OpenGL的鼠標(biāo)交互一、實(shí)驗(yàn)?zāi)康?、掌握OpenGL的鼠標(biāo)按鈕響應(yīng)函數(shù)2、掌握OpenGL的鼠標(biāo)移動(dòng)響應(yīng)函數(shù)3、進(jìn)一步穩(wěn)固OpenGL的根本圖元繪制的根底二、實(shí)驗(yàn)環(huán)境硬件要求：PC機(jī)，主流配置，最好為獨(dú)立顯卡，顯存512M以上。軟件環(huán)境：操作系統(tǒng)：WindowsXP。語言開發(fā)工具：MicrosoftVisualstudio2023,VisualC++。三、實(shí)驗(yàn)內(nèi)容與要求要求：實(shí)驗(yàn)課上老師要求的效果截圖、及其相應(yīng)代碼拷貝到實(shí)驗(yàn)報(bào)告文檔里。WORD文檔命名方式：學(xué)號(hào)姓名-實(shí)驗(yàn)序號(hào)-實(shí)驗(yàn)名稱。內(nèi)容：1)鼠標(biāo)畫草圖-實(shí)現(xiàn)鼠標(biāo)點(diǎn)到哪，線就畫到哪思路：1.在主程序注冊鼠標(biāo)響應(yīng)和鼠標(biāo)移動(dòng)子函數(shù)glutMouseFunc(mymouse);glutMotionFunc(mymotion)；放在display注冊之后和mainloop之前2.在程序頭部聲明鼠標(biāo)響應(yīng)和鼠標(biāo)移動(dòng)子函數(shù)voidmyMouse(intbutton,intstate,intx,inty);voidmyMotion(intx,inty);3.構(gòu)造鼠標(biāo)響應(yīng)子函數(shù)//鼠標(biāo)按鈕響應(yīng)事件..voidmyMouse(intbutton,intstate,intx,inty){//鼠標(biāo)左鍵按下—確定起始點(diǎn)//鼠標(biāo)左鍵松開___畫最后一個(gè)頂點(diǎn)，畫線結(jié)束}4.構(gòu)造鼠標(biāo)移動(dòng)子函數(shù)//鼠標(biāo)移動(dòng)時(shí)獲得鼠標(biāo)移動(dòng)中的坐標(biāo)-----------------------------------------------------voidmyMotion(intx,inty){//鼠標(biāo)移動(dòng)__線畫到哪}5.修改顯示函數(shù)Display();附：畫直線程序框架#include"stdafx.h"#include<glut.h>intww,hh;//fordisplaywindowwidthandheightvoidMyinit(void);voidReshape(intw,inth);voidDisplay(void);intAPIENTRY_tWinMain(HINSTANCEhInstance,HINSTANCEhPrevInstance,LPTSTRlpCmdLine,intnCmdShow){ UNREFERENCED_PARAMETER(hPrevInstance); UNREFERENCED_PARAMETER(lpCmdLine);char*argv[]={"hello",""};intargc=2;//must/shouldmatchthenumberofstringsinargv glutInit(&argc,argv);//初始化GLUT庫；glutInitWindowSize(800,600);//設(shè)置顯示窗口大小glutInitDisplayMode(GLUT_DOUBLE|GLUT_RGB);//設(shè)置顯示模式；〔注意雙緩沖〕glutCreateWindow("鼠標(biāo)畫線小程序演示");//創(chuàng)立顯示窗口Myinit();glutDisplayFunc(Display);//注冊顯示回調(diào)函數(shù)glutReshapeFunc(Reshape);//注冊窗口改變回調(diào)函數(shù) glutMainLoop();//進(jìn)入事件處理循環(huán)return0;}voidMyinit(void){glClearColor(0.0,0.0,0.0,0.0);glLineWidth(3.0);}//渲染繪制子程序--------------------------------------------------------------------------voidDisplay(void){glClear(GL_COLOR_BUFFER_BIT);//刷新顏色緩沖區(qū)；glBegin(GL_LINES);glVertex2f(0,0);glVertex2f(ww,hh);glEnd();glutSwapBuffers();//雙緩沖的刷新模式；}//-----------------------------------------------voidReshape(intw,inth)//窗口改變時(shí)自動(dòng)獲取顯示窗口的寬w和高h(yuǎn){glMatrixMode(GL_PROJECTION);//投影矩陣模式glLoadIdentity();//矩陣堆棧清空glViewport(0,0,w,h);//設(shè)置視區(qū)大小gluOrtho2D(0,w,0,h);//設(shè)置裁剪窗口大小ww=w;hh=h;}2〕鼠標(biāo)畫線閱讀OpenGL鼠標(biāo)畫線程序，能夠?qū)崿F(xiàn)在繪制窗口用鼠標(biāo)交互繪制假設(shè)干條直線，鼠標(biāo)左鍵首先按下，確定直線的起始點(diǎn)，鼠標(biāo)左鍵按下同時(shí)移動(dòng)，看到畫線過程，鼠標(biāo)左鍵松開時(shí)，確定直線的終點(diǎn)，可重復(fù)畫多條直線。