/*VGA256.c -- VGA 256 色编程
*/
#include "dos.h"
#include "conio.h"
#include "stdio.h"void InitScr();
void RstScr();
void PutPoint(int x, int y, int Color);
void Rect(int x1, int y1, int x2, int y2, int Color);
void LineV(int x1, int y1, int x2, int y2, int Color);int main()
{int x1, y1, x2, y2, i, j;x1 = y1 = 0;x2 = 319;y2 = 199;InitScr();for (i = 0; i < 256; i++)LineV(i, 0, i, 199, i);for( i = 18; i < 100; i++)Rect(x1++, y1++, x2--, y2--, i);for( i = 18; i < 50; i++)Rect(x1--, y1--, x2++, y2++, i);getch();RstScr();
}void InitScr()
{union REGS In;In.x.ax = 0x13;                 /*进入13H模式  */int86(0x10, &In, &In);
}void RstScr()
{union REGS In;In.x.ax = 0x03;             /* 退出13H模式 */int86(0x10, &In, &In);
}/* 直接写视频缓冲区 */
void PutPoint(int x, int y, int Color)   /* 画点函数 */
{char far *p;p = (char far *) (0x0a0000000L);* (x+y*320+p) = Color;
}/* 利用VGA BIOS中断在屏幕上画点, 速度慢
void PutPoint(int x, int y, int Color)
{union REGS  In;In.h.ah = 0x0C;In.h.al = Color;In.x.cx = x;In.x.dx = y;In.h.bh = 0;int86(0x10, &In, &In);
}
*/void LineV(int x1, int y1, int x2, int y2, int Color)  /* 画一垂直线 */
{int i;for (i = 0; i < 199; i++)PutPoint(x1, i, Color);
}void Rect(int x1, int y1, int x2, int y2, int Color)  /* 画一矩形*/
{int i;for(i = x1; i <= x2; i++){PutPoint(i, y1, Color);PutPoint(i, y2, Color);}for(i = y1; i <= y2; i++){PutPoint(x1, i, Color);PutPoint(x2, i, Color);}
}