Ogre 2D spritemanager2d

From the official ogre Wiki

In some cases, for example, you need to create an interface, or write a small game instead of a large 3D game, or you may only need Ogre for two-dimensional programming. However, ogre lacks the ability to draw two-dimensional objects on the screen. Here we provide a simple code snippet to solve the small issues left behind in ogre programming.

Of course, the overlays (Surface Layer) provided by ogre and the external cegui are both very powerful, but they cannot fully meet the needs of programming. For example, write a game like Russian bricks or Mario. This does not mean that a two-dimensional program cannot be implemented using the 3D foundation of ogre: To achieve this function, you need to perform a lot of operation management on the hardware cache, however, this is not a simple task.

I provide a simple code snippet here, which allows you to easily draw two-dimensional genie on the screen, just as you did some time programming Games through DirectDraw, it may also be similar to the method of copying programming Games through memory in the DOS system earlier.

Author H. Hernán moraldo

 

The Code and some additional information are listed here:

 

Ogre2d-main.h:

// Ogre 2d: a small wrapper for 2d Graphics Programming in Ogre./*  Wrapper for 2d Graphics in the Ogre 3d engine.  Coded by H. Hernán Moraldo from Moraldo Games  www.hernan.moraldo.com.ar/pmenglish/field.php  Thanks for the Cegui team as their rendering code in Ogre gave me  fundamental insight on the management of hardware buffers in Ogre.  --------------------  Copyright (c) 2006 Horacio Hernan Moraldo  This software is provided 'as-is', without any express or  implied warranty. In no event will the authors be held liable  for any damages arising from the use of this software.  Permission is granted to anyone to use this software for any  purpose, including commercial applications, and to alter it and  redistribute it freely, subject to the following restrictions:  1. The origin of this software must not be misrepresented; you  must not claim that you wrote the original software. If you use  this software in a product, an acknowledgment in the product  documentation would be appreciated but is not required.  2. Altered source versions must be plainly marked as such, and  must not be misrepresented as being the original software.  3. This notice may not be removed or altered from any source  distribution.*/#ifndef __OGRE2D_MAIN_FILE#define __OGRE2D_MAIN_FILE#include <Ogre.h>#include <OgreRenderQueueListener.h>#include <string>#include <list>struct Ogre2dSprite{   double x1, y1, x2, y2;// sprite coordinates   double tx1, ty1, tx2, ty2;// texture coordinates   Ogre::ResourceHandle texHandle;// texture handle};struct VertexChunk {   Ogre::ResourceHandle texHandle;   unsigned int vertexCount;};class Ogre2dManager:public Ogre::RenderQueueListener{private:   Ogre::SceneManager* sceneMan;   Ogre::uint8 targetQueue;   bool afterQueue;public:   Ogre2dManager();   virtual ~Ogre2dManager();   /// Initializes this 2d Manager   /** and registers it as the render queue listener.*/   void init(Ogre::SceneManager* sceneMan, Ogre::uint8 targetQueue, bool afterQueue);   /// Finishes Ogre 2d Manager   void end();   /// Called by Ogre, for being a render queue listener   virtual void renderQueueStarted(      Ogre::uint8 queueGroupId, const Ogre::String &invocation, bool &skipThisInvocation);   /// Called by Ogre, for being a render queue listener   virtual void renderQueueEnded(      Ogre::uint8 queueGroupId, const Ogre::String &invocation, bool &repeatThisInvocation);   /// Buffers a sprite to be sent to the screen at render time.   /**      Sprite coordinates are in screen space: top left pixel is (-1, 1), and bottom right      is (1, -1). The texture space, instead, ranges from (0, 0) to (1, 1).      /param textureName Name of the texture to use in this sprite (remember: texture      name, not material name!). The texture has to be already loaded by Ogre for this      to work.      /param x1 x coordinate for the top left point in the sprite.      /param y1 y coordinate for the top left point in the sprite.      /param x2 x coordinate for the bottom right point in the sprite.      /param y2 y coordinate for the bottom right point in the sprite.      /param tx1 u coordinate for the texture, in the top left point of the sprite.      /param ty1 v coordinate for the texture, in the top left point of the sprite.      /param tx2 u coordinate for the texture, in the bottom right point of the sprite.      /param ty2 u coordinate for the texture, in the bottom right point of the sprite.   */   void spriteBltFull(std::string textureName, double x1, double y1, double x2, double y2,   double tx1=0, double ty1=0, double tx2=1, double ty2=1);private:   /// Render all the 2d data stored in the hardware buffers.   void renderBuffer();   /// Create a new hardware buffer   /**   /param size Vertex count for the new hardware buffer.   */   void createHardwareBuffer(unsigned int size);   /// Destroy the hardware buffer   void destroyHardwareBuffer();   /// Set Ogre for rendering   void prepareForRender();   // ogre specifics   Ogre::RenderOperation renderOp;   Ogre::HardwareVertexBufferSharedPtr hardwareBuffer;   // sprite buffer   std::list<Ogre2dSprite> sprites;}; #endif // __OGRE2D_MAIN_FILE 

