從0到0.01的電腦圖學 Week05

本週主題：Texture貼圖 

a. OpenCV讀圖、秀圖

b. OpenGL貼圖

c. glTexCoord2f(tx,ty); 貼圖座標

教材地點：
https://jsyeh.org/3dcg10/

下載資料：
    a. 05/04 Examples:[data]
    b. 05/04 Examples:[win32]

上課用軟體(OpenCV)地點：

a. moodle→電腦圖學→上課用軟體→OpenCV-2.1.0-win32-vs2008.exe

    note：

    1. 選項請選擇Add OpenCV to ... PATH

    2. 安裝請安裝在預設目錄中(C:\OpenCV2.1)

    3. 安裝完成後，重開CodeBlocks

    4. 設定 Settings-Compiler 要加入3個設定

        4-1. search 目錄 Compiler 的 include 目錄 加 C:\OpenCV2.1\include

        4-2. search 目錄 Linker 的 lib 目錄 加 C:\OpenCV2.1\lib

        4-3. 加入Linker 設定的 3個檔名 cv210 cxcore210 highgui210

1. openCV程式1：讀取圖片與開啟圖片

img中放入圖片的目錄

#include <opencv/highgui.h>
int main(){
    IplImage * img = cvLoadImage("C:/Users/Administrator/Desktop/images.jpg");
    cvShowImage("week05",img);
    cvWaitKey(0);
}

2. 範例程式碼：將data資料夾拉進windows(不要解壓縮)
    windows→Texture

3. GLUT+openCV程式1：整合測試(可以開啟茶壺+自訂圖片)

#include <GL/glut.h>
#include <opencv/highgui.h>
void display(){
    glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
    glutSolidTeapot(0.5);
    glutSwapBuffers();
}
int main(int argc,char*argv[]){
    IplImage * img = cvLoadImage("C:/Users/Administrator/Desktop/images.jpg");
    cvShowImage("opencv",img);
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
    glutCreateWindow("week05");
    glutDisplayFunc(display);
    glutMainLoop();
}

4. GLUT+openCV程式2：

請參考使用教授的程式碼：https://gist.github.com/jsyeh/5ed01210559721ec71b659b3ffed2dd7
找到myTexture.cpp(下段綠色畫線處程式碼)

#include <opencv/highgui.h> ///使用 OpenCV 2.1 比較簡單, 只要用 High GUI 即可
#include <opencv/cv.h>
#include <GL/glut.h>
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 display(){
    glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
    glutSolidTeapot(0.5);
    glutSwapBuffers();
}
int main(int argc,char*argv[]){
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
    glutCreateWindow("week05");
    glutDisplayFunc(display);
    myTexture("C:/Users/Administrator/Desktop/images.jpg");
    glutMainLoop();
}

5. GLUT+openCV程式3：

#include <opencv/highgui.h> ///使用 OpenCV 2.1 比較簡單, 只要用 High GUI 即可
#include <opencv/cv.h>
#include <GL/glut.h>
int myTexture(char * filename)
{
    IplImage * img = cvLoadImage(filename);
    cvCvtColor(img,img, CV_BGR2RGB);
    glEnable(GL_TEXTURE_2D);
    GLuint id;
    glGenTextures(1, &id);
    glBindTexture(GL_TEXTURE_2D, id);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, img->width, img->height, 0, GL_RGB, GL_UNSIGNED_BYTE, img->imageData);
    return id;
}
void display(){
    glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
    glBegin(GL_POLYGON);
        glTexCoord2f(0,0); glVertex2f(-1,-1);
        glTexCoord2f(0,1); glVertex2f(-1,+1);
        glTexCoord2f(1,1); glVertex2f(+1,+1);
        glTexCoord2f(1,0); glVertex2f(+1,-1);
    glEnd();
    //glutSolidTeapot(0.5);
    glutSwapBuffers();
}
int main(int argc,char*argv[]){
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
    glutCreateWindow("week05");
    glutDisplayFunc(display);
    myTexture("C:/Users/Administrator/Desktop/images.jpg");
    glutMainLoop();
}

6. GLUT+openCV程式4：旋轉的地球

#include <opencv/highgui.h>
#include <opencv/cv.h>
#include <GL/glut.h>
GLUquadric * quad = NULL; ///建立空指標
int myTexture(char * filename)
{
    IplImage * img = cvLoadImage(filename);
    cvCvtColor(img,img, CV_BGR2RGB);
    glEnable(GL_TEXTURE_2D);
    GLuint id;
    glGenTextures(1, &id);
    glBindTexture(GL_TEXTURE_2D, id);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, img->width, img->height, 0, GL_RGB, GL_UNSIGNED_BYTE, img->imageData);
    return id;
}
float angle = 0;
void display(){
    glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
    glEnable(GL_DEPTH_TEST);
    glPushMatrix();
        glRotatef(90,1,0,0);
        glRotatef(angle+=1.5,0,0,1);
        gluSphere(quad,1,30,30);
    glPopMatrix();
    glutSwapBuffers();
}
int main(int argc,char*argv[]){
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
    glutCreateWindow("week05");
    glutIdleFunc(display);
    glutDisplayFunc(display);
    myTexture("C:/Users/Administrator/Desktop/earth.jpg");
    quad = gluNewQuadric(); ///把指標設置好
    gluQuadricTexture(quad,1); ///做好地球的貼圖
    glutMainLoop();
}

When the snow falls and you're in pain

Do you think that the white color of the cold snow would turn red

Into a wonderful bed of roses

Are my eyes closed?

If they open,

Will they see that the sky is in the color of blue and not gray

Or am I inside a cage so broken?

Wilt , VerseQuence