在opengl中缩放

我的代码的工作原理如下：绘制一个三角形，然后单击“1”时，缩放三角形，但是发生的是三角形缩放和平移。在opengl中缩放

这里是我的代码：全局变量

#include <glut.h> 

void Display(void); 
void MyKeyboard(unsigned char,int,int); 
void MyMouse(int,int,int,int); 

int x1 =20 .0f; 
int y1 = 30.0f; 
int x2 = 40.0f; 
int y2 = 50.0f; 
int x3 = 60.0f; 
int y3 = 10.0f;

主要方法

void main(int argc,char** argr) 
{ 
glutInit(&argc,argr); 
glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB); 
glutInitWindowSize(1000,600); 
glutInitWindowPosition(50,50); 
glutCreateWindow("Mouse and Keyboard"); 
glutDisplayFunc(Display); 
glutKeyboardFunc(MyKeyboard); 
glutMouseFunc(MyMouse); 
glClearColor(0.0f,0.0f,0.0f,0.0f); 
gluOrtho2D(0.0,1000.0,0.0,600.0); 
glutMainLoop(); 
}

显示方法

void Display() 
{ 
glClear(GL_COLOR_BUFFER_BIT); 
glPushMatrix(); 

    glBegin(GL_TRIANGLES); 
    glColor3f(0.0f,0.0f,1.0f); 

    glVertex3f(x1, 600-y1, 0.0f); 
    glVertex3f(x2, 600-y2, 0.0f); 
    glVertex3f(x3, 600-y3, 0.0f); 

    glEnd(); 
    glPopMatrix(); 
    glFlush(); 
}

键盘事件

void MyKeyboard(unsigned char key,int mouseX,int mouseY) 
{ 
    if (key == '1') 
    { 
     glScaled (0.5f ,0.5f ,1.0f); 
     glutPostRedisplay(); 
     return; 
    }

来源

2012-09-26 ahmed