肯尼斯的學習筆記 Week 3

學習學姐的程式

程式碼：

//Drawing funciton

void draw(void)

{

  FILE *f;

  float w, h, c;

  float r, g, b;

  float i, j, x, y;

  //Background color

  glClearColor(0,0,0,1);

  glClear(GL_COLOR_BUFFER_BIT);

  //Read pixel file

  f = fopen("minion.txt", "r");

  //Read width, height, channel

  fscanf(f, "%f %f %f", &w, &h, &c);

  //Set point size

  glPointSize(10.0f);

  //Begin drawing

  glBegin(GL_POINTS);

  for(i=0; i<w; i++){

    for(j=0; j<h; j++){

      //Read r, g, b

      fscanf(f, "%f %f %f", &r, &g, &b);

      //Geometric transformation

      x = -(i-(w/2.0))/(w/2.0);

      y = (j-(h/2.0))/(h/2.0);

      //Draw(in python, read as bgr)

      glColor3f(b/255.0, g/255.0, r/255.0);

      glVertex3f(y, x, 0);

    }

  }

  //End drawing

  glEnd();

  fclose(f);

  

  //Draw order

  glutSwapBuffers();

}

//Main program

int main(int argc, char **argv)

{

  glutInit(&argc, argv);

  //Simple buffer

  glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE| GLUT_DEPTH);

  glutInitWindowPosition(50,25);

  glutInitWindowSize(300, 300);

  glutCreateWindow("minion");

  //Call to the drawing function

  glutDisplayFunc(draw);

  glutMainLoop();

  return 0;

}

*將minion.txt放進freeglut\bin中

建立3D圖案的程式

1. 下載3D Exploration並安裝

2. 上網任意下載一個3D圖形 (https://free3d.com/)，並在3D Exploration中開啟

3. 再另存新檔為cpp Open GL code類型，下一部的Export Type要設成Sample APP

4. 開啟CodeBlocks建立OpenGL project，再將cpp檔加入

5. 嘗試執行程式，會發生錯誤

6. 刪掉老舊的程式

7. 再次執行就會成功了