DirectX 9.0 C++ 教程 Texture 纹理映射
效果图：Directx SDK上 Texture 略微修改，它是一个旋转的空心圆柱体，我觉得用正方形比较能更好理解纹理坐标。其实用游戏引擎时，是不会关心纹理是如何具体映射的。
对上面这张gif图片是如何制作感兴趣？看截取视频，然后制成gif 教程
1.纹理坐标
DirectX中的纹理跟Opengl中的是类似的，可以参考这篇文章 Android 中使用OpenGL ES进行2D开发（纹理Texture使用）
DirectX 假设纹理图始终为1x1的正方形，其原点位于(0.0)处，右下角为(1,1)。如下图。
纹理坐标与顶点坐标之间的映射如下图：
// A structure for our custom vertex type. We added texture coordinates
struct CUSTOMVERTEX
{
float x, y, z;
unsigned long color;
FLOAT tu, tv; // 纹理坐标
};
// 构造组成物体的顶点，并为其指定纹理坐标
CUSTOMVERTEX Vertices[] =
{
{ -1.0f, -1.0f, 0.0f, D3DCOLOR_XRGB(255,255,255),0,1 }, // x, y, z, rhw, color,tu,tv
{ -1.0f, 1.0f, 0.0f, D3DCOLOR_XRGB(255,255,255), 0,0},
{ 1.0f, -1.0f, 0.0f, D3DCOLOR_XRGB(255,255,255), 1,1},
{ 1.0f, 1.0f, 0.0f, D3DCOLOR_XRGB(255,255,255), 1,0},
};
2.加载纹理图片
//D3DXCreateTextureFromFile函数原型
HRESULT WINAPI D3DXCreateTextureFromFile(
LPDIRECT3DDEVICE9 pDevice, // 设备对象
LPCTSTR pSrcFile, // 图像文件名
LPDIRECT3DTEXTURE9 * ppTexture // 用来储存载入图片的纹理对象实例
);
//具体例子
// 创建纹理
if( FAILED( D3DXCreateTextureFromFile( g_pd3dDevice, "objective-c.png", &g_pTexture ) ) )
{
MessageBox(NULL, "Could not find objective-c.png", "Textures.exe", MB_OK);
return E_FAIL;
}
3.总结一下场景添加纹理映射步骤
1.构造组成物体的顶点，并为其指定纹理坐标
2.用函数D3DXCreateTextureFromFile为LPDIRECT3DTEXTURE9 加载纹理
3.绘制物体前，用函数SetTexture来设定与该物体关联的纹理
纹理复杂起来非常复杂，本篇文章只设计到纹理坐标
4.全部源码(注意中文注释的代码)
//-----------------------------------------------------------------------------
// File: Textures.cpp
// About DirectX Texture
// Copyright (c) Microsoft Corporation. All rights reserved.
//-----------------------------------------------------------------------------
#include
#include
#include
#include
//-----------------------------------------------------------------------------
// Global variables
//-----------------------------------------------------------------------------
LPDIRECT3D9 g_pD3D = NULL; // Used to create the D3DDevice
LPDIRECT3DDEVICE9 g_pd3dDevice = NULL; // Our rendering device
LPDIRECT3DVERTEXBUFFER9 g_pVB = NULL; // Buffer to hold vertices
LPDIRECT3DTEXTURE9 g_pTexture = NULL; // Our texture
// A structure for our custom vertex type. We added texture coordinates
struct CUSTOMVERTEX
{
float x, y, z;
unsigned long color;
FLOAT tu, tv; // 纹理坐标
};
// 多了纹理，增加了D3DFVF_TEX1
#define D3DFVF_CUSTOMVERTEX (D3DFVF_XYZ|D3DFVF_DIFFUSE|D3DFVF_TEX1)
//-----------------------------------------------------------------------------
// Name: InitD3D()
// Desc: Initializes Direct3D
//-----------------------------------------------------------------------------
HRESULT InitD3D( HWND hWnd )
{
// Create the D3D object.
if( NULL == ( g_pD3D = Direct3DCreate9( D3D_SDK_VERSION ) ) )
return E_FAIL;
// Set up the structure used to create the D3DDevice. Since we are now
// using more complex geometry, we will create a device with a zbuffer.
