# Week06
電腦圖學之父 Ivan Sutherland (Sketchpad)
看課本範例
jsyeh.org/3dcg10 下載 windows.zip data.zip
windows.zip => 下載\windows\Transformation.exe
data.zip => 下載\windows\data\3D模型
執行 Transformation.exe
下方可以右鍵 Swap Translate/Rotate
自轉 vs. 公轉
# step01-3
接下來, 今天的主題是keyboard, 我們利用 GLUT 來寫今天的程式, 能 有keyboard互動, 重點是 glutKeyboardFunc(keyboard) 可以註冊 void keyboard(unsigned char key, int x, int y) 這個函式,再配合 stdio.h 的 printf()印出鍵盤的值
實作時間
Maya: qwer
w:移動 e:轉動 r:縮放
0. 安裝 freeglut, lib改一下
1. File-New-Project, GLUT
week06_keyboard
2. 接下來, 從上週 blog 複製我們的程式來用。
多了3行程式, 分別是
int main() 裡 glutCreateWindow()之後
`glutKeyboardFunc(keyboard);`
前面要宣告 `int keyboard(unsigned char key, int x, int y)` 的鍵盤函式
## step01-3
接下來, 今天的主題是keyboard, 我們利用 GLUT 來寫今天的程式, 能 有keyboard互動, 重點是 glutKeyboardFunc(keyboard) 可以註冊 void keyboard(unsigned char key, int x, int y) 這個函式,再配合 stdio.h 的 printf()印出鍵盤的值
```C++
///從上週 blog 貼我們的程式
#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("現在按下:%c 座標在:%d %d\n", key, x, y);
}
int main(int argc, char**argv)
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DOUBLE | GLUT_DEPTH);
glutCreateWindow("week06 keyboard");
glutDisplayFunc(display);
glutKeyboardFunc(keyboard);
glutMainLoop();
}
```
# step02-1
接下來我們稍做修改,除了剛剛的keyboard()函式, 我們再加上 mouse() 及 motion()函式, 希望能完整互動
```C++
#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("現在按下:%c 座標在:%d %d\n", key, x, 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("week06 keyboard mouse motion");
glutDisplayFunc(display);
glutKeyboardFunc(keyboard);
glutMouseFunc(mouse);
glutMotionFunc(motion);
glutMainLoop();
}
```
## step02-2
上上週有教glTranslatef()移動, 我們把它做出來
```C++
#include <GL/glut.h>
#include <stdio.h>
float x=0, y=0, z=0, oldX, oldY;
void display()
{
glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
glPushMatrix();
glTranslatef( (x-150)/150.0 , -(y-150)/150.0 , z ); ///Maya: w
///glRotatef( angle, 0, 0, 1);
///glScalef( scale, scale, scale );
glColor3f( 1, 1, 0 );
glutSolidTeapot(0.3);
glPopMatrix();
glutSwapBuffers();
}
void keyboard( unsigned char key, int mouseX, int mouseY )
{
printf("現在按下:%c 座標在:%d %d\n", key, mouseX, mouseY);
}
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("week06 keyboard mouse motion");
glutDisplayFunc(display);
glutKeyboardFunc(keyboard);
glutMouseFunc(mouse);
glutMotionFunc(motion);
glutMainLoop();
}
```
## step02-3
接下來我們實作出「縮放」的程式,利用 float scale=1.0 這個變數,如果 if(mousX大於oldX)就讓 scale 放大 1%, 反過來就讓 scale 變小 1%, 我們就可以完成這個縮放的版本
```C++
#include <GL/glut.h>
#include <stdio.h>
float x=0, y=0, z=0, scale=1.0, oldX, oldY;
void display()
{
glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
glPushMatrix();
//glTranslatef( (x-150)/150.0 , -(y-150)/150.0 , z ); ///Maya: w
///glRotatef( angle, 0, 0, 1);
glScalef( scale, scale, scale ); ///Maya: r
glColor3f( 1, 1, 0 );
glutSolidTeapot(0.3);
glPopMatrix();
glutSwapBuffers();
}
void keyboard( unsigned char key, int mouseX, int mouseY )
{
printf("現在按下:%c 座標在:%d %d\n", key, mouseX, mouseY);
}
void mouse( int button, int state, int mouseX, int mouseY )
{
oldX = mouseX; oldY = mouseY;
}
void motion( int mouseX, int mouseY )
{
if( mouseX>oldX ) scale = scale * 1.01;
if( mouseX<oldX ) scale = 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("week06 keyboard mouse motion");
glutDisplayFunc(display);
