Category : C Source Code
Archive   : C--EX100.ZIP
Filename : BOUNCE.C--

/*
SPHINX C-- Example File
NAME: BOUNCE.C--
DESCRIPTION: This program demonstrates VGA palette cycling, with
bouncing lines and boxes, and several fancy methods of
clearing the screen.
RUNFILE SIZE: 2136 bytes.
NOTE: 80286 or greater CPU required, and MCGA, VGA or better graphics
card required.
*/

? print "Building BOUNCE.COM, a VGA bouncing line demo. 80286+ required.\n"

? assumeDSSS TRUE // assume DS == SS
? stack 4096 // set stack size
? resize TRUE // resize program memory block
? use80286 // use 80286 instruction optimization
? parsecommandline FALSE // don't bother parsing the command line parameters

?include "KEYCODES.H--" // get k_esc definition
?include "VIDEO.H--" // get video mode definitions
?include "VGA.H--" // get video mode 19 graphics procedures
?include "WRITE.H--" // get WRITESTR procedure
?include "RANDOM.H--" // get RAND procedure
?include "DOS.H--" // get EXIT procedure

?define CHANGE_RANGE 2 /* random range of palette change */
?define CLEARTYPES 9 /* number of screen clearing techniques */

?define PALSIZE 256*3 /* size of palette buffer 256 colours * RGB */
byte palette[PALSIZE]; /* buffer for palette */

?define XMAX 320 // width of the screen
?define YMAX 200 // length of the screen
?define LINESPEED 4 // number of lines to draw before each palette shift
?define BOXSPEED 6 // number of boxes to draw before each palette shift


void main()
{
IF( byte @GETCPU() < 2 ) /* check if 80286 instructions available */
{WRITESTR("80286 or greater CPU required.");
EXIT(1);}
@ SETVIDEOMODE( vid_320x200_256 ); /* set video mode */
IF(byte @GETVIDEOMODE() != vid_320x200_256) /* check if entered the mode */
{WRITESTR("Unable to enter 256 colour mode, VGA required.");
EXIT(1);}

@ RANDOMIZE(); /* seed the random number generator with clock ticks */

FANCYCLEAR(7);
do {
IF( BIOSKEYCHECK() == 0 )
{IF(RAND()%10 >= 5)
fancylines();
ELSE fancysquares();
FANCYCLEAR(RAND()%CLEARTYPES);
}
} while( BIOSEREADKEY() <> k_esc ); // keep going until is pressed

@ SETVIDEOMODE( vid_text80c ); /* return to text mode */
WRITESTR("SPHINX Programming 1994");
}


void fancylines () // do the bouncing lines
byte color,i;
int xloc,yloc;
word xgo,ygo;
int xloc2,yloc2;
word xgo2,ygo2;
{xloc = XMAX /3;
xloc += RAND() % 40;
yloc = YMAX /2;
xloc2 = XMAX /3;
xloc2 += RAND() % 40;
yloc2 = YMAX /3;
yloc2 += RAND() % 40;
xgo = 1;
ygo = 1;
color = 66;
xgo2 = RAND()%2+1;
ygo2 = 1;

do {
i = 0;
advancepalette();
do {
line19(xloc/4,yloc/4,xloc2/4,yloc2/4,color);
color--;
IF( color == 0 )
color--;
xloc += xgo;
yloc += ygo;
IF( xloc < 0 )
{xloc -= xgo;
xgo = RAND()%3+1;}
IF( xloc >= XMAX*4 )
{xloc -= xgo;
xgo = RAND()%3-3;}
IF( yloc < 0 )
{yloc -= ygo;
ygo = RAND()%3+1;}
IF( yloc >= YMAX*4 )
{yloc -= ygo;
ygo = RAND()%3-3;}
xloc2 += xgo2;
yloc2 += ygo2;
IF( xloc2 < 0 )
{xloc2 -= xgo2;
xgo2 = RAND()%3+1;}
IF( xloc2 >= XMAX*4 )
{xloc2 -= xgo2;
xgo2 = RAND()%3-3;}
IF( yloc2 < 0 )
{yloc2 -= ygo2;
ygo2 = RAND()%3+1;}
IF( yloc2 >= YMAX*4 )
{yloc2 -= ygo2;
ygo2 = RAND()%3-3;}
i++;
} while( i < LINESPEED );
} while( BIOSEKEYCHECK() == 0 );
}


