ex14.c

NEO SDK是一个跨平台的免费开源图形软件开发包。它支持基本绘图、多种格式图形显示、鼠标操 作、扩展内存和扩充内存的操作、时钟、音频播放、多种字体的汉字及英文显示等等特性；更激动人心的是

/* 
   Example program for the NEO SDK, by Dong Kai.
   http://neosdk.91i.net
   [e-mail]
   
   演示如何使用兼容Borland Graphics的函数集,它所绘制出来的是
   分形图——羊齿页效果
*/

#include <math.h>
#include <stdlib.h>

/*开启对graphics.h的兼容模式*/
#define NEO_hi_graphics_h_used

#include "neo.h"

void main(void)
{
   int ran_number;
   float a, b, c, d, e, f;
   float x, y, x_pre, y_pre;
   float disp_x, disp_y;

   neo_init();
   install_keyboard();
   setgraphmode(0x101);
   randomize();
   setbkcolor(BLUE);
   setcolor(14);
   x = y = x_pre = y_pre = 0;
   ran_number = 90;
   while (!keypressed())
   {
      ran_number = random(100) + 1;
      if (ran_number == 1)
      {
         a = 0;
         b = 0;
         c = 0;
         d = 0.15;
         e = 0;
         f = 0;
      }
      else if (ran_number > 1 && ran_number <= 86)
      {
         a = 0.87;
         b = 0.014;
         c = -0.014;
         d = 0.87;
         e = 0;
         f = 1.6;
      }
      else if (ran_number > 86 && ran_number <= 93)
      {
         a = 0.26;
         b = 0.472;
         c = 0.772;
         d = 0.34;
         e = 0;
         f = 1.6;
      }
      else
      {
         a = 0.28;
         b = 0.867;
         c = -0.478;
         d = 0.4;
         e = 0;
         f = 0.44;
      }
      x = a * x_pre * cos(b) - d * sin(c) * y_pre + e;
      y = c * x_pre * sin(b) + d * cos(c) * y_pre + f;
      x_pre = x;
      y_pre = y;
      disp_x = (x + 5) * 639 / 12;
      disp_y = 350 - y * 28;
      putpixel((int)disp_x, (int)disp_y, GREEN);
   }
   readkey();
   readkey();
   closegraph();
}