实验3-OpenGL基本图元绘制.doc

实验3 OpenGL基本图元绘制 7 /7实验3、OpenGL基本图元绘制系别：计算机学院 专业班级：10信科2班姓名： 学号：实验日期：2013-5-10 实验报告日期：2013-5-10一、 实验目的1熟悉VC6.0开发平台；2熟悉OpenGL开发库；二、 实验内容：1. 在同一个窗口内绘制以下图元： 用不同颜色绘制大小从1到5的5个点； 用不同颜色绘制宽度为1、3、5的三条直线段； 绘制一条包含5个顶点的折线段； 绘制一个三角形，三个顶点颜色各不相同，三角形内部用平滑方式进行填充； 绘制一个六边形；2. ，不使用反混淆绘制宽度为5的直线；启用反混淆后在不同位置绘制相同的直线，比较两者异同。 三、 一个OpenGL实例1.程序中有关画图的代码：void DrawGLScene(GLvoid)/ 此函数完成图形绘制glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);/ 清除颜色缓冲区和深度缓冲区glLoadIdentity();/ 重置当前模型视图矩阵glTranslatef(-1.5f,0.0f,0.0f);/ 向左平移50个单位glBegin(GL_TRIANGLES);/ 绘制三角形glColor3f(1.0f,0.0f,0.0f);/画笔设置为红色glVertex3f( 0.0f, 1.0f, 0.0f);glColor3f(0.0f,1.0f,0.0f);/ 设置为绿色glVertex3f(-1.0f,-1.0f, 0.0f);glColor3f(0.0f,0.0f,1.0f);/设置为蓝色glVertex3f( 1.0f,-1.0f, 0.0f);glEnd();/ 完成三角形的绘制glTranslatef(3.0f,0.0f,0.0f);/ 向右平移3个单位glColor3f(0.0f,1.0f,1.0f);/ 设为青色glBegin(GL_QUADS);/ 画四边形glVertex3f(-1.0f, 1.0f, 0.0f);glVertex3f( 1.0f, 1.0f, 0.0f);glVertex3f( 1.0f,-1.0f, 0.0f);glVertex3f(-1.0f,-1.0f, 0.0f);/glEnd();/完成四边形绘制glFlush();四、 实验报告内容1程序源码；2对主要画图函数的说明（函数的功能，参数等）。/ 图形.cpp : Defines the entry point for the console application./#include #include #include #include #define MAX 106;/如果需要记录鼠标点的位置，就定义全局变量来保存struct Point int x, y;Point pt2;int pointNum=0;/标记点号，0表示线段起点，1表示线段中点void MyDrawGLScene()/ 此函数完成图形绘制int i;float pSizes5=1.0f,2.0f,3.0f,4.0f,5.0f; /设定五个点的大小float lWidth5=1.0f,2.0f,3.0f,4.0f,5.0f; /设定五条直线的宽度glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);/ 清除颜色缓冲区和深度缓冲区glLoadIdentity();/ 重置当前模型视图矩阵glTranslatef(-1.8f,-0.1f,0.0f);/ 向左平移50个单位/ 绘制五个大小不同的的点glEnable(GL_POINT_SMOOTH); /开启反混淆for( i=0;i5;i+)/ 绘制五个大小不同的的点glPointSize(pSizesi);glTranslatef(0.1f,-0.0f,0.0f);/ 向右平移50个单位 glBegin(GL_POINTS); glColor3f(1.0f,0.0f,0.0f);/画笔设置为红色 glVertex2f(1.0f,1.0f); glEnd(); /绘制五条不同宽度的直线glTranslatef(-0.5f,-0.1f,0.0f);/ 向左平移50个单位 for(i=0;i5;i+) /绘制五条不同宽度的直线 glTranslatef(0.0f,-0.1f,0.0f); glLineWidth(lWidthi); /设定直线的宽度glBegin(GL_LINES); glColor3f(0.0f,1.0f,0.0f);/画笔设置为绿色 glVertex2f(1.0f,1.0f);glVertex2f(2.0f,1.0f);glEnd();/画五个定点的折线glTranslatef(0.0f,-0.2f,0.0f);/ 向左平移50个单位glColor3f(0.0f,0.0f,1.0f);/画笔设置为蓝色 glLineWidth(3.0f); /设定直线的宽度glBegin(GL_LINE_STRIP); /画五个定点的折线 glVertex2f(1.0f,1.0f); glVertex2f(1.2f,1.1f);glVertex2f(1.4f,1.0f);glVertex2f(1.6f,1.1f);glVertex2f(1.8f,1.0f);glEnd(); / 绘制三角形glTranslatef(1.5f,0.7f,0.0f);/ 