()+3, false);
menu->setItemChecked(menu->getSelectedItem()+4, false);
menu->setItemChecked(menu->getSelectedItem()+5, false);
menu->setItemChecked(menu->getSelectedItem()+6, false);
if (Model)
Model->setDebugDataVisible(scene::EDS_OFF);
break;
case GUI_ID_DEBUG_BOUNDING_BOX: // View -> Debug Information
menu->setItemChecked(menu->getSelectedItem(), !menu->isItemChecked(menu->getSelectedItem()));
if (Model)
Model->setDebugDataVisible((scene::E_DEBUG_SCENE_TYPE)(Model->isDebugDataVisible()^scene::EDS_BBOX));
break;
case GUI_ID_DEBUG_NORMALS: // View -> Debug Information
menu->setItemChecked(menu->getSelectedItem(), !menu->isItemChecked(menu->getSelectedItem()));
if (Model)
Model->setDebugDataVisible((scene::E_DEBUG_SCENE_TYPE)(Model->isDebugDataVisible()^scene::EDS_NORMALS));
break;
case GUI_ID_DEBUG_SKELETON: // View -> Debug Information
menu->setItemChecked(menu->getSelectedItem(), !menu->isItemChecked(menu->getSelectedItem()));
if (Model)
Model->setDebugDataVisible((scene::E_DEBUG_SCENE_TYPE)(Model->isDebugDataVisible()^scene::EDS_SKELETON));
break;
case GUI_ID_DEBUG_WIRE_OVERLAY: // View -> Debug Information
menu->setItemChecked(menu->getSelectedItem(), !menu->isItemChecked(menu->getSelectedItem()));
if (Model)
Model->setDebugDataVisible((scene::E_DEBUG_SCENE_TYPE)(Model->isDebugDataVisible()^scene::EDS_MESH_WIRE_OVERLAY));
break;
case GUI_ID_DEBUG_HALF_TRANSPARENT: // View -> Debug Information
menu->setItemChecked(menu->getSelectedItem(), !menu->isItemChecked(menu->getSelectedItem()));
if (Model)
Model->setDebugDataVisible((scene::E_DEBUG_SCENE_TYPE)(Model->isDebugDataVisible()^scene::EDS_HALF_TRANSPARENCY));
break;
case GUI_ID_DEBUG_BUFFERS_BOUNDING_BOXES: // View -> Debug Information
menu->setItemChecked(menu->getSelectedItem(), !menu->isItemChecked(menu->getSelectedItem()));
if (Model)
Model->setDebugDataVisible((scene::E_DEBUG_SCENE_TYPE)(Model->isDebugDataVisible()^scene::EDS_BBOX_BUFFERS));
break;
case GUI_ID_DEBUG_ALL: // View -> Debug Information
menu->setItemChecked(menu->getSelectedItem()-1, true);
menu->setItemChecked(menu->getSelectedItem()-2, true);
menu->setItemChecked(menu->getSelectedItem()-3, true);
menu->setItemChecked(menu->getSelectedItem()-4, true);
menu->setItemChecked(menu->getSelectedItem()-5, true);
menu->setItemChecked(menu->getSelectedItem()-6, true);
if (Model)
Model->setDebugDataVisible(scene::EDS_FULL);
break;
case GUI_ID_ABOUT: // Help->About
showAboutText();
break;
case GUI_ID_MODEL_MATERIAL_SOLID: // View -> Material -> Solid
if (Model)
Model->setMaterialType(video::EMT_SOLID);
break;
case GUI_ID_MODEL_MATERIAL_TRANSPARENT: // View -> Material -> Transparent
if (Model)
Model->setMaterialType(video::EMT_TRANSPARENT_ADD_COLOR);
break;
case GUI_ID_MODEL_MATERIAL_REFLECTION: // View -> Material -> Reflection
if (Model)
Model->setMaterialType(video::EMT_SPHERE_MAP);
break;
case GUI_ID_CAMERA_MAYA:
setActiveCamera(Camera[0]);
break;
case GUI_ID_CAMERA_FIRST_PERSON:
setActiveCamera(Camera[1]);
break;
}
}
E_DEBUG_SCENE_TYPE
An enumeration for all types of debug data for built-in scene nodes (flags)
@ EDS_BBOX_BUFFERS
Show Bounding Boxes of all MeshBuffers.
@ EDS_BBOX
Show Bounding Boxes of SceneNode.
@ EDS_HALF_TRANSPARENCY
Temporary use transparency Material Type.
@ EDS_FULL
Show all debug infos.
@ EDS_NORMALS
Show Vertex Normals.
@ EDS_MESH_WIRE_OVERLAY
Overlays Mesh Wireframe.
@ EDS_SKELETON
Shows Skeleton/Tags.
@ EMT_TRANSPARENT_ADD_COLOR
A transparent material.
@ EMT_SPHERE_MAP
Look like a reflection of the environment around it.
@ EMT_SOLID
Standard solid material.

