1.2 Textures & Sprite 之封装CXTexture & CXSprite
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1、 何为Textures
Textures是在屏幕上显示的平面图形，它能够提供比 surface 更多的图形处理效果——移动、缩放、旋转及作为纹理皮肤粘贴在3D模型上。在Direct3D中，其封装的接口为IDirect3DTexture9。
2、 何为Sprite
IDirect3DTexture9能从文件中读取纹理数据，但由于Textures不能直接复制到 back buffer，因此在屏幕上绘制Textures之前，需要另一个接口——ID3DXSprite（精灵）。ID3DXSprite能够把若干个Textures 复制给back buffer，因此需要ID3DXSprite的一个实例就可以绘制所有的纹理。
所以，IDirect3DTexture9用来存放程序所需的纹理，但它本身又不能绘制纹理，需要借助接口ID3DXSprite。
3、 IDirect3DTexture9和ID3DXSprite的使用过程
定义： ~
创建： D3DXCreateTextureFromFile
D3DXCreateSprite
创建变换矩阵： D3DXMatrixTransformation2D
变换： SetTransform
绘制图象： Draw
释放内存： ~
代码如下：
D3DXCreateTextureFromFile(g_pd3dDevice, "c:\\image.bmp”, &g_Texture);
D3DXCreateSprite(g_pd3dDevice, &g_Sprite);
//--------------------------------------------------------------------------
D3DXVECTOR2 Translation;
Translation.x = 500;
Translation.y = 500;
D3DXVECTOR2 Scaling;
Scaling.x = 1.0;f
Scaling.y = 1.0f;
D3DXMATRIX Mat;
D3DXMatrixTransformation2D(&Mat, NULL, 0, &Scaling, NULL, 0, &
Translation);
g_Sprite->Begin(0);
g_Sprite->SetTransform(&
g_Sprite->Draw(g_Texture,
g_Sprite->End();
4、 如何封装
从以上的基本过程可以看到，CXTexture需要完成的功能：提供与LPDIRECT3DDEVICE9的接口，与纹理文件文件关联，对纹理进行处理（缩放、旋转……）。
class CXTexture
{
protected:
LPDIRECT3DTEXTURE9 m_Texture;
LPDIRECT3DDEVICE9 m_pDevice;
D3DXVECTOR2 m_RotationCenter;
D3DXVECTOR2 m_Translation;
D3DXVECTOR2 m_Scaling;
FLOAT m_Rotation;
RECT m_SrcRect;
public:
CXTexture(LPDIRECT3DDEVICE9 pDevice);
~CXTexture();
LPDIRECT3DTEXTURE9 GetTexture() const {return m_Texture;}
void SetTexture(LPDIRECT3DTEXTURE9 Texture) const {m_Texture = Texture;}
LPDIRECT3DDEVICE9 GetDevice() const {return m_pDevice;}
void SetDevice(LPDIRECT3DDEVICE9 pDevice) const {m_pDevice = pDevice;}
D3DXVECTOR2 GetRotationCenter() const {return m_RotationCenter;}
void SetRotationCenter(D3DXVECTOR2 RotationCenter) {m_RotationCenter =
RotationCenter;}
D3DXVECTOR2 GetTranslation() const {return m_Translation;}
void SetTranslation (D3DXVECTOR2 Translation) const {m_Translation =
Translation;}
D3DXVECTOR2 GetScaling() const {return m_Scaling;}
void SetScaling(D3DXVECTOR2 Scaling) const {m_Scaling = Scaling;}
FLOAT GetRotation() const {return m_Rotation;}
void SetRotation (FLOAT Rotation) const {m_Rotation = Rotation;}
RECT GetRect() const {return m_SrcRect;}
void SetRect(RECT SrcRect) const {m_SrcRect = SrcRect;}
HRESULT LoadFromFile(char* Path);
};
CXSprite的主要功能就是在屏幕上显示 CXTexture，因此需要有与 LPDIRECT3DDEVICE9 接口和 CXTexture连接的函数。
class CXSprite
{
protected:
LPD3DXSPRITE m_Sprite;
LPDIRECT3DDEVICE9 m_pDevice;
public:
CXSprite (LPDIRECT3DDEVICE9 pDevice);
~CXSprite ();
LPD3DXSPRITE GetSprite() const {return m_Sprite;}
void SetSprite(LPD3DXSPRITE Sprite) const {m_Sprite = Sprite;}
LPDIRECT3DDEVICE9 GetDevice() const {return m_pDevice;}
void SetDevice(LPDIRECT3DDEVICE9 pDevice) const {m_pDevice = pDevice;}
HRESULT DrawTexture(CXTexture* Texture);
};
