電腦圖學筆記_week05

 1. jsyeh.org/3dcg10

    windows.zip => 下載\windows\Transformation.exe

    data.zip => 下載\windows\data\模型

    下面區域，可以交換2行程式碼(移動、轉動)會有自轉、通公轉的效果。

2. 介紹完 移動、旋轉、縮放 對應Maya qwer鍵

2.1 先把 freeglut裝改lib\libglut32.a

2.2 File-New-Project ，新的GLUT專案

2.3 把每次的10行copy上來

#include <GL/glut.h>

#include <stdio.h>

void display()

{

    glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);

    glColor3f(1,1,0);

    glutSolidTeapot(0.3);

    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 keyboard");

    glutDisplayFunc(display);

    glutKeyboardFunc(keyboard);

    glutMainLoop();

}

接續剛剛的week05_keyboard我們新增一個專案，叫week_keyboard_mouse_motion在裡面複習本的keyboard()，上上周的mouse()，上週的motion()

#include <GL/glut.h>

#include <stdio.h>

void display()

{

    glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);

    glColor3f(1,1,0);

    glutSolidTeapot(0.3);

    glutSwapBuffers();

}

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

{

}

void mouse(int botton,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 keyboard");

    glutDisplayFunc(display);

    glutKeyboardFunc(keyboard);

    glutMouseFunc(mouse);

    glutMotionFunc(motion);

    glutMainLoop();

}

先做移動的部分，只利用motion裡面，配合x+=(mouseX-oldX)及y+=(mouseY-oldY)並更新oldX=mouseX;oldY=mouseY;來讓x及y可以正確增減。最後我們利用減一半、除一半、y要倒過來的公式，完成移動的任務，其中display()裡面還要有glPushMatrix()備份矩陣 及glPopMatrix()還原矩陣。

#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);

        glutSolidTeapot(0.3);

    glPopMatrix();

    glutSwapBuffers();

}

void keyboard(unsigned char key,int mouseX, int mouseY)

{

}

void mouse(int botton,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 keyboard");

    glutDisplayFunc(display);

    glutKeyboardFunc(keyboard);

    glutMouseFunc(mouse);

    glutMotionFunc(motion);

    glutMainLoop();

}

剛剛只用motion其實有問題，有點不連續，因此，用上週教在mouse()裡面設定oldX=mouseX;oldY=mouseY;去記錄下按下mouse時的位置，才能相對移動正確。

#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);

    glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);

    glPushMatrix();

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

        glColor3f(1,1,0);

        glutSolidTeapot(0.3);

    glPopMatrix();

    glutSwapBuffers();

}

void keyboard(unsigned char key,int mouseX, int mouseY)

{

}

void mouse(int botton,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 keyboard");

    glutDisplayFunc(display);

    glutKeyboardFunc(keyboard);

    glutMouseFunc(mouse);

    glutMotionFunc(motion);

    glutMainLoop();

}

#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);

    glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);

    glPushMatrix();

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

        glScalef(scale,scale,scale);

        glColor3f(1,1,0);

        glutSolidTeapot(0.3);

    glPopMatrix();

    glutSwapBuffers();

}

void keyboard(unsigned char key,int mouseX, int mouseY)

{

}

void mouse(int botton,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;

    oldX=mouseX; oldY=mouseY;

    display();

}

int main(int argc,char**argv)

{

    glutInit(&argc, argv);

    glutInitDisplayMode(GLUT_DOUBLE|GLUT_DEPTH);

    glutCreateWindow("week05 keyboard");

    glutDisplayFunc(display);

    glutKeyboardFunc(keyboard);

    glutMouseFunc(mouse);

    glutMotionFunc(motion);

    glutMainLoop();

}