OpenGL完成对OFF文件的读取和使三维模型旋转

#include<Angel.h> #include<mat.h> #include<vector> #include<string> #include<fstream> #include<sstream> #pragma comment(lib,"glew32.lib") const double DEFAULT_DELTA = 0.03; //旋转偏移量 int sign = 1; //控制是顺时针旋转还是逆时针旋转，1为顺时针旋转。 //矩阵的存储位置 GLint matrixLocation; int mainWindow;// int Xaxis = 0; int Yaxis = 1; int Zaxis = 2; int Axis = Xaxis; //控制是x轴、y轴、z轴旋转。默认是x轴 vec3 Theta(0.0, 0.0, 0.0); //Num_Vertices为顶点的个数 const int NUM_VERTICES = 8; const vec4 vertexColors[NUM_VERTICES] = { vec4(0.0, 0.0, 0.0, 1.0), // Black vec4(1.0, 0.0, 0.0, 1.0), // Red vec4(1.0, 1.0, 0.0, 1.0), // Yellow vec4(0.0, 1.0, 0.0, 1.0), // Green vec4(0.0, 0.0, 1.0, 1.0), // Blue vec4(1.0, 0.0, 1.0, 1.0), // Magenta vec4(1.0, 1.0, 1.0, 1.0), // White vec4(0.0, 1.0, 1.0, 1.0) // Cyan }; int nVertices = 0;//顶点数 int nFaces = 0;//面数 int nEdges;//边数 std::vector<vec4> points; //存放每个顶点的信息 std::vector<vec4> colors; //存放每个顶点的颜色信息 std::vector<vec4> vertices; //存放每个顶点的坐标信息 /* 存放每个顶点的坐标和颜色信息 */ void storePoints(int a, int b, int c) { points.push_back(vertices[a]); points.push_back(vertices[b]); points.push_back(vertices[c]); colors.push_back(vertexColors[a]); colors.push_back(vertexColors[b]); colors.push_back(vertexColors[c]); } /* 读取off文件 */ void read_off(const std::string filename) { if (filename.empty()) {//如果文件为空，则直接返回 return; } std::ifstream fin; int i = 0; fin.open(filename); std::string str; fin >> str; //str的内容为OFF fin >> nVertices; //顶点数 fin >> nFaces; //面数 fin >> nEdges; //边数 for (i = 0; i < nVertices; i++) //读取off中的点坐标数据，存放在points中 { double n1 = 0; double n2 = 0; double n3 = 0; double n4 = 0; fin >> n1; //其坐标值有四个 fin >> n2; fin >> n3; fin >> n4; vec4 new_vec3(n1, n2, n3, n4); vertices.push_back(new_vec3); } for (i = 0; i < nFaces; i++) //读取每个面的信息 { int n1 = 0; int n2 = 0; //每行的第一个为顶点数， int n3 = 0; int n4 = 0; fin >> n1; fin >> n2; fin >> n3; fin >> n4; storePoints(n2, n3, n4); } fin.close(); } void init() { read_off("cube.off"); // 创建顶点数组对象 GLuint vao[1]; glGenVertexArrays(1, vao); glBindVertexArray(vao[0]); // 创建并初始化顶点缓存对象 GLuint buffer; glGenBuffers(1, &buffer); glBindBuffer(GL_ARRAY_BUFFER, buffer); glBufferData(GL_ARRAY_BUFFER, points.size() * sizeof(vec4) + colors.size() * sizeof(vec4), NULL, GL_STATIC_DRAW); // 分别读取数据 glBufferSubData(GL_ARRAY_BUFFER, 0, points.size() * sizeof(vec4), &points[0]); glBufferSubData(GL_ARRAY_BUFFER, points.size() * sizeof(vec4), colors.size() * sizeof(vec4), &colors[0]); // 读取着色器并使用 GLuint program = InitShader("vshader.glsl", "fshader.glsl"); glUseProgram(program); // 从顶点着色器中初始化顶点的位置 GLuint pLocation = glGetAttribLocation(program, "vPosition"); glEnableVertexAttribArray(pLocation); glVertexAttribPointer(pLocation, 4, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(0)); // 从片元着色器中初始化顶点的颜色 GLuint cLocation = glGetAttribLocation(program, "vColor"); glEnableVertexAttribArray(cLocation); glVertexAttribPointer(cLocation, 4, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(points.size() * sizeof(vec4))); // 获得矩阵存储位置 matrixLocation = glGetUniformLocation(program, "matrix"); // 白色背景 glClearColor(1.0, 1.0, 1.0, 1.0); } void display() { // 清理窗口 glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); // 生成变换矩阵 mat4 m(1.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 1.0); m = m*RotateX(Theta[Xaxis]); //绕x轴旋转 m = m*RotateY(Theta[Yaxis]); //绕y轴旋转 m = m*RotateZ(Theta[Zaxis]); //绕z轴旋转 // 从指定位置中传入变换矩阵 glUniformMatrix4fv(matrixLocation, 1, GL_TRUE, m); glDrawArrays(GL_TRIANGLES, 0, points.size()); glFlush(); glutSwapBuffers(); } // 复原Theta和Delta void reset() { Theta = vec3(0.0, 0.0, 0.0); } //更新Theta的值 void update() { Theta[Axis] += sign * DEFAULT_DELTA; //通过修改些值来生成对应的变化矩阵 glutPostWindowRedisplay(mainWindow); //重新显示窗口 } void mouse(int button, int state, int x, int y) { if (state == GLUT_DOWN) { switch(button) { //sign控制是顺时针旋转还是逆时针旋转，1为顺时针旋转。 case GLUT_LEFT_BUTTON: sign = -1; break; case GLUT_RIGHT_BUTTON:sign = 1; break; } } } void keyboard(unsigned char key, int x, int y) { switch (key) { case 'x':case 'X': Axis = Xaxis; //x轴旋转 break; case 'y':case 'Y': Axis = Yaxis; //y轴旋转 break; case 'z':case 'Z': Axis = Zaxis; //z轴旋转 break; case 'r':case 'R' : //重置，还原为原始图 reset(); break; case 033: //退出 case 'q':case 'Q': exit(EXIT_SUCCESS); break; } } void printhelp() { std::cout << "鼠标右键为顺时针，鼠标左键为逆时针\n"; std::cout << "x/X: 沿X轴旋转\n"; std::cout << "y/Y: 沿Y轴旋转\n"; std::cout << "z/Z: 沿Z轴旋转\n"; std::cout << "r/R: 还原为初始图\n"; std::cout << "q/Q/Esc: 退出程序\n"; } int main(int argc, char **argv) { glutInit(&argc, argv); glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_DEPTH); // 窗口支持双重缓冲和深度测试 glutInitWindowPosition(100, 100); glutInitWindowSize(600, 600); mainWindow = glutCreateWindow("欧阳炼均-2014150213-实验二"); glewExperimental = GL_TRUE; glewInit(); init(); glutDisplayFunc(display); glutMouseFunc(mouse); glutKeyboardFunc(keyboard); glutIdleFunc(update); // 输出帮助信息 printhelp(); // 启用深度测试 glEnable(GL_DEPTH_TEST); glutMainLoop(); return 0; }