void fancysquares () // do the bouncing boxes
word xsize,ysize;
byte color;
word xloc,yloc;
int xgo,ygo;
byte i,squares;
word count;
{color = 66;
xgo = 1;
ygo = 1;
squares = RAND() %4;
xsize = RAND() %60 +1;
ysize = xsize;
IF(xsize > 45)
squares = 0;
xloc = XMAX /3;
xloc += RAND() % 40;
yloc = YMAX /2;

do {
advancepalette();
i = 0;
do {
IF( squares >= 3 )
box19(xloc,yloc,xsize,ysize,color);
IF( squares >= 2 )
box19(XMAX-xloc-xsize,YMAX-yloc-ysize,xsize,ysize,color);
IF( squares >= 1 )
box19(xloc,YMAX-xsize-yloc,xsize,ysize,color);
box19(XMAX-xsize-xloc,yloc,xsize,ysize,color);
color++;
IF( color == 0 )
color++;
xloc += xgo;
yloc += ygo;
AX = XMAX - xsize;
IF( xloc > AX )
{-xgo;
xloc += xgo;
}
AX = YMAX - ysize;
IF( yloc > AX )
{-ygo;
yloc += ygo;
}
i++;
} while( i < BOXSPEED );
} while( BIOSEKEYCHECK() == 0 );
}


void advancepalette () // shift the palette forward one
{@ COPYFAR(DS,#palette[3],DS,#palette[6],PALSIZE-6);
palette[PALSIZE-3] += RAND() % CHANGE_RANGE;
palette[PALSIZE-2] += RAND() % CHANGE_RANGE;
palette[PALSIZE-1] += RAND() % CHANGE_RANGE;
@ WAITVSYNC();
@ SETVGADAC(0, ,PALSIZE, , ,#palette);
}


void FANCYCLEAR () // AL = method to clear the screen by
word i;
{
IF( AL == 0 )
CLEARSCREEN19();
else IF( AL == 1 )
{i = 0;
do {advancepalette();
line19(0,0,319,i,255-i);
line19(319,199,0,199-i,255-i);
i++;
} while ( i < 200 );
}
else IF( AL == 2 )
{i = 0;
do {advancepalette();
line19(i,0,i,199,255-i);
line19(319-i,0,319-i,199,255-i);
i++;
} while ( i < 160 );
}
else IF( AL == 3 )
{i = 0;
do {advancepalette();
line19(0,i,319,i,255-i);
line19(0,199-i,319,199-i,255-i);
i++;
} while ( i < 100 );
}
else IF( AL == 4 )
{i = 0;
do {advancepalette();
line19(0,i,319,i,255-i);
i++;
} while ( i < 200 );
}
else IF( AL == 5 )
{i = 0;
do {advancepalette();
line19(0,199-i,319,199-i,255-i);
i++;
} while ( i < 200 );
}
else IF( AL == 6 )
{i = 0;
do {advancepalette();
box19(i,i,160-i*2,100-i*2,255-i);
i++;
} while( i < 100 );
}
else IF( AL == 7 )
{i = 0;
do {advancepalette();
bar19(i%16*20,i/16*20,20,20,255-i);
i++;
} while( i < 16*10 );
}
ELSE{i = 0;
do {advancepalette();
line19(319,0,0,i,255-i);
line19(0,199,319,199-i,255-i);
i++;
} while ( i < 200 );
}
}

/* end of BOUNCE.C-- */