Week03

 

(1) 主題 : 點、線、面

開啟檔案(week01)如下圖

(2)親手打造第GLUT程式
更改面程式碼如下:

void display()
{
    glBegin(GL_POLYGON);///凸多邊形
        glColor3f( 1, 0, 0 );glVertex2f(1,0);
        glColor3f( 0, 1, 0 );glVertex2f(-1,1);
        glColor3f( 0, 0, 1 );glVertex2f(-1,-1);
glEnd();
glutSwapBuffers();


}
如圖所示:

如要改成點程式碼如下:
void display()
{
    glBegin(GL_POINT);
        glColor3f( 1, 0, 0 );glVertex2f(0.9,0);
        glColor3f( 0, 1, 0 );glVertex2f(-0.9,0.9);
        glColor3f( 0, 0, 1 );glVertex2f(-0.9,-0.9);
glEnd();
glutSwapBuffers();

}

如圖所示:

如要改成線程式碼如下:

void display()
{
    glBegin(GL_LINE_LOOP);
        glColor3f( 1, 0, 0 );glVertex2f(0.9,0);
        glColor3f( 0, 1, 0 );glVertex2f(-0.9,0.9);
        glColor3f( 0, 0, 1 );glVertex2f(-0.9,-0.9);
glEnd();
glutSwapBuffers();

}

如圖所示:

(3)實作

#include <GL/glut.h>

void display()

{

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );

    glutSolidTeapot( 0.3 );//實心茶壺

    glutSwapBuffers();

}

int main(int argc, char *argv[])///也可以打**argv蘋果電腦

{

    glutInit(&argc, argv);

    glutInitDisplayMode( GLUT_DOUBLE | GLUT_DEPTH);

    glutCreateWindow("Week03 ");

    glutDisplayFunc(display);

    glutMainLoop();

}

執行如下圖:

如上圖所示要加上色彩只需多打一行程式碼:glColor3f(1,0,0);

void display()
{
        glColor3f(1,0,0);///紅色
glutSolidTeapot( 0.3 );
glutSwapBuffers();

}

*glColor3f(0.5,1,0.3);///綠色