翁驊成的學習筆記 week 03

week 03 補充程式範例&Vertex Buffer/Array

step 1.學姊的小小兵程式範例

#include <GL/glut.h>

#include <stdio.h>

//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 | GL_DEPTH_BUFFER_BIT);

  //Read pixel file //讀檔

  //注意:minion.txt須放到freeglut\bin裡

  

  f = fopen("minion.txt", "r");

  //Read width, height, channel

  fscanf(f, "%f %f %f", &w, &h, &c);

  //Set point size

  glPointSize(10.0f); //放大10倍

  //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); //用這個程式會慢

      //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); //是b,g,r喔!

      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;

}

step 2.足球的程式範例

1.下載3D exploration

2.到http://www.cmlab.csie.ntu.edu.tw/~jsyeh/3dcg10/網站下載圖並拉進3D exploration

3.選SampleAPP

4.建立OpenGL專案並把原本的main從.c檔改成.cpp檔

5.貼上3D足球的程式碼(把會當的地方改掉)

6.完成並執行