D3DPRESENT_PARAMETERS d3dpp;
ZeroMemory( &d3dpp, sizeof(d3dpp) );
d3dpp.Windowed = TRUE;
d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;
d3dpp.BackBufferFormat = D3DFMT_UNKNOWN;
d3dpp.EnableAutoDepthStencil = TRUE;
d3dpp.AutoDepthStencilFormat = D3DFMT_D16;
// Create the D3DDevice
if( FAILED( g_pD3D->CreateDevice( D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, hWnd,
D3DCREATE_SOFTWARE_VERTEXPROCESSING,
&d3dpp, &g_pd3dDevice ) ) )
{
return E_FAIL;
}
// Turn off culling
g_pd3dDevice->SetRenderState( D3DRS_CULLMODE, D3DCULL_NONE );
// Turn off D3D lighting
g_pd3dDevice->SetRenderState( D3DRS_LIGHTING, FALSE );
// Turn on the zbuffer
g_pd3dDevice->SetRenderState( D3DRS_ZENABLE, TRUE );
return S_OK;
}
//-----------------------------------------------------------------------------
// Name: InitGeometry()
// Desc: Create the Textures and vertex buffers
//-----------------------------------------------------------------------------
HRESULT InitGeometry()
{
// 创建纹理
if( FAILED( D3DXCreateTextureFromFile( g_pd3dDevice, "objective-c.png", &g_pTexture ) ) )
{
MessageBox(NULL, "Could not find objective-c.png", "Textures.exe", MB_OK);
return E_FAIL;
}
// 构造组成物体的顶点，并为其指定纹理坐标
CUSTOMVERTEX Vertices[] =
{
{ -1.0f, -1.0f, 0.0f, D3DCOLOR_XRGB(255,255,255),0,1 }, // x, y, z, rhw, color,tu,tv
{ -1.0f, 1.0f, 0.0f, D3DCOLOR_XRGB(255,255,255), 0,0},
{ 1.0f, -1.0f, 0.0f, D3DCOLOR_XRGB(255,255,255), 1,1},
{ 1.0f, 1.0f, 0.0f, D3DCOLOR_XRGB(255,255,255), 1,0},
};
// Create the vertex buffer.
if( FAILED( g_pd3dDevice->CreateVertexBuffer( sizeof(Vertices),
0, D3DFVF_CUSTOMVERTEX,
D3DPOOL_DEFAULT, &g_pVB, NULL ) ) )
{
return E_FAIL;
}
VOID* pVertices;
if( FAILED( g_pVB->Lock( 0, sizeof(Vertices), (void**)&pVertices, 0 ) ) )
return E_FAIL;
memcpy( pVertices, Vertices, sizeof(Vertices) );
g_pVB->Unlock();
return S_OK;
}
//-----------------------------------------------------------------------------
// Name: Cleanup()
// Desc: Releases all previously initialized objects
//-----------------------------------------------------------------------------
VOID Cleanup()
{
if( g_pTexture != NULL )
g_pTexture->Release();
if( g_pVB != NULL )
g_pVB->Release();
if( g_pd3dDevice != NULL )
g_pd3dDevice->Release();
if( g_pD3D != NULL )
g_pD3D->Release();
}
//-----------------------------------------------------------------------------
// Name: SetupMatrices()
// Desc: Sets up the world, view, and projection transform matrices.
