本文模拟了一个非常简单的机器人手臂程序,具体的细节可以参照《OpenGL 编程指南》(Dava Shreiner 著)。
此手臂分为两段,手臂在肩肘或其他关节处用节点进行连接。简单的模型如下图所示。
其中,
1)按下"s“键,肩膀长方体可以绕肩关节逆时针旋转
2)按下”S“键,肩膀长方体可以绕肩关节顺时针旋转
3)按下”e“键,手臂长方体可以绕肩关节逆时针旋转
4)按下”E“键,手臂长方体可以绕肩关节顺时针旋转
代码学习时,关键点在于怎样通过坐标变换,让相应的长方体围绕不同的点就行旋转
具体代码如下:
#include
#include
static int shoulder = 0, elbow = 0;
void init(void)
{
glClearColor (0.0, 0.0, 0.0, 0.0);
glShadeModel (GL_FLAT);
}
void display(void)
{
glClear (GL_COLOR_BUFFER_BIT);
glPushMatrix();
glTranslatef (-1.0, 0.0, 0.0);
glRotatef ((GLfloat) shoulder, 0.0, 0.0, 1.0);
glTranslatef (1.0, 0.0, 0.0);
glPushMatrix();
glScalef (2.0, 0.4, 1.0);
glColor3f(1.0,0.0,0.0);
glutSolidCube(1.0);
glPopMatrix();
glTranslatef (1.0, 0.0, 0.0);
glRotatef ((GLfloat) elbow, 0.0, 0.0, 1.0);
glTranslatef (1.0, 0.0, 0.0);
glPushMatrix();
glScalef (2.0, 0.4, 1.0);
glColor3f(0.0,0.0,1.0);
glutSolidCube(1.0);
glPopMatrix();
glPopMatrix();
glutSwapBuffers();
}
void reshape (int w, int h)
{
glViewport (0, 0, (GLsizei) w, (GLsizei) h);
glMatrixMode (GL_PROJECTION);
glLoadIdentity ();
gluPerspective(65.0, (GLfloat) w/(GLfloat) h, 1.0, 20.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glTranslatef (0.0, 0.0, -5.0);
}
void keyboard (unsigned char key, int x, int y)
{
switch (key) {
case 's':
shoulder = (shoulder + 5) % 360;
glutPostRedisplay();
break;
case 'S':
shoulder = (shoulder - 5) % 360;
glutPostRedisplay();
break;
case 'e':
elbow = (elbow + 5) % 360;
glutPostRedisplay();
break;
case 'E':
elbow = (elbow - 5) % 360;
glutPostRedisplay();
break;
case 27:
exit(0);
break;
default:
break;
}
}
int main(int argc, char** argv)
{
glutInit(&argc, argv);
glutInitDisplayMode (GLUT_DOUBLE | GLUT_RGB);
glutInitWindowSize (500, 500);
glutInitWindowPosition (100, 100);
glutCreateWindow (argv[0]);
init ();
glutDisplayFunc(display);
glutReshapeFunc(reshape);
glutKeyboardFunc(keyboard);
glutMainLoop();
return 0;
}