glut程序

8.多窗口且子窗口能够跟随reshape的变化而变化

///
#include <GL/glut.h>
#include <iostream>///
int winWidth, winHeight;                                    //  <<=======NEW!!!
int mainWinID;                                              //  <<=======NEW!!!
int subWinID0(0), subWinID1(0), subWinID2(0), subWinID3(0); //  <<=======NEW!!!///
void myMainWinDraw(void);
void myMainWinReshape(int _width, int _height);void mySubWinDrawSphere(void);
void mySubWinDrawTeapot(void);
void mySubWinDrawTorus(void);
void mySubWinDrawIcos(void);///
int main(int argc,char** argv) {glutInit(&argc,argv);glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB);glutInitWindowSize(400, 400);glutInitWindowPosition(0, 0);mainWinID = glutCreateWindow("Hello");glutDisplayFunc(myMainWinDraw);glutReshapeFunc(myMainWinReshape);glutMainLoop();return 0;
}///
void myMainWinReshape(int _width, int _height) {winWidth  = _width;                  // <<==============NEW!!!winHeight = _height;                 // <<==============NEW!!!if (subWinID0)                       // <<==============NEW!!!glutDestroyWindow(subWinID0);     // <<==============NEW!!!subWinID0 = glutCreateSubWindow(mainWinID, 0, 0,   // <<=======NEW!!!winWidth>>1, winHeight>>1);glutDisplayFunc(mySubWinDrawSphere);              // <<=======NEW!!!if (subWinID1) {glutDestroyWindow(subWinID1);}subWinID1 = glutCreateSubWindow(mainWinID, winWidth>>1, 0,winWidth>>1, winHeight>>1);glutDisplayFunc(mySubWinDrawTeapot);if (subWinID2)glutDestroyWindow(subWinID2);subWinID2 = glutCreateSubWindow(mainWinID, 0, winHeight>>1,winWidth>>1, winHeight>>1);glutDisplayFunc(mySubWinDrawTorus);if (subWinID3)glutDestroyWindow(subWinID3);subWinID3 = glutCreateSubWindow(mainWinID, winWidth>>1, winHeight>>1,winWidth>>1, winHeight>>1);glutDisplayFunc(mySubWinDrawIcos);
}///
void myMainWinDraw() {glClearColor(0.0, 0.0, 0.0, 0.0);glClear(GL_COLOR_BUFFER_BIT);glFlush();
}///
void mySubWinDrawSphere(void) {glClearColor(0.0, 0.0, 1.0, 0.0);glClear(GL_COLOR_BUFFER_BIT);glRotatef(30, 1.0f, 1.0f, 1.0f);glutWireSphere(0.8f, 20, 20);glFlush();
}///
void mySubWinDrawTeapot(void) {glClearColor(1.0, 1.0, 0.0, 0.0);glClear(GL_COLOR_BUFFER_BIT);glutWireTeapot(0.5f);glFlush();
}///
void mySubWinDrawTorus(void) {glClearColor(0.0, 1.0, 1.0, 0.0);glClear(GL_COLOR_BUFFER_BIT);glutWireTorus(0.3f, 0.6f, 20, 30);glFlush();
}///
void mySubWinDrawIcos(void) {glClearColor(1.0, 0.0, 1.0, 0.0);glClear(GL_COLOR_BUFFER_BIT);glRotatef(30, 1.0f, 1.0f, 1.0f);glutWireIcosahedron();glFlush();
}///

