OpenGL实现四面体位图测试和连续动画.doc

#include windows.h #include gl/glut.h #include math.h #include stdio.h struct vector3 { float x, y, z; }; // 定义四面体的四个点 float r = 1.0; float a[] = {-0.5, -0.5, -0.25}; float b[] = {-0.5, r-0.5, -0.25}; float c[] = {sqrt(3.0)*r/2-0.5, r/2-0.5, -0.25}; float d[] = {sqrt(3.0)*r/6-0.5, r/2-0.5, sqrt(6.0)*r/3-0.25}; // 四个面的法向量 vector3 normalACB, normalABD, normalBCD, normalADC; // 绕 x 轴， y 轴旋转的角度 int anglex = 0, angley = 0; // 定义光源 float light_pos[] = {2.0, 2.0, 2.0, 0.0}; float light_Ka[] = {1.0, 0.0, 0.0, 1.0}; float light_Kd[] = {1.0, 1.0, 1.0, 1.0}; float light_Ks[] = {1.0, 1.0, 1.0, 1.0}; // 计算一个三角形的法向量 vector3 calculateNormal(float a[], float b[], float c[]) { float ab[3], ac[3]; vector3 normal; ab[0] = b[0] - a[0]; ab[1] = b[1] - a[1]; ab[2] = b[2] - a[2]; ac[0] = c[0] - a[0]; ac[1] = c[1] - a[1]; ac[2] = c[2] - a[2]; normal.x = ab[1]*ac[2] - ab[2]*ac[1]; normal.y = ab[0]*ac[2] - ab[2]*ac[0]; normal.z = ab[0]*ac[1] - ab[1]*ac[0]; return normal; } void init() { glClearColor(1.0, 1.0, 1.0, 0.0); glClearDepth(1.0f); glEnable(GL_DEPTH_TEST); glShadeModel(GL_SMOOTH); glHint(GL_LINE_SMOOTH_HINT, GL_NICEST); glLightfv(GL_LIGHT0, GL_POSITION, light_pos); glLightfv(GL_LIGHT0, GL_AMBIENT, light_Ka); glLightfv(GL_LIGHT0, GL_DIFFUSE, light_Kd); glLightfv(GL_LIGHT0, GL_SPECULAR, light_Ks); glEnable(GL_LIGHTING); glEnable(GL_LIGHT0); } void idle() { anglex = (anglex + 1) % 360; angley = (angley + 1) % 360; glutPostRedisplay(); } void display() { glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); // 画坐标轴 glColor3f(1.0, 1.0, 1.0); glBegin(GL_LINES); glVertex3f(0.0, 0.0, 0.0); glVertex3f(5.0, 0.0, 0.0); glVertex3f(0.0, 0.0, 0.0); glVertex3f(0.0, 5.0, 0.0); glVertex3f(0.0, 0.0, 0.0); glVertex3f(0.0, 0.0, 5.0); glEnd(); glPushMatrix(); glRotated(anglex, 1.0, 0.0, 0.0); float a1[3], b1[3], c1[3], d1[3]; // 计算旋转之后的四个点 a1[0] = a[0]; a1[1] = cos(anglex*1.0)*a[1] - sin(anglex*1.0)*a[2]; a1[2] = si