main.cpp

3DS模型的读取与绘制实例

#include "main.h"										
#include "3ds.h"										

bool  g_bFullScreen = true;								
HWND  g_hWnd;											
RECT  g_rRect;											
HDC   g_hDC;											
HGLRC g_hRC;											
HINSTANCE g_hInstance;									


#define FILE_NAME  "F16.3DS"							

UINT g_Texture[MAX_TEXTURES] = {0};						

CLoad3DS g_Load3ds;									
t3DModel g_3DModel;									

int   g_ViewMode	  = GL_TRIANGLES;
bool  g_bLighting     = true;		
float g_RotateX		  = 0.0f;		
float g_RotationSpeed = 0.1f;		


void Init(HWND hWnd)
{
	g_hWnd = hWnd;										
	GetClientRect(g_hWnd, &g_rRect);					
	InitializeOpenGL(g_rRect.right, g_rRect.bottom);

	g_Load3ds.Import3DS(&g_3DModel, FILE_NAME);			// 将3ds文件装入到模型结构体中

	// 遍历所有的材质
	for(int i = 0; i < g_3DModel.numOfMaterials; i++)
	{
		// 判断是否是一个文件名
		if(strlen(g_3DModel.pMaterials[i].strFile) > 0)
		{
			//  使用纹理文件名称来装入位图
			CreateTexture(g_Texture, g_3DModel.pMaterials[i].strFile, i);			
		}

		// 设置材质的纹理ID
		g_3DModel.pMaterials[i].texureId = i;
	}

	glEnable(GL_LIGHT0);								
	glEnable(GL_LIGHTING);								
	glEnable(GL_COLOR_MATERIAL);					

}

WPARAM MainLoop()
{
	MSG msg;

	while(1)											
	{													
		if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE)) 
        { 
			if(msg.message == WM_QUIT)					
				break;
            TranslateMessage(&msg);						
            DispatchMessage(&msg);					
        }
		else									
		{ 
			RenderScene();						
        } 
	}

	// 遍历场景中所有的对象
	for(int i = 0; i < g_3DModel.numOfObjects; i++)
	{
		// 删除所有的变量
		delete [] g_3DModel.pObject[i].pFaces;
		delete [] g_3DModel.pObject[i].pNormals;
		delete [] g_3DModel.pObject[i].pVerts;
		delete [] g_3DModel.pObject[i].pTexVerts;
	}

	DeInit();	
	return(msg.wParam);	
}

void RenderScene() 
{
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);	
	glLoadIdentity();									

	gluLookAt(		0, 1.5f, 8,		0, 0.5f, 0,			0, 1, 0);
	
	glRotatef(g_RotateX, 0, 1.0f, 0);
	g_RotateX += g_RotationSpeed;	

	// 遍历模型中所有的对象
	for(int i = 0; i < g_3DModel.numOfObjects; i++)
	{
		// 如果对象的大小小于0，则退出
		if(g_3DModel.pObject.size() <= 0) break;

		// 获得当前显示的对象
		t3DObject *pObject = &g_3DModel.pObject[i];
			
		// 判断该对象是否有纹理映射
		if(pObject->bHasTexture) {

			// 打开纹理映射
			glEnable(GL_TEXTURE_2D);
			glColor3ub(255, 255, 255);
			glBindTexture(GL_TEXTURE_2D, g_Texture[pObject->materialID]);
		} else {

			// 关闭纹理映射
			glDisable(GL_TEXTURE_2D);
			glColor3ub(255, 255, 255);
		}
		// 开始以g_ViewMode模式绘制
		glBegin(g_ViewMode);					
			// 遍历所有的面
			for(int j = 0; j < pObject->numOfFaces; j++)
			{
				// 遍历三角形的所有点
				for(int whichVertex = 0; whichVertex < 3; whichVertex++)
				{
					// 获得面对每个点的索引
					int index = pObject->pFaces[j].vertIndex[whichVertex];
			
					// 给出法向量
					glNormal3f(pObject->pNormals[ index ].x, pObject->pNormals[ index ].y, pObject->pNormals[ index ].z);
				
					// 如果对象具有纹理
					if(pObject->bHasTexture) {

						// 确定是否有UVW纹理坐标
						if(pObject->pTexVerts) {
							glTexCoord2f(pObject->pTexVerts[ index ].x, pObject->pTexVerts[ index ].y);
						}
					} else {

						if(g_3DModel.pMaterials.size() && pObject->materialID >= 0) 
						{
							BYTE *pColor = g_3DModel.pMaterials[pObject->materialID].color;
							glColor3ub(pColor[0], pColor[1], pColor[2]);
						}
					}
					glVertex3f(pObject->pVerts[ index ].x, pObject->pVerts[ index ].y, pObject->pVerts[ index ].z);
				}
			}

		glEnd();								// 绘制结束
	}

	SwapBuffers(g_hDC);									// 交换缓冲区
}

LRESULT CALLBACK WinProc(HWND hWnd,UINT uMsg, WPARAM wParam, LPARAM lParam)
{
    LONG    lRet = 0; 
    PAINTSTRUCT    ps;

    switch (uMsg)
	{ 
    case WM_SIZE:							
		if(!g_bFullScreen)				
		{
			SizeOpenGLScreen(LOWORD(lParam),HIWORD(lParam));
			GetClientRect(hWnd, &g_rRect);				
		}
        break; 
 
	case WM_PAINT:									
		BeginPaint(hWnd, &ps);						
		EndPaint(hWnd, &ps);					
		break;

	case WM_LBUTTONDOWN:								// 按下鼠标左键，改变绘制模式
		
		if(g_ViewMode == GL_TRIANGLES) {		
			g_ViewMode = GL_LINE_STRIP;		
		} else {
			g_ViewMode = GL_TRIANGLES;	
		}
		break;

	case WM_RBUTTONDOWN:								// 按下鼠标右键，改变光照模式
		
		g_bLighting = !g_bLighting;		

		if(g_bLighting) {					
			glEnable(GL_LIGHTING);			
		} else {
			glDisable(GL_LIGHTING);			
		}
		break;

	case WM_KEYDOWN:									// 键盘响应

		switch(wParam) {								
			case VK_ESCAPE:								// 按下ESC键
				PostQuitMessage(0);					
				break;

			case VK_LEFT:								// 按下向左键
				g_RotationSpeed -= 0.05f;	
				break;

			case VK_RIGHT:								// 按下向右键
				g_RotationSpeed += 0.05f;			
				break;
		}
		break;

    case WM_CLOSE:									
        PostQuitMessage(0);						
        break; 
     
    default:										
        lRet = DefWindowProc (hWnd, uMsg, wParam, lParam); 
        break; 
    } 
 
    return lRet;										
}