1、計(jì)算機(jī)圖形學(xué)基礎(chǔ)實(shí)驗(yàn)2、OpenGL實(shí)現(xiàn)橡皮筋技術(shù)班級(jí)：計(jì)科1101姓名：康磊學(xué)號(hào)：2011110709一、實(shí)驗(yàn)?zāi)康募耙?. 掌握橡皮筋技術(shù)的實(shí)現(xiàn)原理和方法；2. 掌握OpenGL的雙緩存技術(shù)；3. 掌握OpenGL中鼠標(biāo)的使用方法；4. 掌握OpenGL中鍵盤(pán)的使用方法；二、實(shí)驗(yàn)環(huán)境主要是軟件開(kāi)發(fā)環(huán)境：VC 6.0三、實(shí)驗(yàn)內(nèi)容1、OpenGL中利用鼠標(biāo)實(shí)現(xiàn)橡皮筋技術(shù)的例子。2、OpenGL中利用鍵盤(pán)實(shí)現(xiàn)橡皮筋技術(shù)的例子。3、OpenGL實(shí)現(xiàn)拾取操作的例子，演示拾取操作的過(guò)程，其中拾取窗口的寬度和高度都設(shè)置為10。四、實(shí)驗(yàn)結(jié)果1、利用鼠標(biāo)實(shí)現(xiàn)橡皮筋技術(shù)的結(jié)果：2、利于鍵盤(pán)實(shí)現(xiàn)橡皮筋技術(shù)的結(jié)果

2、：3、實(shí)現(xiàn)拾取操作的例子結(jié)果：五、程序代碼1、利用鼠標(biāo)實(shí)現(xiàn)橡皮筋技術(shù)#include <gl/glut.h>int iPointNum = 0; /已確定點(diǎn)的數(shù)目int x1=0,x2=0,y1=0,y2=0; /確定的點(diǎn)坐標(biāo)int winWidth = 400, winHeight = 300; /窗口的寬度和高度void Initial(void)glClearColor(1.0f, 1.0f, 1.0f, 1.0f); void ChangeSize(int w, int h)winWidth = w;winHeight = h;glViewport(0, 0, w, h);

3、 /指定窗口顯示區(qū)域glMatrixMode(GL_PROJECTION); /設(shè)置投影參數(shù)glLoadIdentity();gluOrtho2D(0.0,winWidth,0.0,winHeight);void Display(void)glClear(GL_COLOR_BUFFER_BIT);glColor3f(1.0f, 0.0f, 0.0f); if(iPointNum >= 1)glBegin(GL_LINES); /繪制直線段glVertex2i(x1,y1);glVertex2i(x2,y2);glEnd();glutSwapBuffers(); /交換緩沖區(qū)void Mo

4、usePlot(GLint button, GLint action, GLint xMouse, GLint yMouse)if(button = GLUT_LEFT_BUTTON && action = GLUT_DOWN)if(iPointNum = 0 | iPointNum = 2)iPointNum = 1;x1 = xMouse;y1 = winHeight - yMouse;else iPointNum = 2;x2 = xMouse;y2 = winHeight - yMouse;glutPostRedisplay(); /指定窗口重新繪制if(button=

5、GLUT_RIGHT_BUTTON&&action = GLUT_DOWN)iPointNum = 0;glutPostRedisplay();void PassiveMouseMove (GLint xMouse, GLint yMouse)if(iPointNum = 1)x2 = xMouse;y2 = winHeight - yMouse;glutPostRedisplay();int main(int argc, char* argv)glutInit(&argc, argv);glutInitDisplayMode(GLUT_DOUBLE | GLUT_RG

6、B); /使用雙緩存及RGB模型glutInitWindowSize(400,300); glutInitWindowPosition(100,100);glutCreateWindow("橡皮筋技術(shù)"); glutDisplayFunc(Display); glutReshapeFunc(ChangeSize); /指定窗口在整形回調(diào)函數(shù)glutMouseFunc(MousePlot); /指定鼠標(biāo)響應(yīng)函數(shù)glutPassiveMotionFunc(PassiveMouseMove); /指定鼠標(biāo)移動(dòng)響應(yīng)函數(shù)Initial(); glutMainLoop(); retur

7、n 0;2、利于鍵盤(pán)實(shí)現(xiàn)橡皮筋技術(shù)#include <gl/glut.h>int iPointNum = 0; /已確定點(diǎn)的數(shù)目int x1=0,x2=0,y1=0,y2=0; /確定的點(diǎn)坐標(biāo)int winWidth = 400, winHeight = 300; /窗口的寬度和高度void Initial(void)glClearColor(1.0f, 1.0f, 1.0f, 1.0f); void ChangeSize(int w, int h)winWidth = w;winHeight = h;glViewport(0, 0, w, h); /指定窗口顯示區(qū)域glMatri