glutKeyboardFunc(keyboard);
glutMouseFunc(mouse);
glutMotionFunc(motion);
glutMainLoop();
}
```
## step03-1
今天的主角是keyboard鍵盤函式, 我們 if(key=='w' 或 key=='W') now=1做移動, if(key=='r' 或 key=='R')now=3 做縮放。接下來在 motion()裡, if(now==1)做移動的計算, if(now==3)做縮放的計算, 這樣就可以又移動、又縮放了
```C++
#include <GL/glut.h>
#include <stdio.h>
float x=150, y=150, z=0, scale=1.0, angle=0.0, oldX, oldY;
int now=1;///1:移動, 2:旋轉, 3:縮放
void display()
{
glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
glPushMatrix();
glTranslatef( (x-150)/150.0 , -(y-150)/150.0 , z ); ///Maya: w
//glRotatef( angle, 0, 0, 1); ///Maya: e
glScalef( scale, scale, scale ); ///Maya: r
glColor3f( 1, 1, 0 );
glutSolidTeapot(0.3);
glPopMatrix();
glutSwapBuffers();
}
void keyboard( unsigned char key, int mouseX, int mouseY )
{ //printf("現在按下:%c 座標在:%d %d\n", key, mouseX, mouseY);
if(key=='w' || key=='W') now=1;///移動 (小心不要中文)
//if(key=='e' || key=='E') now=2;///旋轉
if(key=='r' || key=='R') now=3;///縮放
}
void mouse( int button, int state, int mouseX, int mouseY )
{
oldX = mouseX; oldY = mouseY;
}
void motion( int mouseX, int mouseY )
{
if(now==1){///移動
x += (mouseX-oldX);
y += (mouseY-oldY);
}else if(now==3){///縮放
if( mouseX>oldX ) scale = scale * 1.01;
if( mouseX<oldX ) scale = scale * 0.99;
}
oldX = mouseX; oldY = mouseY;
display();
}
int main(int argc, char**argv)
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DOUBLE | GLUT_DEPTH);
glutCreateWindow("week06 keyboard mouse motion");
glutDisplayFunc(display);
glutKeyboardFunc(keyboard);
glutMouseFunc(mouse);
glutMotionFunc(motion);
glutMainLoop();
}
```
## step03-2
今天最後的任務,是加上旋轉。所以用keyboard的 w,e,r 來切換移動、旋轉、縮放。motion()裡面也有對應的程式, display()也會照著進行 glTranslatef() glRotatef() glScalef() 的程式。我們還多學了 glutInitWindowSize(500,500)放大, 導致 glTranslatef()裡面減一半、除一半的地方有修改。.zip
```C++
#include <GL/glut.h>
#include <stdio.h>
float x=250, y=250, z=0, scale=1.0, angle=0.0, oldX, oldY;
int now=1;///1:移動, 2:旋轉, 3:縮放
void display()
{
glClearColor(0.5, 0.5, 0.5, 1);///用來 Clear的色彩 R,G,B,A Alpha沒用到
glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
glPushMatrix();
glTranslatef( (x-250)/250.0 , -(y-250)/250.0 , z ); ///Maya: w
glRotatef( angle, 0, 0, 1); ///Maya: e
glScalef( scale, scale, scale ); ///Maya: r
glColor3f( 1, 1, 0 );
glutSolidTeapot(0.3);
glPopMatrix();
glutSwapBuffers();
}
void keyboard( unsigned char key, int mouseX, int mouseY )
{ //printf("現在按下:%c 座標在:%d %d\n", key, mouseX, mouseY);
if(key=='w' || key=='W') now=1;///移動 (小心不要中文)
if(key=='e' || key=='E') now=2;///旋轉
if(key=='r' || key=='R') now=3;///縮放
}
void mouse( int button, int state, int mouseX, int mouseY )
{
oldX = mouseX; oldY = mouseY;
}
void motion( int mouseX, int mouseY )
{
if(now==1){///移動
x += (mouseX-oldX);
y += (mouseY-oldY);
}else if(now==2){///旋轉
angle += (mouseX-oldX);
}else if(now==3){///縮放
if( mouseX>oldX ) scale = scale * 1.01;
if( mouseX<oldX ) scale = scale * 0.99;
}
oldX = mouseX; oldY = mouseY;
display();
}
int main(int argc, char**argv)
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DOUBLE | GLUT_DEPTH);
glutInitWindowSize(500, 500);
glutCreateWindow("week06 keyboard mouse motion");
glutDisplayFunc(display);
glutKeyboardFunc(keyboard);
glutMouseFunc(mouse);
glutMotionFunc(motion);
glutMainLoop();
}
```
去https://jsyeh.org/3dcg10/下載window.zip data.zip
