画笔 pencil

 

/**/ /*************************************************************************************
      
作者:钟云德

     creat at 2006.3.30
      没有使用 graphics.h 库文件的图象模式
在MyTC 中编译通过
*************************************************************************************/
#include  < stdio.h >
#include  < dos.h >
#include  < ctype.h >
#include  < conio.h >
#include  < math.h >

 
void  setmode( int );
void  palet( int );
void  point( int  X, int  Y, int  color);
void  line( int  X1, int  Y1, int  X2, int  Y2, int  color);
void  boX( int  X1, int  Y1, int  X2, int  Y2, int  color);
void  fillboX( int  X1, int  Y1, int  X2, int  Y2, int  color);
int   getkey( void );
void  Xhair( int  X, int  Y);

void  main()
... {
    union ...{
        char c[2];
        int i;
    }key;
    int X=10,Y=10,cc=2,onflag=1,palnum=1;
    
    int X1=0,Y1=0,X2=10,Y2=150,firstpoint=1;
    int d=1;
    setmode(4);
    palet(0);
    Xhair(X,Y);
    do...{
        key.i=getkey();
        Xhair(X,Y);
        if(!key.c[0])     /**//* 控制画线的方向 */
            switch(key.c[1])...{
                case 75:if(onflag) line(X,Y,X,Y-d,cc); /**//*   LEFT  */
                Y-=d;
                break;
                case 77:if(onflag) line(X,Y,X,Y+d,cc);/**//*   RIGHT  */
                Y+=d;
                break;
                case 72:if(onflag) line(X,Y,X-d,Y,cc);/**//*    UP    */
                X-=d;
                break;
                case 80:if(onflag) line(X,Y,X+d,Y,cc);/**//*    DOWN  */
                X+=d;
                break;
                case 71:if(onflag) line(X,Y,X-d,Y+d,cc);/**//*HOME-UP LEFT*/
                Y+=d;  X-=d;
                break;
                case 73:if(onflag) line(X,Y,X-d,Y+d,cc);/**//*PGUP-UP RIGHT*/
                Y-=d;  X+=d;
                break;
                case 79:if(onflag) line(X,Y,X+d,Y-d,cc);/**//*END-DOWN LEFT*/
                Y-=d;  X+=d;
                break;
                case 81:if(onflag) line(X,Y,X+d,Y+d,cc);/**//*PGUP-DOWN RIGHT*/
                Y+=d;  X+=d;
                break;
                case 59:                               /**//*    F1    */
                d=1;
                break;
                case 60:                               /**//*    F2    */
                d=5;
                break;
            }
        else
            switch(tolower(key.c[0])) ...{
                case 'o':/**//*字母‘o ’,brush on_off,控制画笔的抬起落下*/
                onflag=!onflag;
                break;
                case '1':/**//*color 1：浅蓝*/
                cc=1;
                break;
                case '2':/**//*color 2：紫红*/
                cc=2;
                break;
                case '3':/**//*color 3：白  */
                cc=3;
                break;
                case '0':/**//*color 0:黑（背景色）*/
                cc=0;
                break;
                
                case 'b':/**//*set box*/
                boX(X1,Y1,X2,Y2,cc);
                break;
                case 'f':/**//*set fill box*/
                fillboX(X1,Y1,X2,Y2,cc);
                break;
                case 'l':/**//*set line*/
                line(X1,Y1,X2,Y2,cc);
                break;
                case 'r':/**//* set endpoint */
                if(firstpoint)...{X1=X; Y1=Y; }
                else ...{X2=X; Y2=Y;}
                firstpoint =!firstpoint; /**//* 使firstpoint在真假值之间变化，设置范围的两点*/
                break;
                case 'p':/**//*set color */
                palnum =palnum==1?2:1;
                palet(palnum);
                break;
            }
     Xhair(X,Y);
    }while(key.c[0]!='q');  /**//*退出*/
    getch();
    
    setmode(2);
}

void  setmode( int  mode)
... {
    union REGS regs;
    regs.h.al=mode;
    regs.h.ah=0;
    int86(0x10,&regs,&regs);
}

void  palet( int  pn)
... {
    union REGS regs;
    regs.h.bh =1;
    regs.h.bl=pn;
    regs.h.al=11;
    int86(0x10,&regs,&regs);
}

void  point( int  X, int  Y, int  color)
... {
    union...{
        char cc[2];
        int i;
    } mask;
    int i,index,posit;
    unsigned char t;
    char Xor;
    char far *ptr=(char far*)0Xb8000000;  /**//* 对不同模型的显示器的首地址取值不同                       */
                                          /**//* 控制屏幕单色显示的开始地址是0xB0000，彩色显示的是0xB8000 */
                                          /**//* b8000h~bffffh为80×25彩色字符模式的显示缓冲区，
                                             向此地址写入数据，写入的内容立即出现在屏幕上             */
    mask.i=0xff3f;
    if(X<0||X>199||Y<0||Y>319) return;
    Xor=color&128;
    color=color&127;
    posit=Y%4;
    color<<=2*(3-posit );
    mask.i>>=2*posit;
    index=X*40+(Y/4);
    if(X%2) index+=8152;
    if(!Xor) ...{
        t=*(ptr+index)&mask.cc[0];
        *(ptr+index)=t | color;
    }
    else...{
        t=*(ptr+index) | (char)0;
        *(ptr+index)=t ^ color;
    }
}

void  line( int  X1, int  Y1, int  X2, int  Y2, int  color)
... {
    register int t,dis;  
    int Xerr=0,Yerr=0,dX,dY;
    int incX,incY;
    dX=X2-X1;
    dY=Y2-Y1;

    if(dX>0) incX=1;
    else if(dX==0) incX=0;
    else incX =-1;
    if(dY>0) incY=1;
    else if(dY==0) incY=0;
    else incY =-1;
    dX=abs(dX);      
    dY=abs(dY);
    /**//*dis=dX<dY?dY:dX;*/
    dis=(int)hypot(dX,dY); /**//* modify at 2006.4.8 */
    /**//*已知直角三角形两个直角边长度，求斜边长度hypot(double x, double y) */
    for(t=0;t<dis+1;t++)...{
        point(X1,Y1,color);
        Xerr+=dX;
        Yerr+=dY;
        if(Xerr>dis)...{
            Xerr-=dis;
            X1+=incX;
        }
        if(Yerr>dis)...{
            Yerr-=dis;
            Y1+=incY;
        }
    }
}

void  boX( int  X1, int  Y1, int  X2, int  Y2, int  color)
... {
    line(X1,Y1,X2,Y1,color);
    line(X1,Y1,X1,Y2,color);
    line(X1,Y2,X2,Y2,color);
    line(X2,Y1,X2,Y2,color);
}

void  fillboX( int  X1, int  Y1, int  X2, int  Y2, int  color)
... {
    register int i,begin,end;
    begin=X1<X2? X1:X2;
    end=X1>X2? X1:X2;
    for(i=begin;i<=end;i++) 
      line(i,Y1,i,Y2,color);
}

void  Xhair( int  X, int  Y)
... {
    line(X-4,Y,X+3,Y,1|128);
    line(X,Y+4,X,Y-3,1|128);
}

int  getkey( void )
... {
    union REGS regs;
    regs.h.ah=0;
    return int86(0x16,&regs,&regs);
}