Ogre2d-main.cpp:

 

// Ogre 2d: a small wrapper for 2d Graphics Programming in Ogre./*   Wrapper for 2d Graphics in the Ogre 3d engine.   Coded by H. Hernán Moraldo from Moraldo Games   www.hernan.moraldo.com.ar/pmenglish/field.php   Thanks for the Cegui team as their rendering code in Ogre gave me   fundamental insight on the management of hardware buffers in Ogre.   --------------------   Copyright (c) 2006 Horacio Hernan Moraldo   This software is provided 'as-is', without any express or   implied warranty. In no event will the authors be held liable   for any damages arising from the use of this software.   Permission is granted to anyone to use this software for any   purpose, including commercial applications, and to alter it and   redistribute it freely, subject to the following restrictions:   1. The origin of this software must not be misrepresented; you   must not claim that you wrote the original software. If you use   this software in a product, an acknowledgment in the product   documentation would be appreciated but is not required.   2. Altered source versions must be plainly marked as such, and   must not be misrepresented as being the original software.   3. This notice may not be removed or altered from any source   distribution.*/#include "ogre2d-main.h"#include <Ogre.h>#include <OgreMesh.h>#include <OgreHardwareBuffer.h>  #define OGRE2D_MINIMAL_HARDWARE_BUFFER_SIZE 120Ogre2dManager::Ogre2dManager(){} Ogre2dManager::~Ogre2dManager(){}void Ogre2dManager::init(Ogre::SceneManager* sceneMan, Ogre::uint8 targetQueue, bool afterQueue){   Ogre2dManager::sceneMan=sceneMan;   Ogre2dManager::afterQueue=afterQueue;   Ogre2dManager::targetQueue=targetQueue;   hardwareBuffer.setNull();   sceneMan->addRenderQueueListener(this);}  void Ogre2dManager::end(){   if (!hardwareBuffer.isNull())      destroyHardwareBuffer();   sceneMan->removeRenderQueueListener(this);} void Ogre2dManager::renderQueueStarted(   Ogre::uint8 queueGroupId, const Ogre::String &invocation, bool &skipThisInvocation){   if (!afterQueue && queueGroupId==targetQueue)      renderBuffer();} void Ogre2dManager::renderQueueEnded(   Ogre::uint8 queueGroupId, const Ogre::String &invocation, bool &repeatThisInvocation){    if (afterQueue && queueGroupId==targetQueue)      renderBuffer();}void Ogre2dManager::renderBuffer(){   Ogre::RenderSystem* rs=Ogre::Root::getSingleton().getRenderSystem();   std::list<Ogre2dSprite>::iterator currSpr, endSpr;   VertexChunk thisChunk;   std::list<VertexChunk> chunks;   unsigned int newSize;   newSize=sprites.size()*6;   if (newSize<OGRE2D_MINIMAL_HARDWARE_BUFFER_SIZE)      newSize=OGRE2D_MINIMAL_HARDWARE_BUFFER_SIZE;   // grow hardware buffer if needed   if (hardwareBuffer.isNull() || hardwareBuffer->getNumVertices()<newSize)   {      if (!hardwareBuffer.isNull())         destroyHardwareBuffer();      createHardwareBuffer(newSize);   }   if (sprites.empty()) return;   // write quads to the hardware buffer, and remember chunks   float* buffer;   float z=-1;   buffer=(float*)hardwareBuffer->lock(Ogre::HardwareBuffer::HBL_DISCARD);   endSpr=sprites.end();   currSpr=sprites.begin();   thisChunk.texHandle=currSpr->texHandle;   thisChunk.vertexCount=0;   while (currSpr!=endSpr)   {      // 1st point (left bottom)      *buffer=currSpr->x1; buffer++;      *buffer=currSpr->y2; buffer++;      *buffer=z; buffer++;      *buffer=currSpr->tx1; buffer++;      *buffer=currSpr->ty2; buffer++;      // 2st point (right top)      *buffer=currSpr->x2; buffer++;      *buffer=currSpr->y1; buffer++;      *buffer=z; buffer++;      *buffer=currSpr->tx2; buffer++;      *buffer=currSpr->ty1; buffer++;      // 3rd point (left top)      *buffer=currSpr->x1; buffer++;      *buffer=currSpr->y1; buffer++;      *buffer=z; buffer++;      *buffer=currSpr->tx1; buffer++;      *buffer=currSpr->ty1; buffer++;      // 4th point (left bottom)      *buffer=currSpr->x1; buffer++;      *buffer=currSpr->y2; buffer++;      *buffer=z; buffer++;      *buffer=currSpr->tx1; buffer++;      *buffer=currSpr->ty2; buffer++;      // 5th point (right bottom)      *buffer=currSpr->x2; buffer++;      *buffer=currSpr->y1; buffer++;      *buffer=z; buffer++;      *buffer=currSpr->tx2; buffer++;      *buffer=currSpr->ty1; buffer++;      // 6th point (right top)      *buffer=currSpr->x2; buffer++;      *buffer=currSpr->y2; buffer++;      *buffer=z; buffer++;      *buffer=currSpr->tx2; buffer++;      *buffer=currSpr->ty2; buffer++;      // remember this chunk      thisChunk.vertexCount+=6;      currSpr++;      if (currSpr==endSpr || thisChunk.texHandle!