實(shí)現(xiàn)主要思路：1)寫出畫靜止假設(shè)干條直線程序框架，坐標(biāo)用變量替代；2)在主函數(shù)里注冊鼠標(biāo)按鈕響應(yīng)函數(shù)和鼠標(biāo)移動(dòng)響應(yīng)函數(shù)；3)在鼠標(biāo)按鈕響應(yīng)子函數(shù)里，給出鼠標(biāo)按鈕響應(yīng)事件；4)在鼠標(biāo)移動(dòng)響應(yīng)子函數(shù)里，給出鼠標(biāo)移動(dòng)響應(yīng)事件；5)讀懂程序并分析程序，保存程序。//鼠標(biāo)畫線小程序#include"stdafx.h"#include<glut.h>#defineN1000//maximumlinenumbersintww,hh;//fordisplaywindowwidthandheightintline[N][4],k=0;//forline'sendpointcoordinatesandlinenumbervoidMyinit(void);voidReshape(intw,inth);voidmyMouse(intbutton,intstate,intx,inty);voidmyMotion(intx,inty);voidDisplay(void);voiddrawlines();intAPIENTRY_tWinMain(HINSTANCEhInstance,HINSTANCEhPrevInstance,LPTSTRlpCmdLine,intnCmdShow){ UNREFERENCED_PARAMETER(hPrevInstance); UNREFERENCED_PARAMETER(lpCmdLine);char*argv[]={"hello",""};intargc=2;//must/shouldmatchthenumberofstringsinargv glutInit(&argc,argv);//初始化GLUT庫；glutInitWindowSize(800,600);//設(shè)置顯示窗口大小glutInitDisplayMode(GLUT_DOUBLE|GLUT_RGB);//設(shè)置顯示模式；〔注意雙緩沖〕glutCreateWindow("鼠標(biāo)畫線小程序演示");//創(chuàng)立顯示窗口Myinit();glutDisplayFunc(Display);//注冊顯示回調(diào)函數(shù)glutMouseFunc(myMouse);//注冊鼠標(biāo)按鈕回調(diào)函數(shù)glutMotionFunc(myMotion);//注冊鼠標(biāo)移動(dòng)回調(diào)函數(shù)glutReshapeFunc(Reshape);//注冊窗口改變回調(diào)函數(shù) glutMainLoop();//進(jìn)入事件處理循環(huán)return0;}voidMyinit(void){glClearColor(0.0,0.0,0.0,0.0);glLineWidth(3.0);}//渲染繪制子程序--------------------------------------------------------------------------voidDisplay(void){glClear(GL_COLOR_BUFFER_BIT);//刷新顏色緩沖區(qū)； drawlines();//畫線子程序；glutSwapBuffers();//雙緩沖的刷新模式；}//-----------------------------------------------voidReshape(intw,inth)//窗口改變時(shí)自動(dòng)獲取顯示窗口的寬w和高h(yuǎn){glMatrixMode(GL_PROJECTION);//投影矩陣模式glLoadIdentity();//矩陣堆棧清空glViewport(0,0,w,h);//設(shè)置視區(qū)大小gluOrtho2D(0,w,0,h);//設(shè)置裁剪窗口大小ww=w;hh=h;}//鼠標(biāo)按鈕響應(yīng)事件..voidmyMouse(intbutton,intstate,intx,inty){if(button==GLUT_LEFT_BUTTON&&state==GLUT_DOWN) { line[k][0]=x;//線段起點(diǎn)x坐標(biāo) line[k][1]=hh-y;//線段終點(diǎn)y坐標(biāo) }if(button==GLUT_LEFT_BUTTON&&state==GLUT_UP) { line[k][2]=x;//線段起點(diǎn)x坐標(biāo) line[k][3]=hh-y;//線段終點(diǎn)y坐標(biāo) k++; glutPostRedisplay(); }}//鼠標(biāo)移動(dòng)時(shí)獲得鼠標(biāo)移動(dòng)中的坐標(biāo)-----------------------------------------------------voidmyMotion(intx,inty){//gettheline'smotionpoint