開發(fā)環(huán)境：
CEGUI 0.74，OGRE 1.72
教程：
CEGUI and Ogre
http://www.ogre3d.org/tikiwiki/tiki-print.php?page_ref_id=262&page=Basic%20Tutorial%207#Initializing_CEGUI
The Beginners Guide to Getting CEGUI Rendering
http://www.cegui.org.uk/api_reference/rendering_tutorial.html
CEGUI使用的基本三步驟
- 創(chuàng)建CEGUI::Renderer對(duì)象.
- 創(chuàng)建CEGUI::System 對(duì)象(passing in the renderer created above).
- 在幀循環(huán)中調(diào)用CEGUI::System::renderGUI function to perform the rendering.
創(chuàng)建CEGUI::Renderer對(duì)象
為了創(chuàng)建CEGUI::Renderer對(duì)象,有兩條路可以走:簡(jiǎn)單的和難的。
A.簡(jiǎn)單:bootstrapSystem快速創(chuàng)建。這種方式同時(shí)創(chuàng)建了renderer和system
CEGUI::OgreRenderer& myRenderer = CEGUI::OgreRenderer::bootstrapSystem(); booststrapSystem代碼
OgreRenderer& OgreRenderer::bootstrapSystem()
{
if (System::getSingletonPtr())
CEGUI_THROW(InvalidRequestException("OgreRenderer::bootstrapSystem: "
"CEGUI::System object is already initialised."));
OgreRenderer& renderer = create();
OgreResourceProvider& rp = createOgreResourceProvider();
OgreImageCodec& ic = createOgreImageCodec();
System::create(renderer, &rp, static_cast<XMLParser*>(0), &ic);
return renderer;
}
B.復(fù)雜:手動(dòng)創(chuàng)建
如果不想使用bootstrapSystem創(chuàng)建對(duì)象，你可以手動(dòng)創(chuàng)建。注意:如果已經(jīng)使用了bootstrapSystem，則不能再手動(dòng)創(chuàng)建。手動(dòng)創(chuàng)建需要?jiǎng)?chuàng)建renderer和system。
1.創(chuàng)建CEGUI::Renderer對(duì)象
// Create an OgreRenderer object that uses the default Ogre rendering
// window as the default output surface.
CEGUI::OgreRenderer& myRenderer = CEGUI::OgreRenderer::create();
2.創(chuàng)建CEGUI::System
CEGUI::System::create( myRenderer );
system源碼：
System& System::create(Renderer& renderer, ResourceProvider* resourceProvider,
XMLParser* xmlParser, ImageCodec* imageCodec,
ScriptModule* scriptModule, const String& configFile,
const String& logFile)
{
return *new System(renderer, resourceProvider, xmlParser, imageCodec,
scriptModule, configFile, logFile);
}
可以發(fā)現(xiàn)system的創(chuàng)建函數(shù)就是完成system的構(gòu)造。構(gòu)造函數(shù)的第2個(gè)參數(shù)開始都帶默認(rèn)參數(shù)。
- 刪除Renderer
CEGUI::OgreRenderer::destroySystem();
- 取回Renderer
CEGUI::Renderer中竟然沒有取回renderer的方法!跟蹤代碼后發(fā)現(xiàn)只有system唯一一處保存了renderer。那么當(dāng)然的就可以這樣取回renderer了：
CEGUI::System &sys = CEGUI::System::getSingleton();
CEGUI::Renderer* ceguiRenderer = sys.getRenderer(void);
渲染CEGUIUI
不同的渲染引擎方式都不一樣,一般就是在幀渲染中調(diào)用渲染方法:
System::getSingleton().renderGUI();
但是在Ogre中，CEGUI很巧妙的避免在幀渲染中手動(dòng)添加代碼，使用了監(jiān)聽者處理CEGUI渲染：
1//! call stack
2CEGUIOgreRenderer_d.dll!CEGUI::OgreGUIFrameListener::frameRenderingQueued
3OgreMain_d.dll!Ogre::Root::_fireFrameRenderingQueued
4OgreMain_d.dll!Ogre::Root::_fireFrameRenderingQueued