=currSpr->texHandle)      {         chunks.push_back(thisChunk);         if (currSpr!=endSpr)         {            thisChunk.texHandle=currSpr->texHandle;            thisChunk.vertexCount=0;         }      }   }    hardwareBuffer->unlock();   // set up...   prepareForRender();   // do the real render!   Ogre::TexturePtr tp;   std::list<VertexChunk>::iterator currChunk, endChunk;   endChunk=chunks.end();   renderOp.vertexData->vertexStart=0;   for (currChunk=chunks.begin(); currChunk!=endChunk; currChunk++)   {      renderOp.vertexData->vertexCount=currChunk->vertexCount;      tp=Ogre::TextureManager::getSingleton().getByHandle(currChunk->texHandle);      rs->_setTexture(0, true, tp->getName());      rs->_render(renderOp);      renderOp.vertexData->vertexStart+=currChunk->vertexCount;   }   // sprites go home!   sprites.clear();} void Ogre2dManager::prepareForRender(){    Ogre::LayerBlendModeEx colorBlendMode;   Ogre::LayerBlendModeEx alphaBlendMode;   Ogre::TextureUnitState::UVWAddressingMode uvwAddressMode;   Ogre::RenderSystem* rs=Ogre::Root::getSingleton().getRenderSystem();   colorBlendMode.blendType=Ogre::LBT_COLOUR;   colorBlendMode.source1=Ogre::LBS_TEXTURE;   colorBlendMode.operation=Ogre::LBX_SOURCE1;   alphaBlendMode.blendType=Ogre::LBT_ALPHA;   alphaBlendMode.source1=Ogre::LBS_TEXTURE;   alphaBlendMode.operation=Ogre::LBX_SOURCE1;   uvwAddressMode.u=Ogre::TextureUnitState::TAM_CLAMP;   uvwAddressMode.v=Ogre::TextureUnitState::TAM_CLAMP;   uvwAddressMode.w=Ogre::TextureUnitState::TAM_CLAMP;   rs->_setWorldMatrix(Ogre::Matrix4::IDENTITY);   rs->_setViewMatrix(Ogre::Matrix4::IDENTITY);   rs->_setProjectionMatrix(Ogre::Matrix4::IDENTITY);   rs->_setTextureMatrix(0, Ogre::Matrix4::IDENTITY);   rs->_setTextureCoordSet(0, 0);   rs->_setTextureCoordCalculation(0, Ogre::TEXCALC_NONE);   rs->_setTextureUnitFiltering(0, Ogre::FO_LINEAR, Ogre::FO_LINEAR, Ogre::FO_POINT);   rs->_setTextureBlendMode(0, colorBlendMode);   rs->_setTextureBlendMode(0, alphaBlendMode);   rs->_setTextureAddressingMode(0, uvwAddressMode);   rs->_disableTextureUnitsFrom(1);   rs->setLightingEnabled(false);   rs->_setFog(Ogre::FOG_NONE);   rs->_setCullingMode(Ogre::CULL_NONE);   rs->_setDepthBufferParams(false, false);   rs->_setColourBufferWriteEnabled(true, true, true, false);   rs->setShadingType(Ogre::SO_GOURAUD);   rs->_setPolygonMode(Ogre::PM_SOLID);   rs->unbindGpuProgram(Ogre::GPT_FRAGMENT_PROGRAM);   rs->unbindGpuProgram(Ogre::GPT_VERTEX_PROGRAM);   rs->_setSceneBlending(Ogre::SBF_SOURCE_ALPHA, Ogre::SBF_ONE_MINUS_SOURCE_ALPHA);   rs->_setAlphaRejectSettings(Ogre::CMPF_ALWAYS_PASS, 0);}  void Ogre2dManager::createHardwareBuffer(unsigned int size){   Ogre::VertexDeclaration* vd;   renderOp.vertexData=new Ogre::VertexData;   renderOp.vertexData->vertexStart=0;   vd=renderOp.vertexData->vertexDeclaration;   vd->addElement(0, 0, Ogre::VET_FLOAT3, Ogre::VES_POSITION);   vd->addElement(0, Ogre::VertexElement::getTypeSize(Ogre::VET_FLOAT3),      Ogre::VET_FLOAT2, Ogre::VES_TEXTURE_COORDINATES);   hardwareBuffer=Ogre::HardwareBufferManager::getSingleton().createVertexBuffer(      vd->getVertexSize(0),      size,// buffer size      Ogre::HardwareBuffer::HBU_DYNAMIC_WRITE_ONLY_DISCARDABLE,       false);// use shadow buffer? no   renderOp.vertexData->vertexBufferBinding->setBinding(0, hardwareBuffer);   renderOp.operationType=Ogre::RenderOperation::OT_TRIANGLE_LIST;   renderOp.useIndexes=false;} void Ogre2dManager::destroyHardwareBuffer(){   delete renderOp.vertexData;   renderOp.vertexData=0;   hardwareBuffer.setNull();}void Ogre2dManager::spriteBltFull(   std::string textureName,   double x1, double y1, double x2, double y2,   double tx1, double ty1, double tx2, double ty2){   Ogre::TexturePtr tp;   Ogre2dSprite spr;   spr.x1=x1;   spr.y1=y1;   spr.x2=x2;   spr.y2=y2;   spr.tx1=tx1;   spr.ty1=ty1;   spr.tx2=tx2;   spr.ty2=ty2;   tp=Ogre::TextureManager::getSingleton().getByName(textureName);   spr.texHandle=tp->getHandle();   sprites.push_back(spr);}  

