创建游戏内核（9）

本篇是创建游戏内核（8）的续篇，其中涉及到的纹理知识请参阅D3D 中的纹理贴图（1）。

图像和TEXTURE

纹理使3D看起来更货真价实，使用全彩色成像可以使简单的多边形显得逼真，尝试保存一个纹理列表是一个不错的选择，但有了TEXTURE的帮助，就能使问题变得更容易。

来看看TEXTURE的定义:

class TEXTURE
{
protected:
    GRAPHICS*           _graphics;      // pointer to GRAPHICS object
    IDirect3DTexture9*  _texture;       // pointer to texture object
    unsigned long _width, _height;      // dimensions of texture image

public:
    TEXTURE();
    ~TEXTURE();

    IDirect3DTexture9* Get_Texture_COM();

    BOOL Load(GRAPHICS* graphics, char* filename, DWORD transparent = 0, D3DFORMAT format = D3DFMT_UNKNOWN);

    BOOL Create(GRAPHICS* graphics, DWORD width, DWORD height, D3DFORMAT format);
    BOOL Create(GRAPHICS* graphics, IDirect3DTexture9* texture);

    void Free();

    BOOL Is_Loaded();

    long Get_Width();
    long Get_Height();

    D3DFORMAT Get_Format();

    BOOL Blit(long dest_x, long dest_y,
              long src_x = 0, long src_y = 0,
              long width = 0, long height = 0,
              float x_scale = 1.0f, float y_scale = 1.0f,
              D3DCOLOR color = 0xFFFFFFFF);
};

接着来看看TEXTURE类的实现：

//---------------------------------------------------------------------------
// Constructor, initialize data member.
//---------------------------------------------------------------------------
TEXTURE::TEXTURE()
{
    _graphics = NULL;
    _texture  = NULL;
    _width = _height = 0;
}

//-------------------------------------------------------------------
// Destructor, free Direct3D COM object.
//-------------------------------------------------------------------
TEXTURE::~TEXTURE()
{
    Free();
}

//-------------------------------------------------------------------
// Create texture object from specified file, you can specify transparent
// value and pixel format of the texture.
//-------------------------------------------------------------------
BOOL TEXTURE::Load(GRAPHICS* graphics, char* filename, DWORD transparent, D3DFORMAT format)
{
    // Free Direct3D COM object
    Free();

    // Check if condition is sufficient.

    if((_graphics = graphics) == NULL)
        return FALSE;

    if(graphics->Get_Device_COM() == NULL)
        return FALSE;

    if(filename == NULL)
        return FALSE;

    // Creates a texture from a file
    if(FAILED(D3DXCreateTextureFromFileEx(graphics->Get_Device_COM(), filename, D3DX_DEFAULT, D3DX_DEFAULT,
        D3DX_DEFAULT, 0, format, D3DPOOL_MANAGED, D3DX_FILTER_TRIANGLE, D3DX_FILTER_TRIANGLE,
        transparent, NULL, NULL, &_texture)))
    {
        return FALSE;
    }

    _width  = Get_Width();
    _height = Get_Height();

    return TRUE;
}

//-------------------------------------------------------------------
// Creates a texture resource.
//-------------------------------------------------------------------
BOOL TEXTURE::Create(GRAPHICS* graphics, DWORD width, DWORD height, D3DFORMAT format)
{
    Free();

    if((_graphics = graphics) == NULL)
        return FALSE;

    if(FAILED(_graphics->Get_Device_COM()->CreateTexture(width, height, 0, 0, format, D3DPOOL_MANAGED, &_texture, NULL)))
        return FALSE;

    return TRUE;
}

//-------------------------------------------------------------------
// Configure a TEXTURE class from an existing IDirect3DTexture9 object
// instance.
//-------------------------------------------------------------------
BOOL TEXTURE::Create(GRAPHICS* graphics, IDirect3DTexture9* texture)
{
    D3DLOCKED_RECT src_rect, dest_rect;
    D3DSURFACE_DESC surface_desc;

    Free();

    _graphics = graphics;

    // check condition
    if(_graphics == NULL || texture == NULL)
        return FALSE;

    // copy texture over, from source to dest.

    texture->GetLevelDesc(0, &surface_desc);

    _width  = surface_desc.Width;
    _height = surface_desc.Height;

    _graphics->Get_Device_COM()->CreateTexture(_width, _height, 0, 0, surface_desc.Format, D3DPOOL_MANAGED,
                                               &_texture, NULL);