5OgreMain_d.dll!Ogre::Root::_updateAllRenderTargets
6OgreMain_d.dll!Ogre::Root::renderOneFrame
7OgreMain_d.dll!Ogre::Root::startRendering
8
9//!source code
10bool OgreGUIFrameListener::frameRenderingQueued(const Ogre::FrameEvent&)
11{
12 if (d_enabled)
13 System::getSingleton().renderGUI();
14
15 return true;
16}
那么cegui的幀監(jiān)聽者是如何創(chuàng)建的呢？
首先這個(gè)監(jiān)聽者是個(gè)靜態(tài)對(duì)象，并且是用了全局唯一的方式聲明。好像和單間模式的作用差不多。也許是作者的個(gè)人習(xí)慣吧。
// Internal Ogre::FrameListener based class. This is how we noew hook into the
// rendering process (as opposed to render queues previously)
static class OgreGUIFrameListener : public Ogre::FrameListener
{
public:
OgreGUIFrameListener();
void setCEGUIRenderEnabled(bool enabled);
bool isCEGUIRenderEnabled() const;
bool frameRenderingQueued(const Ogre::FrameEvent& evt);
private:
bool d_enabled;
} S_frameListener;
其次這個(gè)監(jiān)聽者是在bootstrapSystem中創(chuàng)建的，正好是在OgreRenderer創(chuàng)建的同時(shí)創(chuàng)建
//! call stack
CEGUIOgreRenderer_d.dll!CEGUI::OgreRenderer::constructor_impl
CEGUIOgreRenderer_d.dll!CEGUI::OgreRenderer::OgreRenderer
CEGUIOgreRenderer_d.dll!CEGUI::OgreRenderer::create
CEGUIOgreRenderer_d.dll!CEGUI::OgreRenderer::bootstrapSystem
//! source code
void OgreRenderer::constructor_impl(Ogre::RenderTarget& target)
{
d_renderSystem = d_ogreRoot->getRenderSystem();
d_displaySize.d_width = target.getWidth();
d_displaySize.d_height = target.getHeight();
// create default target & rendering root (surface) that uses it
d_defaultTarget = new OgreWindowTarget(*this, *d_renderSystem, target);
d_defaultRoot = new RenderingRoot(*d_defaultTarget);
// hook into the rendering process
d_ogreRoot->addFrameListener(&S_frameListener);
}
至此cegui的幀渲染水落石出。
注入按鍵事件
CEGUI::System &sys = CEGUI::System::getSingleton();
//!按下 ，同事需要注入字符，以便于處理非英語(yǔ)國(guó)家的utf8字符
sys.injectK;
sys.injectChar(arg.text);
//! 按鍵彈起
CEGUI::System::getSingleton().injectKeyUp(arg.key);
注入鼠標(biāo)事件
code:
CEGUI::System::getSingleton().injectMouseButtonDown(convertButton(id));
CEGUI::System::getSingleton().injectMouseButtonUp(convertButton(id));
CEGUI::System &sys = CEGUI::System::getSingleton().injectMouseMove(arg.state.X.rel, arg.state.Y.rel);
CEGUI::MouseButton convertButton(OIS::MouseButtonID buttonID)
{
switch (buttonID)
{
case OIS::MB_Left:
return CEGUI::LeftButton;
case OIS::MB_Right:
return CEGUI::RightButto case OIS::MB_Middle:
return CEGUI::MiddleButton;
default:
return CEGUI::LeftButton;
}
}
加載CEGUI編輯器產(chǎn)生的窗口
code:
CEGUI::Window *guiRoot = CEGUI::WindowManager::getSingleton().loadWindowLayout("TextDemo.layout");
CEGUI::System::getSingleton().setGUISheet(guiRoot);
手動(dòng)創(chuàng)建CEGUI窗口對(duì)象
code:
//! 必須使用框架提供的管理器，窗口必須作為sheet的子窗口出現(xiàn)
