OpenGL編程輕松入門之菜單管理2006-05-23 08:55作者：黃燕出處：天極開發(fā)責任編輯：方舟菜單是我們經常使用的工具，很方便，直觀。本節(jié)討論在OpenGL中如何進行菜單管理。例17：本例在藍色的背景上繪制一個白色的正方形，在窗口內單擊鼠標右鍵，彈出菜單，當選擇不同菜單項時命令窗口會顯示出是哪個菜單的哪個菜單相被激活。本例一個主菜單，主菜單有3個菜單條目及兩個子菜單。兩個子菜單都有3個菜單條目。#include #include int menu,subMenu1,subMenu2;/*在藍色的背景上繪制一個白色的正方形*/void myDraw(void)glClearColor(0.0,0.0,1.0,0.0);glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);glColor3f(1.0,1.0,1.0);glOrtho(-1.0,1.0,-1.0,1.0,-1.0,1.0);glBegin(GL_POLYGON);glVertex2f(-0.5,-0.5);glVertex2f(-0.5,0.5);glVertex2f(0.5,0.5);glVertex2f(0.5,-0.5);glEnd();glutSwapBuffers();/*寫出當前是哪個菜單*/void GetCurrentMenu(void)int nMenu;nMenu = glutGetMenu();if(nMenu = menu)printf(The current menu is Main Menu.n);if(nMenu = subMenu1)printf(The current menu is SubMenu1.n);if(nMenu = subMenu2)printf(The current menu is SubMenu2.n);/*子菜單1*/void SubMenuFunc1(int data)GetCurrentMenu();switch(data)case 1:printf(SubMenu1s item 1 is triggered.n);break;case 2:printf(SubMenu1s item 2 is triggered.n);break;case 3:printf(SubMenu1s item 3 is triggered.n);break;/*子菜單2*/void SubMenuFunc2(int data)GetCurrentMenu();switch(data)case 1:printf(SubMenu2s item 1 is triggered.n);break;case 2:printf(SubMenu2s item 2 is triggered.n);break;case 3:printf(SubMenu2s item 3 is triggered.n);break;/*主菜單*/void MenuFunc(int data)GetCurrentMenu();switch(data)case 1:printf(MainMenus item 1 is triggered.n);break;case 2:printf(MainMenus item 2 is triggered.n);break;case 3:printf(MainMenus item 3 is triggered.n);break;int main(int argc,char * argv)/*初始化*/glutInit(&argc,argv);glutInitDisplayMode(GLUT_DOUBLE|GLUT_RGB|GLUT_DEPTH);glutInitWindowSize(500,400);glutInitWindowPosition(100,100);/*創(chuàng)建窗口*/glutCreateWindow( MENU);glutDisplayFunc(myDraw);/*創(chuàng)建子菜單1并加入菜單條目*/subMenu1 = glutCreateMenu(SubMenuFunc1);glutAddMenuEntry(SubMenu1s item1,1);glutAddMenuEntry(SubMenu1s item2,2);glutAddMenuEntry(SubMenu1s item3,3);glutAttachMenu(GLUT_RIGHT_BUTTON);/*創(chuàng)建子菜單2并加入菜單條目*/subMenu2 = glutCreateMenu(SubMenuFunc2);glutAddMenuEntry(SubMenu2s item1,1);glutAddMenuEntry(SubMenu2s item2,2);glutAddMenuEntry(SubMenu2s item3,3);glutAttachMenu(GLUT_RIGHT_BUTTON);/*創(chuàng)建主菜單并加入菜單條目及子菜單*/menu = glutCreateMenu(MenuFunc);glutAddMenuEntry(Item1,1);glutAddMenuEntry(Item2,2);glutAddMenuEntry(Item3,3);glutAddSubMenu(SubMenu 1,subMenu1);glutAddSubMenu(SubMenu 2,subMenu2);glutAttachMenu(GLUT_RIGHT_BUTTON);glutMainLoop();/進入GLUT事件處理循環(huán)return 0;int glutCreateMenu（void（*func）（int value）創(chuàng)建一個新的彈出式菜單并返回一個唯一標識此菜單的整型表示符。func指明此菜單的功能。int glutAddMenuEntry（char *name，int value）在當前菜單底部增加一個菜單條目。name指定顯示在新菜單條目上的ASCII碼字符串。value指定當選擇該菜單條目時傳遞到菜單回調函數中的數值。void glutAddSubMenu（char *name，int menu）在當前菜單的底部增加一個子菜單觸發(fā)條目。name指定顯示在新菜單觸發(fā)條目上的ASCII碼字符串。meun當選擇該子菜單觸發(fā)條目時彈出的子菜單的標識符。void glutAttachMenu（int button）把當前窗口的一個鼠標按鍵與當前菜單的標識符聯系起來。button指明鼠