向左平移50个单位glPolygonMode(GL_FRONT_AND_BACK,GL_FILL); /选择三角形的光栅化模式为多边形内部被填充，选用参数GL_FILLglEnable(GL_POLYGON_STIPPLE); /平滑填充三角形 glBegin(GL_TRIANGLES);glColor3f(1.0f,0.0f,0.0f);/画笔设置为红色glVertex3f( 0.0f, 0.15f, 0.0f);glColor3f(0.0f,0.5f,0.0f);/ 设置为绿色glVertex3f(-0.15f,-0.15f, 0.0f);glColor3f(0.0f,0.0f,1.0f);/设置为蓝色glVertex3f(0.15f,-0.15f, 0.0f);glEnd();/ 完成三角形的绘制 / 画正六形glTranslatef(0.5f,0.0f,0.0f);/ 向右平移0.5个单位glColor3f(0.0f,1.0f,1.0f);/ 设为青色glBegin(GL_POLYGON);glVertex3f(-0.2f, 0.0f, 0.0f);glVertex3f(-0.1f, 0.1732f, 0.0f);glVertex3f( 0.1f,0.1732f, 0.0f);glVertex3f(0.2f,0.0f, 0.0f);glVertex3f(0.1f,-0.1732f, 0.0f);glVertex3f(-0.1f,-0.1732f, 0.0f); glEnd();/完成正六边形形绘制 /使用反混淆绘制宽度为5的直线glTranslatef(-0.4f,-0.3f,0.0f);/ 向下平移0.3个单位glLineWidth(5.0f); /设定直线的宽度为5glColor3f(0.3f,0.5f,0.9f);/画笔设置为紫色glEnable(GL_LINE_SMOOTH); glBegin(GL_LINES); /使用反混淆绘制宽度为5的直线 glVertex3f(-0.5f, -0.1f, 0.0f);glVertex3f(0.5f, 0.1f, 0.0f);glEnd(); /不适用反混淆方式绘制宽度为5的直线glDisable(GL_LINE_SMOOTH); /关闭反混淆glBegin(GL_LINES); /不适用反混淆方式绘制宽度为5的直线 glVertex3f(-0.1f, -0.1f, 0.0f);glVertex3f(0.9f, 0.1f, 0.0f);glEnd();glFlush();void myDisplay()glClear(GL_COLOR_BUFFER_BIT);/画图之前先设置画图区的背景色glColor3f (1.0f, 0.0f, 0.0f);/设置前景色（相当于画笔颜色） LARGE_INTEGER Freq; LARGE_INTEGER start; LARGE_INTEGER end; QueryPerformanceFrequency(&Freq); / 获取时钟周期 if(pointNum = 2) QueryPerformanceCounter(&start); / 获取时钟计数 MyDrawGLScene();QueryPerformanceCounter(&end);printf(用时%d微秒n,(end.QuadPart-start.QuadPart)*1000000/Freq.QuadPart); glFlush();/强制刷新缓冲，保证绘图命令被立即执行void Init()glClearColor(0.0, 0.0, 0.0, 0.0);glShadeModel(GL_SMOOTH);/设置平滑颜色过渡模式（相当于在两种颜色间进行差值，想象一下线段的两个端点颜色不一样，线段中间该是什么颜色）printf(这是一个演示程序!n);/在窗口中给出提示void Reshape(int w, int h)glViewport(0, 0, (GLsizei) w, (GLsizei) h);/设置视口大小与窗口大小完全一致glMatrixMode(GL_PROJECTION);/指定当前矩阵为投影矩阵glLoadIdentity();/将投影矩阵初始化为单位矩阵gluOrtho2D(0.0, (GLdouble) w, 0.0, (GLdouble) h);/定义二维投影矩阵/自定义的键盘消息处理函数，需要在main函数中调用对应的回调函数才能起作用void keyboard(unsigned char key, int x, int y)switch (key)case c:break;case r:break;case x:exit(0);break; default: break; void mouse(int button, int state, int x, int y) /鼠标处理回调函数if (button = GLUT_LEFT_BUTTON & state = GLUT_DOWN) /如果鼠标左键按下if(pointNum = 2) pointNum=0; /重新记录线段的端点ptpointNum.x=x;/保存线段端点的横坐标ptpointNum.y=600-y;/保存线段端点的纵坐标 由于屏幕坐标的纵轴向下，而画图时坐标向上，因此需要取反pointNum+;glutPostRedisplay(); void main(int argc, char *argv)glutInit(&argc, argv);glutInitDisplayMode(GLUT_RGB | GLUT_SINGLE);gl