Handle the event that one of the texture-filters was selected in the corresponding combobox.

void OnTextureFilterSelected( IGUIComboBox* combo )
{
s32 pos = combo->getSelected();
switch (pos)
{
case 0:
if (Model)
{
Model->setMaterialFlag(video::EMF_BILINEAR_FILTER, false);
Model->setMaterialFlag(video::EMF_TRILINEAR_FILTER, false);
Model->setMaterialFlag(video::EMF_ANISOTROPIC_FILTER, false);
}
break;
case 1:
if (Model)
{
Model->setMaterialFlag(video::EMF_BILINEAR_FILTER, true);
Model->setMaterialFlag(video::EMF_TRILINEAR_FILTER, false);
}
break;
case 2:
if (Model)
{
Model->setMaterialFlag(video::EMF_BILINEAR_FILTER, false);
Model->setMaterialFlag(video::EMF_TRILINEAR_FILTER, true);
}
break;
case 3:
if (Model)
{
Model->setMaterialFlag(video::EMF_ANISOTROPIC_FILTER, true);
}
break;
case 4:
if (Model)
{
Model->setMaterialFlag(video::EMF_ANISOTROPIC_FILTER, false);
}
break;
}
}
};
@ EMF_TRILINEAR_FILTER
Is trilinear filtering enabled? Default: false.
@ EMF_ANISOTROPIC_FILTER
Is anisotropic filtering? Default: false.
@ EMF_BILINEAR_FILTER
Is bilinear filtering enabled? Default: true.

Most of the hard work is done. We only need to create the Irrlicht Engine device and all the buttons, menus and toolbars. We start up the engine as usual, using createDevice(). To make our application catch events, we set our eventreceiver as parameter. As you can see, there is also a call to IrrlichtDevice::setResizeable(). This makes the render window resizeable, which is quite useful for a mesh viewer.

