Ogre贴花

最新推荐文章于 2022-04-04 01:21:48 发布

pizi0475

最新推荐文章于 2022-04-04 01:21:48 发布

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分类专栏： OGRE 文章标签： float vector iterator delete string 2010

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Ogre的贴花操作….

说明:

ManualObject需要在Begin()与End()之间执行创建位置与纹理坐标等操作, 如果需要对手动物体添加贴图, 则在Begin(“MatName”)传入材质名称.

关于创建顶点索引,这里是以正方形顺时针创建.

#pragma once

#include <Ogre.h>
#include <string>
#include "Util.h"

class Decal
{
public:
Decal(const std::string &name, const std::string &matName,
     const Ogre::Vector2 &dimen, const Ogre::Vector2 &position,
     float heightOffset = 0.5, int resolution = 4,
     Ogre::SceneManager *sceneMgr = Util::getSceneManager())
     : mDim(dimen), mHeightOffset(heightOffset), mRes(resolution)
{
  mDecal = new Ogre::ManualObject(name);

  mDecal->setCastShadows(false);
  mDecal->setDynamic(true);
  //mDecal->setRenderQueueGroup(Ogre::RENDER_QUEUE_WORLD_GEOMETRY_2);

  mDecal->begin(matName);
  for (int i = 0; i <= mRes; i++)
  {
   for (int j = 0; j <= mRes; j++)
   {
    // 顶点坐标
    mDecal->position(i, 0, j);
    // 纹理坐标[0~1]
    mDecal->textureCoord(i / (float)mRes, j / (float)mRes);
   }
  }

  // 顶点索引处不<=
  for (int i = 0; i < mRes; i++)
  {
   for (int j = 0; j < mRes; j++)
   {
    // 顶点索引, 顺时针,小方格
    mDecal->quad(i * (mRes + 1) + j,
      i * (mRes + 1) + j + 1,
      (i + 1) * (mRes + 1) + j + 1,
      (i + 1) * (mRes + 1) + j);
   }
  }
  mDecal->end();

mDecalNode = sceneMgr->getRootSceneNode()->createChildSceneNode();
mDecalNode->attachObject(mDecal);

mQuery = sceneMgr->createRayQuery(Ogre::Ray());

moveTo(position);
}

~Decal(void)
{
  delete mQuery;
  mDecalNode->detachAllObjects();
  mDecalNode->getParent()->removeChild(mDecalNode);
  delete mDecal;
}

void moveTo(const Ogre::Vector2& pos)
{
float xBegin = pos.x - (mDim.x / 2);
float zBegin = pos.y - (mDim.y / 2);

float xWidth = mDim.x / mRes;
float zWidth = mDim.y / mRes;

  // 更新
  mDecal->beginUpdate(0);
  for (int i = 0; i <= mRes; i++)
  {
   for (int j = 0; j <= mRes; j++)
   {
    float x = xBegin + (xWidth * i);
    float z = zBegin + (zWidth * j);
    float y = getHeight(x, z) + mHeightOffset;

    mDecal->position(x, y, z);
    mDecal->textureCoord(i / (float)mRes, j / (float)mRes);
   }
  }

  for (int i = 0; i < mRes; i++)
  {
   for (int j = 0; j < mRes; j++)
   {
    mDecal->quad(i * (mRes + 1) + j,
      i * (mRes + 1) + j + 1,
      (i + 1) * (mRes + 1) + j + 1,
      (i + 1) * (mRes + 1) + j);
   }
  }
  mDecal->end();
}

private:
float getHeight(float x, float z)
{
mQuery->setRay(Ogre::Ray(Ogre::Vector3(x, 5000, z), Ogre::Vector3::NEGATIVE_UNIT_Y));

Ogre::RaySceneQueryResult &result = mQuery->execute();
Ogre::RaySceneQueryResult::iterator i = result.begin();

if(i != result.end() && i->worldFragment)
return i->worldFragment->singleIntersection.y;

return 0;
}

private:
Ogre::ManualObject *mDecal;
Ogre::SceneNode  *mDecalNode;
Ogre::Vector2  mDim;
float   mHeightOffset;
Ogre::RaySceneQuery *mQuery;

int mRes;
};