8、xMode(GL_PROJECTION); /設(shè)置投影參數(shù)glLoadIdentity();gluOrtho2D(0.0,winWidth,0.0,winHeight);void Display(void)glClear(GL_COLOR_BUFFER_BIT);glColor3f(1.0f, 0.0f, 0.0f); if(iPointNum >= 1)glBegin(GL_LINES); /繪制直線段glVertex2i(x1,y1);glVertex2i(x2,y2);glEnd();glutSwapBuffers(); /交換緩沖區(qū)void PassiveMouseMove (G

9、Lint xMouse, GLint yMouse)if(iPointNum = 1)x2 = xMouse;y2 = winHeight - yMouse;glutPostRedisplay();void Key(unsigned char key, int x, int y)switch(key)case 'p':if(iPointNum = 0 | iPointNum = 2)iPointNum = 1;x1 = x;y1 = winHeight - y;elseiPointNum = 2;x2 = x;y2 = winHeight - y;glutPostRedispl

10、ay();break;default: break;int main(int argc, char* argv)glutInit(&argc, argv);glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB); /使用雙緩存及RGB模型glutInitWindowSize(400,300); glutInitWindowPosition(100,100);glutCreateWindow("橡皮筋技術(shù)"); glutDisplayFunc(Display); glutReshapeFunc(ChangeSize); /指定窗口在整形

11、回調(diào)函數(shù)glutKeyboardFunc(Key); /指定鍵盤(pán)響應(yīng)函數(shù)glutPassiveMotionFunc(PassiveMouseMove); /指定鼠標(biāo)移動(dòng)響應(yīng)函數(shù)Initial(); glutMainLoop(); return 0;3、實(shí)現(xiàn)拾取操作的例子#include <gl/glut.h>#include "stdio.h"const GLint pickSize = 32;int winWidth = 400, winHeight = 300;void Initial(void)glClearColor(1.0f, 1.0f, 1.0f,

12、1.0f); void DrawRect(GLenum mode)if(mode = GL_SELECT) glPushName(1); /壓入堆棧glColor3f(1.0f,0.0f,0.0f);glRectf(60.0f,50.0f,150.0f,150.0f);if(mode = GL_SELECT) glPushName(2); /壓入堆棧glColor3f(0.0f,1.0f,0.0f);glRectf(230.0f,50.0f,330.0f,150.0f);if(mode = GL_SELECT) glPushName(3); /壓入堆棧glColor3f(0.0f,0.0f,1

13、.0f);glRectf(140.0f,140.0f,240.0f,240.0f);void ProcessPicks(GLint nPicks, GLuint pickBuffer)GLint i;GLuint name, *ptr;printf("選中的數(shù)目為%d個(gè)n",nPicks);ptr=pickBuffer;for(i=0;i<nPicks; i+)name=*ptr; /選中圖元在堆棧中的位置ptr+=3; /跳過(guò)名字和深度信息ptr+=name-1; /根據(jù)位置信息獲得選中的圖元名字if(*ptr=1) printf("你選擇了紅色圖元n&q

14、uot;);if(*ptr=2) printf("你選擇了綠色圖元n");if(*ptr=3) printf("你選擇了藍(lán)色圖元n");ptr+;printf("nn");void ChangeSize(int w, int h)winWidth = w;winHeight = h;glViewport(0, 0, w, h);glMatrixMode(GL_PROJECTION); glLoadIdentity();gluOrtho2D(0.0,winWidth,0.0,winHeight);void Display(void)gl

15、Clear(GL_COLOR_BUFFER_BIT);DrawRect(GL_RENDER);glFlush();void MousePlot(GLint button, GLint action, GLint xMouse, GLint yMouse)GLuint pickBufferpickSize;GLint nPicks, vp4;if(button = GLUT_LEFT_BUTTON && action = GLUT_DOWN)glSelectBuffer(pickSize,pickBuffer); /設(shè)置選擇緩沖區(qū)glRenderMode(GL_SELECT);

16、/激活選擇模式glInitNames(); /初始化名字堆棧glMatrixMode(GL_PROJECTION);glPushMatrix();glLoadIdentity();glGetIntegerv(GL_VIEWPORT, vp);/定義一個(gè)10×10的選擇區(qū)域gluPickMatrix(GLdouble(xMouse), GLdouble(vp3-yMouse),10.0,10.0,vp);gluOrtho2D(0.0,winWidth,0.0,winHeight);DrawRect(GL_SELECT);/恢復(fù)投影變換glMatrixMode(GL_PROJECTION);glPopMatrix();glFlush();/獲得選擇集并輸出nPicks = glRenderMode(GL_RENDER);ProcessPicks(nPicks, pickBuffer);glutPostRedisplay();int main(int argc, char* argv)glutInit(&argc, argv);glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB); glutInitWindowSize(400,300); glutIn