OGRE 二维精灵SpriteManager2d
来自 Ogre官方 Wiki
在一些情况下，比如需要做一个界面，或者需要写一个小游戏而不是大型三维游戏，也可能只是需要Ogre进行二维的编程。但Ogre自身缺乏对在屏幕上绘制二维对象的能力。这里提供了一个简单的代码片段，用来解决这个在Ogre程序设计中遗留的小问题。
当然，Ogre中提供的Overlays（表层）和外部的CEGUI都很好很强大，但是他们却不能充分满足程序设计的需要。例如，写一个俄罗斯方砖或者马里奥那样的游戏。这并不代表不能用Ogre的三维基础实现一个二维的程序：为了实现这个功能，你需要对硬件缓存进行大量的操作管理，但是这并不是一个简单容易的工作。
我在这里提供了一个简单的代码片断，这个以让你简单的在屏幕上绘制一些二维精灵，就如同你之前一些时候通过DirectDraw编程游戏时候一样，哦，可能也类似更早以前在Dos系统中通过内存拷贝编程游戏的方法。
本文作者H. Hernán Moraldo
在这里列出代码以及一些额外的信息：
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 120
Ogre2dManager::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);
}
在Ogre论坛中原始的讨论帖子。
代码中一些需要注意的问题：
- 你可以通过下面的代码进行初始化工作:
Ogre2dManager* ogre2dManager=new Ogre2dManager; ogre2dManager->init(mSceneMgr, Ogre::RENDER_QUEUE_OVERLAY, true);
- 在需要对管理器进行释放的时候调用以下代码：
ogre2dManager->end(); delete ogre2dManager;
- 在每一帧中（比如开始的时候），你可以在屏幕上绘制大量的精灵...事实上是在渲染的时候绘制到缓存中来，最后最后再屏幕上显示硬件缓存中的内容。并且缓存在屏幕上每一帧渲染结束后就被清理了...不要把精灵当成Ogre中的模型，他们并不会在场景中保存，在每一帧你都可以汇至大量的精灵，在下一帧你可以绘制完全不同的另外一批。
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);
- 在使用精灵之前，你要确保纹理已经被载入到Ogre系统中并可以工作了。这很重要！否则你会得到一个抛出的异常。
- 如果你有麻烦的话，可以在Eihort版本中尝试通过下面的方法载入所需纹理:
Ogre::TextureManager::getSingleton().load("Image.jpg",ResourceGroupManager::DEFAULT_RESOURCE_GROUP_NAME);
并在释放的时候调用下面代码：
Ogre::TextureManager::getSingleton().unload("Image.jpg");