int main(int argc, char* argv[])
{
// ask user for driver
video::E_DRIVER_TYPE driverType=driverChoiceConsole();
if (driverType==video::EDT_COUNT)
return 1;
// create device and exit if creation failed
MyEventReceiver receiver;
Device = createDevice(driverType, core::dimension2d<u32>(800, 600),
16, false, false, false, &receiver);
if (Device == 0)
return 1; // could not create selected driver.
Device->setResizable(true);
Device->setWindowCaption(L"Irrlicht Engine - Loading...");
video::IVideoDriver* driver = Device->getVideoDriver();
IGUIEnvironment* env = Device->getGUIEnvironment();
scene::ISceneManager* smgr = Device->getSceneManager();
smgr->getParameters()->setAttribute(scene::COLLADA_CREATE_SCENE_INSTANCES, true);
driver->setTextureCreationFlag(video::ETCF_ALWAYS_32_BIT, true);
smgr->addLightSceneNode(0, core::vector3df(200,200,200),
video::SColorf(1.0f,1.0f,1.0f),2000);
smgr->setAmbientLight(video::SColorf(0.3f,0.3f,0.3f));
// add our media directory as "search path"
Device->getFileSystem()->addFileArchive("../../media/");
const c8 *const COLLADA_CREATE_SCENE_INSTANCES
Name of the parameter specifying the COLLADA mesh loading mode.
@ ETCF_ALWAYS_32_BIT
Definition: ITexture.h:41
E_DRIVER_TYPE
An enum for all types of drivers the Irrlicht Engine supports.
Definition: EDriverTypes.h:15
@ EDT_COUNT
No driver, just for counting the elements.
Definition: EDriverTypes.h:56
IRRLICHT_API IrrlichtDevice *IRRCALLCONV createDevice(video::E_DRIVER_TYPE deviceType=video::EDT_SOFTWARE, const core::dimension2d< u32 > &windowSize=(core::dimension2d< u32 >(640, 480)), u32 bits=16, bool fullscreen=false, bool stencilbuffer=false, bool vsync=false, IEventReceiver *receiver=0)
Creates an Irrlicht device. The Irrlicht device is the root object for using the engine.

The next step is to read the configuration file. It is stored in the xml format and looks a little bit like this:

    <?xml version="1.0"?>
    <config>
        <startUpModel file="some filename" />
        <messageText caption="Irrlicht Engine Mesh Viewer">
            Hello!
        </messageText>
    </config>

We need the data stored in there to be written into the global variables StartUpModelFile, MessageText and Caption. This is now done using the Irrlicht Engine integrated XML parser:

// read configuration from xml file
io::IXMLReader* xml = Device->getFileSystem()->createXMLReader( L"config.xml");
while(xml && xml->read())
{
switch(xml->getNodeType())
{
// in this xml file, the only text which occurs is the
// messageText
MessageText = xml->getNodeData();
break;
{
if (core::stringw("startUpModel") == xml->getNodeName())
StartUpModelFile = xml->getAttributeValue(L"file");
else
if (core::stringw("messageText") == xml->getNodeName())
Caption = xml->getAttributeValue(L"caption");
}
break;
default:
break;
}
}
if (xml)
xml->drop(); // don't forget to delete the xml reader
if (argc > 1)
StartUpModelFile = argv[1];
@ EXN_TEXT
Definition: irrXML.h:194
@ EXN_ELEMENT
An xml element such as <foo>.
Definition: irrXML.h:187
IIrrXMLReader< wchar_t, IReferenceCounted > IXMLReader
An xml reader for wide characters, derived from IReferenceCounted.
Definition: IXMLReader.h:19

That wasn't difficult. Now we'll set a nicer font and create the Menu. It is possible to create submenus for every menu item. The call menu->addItem(L"File", -1, true, true); for example adds a new menu Item with the name "File" and the id -1. The following parameter says that the menu item should be enabled, and the last one says, that there should be a submenu. The submenu can now be accessed with menu->getSubMenu(0), because the "File" entry is the menu item with index 0.