    // Locks a rectangle on a texture resource.
    texture->LockRect(0, &src_rect, NULL, D3DLOCK_READONLY);
    _texture->LockRect(0, &dest_rect, NULL, 0);

    memcpy(dest_rect.pBits, src_rect.pBits, src_rect.Pitch * _height);

    // unlocks a rectangle on a texture resource
    _texture->UnlockRect(0);
    texture->UnlockRect(0);

    return TRUE;
}

//-------------------------------------------------------------------
// Free Direct3D COM object.
//-------------------------------------------------------------------
void TEXTURE::Free()
{
    Release_COM(_texture);
    _graphics = NULL;
    _width = _height = 0;
}

//-------------------------------------------------------------------
// Check if loaded texture successfully.
//-------------------------------------------------------------------
BOOL TEXTURE::Is_Loaded()
{
    return (_texture != NULL);
}

//-------------------------------------------------------------------
// Get texture component.
//-------------------------------------------------------------------
IDirect3DTexture9* TEXTURE::Get_Texture_COM()
{
    return _texture;
}

//-------------------------------------------------------------------
// Get width of the texture.
//-------------------------------------------------------------------
long TEXTURE::Get_Width()
{
    D3DSURFACE_DESC surface_desc;

    if(_texture == NULL)
        return 0;

    if(FAILED(_texture->GetLevelDesc(0, &surface_desc)))
        return 0;

    return surface_desc.Width;
}

//-------------------------------------------------------------------
// Get height of the texture.
//-------------------------------------------------------------------
long TEXTURE::Get_Height()
{
    D3DSURFACE_DESC surface_desc;

    if(_texture == NULL)
        return 0;

    if(FAILED(_texture->GetLevelDesc(0, &surface_desc)))
        return 0;

    return surface_desc.Height;
}

//-------------------------------------------------------------------
// Get texture storage format.
//-------------------------------------------------------------------
D3DFORMAT TEXTURE::Get_Format()
{
    D3DSURFACE_DESC surface_desc;

    if(_texture == NULL)
        return D3DFMT_UNKNOWN;

    if(FAILED(_texture->GetLevelDesc(0, &surface_desc)))
        return D3DFMT_UNKNOWN;

    return surface_desc.Format;
}

//-------------------------------------------------------------------
// Draw a 2-D portion of texture to device.
//-------------------------------------------------------------------
BOOL TEXTURE::Blit(long dest_x, long dest_y,
                   long src_x,  long src_y,
                   long width,  long height,
                   float x_scale, float y_scale,
                   D3DCOLOR color)
{
    RECT rect;
    ID3DXSprite* sprite;

    // check condition

    if(_texture == NULL || _graphics == NULL)
        return FALSE;

    if((sprite = _graphics->Get_Sprite_COM()) == NULL)
        return FALSE;

    // If no specify width and height, set with member width and height.

    if(width == 0)
        width = _width;

    if(height == 0)
        height = _height;

    // set the portion of the source texture to use for the sprite will to be drawed

    rect.left   = src_x;
    rect.top    = src_y;
    rect.right  = rect.left + width;
    rect.bottom = rect.top + height;

    D3DXMATRIX transform_matrix(x_scale,        0,              0,  0,
                                0,              y_scale,        0,  0,
                                0,              0,              0,  0,
                                (float)dest_x,  (float)dest_y,  0,  0);

    // Sets the sprite transform
    sprite->SetTransform(&transform_matrix);

    // Adds a sprite to the list of batched sprites.
    if(FAILED(sprite->Draw(_texture, &rect, NULL, NULL, color)))
        return FALSE;

    return TRUE;
}

TEXTURE类能够从磁盘上的一幅图像文件或一个现有的IDirect3DTexture9对象加载纹理。从磁盘加载一幅图像，需要调用 TEXTURE::Load函数。此函数需要几个参数才能起作用，第一个参数是预初始化的GRAPHICS对象，第二个参数是要加载的图像的文件名。

TEXTURE:: Load还带有两个可选参数，分别是透明关键色（如果使用带有透明像素的纹理，就要使用此参数）和存储格式。transparent参数的缺省值为0，意味着Load函数不使用透明像素，如果要使用透明像素，可以给这个参数指定一个 D3DCOLOR_RGBA值（确保给alpha参数指定255）。

对于format参数，要使用诸如 D3DFMT_A1R5G5B5之类的Direct3D纹理存储格式，记住带有透明像素的纹理必须使用alpha通道，因此要确保使用诸如 D3DFMT_A1R5G5B5或D3DFMT_A8R8G8B8的格式。