CEGUI::WindowManager &wmgr = CEGUI::WindowManager::getSingleton();
CEGUI::Window *sheet = wmgr.createWindow("DefaultWindow", "CEGUIDemo/Sheet");
//! 創(chuàng)建一個(gè)窗口，此時(shí)并未接入sheet作為子窗口，所以并未展現(xiàn)
CEGUI::Window *quit = wmgr.createWindow("TaharezLook/Button", "CEGUIDemo/QuitButton");
quit->setText("Quit");
quit->setSize(CEGUI::UVector2(CEGUI::UDim(0.15, 0), CEGUI::UDim(0.05, 0)));
//! 窗口加入sheet以便展現(xiàn)
sheet->addChildWindow(quit);
CEGUI::System::getSingleton().setGUISheet(sheet);
//! 以上創(chuàng)建的是一個(gè)按鈕，名字為“Quit”，為了響應(yīng)按鈕按下消息，需要在框架中注冊(cè)監(jiān)聽消息,鏈接監(jiān)聽回調(diào)
quit->subscribeEvent(CEGUI::PushButton::EventClicked, CEGUI::Event::Subscriber(&BasicTutorial7::quit, this));
渲染到紋理、畫中畫效果
code:
//! 創(chuàng)建自定義紋理對(duì)象
Ogre::TexturePtr tex = mRoot->getTextureManager()->createManual(
"RTT",
Ogre::ResourceGroupManager::DEFAULT_RESOURCE_GROUP_NAME,
Ogre::TEX_TYPE_2D,
512,
512,
0,
Ogre::PF_R8G8B8,
Ogre::TU_RENDERTARGET);
Ogre::RenderTexture *rtex = tex->getBuffer()->getRenderTarget();
//! 創(chuàng)建一個(gè)新的照相機(jī)和視口，記得關(guān)閉視口的一些特性例如Overlays,否則我們創(chuàng)建的CEGUI窗口和OGRE會(huì)出現(xiàn)重疊
Ogre::Camera *cam = mSceneMgr->createCamera("RTTCam");
cam->setPosition(100, -100, -400);
cam->lookAt(0, 0, -300);
Ogre::Viewport *v = rtex->addViewport(cam);
v->setOverlaysEnabled(false);
v->setClearEveryFrame(true);
v->setBackgroundColour(Ogre::ColourValue::Black);
//! 從CEGUI引導(dǎo)對(duì)象創(chuàng)建CEGUI紋理
//! mRenderer(類型為CEGUI::OgreRenderer*)正是第一部創(chuàng)建的CEGUI引導(dǎo)對(duì)象，
CEGUI::Texture &guiTex = mRenderer->createTexture(tex);
//! 創(chuàng)建CEGUI圖像對(duì)象集。注意:與CEGUI窗口對(duì)象需要在窗口對(duì)象集(sheet)的管理下使用類似，圖像對(duì)象也需要在圖像對(duì)象集的管理下使用
CEGUI::Imageset &imageSet =
CEGUI::ImagesetManager::getSingleton().create("RTTImageset", guiTex);
imageSet.defineImage("RTTImage",
CEGUI::Point(0.0f, 0.0f),
CEGUI::Size(guiTex.getSize().d_width,
guiTex.getSize().d_height),
CEGUI::Point(0.0f, 0.0f));
//! 創(chuàng)建CEGUI窗口，之前已經(jīng)介紹過，這里和它沒有區(qū)別
CEGUI::Window *si = CEGUI::WindowManager::getSingleton().createWindow("TaharezLook/StaticImage", "RTTWindow");
si->setSize(CEGUI::UVector2(CEGUI::UDim(0.5f, 0),
CEGUI::UDim(0.4f, 0)));
si->setPosition(CEGUI::UVector2(CEGUI::UDim(0.5f, 0),
CEGUI::UDim(0.0f, 0)));
//! 指定窗口中展現(xiàn)的圖片，取得圖像對(duì)象依然必須經(jīng)過圖像集對(duì)象
si->setProperty("Image", CEGUI::PropertyHelper::imageToString(&imageSet.getImage("RTTImage")));
//! 將窗口加入窗口集(sheet),前面已經(jīng)介紹過
sheet->addChildWindow(si);
加載CEGUI資源
考察一個(gè)這樣加載資源的過程：
CEGUI::SchemeManager::getSingleton().create("TaharezLook.scheme"); 加載之前先設(shè)置schememanager的資源分組
CEGUI::Scheme::setDefaultResourceGroup("Schemes"); 在資源配置里這樣設(shè)置：
[Schemes]