// set a nicer font
IGUISkin* skin = env->getSkin();
IGUIFont* font = env->getFont("fonthaettenschweiler.bmp");
if (font)
skin->setFont(font);
// create menu
gui::IGUIContextMenu* menu = env->addMenu();
menu->addItem(L"File", -1, true, true);
menu->addItem(L"View", -1, true, true);
menu->addItem(L"Camera", -1, true, true);
menu->addItem(L"Help", -1, true, true);
gui::IGUIContextMenu* submenu;
submenu = menu->getSubMenu(0);
submenu->addItem(L"Open Model File & Texture...", GUI_ID_OPEN_MODEL);
submenu->addItem(L"Set Model Archive...", GUI_ID_SET_MODEL_ARCHIVE);
submenu->addItem(L"Load as Octree", GUI_ID_LOAD_AS_OCTREE);
submenu->addSeparator();
submenu->addItem(L"Quit", GUI_ID_QUIT);
submenu = menu->getSubMenu(1);
submenu->addItem(L"sky box visible", GUI_ID_SKY_BOX_VISIBLE, true, false, true);
submenu->addItem(L"toggle model debug information", GUI_ID_TOGGLE_DEBUG_INFO, true, true);
submenu->addItem(L"model material", -1, true, true );
submenu = submenu->getSubMenu(1);
submenu->addItem(L"Off", GUI_ID_DEBUG_OFF);
submenu->addItem(L"Bounding Box", GUI_ID_DEBUG_BOUNDING_BOX);
submenu->addItem(L"Normals", GUI_ID_DEBUG_NORMALS);
submenu->addItem(L"Skeleton", GUI_ID_DEBUG_SKELETON);
submenu->addItem(L"Wire overlay", GUI_ID_DEBUG_WIRE_OVERLAY);
submenu->addItem(L"Half-Transparent", GUI_ID_DEBUG_HALF_TRANSPARENT);
submenu->addItem(L"Buffers bounding boxes", GUI_ID_DEBUG_BUFFERS_BOUNDING_BOXES);
submenu->addItem(L"All", GUI_ID_DEBUG_ALL);
submenu = menu->getSubMenu(1)->getSubMenu(2);
submenu->addItem(L"Solid", GUI_ID_MODEL_MATERIAL_SOLID);
submenu->addItem(L"Transparent", GUI_ID_MODEL_MATERIAL_TRANSPARENT);
submenu->addItem(L"Reflection", GUI_ID_MODEL_MATERIAL_REFLECTION);
submenu = menu->getSubMenu(2);
submenu->addItem(L"Maya Style", GUI_ID_CAMERA_MAYA);
submenu->addItem(L"First Person", GUI_ID_CAMERA_FIRST_PERSON);
submenu = menu->getSubMenu(3);
submenu->addItem(L"About", GUI_ID_ABOUT);
virtual IGUIFont * getFont(EGUI_DEFAULT_FONT which=EGDF_DEFAULT) const =0
returns the default font

Below the menu we want a toolbar, onto which we can place colored buttons and important looking stuff like a senseless combobox.

// create toolbar
gui::IGUIToolBar* bar = env->addToolBar();
video::ITexture* image = driver->getTexture("open.png");
bar->addButton(GUI_ID_BUTTON_OPEN_MODEL, 0, L"Open a model",image, 0, false, true);
image = driver->getTexture("tools.png");
bar->addButton(GUI_ID_BUTTON_SHOW_TOOLBOX, 0, L"Open Toolset",image, 0, false, true);
image = driver->getTexture("zip.png");
bar->addButton(GUI_ID_BUTTON_SELECT_ARCHIVE, 0, L"Set Model Archive",image, 0, false, true);
image = driver->getTexture("help.png");
bar->addButton(GUI_ID_BUTTON_SHOW_ABOUT, 0, L"Open Help", image, 0, false, true);
// create a combobox for texture filters
gui::IGUIComboBox* box = env->addComboBox(core::rect<s32>(250,4,350,23), bar, GUI_ID_TEXTUREFILTER);
box->addItem(L"No filtering");
box->addItem(L"Bilinear");
box->addItem(L"Trilinear");
box->addItem(L"Anisotropic");
box->addItem(L"Isotropic");

To make the editor look a little bit better, we disable transparent gui elements, and add an Irrlicht Engine logo. In addition, a text showing the current frames per second value is created and the window caption is changed.

