電腦圖學筆記_week05

去https://jsyeh.org/3dcg10/網頁裡下載data和win32

打開transformation.exe後試著調整glScalef的數值

開啟codeblocks，貼上之前的程式碼並且稍作修改，加上keyboard函式。

按下鍵盤任一按鍵，會顯示按下的鍵和目前滑鼠所在的位置座標。

#include <GL/glut.h>

#include <stdio.h>

void display()

{

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    glColor3f(1,1,0);///黃色的

    glutSolidTeapot(0.3);///茶壺

    glutSwapBuffers();

}

void keyboard(unsigned char key,int x,int y)

{

    printf("你按下了 %c 在 %d %d 座標\n",key,x,y);

}

int main(int argc,char** argv)

{

    glutInit(&argc,argv);

    glutInitDisplayMode(GLUT_DOUBLE|GLUT_DEPTH);

    glutCreateWindow("week05");

    glutDisplayFunc(display);

    glutKeyboardFunc(keyboard);

    glutMainLoop();

}

接續剛剛的程式碼改成keyboard+mouse+motion

#include <GL/glut.h>

#include <stdio.h>

void display()

{

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    glColor3f(1,1,0);///黃色的

    glutSolidTeapot(0.3);///茶壺

    glutSwapBuffers();

}

void keyboard(unsigned char key,int x,int y)

{

}

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

{

}

void motion(int x,int y)

{

}

int main(int argc,char** argv)

{

    glutInit(&argc,argv);

    glutInitDisplayMode(GLUT_DOUBLE|GLUT_DEPTH);

    glutCreateWindow("week05");

    glutDisplayFunc(display);

    glutKeyboardFunc(keyboard);

    glutMouseFunc(mouse);

    glutMotionFunc(motion);

    glutMainLoop();

}

再加上motion的程式碼讓茶壺能夠跟著滑鼠移動。

#include <GL/glut.h>

#include <stdio.h>

float x=0,y=0,z=0;

int oldX=0,oldY=0;

void display()

{

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    glPushMatrix();

        glTranslatef((x-150)/150.0,-(y-150)/150.0,z);

        glColor3f(1,1,0);///黃色的

        glutSolidTeapot(0.3);///茶壺

    glPopMatrix();

    glutSwapBuffers();

}

void keyboard(unsigned char key,int x,int y)

{

}

void mouse(int button,int state,int mouseX,int mouseY)

{

}

void motion(int mouseX,int mouseY)

{

    x+= (mouseX-oldX);y+=(mouseY-oldY);

    oldX=mouseX; oldY=mouseY;

    display();

}

int main(int argc,char** argv)

{

    glutInit(&argc,argv);

    glutInitDisplayMode(GLUT_DOUBLE|GLUT_DEPTH);

    glutCreateWindow("week05");

    glutDisplayFunc(display);

    glutKeyboardFunc(keyboard);

    glutMouseFunc(mouse);

    glutMotionFunc(motion);

    glutMainLoop();

}

然後我們改良程式碼，讓茶壺不會在滑鼠點下去的時候瞬間移動。

並且加上背景顏色的程式碼glClearColor()

#include <GL/glut.h>

#include <stdio.h>

float x=150,y=150,z=0;

int oldX=0,oldY=0;

void display()

{

    glClearColor(0.5,0.5,0.5,1);///R,G,B,A 其中A半透明功能，目前沒開

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    glPushMatrix();

        glTranslatef((x-150)/150.0,-(y-150)/150.0,z);

        glColor3f(1,1,0);///黃色的

        glutSolidTeapot(0.3);///茶壺

    glPopMatrix();

    glutSwapBuffers();

}

void keyboard(unsigned char key,int x,int y)

{

}

void mouse(int button,int state,int mouseX,int mouseY)

{

    oldX=mouseX;oldY=mouseY;

}

void motion(int mouseX,int mouseY)

{

    x+= (mouseX-oldX);y+=(mouseY-oldY);

    oldX=mouseX; oldY=mouseY;

    display();

}

int main(int argc,char** argv)

{

    glutInit(&argc,argv);

    glutInitDisplayMode(GLUT_DOUBLE|GLUT_DEPTH);

    glutCreateWindow("week05");

    glutDisplayFunc(display);

    glutKeyboardFunc(keyboard);

    glutMouseFunc(mouse);

    glutMotionFunc(motion);

    glutMainLoop();

}

我們可以透過scale數值來調整茶壺大小。

如果往右邊拉，oldX就會大於0，此時我們就把scale*1.01讓茶壺放大

如果往左邊拉，oldX就會小於0，此時我們就把scale*0.99讓茶壺縮小

#include <GL/glut.h>

#include <stdio.h>

float x=150,y=150,z=0,scale=1.0;

int oldX=0,oldY=0;

void display()

{

    glClearColor(0.5,0.5,0.5,1);///R,G,B,A 其中A半透明功能，目前沒開

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    glPushMatrix();

        glTranslatef((x-150)/150.0,-(y-150)/150.0,z);

        glScalef(scale,scale,scale);///都縮放成scale倍

        glColor3f(1,1,0);///黃色的

        glutSolidTeapot(0.3);///茶壺

    glPopMatrix();

    glutSwapBuffers();

}

void keyboard(unsigned char key,int x,int y)

{

}

void mouse(int button,int state,int mouseX,int mouseY)

{

    oldX=mouseX;oldY=mouseY;

}

void motion(int mouseX,int mouseY)

{

    if(mouseX-oldX>0)scale*=1.01;

    if(mouseX-oldX<0)scale*=0.99;

   ///x+= (mouseX-oldX);y+=(mouseY-oldY);

    oldX=mouseX; oldY=mouseY;

    display();

}

int main(int argc,char** argv)

{

    glutInit(&argc,argv);

    glutInitDisplayMode(GLUT_DOUBLE|GLUT_DEPTH);

    glutCreateWindow("week05");

    glutDisplayFunc(display);

    glutKeyboardFunc(keyboard);

    glutMouseFunc(mouse);

    glutMotionFunc(motion);

    glutMainLoop();

}