下面给出测试代码：

点击下载源码和工程

/*****************************************************************************
PURPOSE:
    Test for class TEXTURE.
*****************************************************************************/

#include "Core_Global.h"

#pragma warning(disable : 4996)

//===========================================================================
// Defines class APP which public inherits from class APPLICATION.
//===========================================================================
class APP : public APPLICATION
{
private:
    GRAPHICS        _graphics;
    TEXTURE         _texture;
    VERTEX_BUFFER   _vertex_buffer;

    // The 3D vertex format and descriptor
    typedef struct
    {
        float x, y, z;  // 3D coordinates
        float u, v;     // texture coordinates
    } VERTEX;

    #define VERTEX_FVF   (D3DFVF_XYZ | D3DFVF_TEX1)

public:
    BOOL Init();
    BOOL Shutdown();
    BOOL Frame();
};

//-----------------------------------------------------------------------------
// Initialize graphics, set display mode, set vertex buffer, load texture file.
//-----------------------------------------------------------------------------
BOOL APP::Init()
{
    D3DXMATRIX mat_view;

    // initialize vertex data
    VERTEX verts[] = {
      { -100.0f,  100.0f, 0.0f, 0.0f, 0.0f },
      {  100.0f,  100.0f, 0.0f, 1.0f, 0.0f },
      { -100.0f, -100.0f, 0.0f, 0.0f, 1.0f },
      {  100.0f, -100.0f, 0.0f, 1.0f, 1.0f }
    };

    // initialize graphics
    if (! _graphics.Init())
        return FALSE;

    // set display mode for graphics
    if(! _graphics.Set_Mode(Get_Hwnd(), TRUE, TRUE, 400, 400, 32))
        return FALSE;

    // disable D3D lighting
    _graphics.Enable_Lighting(FALSE);
    // enable z-buffer
    _graphics.Enable_ZBuffer(TRUE);

    // set perspective projection transform matrix.
    _graphics.Set_Perspective(D3DX_PI/4.0f, 1.33333f, 1.0f, 1000.0f);

    // create and set the view matrix
    D3DXMatrixLookAtLH(&mat_view,
                       &D3DXVECTOR3(0.0, 0.0, -500.0),
                       &D3DXVECTOR3(0.0f, 0.0f, 0.0f),
                       &D3DXVECTOR3(0.0f, 1.0f, 0.0f));

    _graphics.Get_Device_COM()->SetTransform(D3DTS_VIEW, &mat_view);

    // create the vertex buffer
    _vertex_buffer.Create(&_graphics, 8, sizeof(VERTEX), VERTEX_FVF);

    // Copy vertex data from VertexList to vertex buffer.
    _vertex_buffer.Set(0, 4, verts);

    // Create texture object from specified file,
    _texture.Load(&_graphics, "texture.jpg");

    return TRUE;
}

//-----------------------------------------------------------------------------
// Release all d3d resource.
//-----------------------------------------------------------------------------
BOOL APP::Shutdown()
{
    // Free vertex buffer resource, reset data member.
     _vertex_buffer.Free();

     // free texture resouece
     _texture.Free();

     // free graphics resouece
     _graphics.Shutdown();

    return TRUE;
}

//-----------------------------------------------------------------------------
// Render a frame.
//-----------------------------------------------------------------------------
BOOL APP::Frame()
{
    D3DXMATRIX mat_world;

    // clear display with specified color
    _graphics.Clear(D3DCOLOR_RGBA(0, 0, 0, 255), 1.0);

    // begin scene
    if(_graphics.Begin_Scene())
    {
        // create and set the world transformation matrix
        // rotate object along z-axis
        D3DXMatrixRotationZ(&mat_world, (float) (timeGetTime() / 1000.0));

        _graphics.Get_Device_COM()->SetTransform(D3DTS_WORLD, &mat_world);

        // assigns a texture to a stage for a device
        _graphics.Set_Texture(0, &_texture);

        // Render vertex buffer into display.
        _vertex_buffer.Render(0, 2, D3DPT_TRIANGLESTRIP);

        // release texture
        _graphics.Get_Device_COM()->SetTexture(0, NULL);

        // end the scene
        _graphics.End_Scene();
    }

    // display video buffer
    _graphics.Display();

    return TRUE;
}

int PASCAL WinMain(HINSTANCE inst, HINSTANCE, LPSTR cmd_line, int cmd_show)
{
    APP app;

    return app.Run();
}

运行截图：

posted on 2007-09-02 01:27 lovedday 阅读(589) 评论(0) 编辑收藏引用

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