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一. 实现简述
Assignment 2 Report
目标:画一个安卓机器人。
代码结构:在 glutDisplayFunc(drawRobot)中的参数 drawRobot 函数是实 现画机器人的最外层函数,其中包括画脸、画身体、画手和画脚。每个函数又继 续细分画的步骤和方法。如下图所示:
二. 心得体会
这次任务让我对 OpenGl 有了初步认识。通过阅读课本和网上的资料,掌握
使用 OpenGl 的基本功能,比如如何画基本的点、线和多边形。并理解了一些之 前没明白的重要概念,比如 glLoadIdentity 和 glPushMatrix、glPopMatrix 的区 别。根据我现在的理解,glLoadIdentity 是将矩阵堆栈中栈顶的矩阵置为单位矩 阵,相当于坐标原点回到一开始的设置,也就忽略了之前平移、旋转等导致坐标 原点位置的改变。而 glPushMaxtrix 和 glPopMatrix 则是用于将当前矩阵压入栈 中,然后执行一些变换,这些变换是基于之前已经变换过的坐标,最后再出栈, 回到入栈前的坐标。
接下来我将继续学习 OpenGL 更多强大的功能。
#include <gl/glut.h> #include <math.h> int i; const GLfloat PI = 3.1415926536f; const int n = 1000; const GLfloat eyeR = 0.025f; //radius of eye const GLfloat faceR = 0.3f; //radius of face const GLfloat bodyR = 0.05f; //radius of the corner of body const GLfloat limbR = 0.06f; //radius of limb in both ends void drawLimb(void) { //draw a half circle at one end glBegin(GL_POLYGON); for (i = 0; i < n; i++) { glVertex2f(limbR * cos(2 * PI / n * i), limbR * sin(2 * PI / n * i)); } glEnd(); //draw a rectangle glTranslatef(-0.06f, 0.0f, 0.0f); glRectf(0.0f, 0.0f, 0.12f, -0.3f); glEnd(); //draw a half circle at the other end glTranslatef(0.06f, -0.3f, 0.0f); glBegin(GL_POLYGON); for (i = 0; i < n; i++) { glVertex2f(limbR * cos(2 * PI / n * i), limbR * sin(2 * PI / n * i)); } glEnd(); glFlush(); } void drawHands(void) { glLoadIdentity(); glTranslatef(-0.38f, 0.2f, 0.0f); drawLimb(); glLoadIdentity(); glTranslatef(0.38f, 0.2f, 0.0f); drawLimb(); } void drawBody(void) { glLoadIdentity(); //draw a rectangle first glTranslatef(-0.3f, 0.25f, 0.0f); glRectf(0.0f, 0.0f, 0.6f, -0.45f); glEnd(); //draw a half circle at the left bottom glTranslatef(0.05f, -0.45f, 0.0f); glBegin(GL_POLYGON); for (i = 0; i < n; i++) { if (sin(2 * PI / n * i) < 0) { glVertex2f(bodyR * cos(2 * PI / n * i), bodyR * sin(2 * PI / n * i)); } } glEnd(); //draw a half circle at the right bottom glTranslatef(0.5f, 0.0f, 0.0f); glBegin(GL_POLYGON); for (i = 0; i < n; i++) { if (sin(2 * PI / n * i) < 0) { glVertex2f(bodyR * cos(2 * PI / n * i), bodyR * sin(2 * PI / n * i)); } } glEnd(); //draw the bottom rectangle glRectf(0.0f, 0.0f, -0.5f, -0.05f); glEnd(); glFlush(); } void drawLegs(void) { glLoadIdentity(); glTranslatef(-0.11f, -0.08f, 0.0f); drawLimb(); glLoadIdentity(); glTranslatef(0.11f, -0.08f, 0.0f); drawLimb(); } void drawLine(void) { glLineWidth(5.0f); glBegin(GL_LINES); glVertex2f(0.0f, 0.0f); glVertex2f(0.0f, 0.15f); glEnd(); glFlush(); } void drawEye(void) { glColor3f(1.0f, 1.0f, 1.0f); glBegin(GL_POLYGON); for (i = 0; i < n; i++) { glVertex2f(eyeR * cos(2 * PI / n * i), eyeR * sin(2 * PI / n * i)); } glEnd(); glColor3ub(164, 202, 57); glFlush(); } void drawFaceShape(void) { glBegin(GL_POLYGON); for (i = 0; i < n; i++) { if (sin(2 * PI / n * i) >= 0) { glVertex2f(faceR * cos(2 * PI / n * i), faceR * sin(2 * PI / n * i)); } } glEnd(); glFlush(); } void drawFace(void) { glLoadIdentity(); glTranslatef(0.0f, 0.27f, 0.0f); drawFaceShape();//draw the overall shape of face //draw left eye glLoadIdentity(); glTranslatef(-0.13f, 0.42f, 0.0f); drawEye(); //draw right eye glLoadIdentity(); glTranslatef(0.13f, 0.42f, 0.0f); drawEye(); //draw left line glLoadIdentity(); glTranslatef(-0.13f, 0.5f, 0.0f); glRotated(30.0f, 0.0f, 0.0f, 1.0f); drawLine(); //draw right line glLoadIdentity(); glTranslatef(0.13f, 0.5f, 0.0f); glRotated(-30.0f, 0.0f, 0.0f, 1.0f); drawLine(); } void drawRobot(void) { glClearColor(1.0f, 1.0f, 1.0f, 0.0f);//set background color to white glClear(GL_COLOR_BUFFER_BIT); glLoadIdentity(); glColor3ub(164, 202, 57);//color of robot drawFace(); drawBody(); drawHands(); drawLegs(); } int main(int argc, char *argv[]) { glutInit(&argc, argv); glutInitDisplayMode(GLUT_RGB | GLUT_SINGLE); glutInitWindowPosition(100, 100); glutInitWindowSize(400, 400); glutCreateWindow("Android Robot"); glutDisplayFunc(drawRobot); glutMainLoop(); return 0; }
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原文地址：http://www.cnblogs.com/xiaovid/p/4455176.html