FileSystem=../media/cegui/datafiles/schemes 則創(chuàng)建"taharezlook.scheme"的時(shí)候會(huì)在"...datafiles/schemes"中查找對(duì)應(yīng)的文件。
代碼分析：
call stack
CEGUIOgreRenderer_d.dll!CEGUI::OgreResourceProvider::loadRawDataContainer
CEGUIExpatParser_d.dll!CEGUI::ExpatParser::parseXMLFile
CEGUIBase_d.dll!CEGUI::Scheme_xmlHandler::Scheme_xmlHandler
CEGUIBase_d.dll!CEGUI::NamedXMLResourceManager<CEGUI::Scheme,CEGUI::Scheme_xmlHandler>::create
Tutorial7.exe!Tutorial7::createScene 加載資源
1void OgreResourceProvider::loadRawDataContainer(const String& filename,
2 RawDataContainer& output,
3 const String& resourceGroup)
4{
5 String orpGroup;
6 if (resourceGroup.empty())
7 orpGroup = d_defaultResourceGroup.empty() ?
8 Ogre::ResourceGroupManager::DEFAULT_RESOURCE_GROUP_NAME.c_str() :
9 d_defaultResourceGroup;
10 else
11 orpGroup = resourceGroup;
12
13 Ogre::DataStreamPtr input = Ogre::ResourceGroupManager::getSingleton().
14 openResource(filename.c_str(), orpGroup.c_str());
15
16 if (input.isNull())
17 CEGUI_THROW(InvalidRequestException(
18 "OgreCEGUIResourceProvider::loadRawDataContainer: Unable to open "
19 "resource file '" + filename + "' in resource group '" + orpGroup +
20 "'."));
21
22 Ogre::String buf = input->getAsString();
23 const size_t memBuffSize = buf.length();
24
25 unsigned char* mem = new unsigned char[memBuffSize];
26 memcpy(mem, buf.c_str(), memBuffSize);
27
28 output.setData(mem);
29 output.setSize(memBuffSize);
30} 由此可見ceguiogrerenderer將cegui的資源加載與ogre鏈接起來了。
用std::string替換CEGUI::String
幸運(yùn)的是cegui開發(fā)小組已經(jīng)完成了這個(gè)小工作，不幸的是這項(xiàng)工作在cegui 0.8才會(huì)有。不過也可以自己手動(dòng)修改。這個(gè)修改作為cegui 的一個(gè)issue發(fā)布了：
| Description |
I have created a patch that allows CEGUI to use both the inbuilt utf32 String as well as std::string (with 8bit characters). std::string has lower memory requirements and can be (in very special circumstances) faster (easier pass by const reference, etc...).
This is intended for library users not needing Unicode support (which I imagine is a large percentage). |
| Additional Information |
This patch adds a configuration switch CEGUI_STRING_CLASS, three options are available:
Unicode - utf32 inbuilt string - utf8 and utf32 support
std::string - no unicode support
std::string allocated with allocators - same but pass by reference can be harder but is allocated according to the allocator config
This has not been committed yet! The only macro preprocessor if/ifdefs are in CEGUIString.h and CEGUIDefaultResourceProvider.h (in the Windows-only utf16 to utf8/char conversion functions). |
詳情:
0000421: Configuration option to use std::string as CEGUI::String
若干不勝其煩的小失誤
大小寫敏感---這個(gè)小錯(cuò)誤讓偶跟蹤了一個(gè)多小時(shí)cegui源碼，誰會(huì)想到是拼寫錯(cuò)誤呢