计算机图形学实验三(纹理映射)

实验三 纹理映射 一、实验目的 （1）掌握OpenGl的三维图形制作方法 （2）掌握Visual C++环境下的OpenGL图形开发 二、实验内容 在三维图像上添加纹理映射 三、实验结果 实验代码如下： /*********************************************** * glut_application writen by yyb * ***********************************************/

#include #include #include #include #pragma comment(lib,"glaux.lib") #define MAX_TEXTURES 6 // max textures displayed /* creates a enum type for mouse buttons */ enum { BUTTON_LEFT = 0, BUTTON_RIGHT, BUTTON_LEFT_TRANSLATE, };

int mButton = -1; int mOldY, mOldX; bool fullscreen;

//////////////////////////////////// float eye[3] = {0.0f, 0.0f, 7.0f}; float rot[3] = {45.0f, 45.0f, 0.0f};

const int ESC = 27; int wireframe = 0;

const int GL_WIN_WIDTH = 640; const int GL_WIN_HEIGHT = 480; const int GL_WIN_INITIAL_X = 0; const int GL_WIN_INITIAL_Y = 0;

/* array to hold texture handles */ GLuint g_TexturesArray[MAX_TEXTURES]; BOOL LoadTextureGL(char *Filename,GLuint &texture) // 加载一个bmp图片(new) { AUX_RGBImageRec *TextureImage; // 为纹理开辟存储空间

FILE *File = NULL; // 文件句柄 if (!Filename) // 确保文件名已经提供 { return NULL; // 如果没有则返回NULL }

File = fopen(Filename,"r"); // 检查文件是否存在 if (File) // 文件存在吗？ { fclose(File); // 关闭File文件句柄 TextureImage=auxDIBImageLoad(Filename); // 载入图片并返回其指针 } glGenTextures(1, &texture); // 返回唯一的纹理名字来标识纹理,保存在texture中 // 使用来自位图数据生成的典型纹理 glBindTexture(GL_TEXTURE_2D, texture); // 生成纹理 glTexImage2D(GL_TEXTURE_2D, 0, 3, TextureImage->sizeX, TextureImage->sizeY, 0, GL_RGB, GL_UNSIGNED_BYTE, TextureImage->data); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); // 线形滤波 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); // 线形滤波

if (TextureImage) // 纹理是否存在 { if (TextureImage->data) // 纹理图像是否存在 { free(TextureImage->data); // 释放纹理存储空间 } free(TextureImage); // 释放图像结构 } return true; }

bool LoadBMP(char *filename, GLuint &texture)//调贴图大小为2的幂 { AUX_RGBImageRec *pImage = NULL; pImage = auxDIBImageLoad(filename); // 装入位图 if(pImage == NULL) return false; // 位图没装入返回错误 glGenTextures(1, &texture); // 生成贴图(纹理) glBindTexture (GL_TEXTURE_2D,texture);// 捆绑贴图(纹理) gluBuild2DMipmaps(GL_TEXTURE_2D,4, // pImage->sizeX, // 图形宽 pImage->sizeY, // 图形高 GL_RGB, GL_UNSIGNED_BYTE, pImage->data // 图形数据 ); free(pImage->data); // 释放位图数据占据的内存资源 free(pImage); return true; // 返回成功 }

void Init() { //glHint(GL_PERSPECTIVE_CORRECTION_HINT,GL_NICEST); //glShadeModel(GL_SMOOTH); glEnable(GL_DEPTH_TEST); glClearColor(0.0,0.0,0.0,1.0); // enable texture and binds a texture to the first element of the array glEnable(GL_TEXTURE_2D); // LoadTextureGL("mybmp1.bmp",g_TexturesArray[0]); // LoadTextureGL("Cars.bmp",g_TexturesArray[1]); LoadBMP("1.bmp",g_TexturesArray[0]); LoadBMP("2.bmp",g_TexturesArray[1]); LoadBMP("3.bmp",g_TexturesArray[2]); LoadBMP("4.bmp",g_TexturesArray[3]); LoadBMP("5.bmp",g_TexturesArray[4]); LoadBMP("6.bmp",g_TexturesArray[5]); return; } //------------------------------------------------------------------------ // Window resize function //------------------------------------------------------------------------ void glutResize(int width, int height) { glViewport(0, 0, width, height); glMatrixMode(GL_PROJECTION); glLoadIdentity(); /* modify this line to change perspective values */ gluPerspective(45.0, (float)width/(float)height, 1.0, 300.0); glMatrixMode(GL_MODELVIEW); glLoadIdentity(); }

//------------------------------------------------------------------------ // Function that handles keyboard inputs //------------------------------------------------------------------------ void glutKeyboard(unsigned char key, int x, int y) { switch (key) { case ESC: exit(0); case 'W': case 'w': wireframe = !wireframe; } }

void clamp(float *v) { int i;

for (i = 0; i < 3; i ++) if (v[i] > 360 || v[i] < -360) v[i] = 0; }

//------------------------------------------------------------------------ // Moves the screen based on mouse pressed button //------------------------------------------------------------------------ void glutMotion(int x, int y) { if (mButton == BUTTON_LEFT) { /* rotates screen */ rot[0] -= (mOldY - y); rot[1] -= (mOldX - x); clamp (rot); } else if (mButton == BUTTON_RIGHT) {

eye[2] -= (mOldY - y) * 0.05f; // here I multiply by a 0.2 factor to