蓝天白云图

蓝天白云图

以下采用随机函数产生点的颜色，输出到屏幕缓冲区中，得到较迷幻的图象蓝天白云图的程序：

#include <stdio.h>
#include <dos.h>
#include <math.h>
long Addr[768];
int Mode;
Set_Mode (int mode)
{
union REGS r;
r.h.ah=0;
r.h.al=mode;
int86 (0x10,&r,&r);
}
Set_Graphics_Mode (unsigned x,unsigned y)
{
long i;
if ((x<321)&&(y<201)) {
Set_Mode (0x13);
Mode=0x13;
for (i=0;i<200;i++) Addr[i]=320*i;
}
else if ((x<641)&&(y<401)) {
Set_Mode (0x5c);
Mode=0x5c;
for (i=0;i<400;i++) Addr[i]=640*i;
}
else if ((x<641)&&(y<481)) {
Set_Mode (0x5d);
Mode=0x5d;
for (i=0;i<480;i++) Addr[i]=640*i;
}
else if ((x<641)&&(y<481)) {
Set_Mode (0x5d);
Mode=0x5d;
for (i=0;i<480;i++) Addr[i]=640*i;
}
else if ((x<801)&&(y<601)) {
Set_Mode (0x5e);
Mode=0x5e;
for (i=0;i<600;i++) Addr[i]=800*i;
}
else if ((x<1025)&&(y<769)) {
Set_Mode (0x62);
Mode=0x62;
for (i=0;i<768;i++) Addr[i]=1024*i;
}
else {
Set_Mode (3);
printf ("Not support this mode ./n");
getch ();
}
}
set_pattern ()
{
int i;
unsigned char pat[256][3];
struct SREGS inreg;
union REGS reg;
pat[0][0]=0;pat[0][1]=0;pat[0][2]=0;
for (i=1;i<=255;i++) {
pat[i][0]=(unsigned char)((float)(abs(i-127)*63)/127.0+0.5);
pat[i][1]=(unsigned char)((float)(abs(i-127)*63)/127.0+0.5);
pat[i][2]=63;
}
reg.x.ax=0x1012;
reg.x.bx=0;
reg.x.cx=256;
reg.x.dx=FP_OFF(pat);
inreg.es=FP_SEG(pat);
int86x (0x10,&reg,&reg,&inreg);
}
plot (int x,int y,unsigned char color)
{
long offset;
char Page;
unsigned char far *address;
switch (Mode) {
case 0x13:
offset=Addr[y]+x;
address=(unsigned char far *)(0xa0000000L+offset);
*address=color;
break;
case 0x5c:
case 0x5d:
case 0x5e:
offset=Addr[y]+x;
Page=(offset>>16);
outportb (0x3c4,0xe);
outportb (0x3c5,Page^0x02);
offset=offset&65535;
address=(unsigned char far *)(0xa0000000L+offset);
*address=color;
break;
case 0x62:
offset=Addr[y]+x;
Page=y>>6;
outportb (0x3c4,0xe);
outportb (0x3c5,Page^0x02);
offset=offset&65535;
address=(unsigned char far *)(0xa0000000L+offset);
*address=color;
break;
default:
break;
}
}
get_pixel (int x,int y)
{
long offset;
char Page;
unsigned char far *address;
unsigned char color;
switch (Mode) {
case 0x13:
offset=Addr[y]+x;
address=(unsigned char far *)(0xa0000000+offset);
color=*address;
break;
case 0x5c:
case 0x5d:
case 0x5e:
offset=Addr[y]+x;
Page=(offset>>16);
outportb (0x3c4,0xe);
outportb (0x3c5,Page^0x02);
offset=offset&65535;
address=(unsigned char far *)(0xa0000000L+offset);
color=*address;
break;
case 0x62:
offset=Addr[y]+x;
Page=y>>6;
outportb (0x3c4,0xe);
outportb (0x3c5,Page^0x02);
offset=offset&65535;
address=(unsigned char far *)(0xa0000000L+offset);
color=*address;
break;
default:
break;
}
return (color);
}
randint (unsigned int range)
{
float sigma=423.1966;
static double OldRand=0.4231967;
double temp;
temp=sigma*OldRand;
OldRand=temp-(int)temp;
return (int)(OldRand*(float)range);
}
void New_Col (int xa,int ya,int x,int y,int xb,int yb)
{
unsigned int color;
color=abs(xa-xb)+abs(ya-yb);
color=randint(color<<1)-color;
color=color+(get_pixel(xa,ya)+get_pixel(xb,yb)+1)>>1;
if (color<1) color=1;
else if (color>255) color=255;
if ((get_pixel(x,y)==0)) plot (x,y,color);
}
void Sub_Divide (int x1,int y1,int x2,int y2)
{
int x,y;
unsigned char color;
if (!((x2-x1<2)&&(y2-y1<2))) {
x=(x1+x2)>>1;
y=(y1+y2)>>1;
New_Col (x1,y1,x,y1,x2,y1);
New_Col (x2,y1,x2,y,x2,y2);
New_Col (x1,y2,x,y2,x2,y2);
New_Col (x1,y1,x1,y,x1,y2);
color=(get_pixel(x1,y1)+get_pixel(x2,y1)+get_pixel(x2,y2)+get_pixel (x1,y2)+2)>>2;
plot (x,y,color);
Sub_Divide (x1,y1,x,y);
Sub_Divide (x,y1,x2,y);
Sub_Divide (x,y,x2,y2);
Sub_Divide (x1,y,x,y2);
}
}
main ()
{
int x,y;
x=320;y=200;
Set_Graphics_Mode (x,y);
set_pattern ();
plot (0,0,randint(254)+1);
plot (x-1,0,randint(254)+1);
plot (x-1,y-1,randint(254)+1);
plot (0,y-1,randint(254)+1);
Sub_Divide (0,0,x-1,y-1);
getch();
Set_Mode (0x03);
}