蒲立年的學習筆記 Week 13

一、色彩系統

程式碼如下:

RGB模式:

size(255,255);
colorMode(RGB,255);
for(int x=0;x<255;x++)
{
    for(int y=0;y<255;y++)
    {
      stroke(x,y,255);
      point(x,y);
    }

}

HSB模式:

size(255,255);

colorMode(HSB,255);
for(int x=0;x<255;x++)
{
    for(int y=0;y<255;y++)
    {
      stroke(x,y,255);
      point(x,y);
    }

}

二、足球軌跡、等速茶壺

程式碼如下:

#include <opencv/highgui.h> ///for cvLoadImage()

#include <opencv/cv.h> ///for cvCvtColor()

#include <GL/glut.h>

#include <stdlib.h>

#include <stdio.h>

#include <math.h>

float mat[]={1,0,0,0, 0,1,0,0, 0,0,1,0, 0,0,0,1};

GLUquadric * quad;

GLuint idBall, idCanvas, idTeapot;

float ballSize=0.2;

float posX=0.5, posY=0.5, posWin=0.1;

int oldX=0, oldY=0;

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

{

    oldX=x; oldY=y;

}

double dist(float x, float y){

    return sqrt(x*x+y*y);

}

void motion(int x, int y){

    int dx=x-oldX, dy=oldY-y;

    oldX=x; oldY=y;

    glPushMatrix();

        glRotatef( dist(dx,dy)/2, dy, -dx, 0);

        glMultMatrixf(mat);

        glGetFloatv(GL_MODELVIEW_MATRIX, mat);

    glPopMatrix();

    glutPostRedisplay();

    posX+=dx/500.0*posWin;

    posY-=dy/500.0*posWin;

    static FILE * fout=NULL;

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

    fprintf(fout, "%d %d\n", dx, dy);

    static IplImage * img = NULL;

    if(img==NULL){

        img=cvLoadImage("imgCanvas.png"); ///OpenCV讀圖

    }

    int px=posX*img->width, py=posY*img->height, pdx=-(dx/200.0*posWin)*img->width, pdy=(dy/500.0*posWin)*img->height;

    cvLine(img, cvPoint(px,py), cvPoint(px+pdx, py+pdy), cvScalar(255,0,0) );

    glBindTexture(GL_TEXTURE_2D, idCanvas); ///綁定bind 貼圖ID

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT); /// 貼圖參數, 超過包裝的範圖T, 就重覆貼圖

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT); /// 貼圖參數, 超過包裝的範圖S, 就重覆貼圖

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); /// 貼圖參數, 放大時的內插, 用最近點

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); /// 貼圖參數, 縮小時的內插, 用最近點

    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, img->width, img->height, 0, GL_RGB, GL_UNSIGNED_BYTE, img->imageData);

}

void display()

{

    glEnable(GL_DEPTH_TEST); ///要啟動 Detph Test 深度值的測試,3D顯示才正確

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    glLoadIdentity();

    glPushMatrix();

        glTranslatef(0, 0.5, 0);

        glBindTexture(GL_TEXTURE_2D, idTeapot);

        glutSolidTeapot(0.3);

    glPopMatrix();

    glPushMatrix();

        glTranslatef(0,0, ballSize);

        glNormal3f(0,0,-1);

        glColor3f(1,1,1);

        glBindTexture(GL_TEXTURE_2D, idCanvas);

        glBegin(GL_POLYGON);

            glTexCoord2f(posX-posWin,posY-posWin);glVertex2f(-1,+1);

            glTexCoord2f(posX-posWin,posY+posWin);glVertex2f(-1,-1);

            glTexCoord2f(posX+posWin,posY+posWin);glVertex2f(+1,-1);

            glTexCoord2f(posX+posWin,posY-posWin);glVertex2f(+1,+1);

        glEnd();

    glPopMatrix();

    glPushMatrix();

        glMultMatrixf(mat);

        glBindTexture(GL_TEXTURE_2D, idBall);

        gluQuadricTexture(quad, 1);

        gluQuadricOrientation(quad, GLU_OUTSIDE);

        gluSphere(quad, ballSize, 30, 30);///glutSolidTeapot(0.3);

    glPopMatrix();

    glutSwapBuffers();

}

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

    if(key==27)exit(0);

}

int myTexture(char *filename)

{

    IplImage * img = cvLoadImage(filename); ///OpenCV讀圖

    cvCvtColor(img,img, CV_BGR2RGB); ///OpenCV轉色彩 (需要cv.h)

    glEnable(GL_TEXTURE_2D); ///1. 開啟貼圖功能

    GLuint id; ///準備一個 unsigned int 整數, 叫 貼圖ID

    glGenTextures(1, &id); /// 產生Generate 貼圖ID

    glBindTexture(GL_TEXTURE_2D, id); ///綁定bind 貼圖ID

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT); /// 貼圖參數, 超過包裝的範圖T, 就重覆貼圖

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT); /// 貼圖參數, 超過包裝的範圖S, 就重覆貼圖

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); /// 貼圖參數, 放大時的內插, 用最近點

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); /// 貼圖參數, 縮小時的內插, 用最近點

    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, img->width, img->height, 0, GL_RGB, GL_UNSIGNED_BYTE, img->imageData);

    return id;

}

void myLighting(){

    GLfloat light_position[] = {0,0,-1,0};

    glEnable(GL_LIGHT0);

    glEnable(GL_LIGHTING);

    glLightfv(GL_LIGHT0,GL_POSITION, light_position);

}

int main(int argc, char**argv){

    glutInit(&argc, argv);

    glutInitDisplayMode(GLUT_DOUBLE | GLUT_DEPTH);

    glutInitWindowSize(500,500);

    glutCreateWindow("roach");

    glutDisplayFunc(display);

    glutMotionFunc(motion);

    glutMouseFunc(mouse);

    glutKeyboardFunc(keyboard);

    printf("Use mouse to roll the ball and to draw trace\n");

    quad = gluNewQuadric();

    idBall = myTexture("imgBall.png");///重點:一定不可在display()讀圖檔

    idCanvas=myTexture("imgCanvas.png");///重點: 你要在main()只讀一次

    idTeapot=myTexture("idTeapot.jpg");

    myLighting();///時機點要在 glutMainLoop()之前, glutCreateWindow()之後

    glutMainLoop();

}