//-----------------------------------------------------------------------------
VOID SetupMatrices()
{
// 一定时间绕Y轴旋转
D3DXMATRIXA16 matWorld;
D3DXMatrixIdentity( &matWorld );
D3DXMatrixRotationY( &matWorld, timeGetTime()/1000.0f );
g_pd3dDevice->SetTransform( D3DTS_WORLD, &matWorld );
// 设置摄像头的位置等
D3DXVECTOR3 vEyePt( 0.0f, 3.0f,-5.0f );
D3DXVECTOR3 vLookatPt( 0.0f, 0.0f, 0.0f );
D3DXVECTOR3 vUpVec( 0.0f, 1.0f, 0.0f );
D3DXMATRIXA16 matView;
D3DXMatrixLookAtLH( &matView, &vEyePt, &vLookatPt, &vUpVec );
g_pd3dDevice->SetTransform( D3DTS_VIEW, &matView );
// 设置视锥体
D3DXMATRIXA16 matProj;
D3DXMatrixPerspectiveFovLH( &matProj, D3DX_PI/4, 1.0f, 1.0f, 100.0f );
g_pd3dDevice->SetTransform( D3DTS_PROJECTION, &matProj );
}
//-----------------------------------------------------------------------------
// Name: Render()
// Desc: Draws the scene
//-----------------------------------------------------------------------------
VOID Render()
{
// Clear the backbuffer and the zbuffer
g_pd3dDevice->Clear( 0, NULL, D3DCLEAR_TARGET|D3DCLEAR_ZBUFFER,
D3DCOLOR_XRGB(0,0,255), 1.0f, 0 );
// Begin the scene
if( SUCCEEDED( g_pd3dDevice->BeginScene() ) )
{
// Setup the world, view, and projection matrices
SetupMatrices();
// 绘制物体前，设置物体关联的纹理
g_pd3dDevice->SetTexture( 0, g_pTexture );
// Render the vertex buffer contents
g_pd3dDevice->SetStreamSource( 0, g_pVB, 0, sizeof(CUSTOMVERTEX) );
g_pd3dDevice->SetFVF( D3DFVF_CUSTOMVERTEX );
//两个三角形组成矩形
g_pd3dDevice->DrawPrimitive( D3DPT_TRIANGLESTRIP, 0, 2);
// End the scene
g_pd3dDevice->EndScene();
}
// Present the backbuffer contents to the display
g_pd3dDevice->Present( NULL, NULL, NULL, NULL );
}
//-----------------------------------------------------------------------------
// Name: MsgProc()
// Desc: The window's message handler
//-----------------------------------------------------------------------------
LRESULT WINAPI MsgProc( HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam )
{
switch( msg )
{
case WM_DESTROY:
Cleanup();
PostQuitMessage( 0 );
return 0;
}
return DefWindowProc( hWnd, msg, wParam, lParam );
}
//-----------------------------------------------------------------------------
// Name: WinMain()
// Desc: The application's entry point
//-----------------------------------------------------------------------------
INT WINAPI WinMain( HINSTANCE hInst, HINSTANCE, LPSTR, INT )
{
// Register the window class
WNDCLASSEX wc = { sizeof(WNDCLASSEX), CS_CLASSDC, MsgProc, 0L, 0L,
GetModuleHandle(NULL), NULL, NULL, NULL, NULL,
"D3D Tutorial", NULL };
RegisterClassEx( &wc );
// Create the application's window
HWND hWnd = CreateWindow( "D3D Tutorial", "D3D Tutorial 05: Textures",
WS_OVERLAPPEDWINDOW, 100, 100, 300, 300,
GetDesktopWindow(), NULL, wc.hInstance, NULL );
// Initialize Direct3D
if( SUCCEEDED( InitD3D( hWnd ) ) )
{
// Create the scene geometry
if( SUCCEEDED( InitGeometry() ) )
{
// Show the window
ShowWindow( hWnd, SW_SHOWDEFAULT );
UpdateWindow( hWnd );
// Enter the message loop
MSG msg;
ZeroMemory( &msg, sizeof(msg) );
while( msg.message!=WM_QUIT )
{
if( PeekMessage( &msg, NULL, 0U, 0U, PM_REMOVE ) )
{
TranslateMessage( &msg );
DispatchMessage( &msg );
}
else
Render();
}
}
}
UnregisterClass( "D3D Tutorial", wc.hInstance );
return 0;
}
项目下载： Textures.rar（本站下载）
文章源地址：http://www.waitingfy.com/?p=238
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