week03 - 移動

 

一、老師帶大家載資料，並呈現車子的模型

老師的網站網址(https://jsyeh.org/3dcg10/)

data.zip、win32、glut32.dll

二、簡單的移動

#include <GL/glut.h>

void display()

{

    glPushMatrix();///備份矩陣

        glTranslatef(0.5,0,0);///只有這行還不夠

        glutSolidTeapot(0.3);

    glPopMatrix();///還原矩陣

    glutSwapBuffers();

}

int main(int argc, char *argv[])

{

    glutInit(&argc, argv);

glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);

glutCreateWindow("GLUT Shapes");

    glutDisplayFunc(display);

    glutMainLoop();

}

三、使用mouse函式

#include <stdio.h>

void mouse(int botton,int state,int x,int y)

{///請mouse函式幫忙

    printf("%d %d %d %d\n",botton,state,x,y);

}

float X=0,Y=0;///利用global變數,在函數之間傳值(大寫的)

///#include <stdio.h>

void mouse(int botton,int state,int x,int y)

{///請mouse函式幫忙

    X = (x-150)/150.0;///printf("%d %d %d %d\n",botton,state,x,y);

    Y = -(y-150)/150.0;///口訣:減一半、除一半、y負號

}

最後執行時可以使用滑鼠來讓茶壺移動

#include <GL/glut.h>

float X=0,Y=0;///利用global變數,在函數之間傳值(大寫的)

void display()

{

    glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );///清背景

    glPushMatrix();///備份矩陣

        glTranslatef(X,Y,0);///只有這行還不夠

        glutSolidTeapot(0.3);

    glPopMatrix();///還原矩陣

    glutSwapBuffers();

}

///#include <stdio.h>

void mouse(int botton,int state,int x,int y)

{///請mouse函式幫忙

    X = (x-150)/150.0;///printf("%d %d %d %d\n",botton,state,x,y);

    Y = -(y-150)/150.0;///口訣:減一半、除一半、y負號

}

int main(int argc, char *argv[])

{

    glutInit(&argc, argv);

glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);

glutCreateWindow("GLUT Shapes");

    glutDisplayFunc(display);

    glutMouseFunc(mouse);

    glutMainLoop();

}

四、用上面的mouse函式把第二週的作業做出來

void display()

{

    glBegin(GL_POLYGON);

    glVertex2f(-0.540, 0.468);

    glVertex2f(-0.544, -0.404);

    glVertex2f(0.584, -0.388);

    glVertex2f(0.444, 0.612);

    glEnd();

    glutSwapBuffers();

}

#include <GL/glut.h>

#include <stdio.h>

void display()

{

    glBegin(GL_POLYGON);

    glVertex2f(-0.540, 0.468);

    glVertex2f(-0.544, -0.404);

    glVertex2f(0.584, -0.388);

    glVertex2f(0.444, 0.612);

    glEnd();

    glutSwapBuffers();

}

void mouse(int botton,int state,int x,int y)

{

    float X = (x-250)/250.0;

    float Y = -(y-250)/250.0;///口訣:減一半、除一半、y負號

    if(state==GLUT_DOWN){

        printf("    glVertex2f(%.3f, %.3f);\n", X, Y);

    }

}

int main(int argc, char *argv[])

{

    glutInit(&argc, argv);

glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);

glutInitWindowSize(500,500);

glutCreateWindow("GLUT Shapes");

    glutDisplayFunc(display);

    glutMouseFunc(mouse);

    glutMainLoop();

}