added facilities for fading the screen in/out

ogre/fader.cpp

@@ -0,0 +1,104 @@
+#include "fader.hpp"
+
+#include <OgreOverlayManager.h>
+#include <OgreOverlayContainer.h>
+#include <OgreOverlay.h>
+#include <OgreMaterial.h>
+#include <OgreTechnique.h>
+#include <OgreMaterialManager.h>
+#include <OgreResourceGroupManager.h>
+
+#include <assert.h>
+
+#define FADE_OVERLAY_NAME       "FadeInOutOverlay"
+#define FADE_OVERLAY_PANEL_NAME "FadeInOutOverlayPanel"
+#define FADE_MATERIAL_NAME      "FadeInOutMaterial"
+
+using namespace Ogre;
+using namespace OEngine::Render;
+
+Fader::Fader() : 
+    mMode(FadingMode_None),
+    mRemainingTime(0.f),
+    mTargetTime(0.f),
+    mTargetAlpha(0.f)
+{
+
+    // Create the fading material
+    MaterialPtr material = MaterialManager::getSingleton().create( FADE_MATERIAL_NAME, ResourceGroupManager::DEFAULT_RESOURCE_GROUP_NAME );
+    Pass* pass = material->getTechnique(0)->getPass(0);
+    pass->setSceneBlending(SBT_TRANSPARENT_ALPHA);
+    mFadeTextureUnit = pass->createTextureUnitState();
+    mFadeTextureUnit->setColourOperationEx(LBX_SOURCE1, LBS_MANUAL, LBS_CURRENT, ColourValue(0.f, 0.f, 0.f)); // always black colour    
+
+    // Create the overlay
+    OverlayManager& ovm = OverlayManager::getSingleton();
+
+    mOverlay = ovm.create( FADE_OVERLAY_NAME );
+    
+    OverlayContainer* overlay_panel;
+    overlay_panel = (OverlayContainer*)ovm.createOverlayElement("Panel", FADE_OVERLAY_PANEL_NAME);
+    
+    // position it over the whole screen
+    overlay_panel->_setPosition(0, 0);
+    overlay_panel->_setDimensions(1, 1);
+    
+    overlay_panel->setMaterialName( FADE_MATERIAL_NAME );
+    overlay_panel->show();
+    mOverlay->add2D(overlay_panel);
+    mOverlay->hide();
+}
+
+void Fader::update(float dt)
+{
+    if (mMode == FadingMode_None) return;
+    
+    if (mRemainingTime > 0)
+    {
+        mOverlay->show();
+        float alpha;
+        if (mMode == FadingMode_In)
+            alpha = (mRemainingTime/mTargetTime) * 1.f;
+        else if (mMode == FadingMode_Out)
+            alpha = (1-(mRemainingTime/mTargetTime)) * 1.f;
+        else if (mMode == FadingMode_To)
+            alpha = (1-(mRemainingTime/mTargetTime)) * mTargetAlpha;
+            
+        mFadeTextureUnit->setAlphaOperation(LBX_SOURCE1, LBS_MANUAL, LBS_CURRENT, alpha);
+        
+        mRemainingTime -= dt;
+    }
+    else
+    {
+        mMode = FadingMode_None;
+        mOverlay->hide();
+    }
+}
+
+void Fader::fadeIn(float time)
+{
+    if (time<=0) return;
+    
+    mMode = FadingMode_In;
+    mTargetTime = time;
+    mRemainingTime = time;
+}
+
+void Fader::fadeOut(const float time)
+{
+    if (time<=0) return;
+    
+    mMode = FadingMode_Out;
+    mTargetTime = time;
+    mRemainingTime = time;
+}
+
+void Fader::fadeTo(const int percent, const float time)
+{
+    if (time<=0) return;
+    
+    mMode = FadingMode_To;
+    mTargetTime = time;
+    mRemainingTime = time;
+    mTargetAlpha = percent/100.f;
+}

ogre/fader.hpp

@@ -0,0 +1,54 @@
+#ifndef OENGINE_OGRE_FADE_H
+#define OENGINE_OGRE_FADE_H
+
+/*
+  A class that handles fading in the screen from black or fading it out to black.
+  
+  To achieve this, it uses a full-screen Ogre::Overlay
+  
+  inspired by http://www.ogre3d.org/tikiwiki/FadeEffectOverlay (heavily adjusted)
+ */
+ 
+#include <OgreFrameListener.h>
+
+namespace Ogre
+{
+    class TextureUnitState;
+    class Overlay;
+}
+
+namespace OEngine {
+namespace Render
+{
+  class Fader
+  {
+  public:
+    Fader();
+    
+    void update(float dt);
+    
+    void fadeIn(const float time);
+    void fadeOut(const float time);
+    void fadeTo(const int percent, const float time);
+    
+  private:
+    enum FadingMode
+    {
+        FadingMode_In,
+        FadingMode_Out,
+        FadingMode_To,
+        FadingMode_None // no fading
+    };
+  
+    Ogre::TextureUnitState* mFadeTextureUnit;
+    Ogre::Overlay* mOverlay;
+    
+    FadingMode mMode;
+    float mRemainingTime;
+    float mTargetTime;
+    float mTargetAlpha;
+    
+  protected:
+  };
+}}
+#endif

ogre/renderer.cpp

@@ -1,4 +1,5 @@
 #include "renderer.hpp"
+#include "fader.hpp"
 
 #include "OgreRoot.h"
 #include "OgreRenderWindow.h"
@@ -12,6 +13,8 @@ using namespace OEngine::Render;
 
 void OgreRenderer::cleanup()
 {
+  delete mFader;
+  
   if(mRoot)
     delete mRoot;
   mRoot = NULL;
@@ -22,6 +25,11 @@ void OgreRenderer::start()
   mRoot->startRendering();
 }
 
+void OgreRenderer::update(float dt)
+{
+  mFader->update(dt);
+}
+
 void OgreRenderer::screenshot(const std::string &file)
 {
   mWindow->writeContentsToFile(file);
@@ -98,4 +106,6 @@ void OgreRenderer::createScene(const std::string camName, float fov, float nearC
 
   // Alter the camera aspect ratio to match the viewport
   mCamera->setAspectRatio(Real(mView->getActualWidth()) / Real(mView->getActualHeight()));
+  
+  mFader = new Fader();
 }

ogre/renderer.hpp

@@ -19,6 +19,7 @@ namespace Ogre
 namespace OEngine {
 namespace Render
 {
+  class Fader;
   class OgreRenderer
   {
     Ogre::Root *mRoot;
@@ -26,6 +27,7 @@ namespace Render
     Ogre::SceneManager *mScene;
     Ogre::Camera *mCamera;
     Ogre::Viewport *mView;
+    Fader* mFader;
     bool logging;
 
   public:
@@ -66,6 +68,8 @@ namespace Render
 
     /// Start the main rendering loop
     void start();
+    
+    void update(float dt);
 
     /// Write a screenshot to file
     void screenshot(const std::string &file);
@@ -80,6 +84,9 @@ namespace Render
 
     /// Get the scene manager
     Ogre::SceneManager *getScene() { return mScene; }
+    
+    /// Get the screen colour fader
+    Fader *getFader() { return mFader; }
 
     /// Camera
     Ogre::Camera *getCamera() { return mCamera; }