Original Discussion post in the Ogre forum.

Some notes in the Code:

• You can perform initialization using the following code:

Ogre2dManager* ogre2dManager=new Ogre2dManager;ogre2dManager->init(mSceneMgr, Ogre::RENDER_QUEUE_OVERLAY, true);

• Call the following code to release the Manager:

ogre2dManager->end();delete ogre2dManager;

• In each frame (such as at the beginning), you can draw a large number of genie on the screen... in fact, it is drawn to the Cache during rendering, and finally the content in the hardware cache is displayed on the screen. And the cache is cleared after each frame of the screen is rendered... don't think of genie as models in ogre. They won't be saved in the scene. You can combine a large number of genie in each frame. In the next frame, you can draw another batch of completely different ones.

ogre2dManager->spriteBltFull("myjpg1.jpg", -0.5, 0.5, 0.5, -0.5);ogre2dManager->spriteBltFull("mytexture.jpg", -0.3, 0.3, 0.3, -0.3);ogre2dManager->spriteBltFull("mytexture.jpg", 0.3, 0.2, 0.7, -0.2);ogre2dManager->spriteBltFull("othertexture.jpg", -0.1, 0.1, 0.1, -0.1);

• Before using the genie, make sure that the texture has been loaded into the Ogre system and can work. This is important! Otherwise, you will get an exception thrown.
• If you are in trouble, you can try to load the required texture in eihort:

Ogre::TextureManager::getSingleton().load("Image.jpg",ResourceGroupManager::DEFAULT_RESOURCE_GROUP_NAME);

The following code is called during release:

Ogre::TextureManager::getSingleton().unload("Image.jpg");