新增的知识点：

1.回调函数myMainWinReshape中：改变窗口大小时，先将原来子窗口销毁（如果存在的话），再重新产生新的子窗口。

2.glutDestroyWindow：销毁窗口

道理上是这个样子，但是我在实际运行过程中，拖动鼠标改变窗口大小时，出现了问题。 

差不多是说，没有注册给窗口6的回调函数。可能和我这个freeglut有关系的。暂时没有解决。

9.可控制的子窗口显示

///
#include <GL/ogl.h>
#include <iostream>///
void myMainWinDraw(void);
void myMainWinReshape(int _width, int _height);
void myMainWinKeyboard(unsigned char _key, int _x, int _y);void mySubWinDrawSphere(void);
void mySubWinDrawTeapot(void);
void mySubWinDrawTorus(void);
void mySubWinDrawIcos(void);///
int winWidth, winHeight;
int mainWinID;
int subWinID0(0), subWinID1(0), subWinID2(0), subWinID3(0);// <<================= NEW !!!!!!
bool isShowSubWin0(1), isShowSubWin1(1), isShowSubWin2(1), isShowSubWin3(1);///
int main(int argc,char** argv) {glutInit(&argc,argv);glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB);glutInitWindowSize(400, 400);glutInitWindowPosition(0, 0);mainWinID = glutCreateWindow("Hello");glutDisplayFunc(myMainWinDraw);glutReshapeFunc(myMainWinReshape);glutKeyboardFunc(myMainWinKeyboard);glutMainLoop();return 0;
}///
void myMainWinReshape(int _width, int _height) {winWidth  = _width;winHeight = _height;if (subWinID0) {glutDestroyWindow(subWinID0);subWinID0 = 0;}if (isShowSubWin0) {subWinID0 = glutCreateSubWindow(mainWinID, 0, 0,  winWidth>>1, winHeight>>1);glutDisplayFunc(mySubWinDrawSphere);}if (subWinID1) {glutDestroyWindow(subWinID1);subWinID1 = 0;}if (isShowSubWin1) {subWinID1 = glutCreateSubWindow(mainWinID, winWidth>>1, 0,winWidth>>1, winHeight>>1);glutDisplayFunc(mySubWinDrawTeapot);}if (subWinID2) {glutDestroyWindow(subWinID2);subWinID2 = 0;}if (isShowSubWin2) {subWinID2 = glutCreateSubWindow(mainWinID, 0, winHeight>>1,winWidth>>1, winHeight>>1);glutDisplayFunc(mySubWinDrawTorus);}if (subWinID3) {glutDestroyWindow(subWinID3);subWinID3 = 0;}if (isShowSubWin3) {subWinID3 = glutCreateSubWindow(mainWinID, winWidth>>1, winHeight>>1,winWidth>>1, winHeight>>1);glutDisplayFunc(mySubWinDrawIcos);}
}///
void myMainWinDraw() {glClearColor(0.0, 0.0, 0.0, 0.0);glClear(GL_COLOR_BUFFER_BIT);glFlush();
}//      <<<<<===================== NEW !!!!!
#define RENEW    myMainWinReshape(winWidth, winHeight);\glutPostRedisplay();\//myMainWinDraw();///
void myMainWinKeyboard(unsigned char _key, int _x, int _y) {switch (_key) {case 'a':isShowSubWin0 = !isShowSubWin0;RENEW;break;case 's':isShowSubWin1 = !isShowSubWin1;RENEW;break;case 'z':isShowSubWin2 = !isShowSubWin2;RENEW;break;case 'x':isShowSubWin3 = !isShowSubWin3;RENEW;break;case 'f':// <<================== NEW !!!glutFullScreen();break;case 'v':// <<================== NEW !!!glutSetWindow(mainWinID);glutReshapeWindow(300, 300);break;case 'w':// <<================== NEW !!!glutSetWindow(subWinID0);glutReshapeWindow(100, 100);}
}#undef RENEW    // <<================== NEW !!!///
void mySubWinDrawSphere(void) {glClearColor(0.0, 0.0, 1.0, 0.0);glClear(GL_COLOR_BUFFER_BIT);glRotatef(30, 1.0f, 1.0f, 1.0f);glutWireSphere(0.8f, 20, 20);glFlush();
}///
void mySubWinDrawTeapot(void) {glClearColor(1.0, 1.0, 0.0, 0.0);glClear(GL_COLOR_BUFFER_BIT);glutWireTeapot(0.5f);glFlush();
}///
void mySubWinDrawTorus(void) {glClearColor(0.0, 1.0, 1.0, 0.0);glClear(GL_COLOR_BUFFER_BIT);glutWireTorus(0.3f, 0.6f, 20, 30);glFlush();
}///
void mySubWinDrawIcos(void) {glClearColor(1.0, 0.0, 1.0, 0.0);glClear(GL_COLOR_BUFFER_BIT);glRotatef(30, 1.0f, 1.0f, 1.0f);glutWireIcosahedron();glFlush();
}///

引入bool量isShowSubWin0, isShowSubWin1, isShowSubWin2, isShowSubWin3来判断是否应该显示该子窗口。