// disable alpha
for (s32 i=0; i<gui::EGDC_COUNT ; ++i)
{
video::SColor col = env->getSkin()->getColor((gui::EGUI_DEFAULT_COLOR)i);
col.setAlpha(255);
env->getSkin()->setColor((gui::EGUI_DEFAULT_COLOR)i, col);
}
// add a tabcontrol
createToolBox();
// create fps text
IGUIStaticText* fpstext = env->addStaticText(L"",
core::rect<s32>(400,4,570,23), true, false, bar);
IGUIStaticText* postext = env->addStaticText(L"",
core::rect<s32>(10,50,470,80),false, false, 0, GUI_ID_POSITION_TEXT);
postext->setVisible(false);
// set window caption
Caption += " - [";
Caption += driver->getName();
Caption += "]";
Device->setWindowCaption(Caption.c_str());

That's nearly the whole application. We simply show the about message box at start up, and load the first model. To make everything look better, a skybox is created and a user controlled camera, to make the application a little bit more interactive. Finally, everything is drawn in a standard drawing loop.

// show about message box and load default model
if (argc==1)
showAboutText();
loadModel(StartUpModelFile.c_str());
// add skybox
SkyBox = smgr->addSkyBoxSceneNode(
driver->getTexture("irrlicht2_up.jpg"),
driver->getTexture("irrlicht2_dn.jpg"),
driver->getTexture("irrlicht2_lf.jpg"),
driver->getTexture("irrlicht2_rt.jpg"),
driver->getTexture("irrlicht2_ft.jpg"),
driver->getTexture("irrlicht2_bk.jpg"));
// add a camera scene node
Camera[0] = smgr->addCameraSceneNodeMaya();
Camera[0]->setFarValue(20000.f);
// Maya cameras reposition themselves relative to their target, so target the location
// where the mesh scene node is placed.
Camera[0]->setTarget(core::vector3df(0,30,0));
Camera[1] = smgr->addCameraSceneNodeFPS();
Camera[1]->setFarValue(20000.f);
Camera[1]->setPosition(core::vector3df(0,0,-70));
Camera[1]->setTarget(core::vector3df(0,30,0));
setActiveCamera(Camera[0]);
// load the irrlicht engine logo
IGUIImage *img =
env->addImage(driver->getTexture("irrlichtlogo2.png"),
core::position2d<s32>(10, driver->getScreenSize().Height - 128));
// lock the logo's edges to the bottom left corner of the screen
img->setAlignment(EGUIA_UPPERLEFT, EGUIA_UPPERLEFT,
// remember state so we notice when the window does lose the focus
bool hasFocus = Device->isWindowFocused();
// draw everything
while(Device->run() && driver)
{
// Catch focus changes (workaround until Irrlicht has events for this)
bool focused = Device->isWindowFocused();
if ( hasFocus && !focused )
onKillFocus();
hasFocus = focused;
if (Device->isWindowActive())
{
driver->beginScene(true, true, video::SColor(150,50,50,50));
smgr->drawAll();
env->drawAll();
driver->endScene();
// update information about current frame-rate
core::stringw str(L"FPS: ");
str.append(core::stringw(driver->getFPS()));
str += L" Tris: ";
str.append(core::stringw(driver->getPrimitiveCountDrawn()));
fpstext->setText(str.c_str());
// update information about the active camera
scene::ICameraSceneNode* cam = Device->getSceneManager()->getActiveCamera();
str = L"Pos: ";
str.append(core::stringw(cam->getPosition().X));
str += L" ";
str.append(core::stringw(cam->getPosition().Y));
str += L" ";
str.append(core::stringw(cam->getPosition().Z));
str += L" Tgt: ";
str.append(core::stringw(cam->getTarget().X));
str += L" ";
str.append(core::stringw(cam->getTarget().Y));
str += L" ";
str.append(core::stringw(cam->getTarget().Z));
postext->setText(str.c_str());
// update the tool dialog
updateToolBox();
}
else
Device->yield();
}
Device->drop();
return 0;
}
@ EGUIA_LOWERRIGHT
Aligned to parent's bottom or right side.
Definition: EGUIAlignment.h:17
@ EGUIA_UPPERLEFT
Aligned to parent's top or left side (default)
Definition: EGUIAlignment.h:15