line[k][2]=x;//動(dòng)態(tài)終點(diǎn)的x坐標(biāo) line[k][3]=hh-y;//動(dòng)態(tài)終點(diǎn)的y坐標(biāo) glutPostRedisplay();}//畫線子程序voiddrawlines(){for(inti=0;i<=k;i++)//******** { glBegin(GL_LINES); glVertex2f(line[i][0],line[i][1]); glVertex2f(line[i][2],line[i][3]); glEnd(); }}鼠標(biāo)畫線程序運(yùn)行后，程序效果如圖3-3所示。圖3-33〕鼠標(biāo)繪制矩形〔將此修改代碼貼到實(shí)驗(yàn)報(bào)告中〕修改鼠標(biāo)畫線程序，要求：能夠?qū)崿F(xiàn)在繪制窗口用鼠標(biāo)交互繪制假設(shè)干矩形，鼠標(biāo)左鍵首先按下，確定矩形對角線的起始點(diǎn)，鼠標(biāo)左鍵按下同時(shí)移動(dòng)時(shí)，看到畫矩形過程，鼠標(biāo)左鍵松開，確定矩形對角線的另一點(diǎn)，可重復(fù)畫多個(gè)矩形。如圖3-4所示。圖3-44〕思考題鼠標(biāo)畫圓鼠標(biāo)畫圓應(yīng)如何修改代碼？四、參考函數(shù)：1、根本圖元函數(shù)繪制舉例1〕、點(diǎn)繪制舉例glPointSize(2.0)//點(diǎn)的大小設(shè)置glBegin(GL_POINTS);glColor3f(1.0,1.0,1.0);glVertex2f(-0.5,-0.5);//頂點(diǎn)glColor3f(1.0,0.0,1.0);glVertex2f(-0.5,0.5);glColor3f(0.0,1.0,1.0);glVertex2f(0.5,0.5);glColor3f(1.0,1.0,0.0);glVertex2f(0.5,-0.5);glEnd()2〕、直線/三角形/四邊形繪制舉例glLineWidth(2.0);glBegin(GL_LINES);//glBegin(GL_LINE_STRIP);//glBegin(GL_LINE_LOOP);//glBegin(GL_TRIANGLES);//glBegin(GL_TRIANGLE_STRIP);//glBegin(GL_TRIANGLE_FAN);//glBegin(GL_QUADS);//glBegin(GL_TRIANGLE_STRIP);glVertex2f(-0.5,0.5);glVertex2f(-0.5,-0.5);glColor3f(1.0,1.0,1.0);glVertex2f(-0.5,0.5);glColor3f(1.0,1.0,0.0);glVertex2f(0.5,-0.5);glEnd();3〕、多邊形舉例glBegin(GL_POLYGON);glVertex2f(-0.5,0.5);glVertex2f(-0.5,-0.5);glColor3f(1.0,1.0,1.0);glVertex2f(0,-0.5);glColor3f(1.0,1.0,0.0);glVertex2f(0.5,-0.5);glVertex2f(0.5,0.5);glEnd();4〕、圓的繪制1〕圓盤繪制方法GLUquadricObj*disk;//定義二次曲面對象disk=gluNewQuadric();//生成二次去面對像gluDisk(disk,0.8,1,50,50);//內(nèi)徑0.8，外徑1，盤心在原點(diǎn)2)球的繪制方法glutSolidSphere(1,80,80);//半徑為1的球，球心在原點(diǎn)glutWireSphere(1,80,80);//半徑為1的球，球心在原點(diǎn)5)裁剪窗口設(shè)置函數(shù)：gluOrtho2D(xwmin,xwmax,ywmin,ywmax);xwmin,xwmax,ywmin,ywmax為裁剪窗口在世界坐標(biāo)系的位置，分別為x最小，x最大，y最小，y最大6)視區(qū)設(shè)置函數(shù)：glViewport(startx,starty,viewport_width,viewport_height);繪圖區(qū)在顯示窗口中的位置，以屏幕坐標(biāo)系為參考startx,starty,viewport_width,viewport_height分別為繪圖區(qū)在顯示窗口的起點(diǎn)位置，以及繪圖區(qū)的寬度和高度7)鼠標(biāo)按鈕響應(yīng)相關(guān)函數(shù)voidglutMouseFunc(void(*f)(intbutton,intstate,intx,inty))Mousecallbackfunction。在主程序中調(diào)用。button:GLUT_LEFT_BUTTON,GLUT_MIDDLE_BUTTON,GLUT_RIGHT_BUTTONstate:GLUT_UP,GLUT_DOWNx,y:返回鼠標(biāo)在窗口的位置(原點(diǎn)在左上角)。例如，主程序注冊:glutMouseFunc(mymouse);voidmym