Code Talker Week14 Timer 內插

 STEP  01

1.先下載git，避免當機

2.打開一個glut專案，打上程式碼:

#include <GL/glut.h>

float angle=0;

void display()

{

    glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);

glPushMatrix();

        glRotatef(angle, 0, 0, 1);

        glutSolidTeapot(0.3);

    glPopMatrix();

glutSwapBuffers();

}

void timer(int t)

{

    glutTimerFunc(500, timer, t+1);

    angle += 90;//增加90度

    glutPostRedisplay();//重畫畫面

}

int main(int argc, char** argv)

{

    glutInit(&argc, argv);

    glutInitDisplayMode(GLUT_DOUBLE | GLUT_DEPTH);

    glutCreateWindow("Week14");

    glutDisplayFunc(display);

    glutTimerFunc(2000, timer, 0);

    glutMainLoop();

}

執行結果:

等待2秒...

轉了90度

STEP 02

1.修改上述程式碼，將glutTimerFunc(2000, timer, 0);註解掉，加上glutKeyboardFunc(keyboard);

2.加上程式碼，告訴他keyboard要做甚麼 

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

{

    glutTimerFunc(0, timer, 0);

}

3.執行結果:按下空白鍵，即可使茶壺開始旋轉

STEP 03

1.打開excel，建立欄位時間t，alpha，新角度，舊角度，現在的角度，如圖:

2.對現在的角度欄位套用公式，公式如圖中

STEP 04

1.建立一個新專案

2.將剛才的14-2複製過來用，加上mouse()和motion()

3.將程式碼修改如下:

#include <GL/glut.h>

float angle=0, oldAngle=0, newAngle=0;

void display()

{

    glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);

glPushMatrix();

        glRotatef(angle, 0, 0, 1);

        glutSolidTeapot(0.3);

    glPopMatrix();

glutSwapBuffers();

}

void timer(int t)

{

    if(t<100) glutTimerFunc(50, timer, t+1);

    float alpha = t/100.0;

    angle = newAngle*alpha + (1-alpha) * oldAngle;

    glutPostRedisplay();//重畫畫面

}

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

{

    glutTimerFunc(0, timer, 0);

}

void motion(int x, int y)

{

    angle = x;

    glutPostRedisplay();

}

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

{

    if(state==GLUT_DOWN) oldAngle = x;//按下去

    if(state==GLUT_UP) newAngle = x;//放開來

    glutPostRedisplay();

}

int main(int argc, char** argv)

{

    glutInit(&argc, argv);

    glutInitDisplayMode(GLUT_DOUBLE | GLUT_DEPTH);

    glutCreateWindow("Week14");

    glutDisplayFunc(display);

    glutMouseFunc(mouse);

    glutMotionFunc(motion);

    glutKeyboardFunc(keyboard);

    glutMainLoop();

}

4.執行結果:

用滑鼠按著轉動茶壺，藉由按著放開，獲得新角度和舊角度，再按下空白鍵，使茶壺旋轉至滑鼠調整的位置

STEP  05

1.打開final_project

2.將程式碼修改如下:

#include <stdio.h>

#include <GL/glut.h>

#include "glm.h"

GLMmodel * head = NULL;

GLMmodel * body = NULL;

GLMmodel * uparmR = NULL;

GLMmodel * lowarmR = NULL;

int show[4] = {1, 1, 1, 1};

int ID=0;//0頭1身2上手臂3下手臂

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

    if(key=='0') ID=0;

    if(key=='1') ID=1;

    if(key=='2') ID=2;

    if(key=='3') ID=3;

    ///if(key=='0') show[0] = !show[0];

    ///if(key=='1') show[1] = !show[1];

    ///if(key=='2') show[2] = !show[2];

    ///if(key=='3') show[3] = !show[3];

    glutPostRedisplay();

}

FILE * fout = NULL;

FILE * fin = NULL;

float teapotX=0, teapotY=0;

float angle=0, angle2=0, angle3=0;

void display()

{

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    glPushMatrix();

        glScalef(0.2, 0.2, 0.2);

        if(body==NULL){

            body = glmReadOBJ("model/body.obj");

            head = glmReadOBJ("model/head.obj");

            uparmR = glmReadOBJ("model/uparmR.obj");

            lowarmR = glmReadOBJ("model/lowarmR.obj");

            //glmUnitize(body);

        }

        if(ID==0) glColor3f(1,0,0);

        else glColor3f(1,1,1);

        if(show[0]) glmDraw(head, GLM_MATERIAL);

        if(ID==1) glColor3f(1,0,0);

        else glColor3f(1,1,1);

        if(show[1]) glmDraw(body, GLM_MATERIAL);

        glPushMatrix();

            glTranslatef(teapotX, teapotY, 0);

            if(ID==2) glColor3f(1,0,0);

        else glColor3f(1,1,1);

            if(show[2]) glmDraw(uparmR, GLM_MATERIAL);

        glPopMatrix();

        if(ID==3) glColor3f(1,0,0);

        else glColor3f(1,1,1);

        if(show[3]) glmDraw(lowarmR, GLM_MATERIAL);

    glPopMatrix();

    glutSwapBuffers();

}

int oldX = 0, oldY = 0;

void motion(int x, int y){

    teapotX += (x - oldX)/150.0;

    teapotY -= (y - oldY)/150.0;

    oldX = x;

    oldY = y;

    printf("glTranslatef(%f, %f, 0);\n", teapotX, teapotY);

    glutPostRedisplay();

}

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

{

    if(state==GLUT_DOWN){

        teapotX = (x-150)/150.0;

        teapotY = (150-y)/150.0;

        if(fout==NULL) fout = fopen("file4.txt","w");

        fprintf(fout, "%f %f\n", teapotX, teapotY);

    }

    display();

}

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

//{

//    if(fin==NULL){

//        fclose(fout);

//        fin = fopen("file4.txt","r");

//    }

//    fscanf(fin, "%f %f", &teapotX, &teapotY);

//    display();

//}

int main(int argc, char *argv[])//main()主函式 進階版

{

    glutInit(&argc,argv);//把參數送給glutInit初始化

    glutInitDisplayMode(GLUT_DOUBLE|GLUT_DEPTH);//雙緩衝區+3D深度功能

    glutCreateWindow("week12");//開GLUT視窗

    glutDisplayFunc(display);//顯示用的函式

    glutMouseFunc(mouse);

    glutMotionFunc(motion);

    glutKeyboardFunc(keyboard);

    glutMainLoop();

}

讓選取的部分變紅色

STEP  06

1.將上面程式碼備份