Sample_CelShading源码简析

 

#ifndef __CelShading_H__
#define __CelShading_H__

#include "SdkSample.h"

using namespace Ogre;
using namespace OgreBites;

class _OgreSampleClassExport Sample_CelShading : public SdkSample
{
public:

 Sample_CelShading()
 {
  mInfo["Title"] = "Cel-shading";
  mInfo["Description"] = "A demo of cel-shaded graphics using vertex & fragment programs.";
  mInfo["Thumbnail"] = "thumb_cel.png";
  mInfo["Category"] = "Lighting";
 }

 StringVector getRequiredPlugins()
 {
  StringVector names;
  names.push_back("Cg Program Manager");
  return names;
 }

 void testCapabilities(const RenderSystemCapabilities* caps)
 {
  if (!caps->hasCapability(RSC_VERTEX_PROGRAM) || !caps->hasCapability(RSC_FRAGMENT_PROGRAM))
        {
   OGRE_EXCEPT(Exception::ERR_NOT_IMPLEMENTED, "Your graphics card does not support vertex and fragment"
    " programs, so you cannot run this sample. Sorry!", "CelShadingSample::testCapabilities");
        }
 }

如果图形卡不支持顶点和段处理，那就会报错。反正我的电脑是用不起。

 bool frameRenderingQueued(const FrameEvent& evt)
 {
  // make the light revolve around our model if and only if the check box is checked
  if (mMoveLight->isChecked()) mLightPivot->yaw(Degree(evt.timeSinceLastFrame * 30));

  return SdkSample::frameRenderingQueued(evt);  // don't forget the parent class updates!
 }

protected:

 void setupContent()
 {    
  mViewport->setBackgroundColour(ColourValue::White);

  // set our camera to orbit around the origin and show cursor
  mCameraMan->setStyle(CS_ORBIT);
  mTrayMgr->showCursor();

  // create a basic point light with an offset
  Light* light = mSceneMgr->createLight();
  light->setPosition(20, 40, 50);

  // attach the light to a pivot node
  mLightPivot = mSceneMgr->getRootSceneNode()->createChildSceneNode();
  mLightPivot->attachObject(light);

  // create our model, give it the shader material, and place it at the origin
        Entity *ent = mSceneMgr->createEntity("Head", "ogrehead.mesh");
  ent->setMaterialName("Examples/CelShading");

其实这个demo中最主要的就是这一句话，这里关系到Ogre材质脚本的知识，请看链接

http://blog.csdn.net/a523330620/article/details/7270252
  mSceneMgr->getRootSceneNode()->attachObject(ent);

        /* We set the same material for all parts of the head, but use custom shader parameters to set the
  colours for each part. See Examples-Advanced.material for how these are bound to GPU parameters. */

        SubEntity* sub;
       
        sub = ent->getSubEntity(0);    // eyes
        sub->setCustomParameter(SP_SHININESS, Vector4(35, 0, 0, 0));
        sub->setCustomParameter(SP_DIFFUSE, Vector4(1, 0.3, 0.3, 1));
        sub->setCustomParameter(SP_SPECULAR, Vector4(1, 0.6, 0.6, 1));

这里的SP_SHININESS难道就是材质脚本中使用shininess(脚本中是没有大小写之分的)？我想应该是吧，不然还真理解不了。不过脚本中已经有对shininess这些参数的设置了，这里可能是用来自定义的吧。

        sub = ent->getSubEntity(1);    // skin
        sub->setCustomParameter(SP_SHININESS, Vector4(10, 0, 0, 0));
        sub->setCustomParameter(SP_DIFFUSE, Vector4(0, 0.5, 0, 1));
        sub->setCustomParameter(SP_SPECULAR, Vector4(0.3, 0.5, 0.3, 1));

        sub = ent->getSubEntity(2);    // earring
        sub->setCustomParameter(SP_SHININESS, Vector4(25, 0, 0, 0));
        sub->setCustomParameter(SP_DIFFUSE, Vector4(1, 1, 0, 1));
        sub->setCustomParameter(SP_SPECULAR, Vector4(1, 1, 0.7, 1));

        sub = ent->getSubEntity(3);    // teeth
        sub->setCustomParameter(SP_SHININESS, Vector4(20, 0, 0, 0));
        sub->setCustomParameter(SP_DIFFUSE, Vector4(1, 1, 0.7, 1));
        sub->setCustomParameter(SP_SPECULAR, Vector4(1, 1, 1, 1));

  // create a check box to toggle light movement
  mMoveLight = mTrayMgr->createCheckBox(TL_TOPLEFT, "MoveLight", "Move Light");
  mMoveLight->setChecked(true);
 }

 // custom shader parameter bindings
 enum ShaderParam { SP_SHININESS = 1, SP_DIFFUSE, SP_SPECULAR };

 SceneNode* mLightPivot;
 CheckBox* mMoveLight;
};

#endif