week04_mouse_glScalef 凱

 week04

## glscalef

1.下載課本範例 https://jsyeh.org/3dcg10/

2. data,win32

3. windows.zip = >

4.data.zip =>

5.試 glscalef(x,y,z) 

## week04_mouse_glscalef  (綠色茶壺)

1.安裝freeglut,同時把lib\libfreeglut.a 複製成 libglut32.a

2.flie-new-project, glut 專案

## week04_mouse_glscalef  (按著活數可以移動,變大變小)

1. 程式碼

#include <GL/glut.h>

float s = 1;///一開始是原本的1倍

void display()

{///設定 "清背景" 顏色

    glClearColor(1,1,0.9,1);///顏色R,G,B,A

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

    glColor3f(0,1,0);///3F就是R,G,B

    glPushMatrix();///備份矩陣

            glScalef(s,s,s);///縮放s倍

            glutSolidTeapot( 0.3 );

    glPopMatrix();

    glutSwapBuffers();

}

void motion(int x,int y)

{

    s = 1 + (x-150)/150.0;///會變大變小的變數 0-1

    display();

}

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

{

    glutInit(&argc, argv);

    glutInitDisplayMode(GLUT_DOUBLE | GLUT_DEPTH);

    glutCreateWindow("week04_mouse_glScalef");

    glutDisplayFunc(display);

    glutMotionFunc(motion);

    glutMainLoop();

}

##試著交換 translate/rotate 兩航程式 i

1.試一下課本範例 transformation

2.先把 translate 移到右方,再rotate看看

3.下方程式,按右鍵,可 swap translate/rotate交換

4. translate是公轉 rotate是自轉

##理解的技巧 

1.把左耳 "靠著" 左肩，在看程式碼(從下往上看)

2.把 "旋轉中，長胖的藍色的車子" 移到右邊去

##week04_translate_rotate_scale

1.file_new_ project, GLUT專案  week04_translate_rotate_scale

2.把剛剛的week04_mouse_glScalef 程式

3.整個 "旋轉中的縮很小的綠色茶壺" 

##week04_rotate_translate_scale (茶壺轉圈圈) => 逆時針 

1.程式碼

#include <GL/glut.h>

float teapotX = 0.5,teapotY = 0;

float angle = 0;

float s = 0.3;///一開始是原本的1倍

void display()

{///設定 "清背景" 顏色

    glClearColor(1,1,0.9,1);///顏色R,G,B,A

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

    glColor3f(0,1,0);///3F就是R,G,B

    glPushMatrix();///備份矩陣

        glRotatef(angle++,0,0,1);

        glTranslatef(teapotX,teapotY,0);

        glScalef(s,s,s);///縮放s倍

        glutSolidTeapot( 0.3 );

    glPopMatrix();

    glutSwapBuffers();

}

void motion(int x,int y)

{

    s = 1 + (x-150)/150.0;///會變大變小的變數 0-1

    display();

}

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

{

    glutInit(&argc, argv);

    glutInitDisplayMode(GLUT_DOUBLE | GLUT_DEPTH);

    glutCreateWindow("week04_mouse_glScalef");

    glutIdleFunc(display);

    glutDisplayFunc(display);

    glutMotionFunc(motion);

    glutMainLoop();

}

##week04_keyboard_mouse_motion 

1.file-new-project, GLUT專案  week04_keyboard_mouse_motion

2. 程式碼

#include <GL/glut.h>

#include <stdio.h>

void display()

{

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    glutSolidTeapot( 0.3 );

    glutSwapBuffers();

}

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

    printf("key:%c  x:%d  y:%d\n",key,x,y);

}

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

{

    glutInit(&argc, argv);

    glutInitDisplayMode(GLUT_DOUBLE | GLUT_DEPTH);

    glutCreateWindow("week04_keyboard_mouse_motion");

    glutDisplayFunc(display);

    glutKeyboardFunc(keyboard);

    glutMainLoop();

}

1-2 (按滑鼠自動貼上茶壺)

2. 程式碼

#include <GL/glut.h>

#include <stdio.h>

int N = 0;

float teapotX[1000],teapotY[1000];

void display()

{

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    for(int i=0; i<N; i++){

        glPushMatrix();

            glTranslatef(teapotX[i],teapotY[i],0);

            glutSolidTeapot( 0.1 );

        glPopMatrix();

    }

    glutSwapBuffers();

}

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

    printf("key:%c  x:%d  y:%d\n",key,x,y);

}

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

    teapotX[N] = (x-150)/150.0;

    teapotY[N] = -(y-150)/150.0;

    N++;

}

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

{

    glutInit(&argc, argv);

    glutInitDisplayMode(GLUT_DOUBLE | GLUT_DEPTH);

    glutCreateWindow("week04_keyboard_mouse_motion");

    glutDisplayFunc(display);

    glutKeyboardFunc(keyboard);

    glutMouseFunc(mouse);

    glutMainLoop();

}