HPAVC/HPAVC CD-ROM.iso/pc/FGFX11.ZIP/EFFECTS.C

C/C++ Source or Header | 1994-04-11 | 21.3 KB | 654 lines

/****************************************************************************\
*                                                                            *
*  EFFECTS.C                                                                 *
*                                                                            *
*  This program demonstrates several methods of fading in an image from an   *
*  off-screen video page using either Fastgraph or Fastgraph/Light.  The set *
*  of routines provided herein are written for 320 x 200 graphics video      *
*  modes, but they could easily be extended to work in other resolutions.    *
*                                                                            *
*  The examples are by no means all inclusive.  Rather, their purpose is to  *
*  illustrate a few methods of creating special effects with Fastgraph or    *
*  Fastgraph/Light.                                                          *
*                                                                            *
*  To compile this program and link it with Fastgraph:                       *
*                                                                            *
*     BCC -ms EFFECTS.C FGS.LIB    (Borland C++)                             *
*                                                                            *
*     CL /AS EFFECTS.C /link FGS   (Microsoft C)                             *
*                                                                            *
*     QCL /AS EFFECTS.C /link FGS  (Microsoft QuickC)                        *
*                                                                            *
*     PC /ms EFFECTS               (Power C)                                 *
*     PCL EFFECTS ;FGS                                                       *
*                                                                            *
*     TCC -ms EFFECTS.C FGS.LIB    (Turbo C and C++)                         *
*                                                                            *
*     ZTC -ms EFFECTS.C FGS.LIB    (Zortech C++)                             *
*                                                                            *
*  This program also can be linked with Fastgraph/Light if you replace the   *
*  FGS library references with FGLS.                                         *
*                                                                            *
*  Fastgraph (tm) and Fastgraph/Light (tm) are graphics libraries published  *
*  by Ted Gruber Software.  For more info, please call, write, or FAX.       *
*                                                                            *
*  Ted Gruber Software                           orders/info [phone]  *
*  PO Box 13408                                          FAX [phone]  *
*  Las Vegas, NV  89112                                  BBS [phone]  *
*                                                                            *
\****************************************************************************/

#include <fastgraf.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

/* function prototypes */

void main(void);

void announce(char *);
int  irandom(int,int);

void curtain(int);
void diagonal_fade(int);
void horizontal_random_fade(int);
void inward_tunnel_effect(int);
void outward_tunnel_effect(int);
void spiral_dual(int);
void spiral_layered(int);
void spiral_normal(int);
void split_screen(int);
void unveil(int);
void venetian_blind(int);

/* global variables */

int delay;
int scroll_delay;

/* main program */

void main()
{
   int old_mode, new_mode;
   unsigned int count;
   unsigned long start_time;

   /* make sure a 320 x 200 color graphics mode is available */

   new_mode = fg_bestmode(320,200,2);
   if (new_mode < 0 || new_mode == 12)
   {
      printf("This program requires a 320 x 200 color graphics mode.\n");
      exit(1);
   }

   /* determine the number of delay units per half clock tick */

   delay = fg_measure() / 2;

   /* initialize Fastgraph for the selected video mode */

   old_mode = fg_getmode();
   fg_setmode(new_mode);
   fg_allocate(1);

   /* display a packed pixel run file on a hidden page */

   fg_sethpage(1);
   fg_setpage(1);
   fg_move(0,199);
   fg_dispfile("FG.PPR",320,1);
   fg_setpage(0);

   /* compute the number of delay units needed to make the text scroll */
   /* down at the same rate, regardless of the CPU speed or video mode */

   count = 0;
   fg_waitfor(1);
   start_time = fg_getclock();
   do
   {
      fg_scroll(0,319,0,7,4,1);
      count++;
   }
   while (fg_getclock() == start_time);

   scroll_delay = (delay / 8) - (delay * 2) / count;
   if (scroll_delay < 0) scroll_delay = 0;

   /* demonstrate the inward tunnel effect */

   announce("inward tunnel effect");
   inward_tunnel_effect(0);
   fg_waitfor(27);
   announce("inward tunnel effect with delay");
   inward_tunnel_effect(delay);
   fg_waitfor(27);

   /* demonstrate the outward tunnel effect */

   announce("outward tunnel effect");
   outward_tunnel_effect(0);
   fg_waitfor(27);
   announce("outward tunnel effect with delay");
   outward_tunnel_effect(delay);
   fg_waitfor(27);

   /* demonstrate the diagonal fade */

   announce("diagonal fade");
   diagonal_fade(0);
   fg_waitfor(27);
   announce("diagonal fade with delay");
   diagonal_fade(delay/2);
   fg_waitfor(27);

   /* demonstrate the horizontal random fade */

   announce("horizontal random fade");
   horizontal_random_fade(delay);
   fg_waitfor(27);

   /* demonstrate the curtain effect */

   announce("curtain");
   curtain(delay/8);
   fg_waitfor(27);

   /* demonstrate the spiral effect */

   announce("spiral");
   spiral_normal(delay*2);
   fg_waitfor(27);

   /* demonstrate the layered spiral effect */

   announce("layered spiral");
   spiral_layered(delay);
   fg_waitfor(27);

   /* demonstrate the dual spiral effect */

   announce("dual spiral");
   spiral_dual(delay/2);
   fg_waitfor(27);

   /* demonstrate the split screen effect */

   announce("split screen");
   split_screen(delay/2);
   fg_waitfor(27);

   /* demonstrate the unveil effect */

   announce("unveil");
   unveil(delay/4);
   fg_waitfor(27);

   /* demonstrate the "venetian blind" effect */

   announce("venetian blind");
   venetian_blind(delay);
   fg_waitfor(27);

   /* restore the original video mode and screen attributes */

   fg_freepage(1);
   fg_setmode(old_mode);
   fg_reset();
}

/****************************************************************************\
*                                                                            *
*  announce                                                                  *
*                                                                            *
*  Display the name of the special effect we're about to see.                *
*                                                                            *
\****************************************************************************/

void announce(message)
char *message;
{
   register int y;
   int length;

   /* clear the screen */

   fg_erase();

   /* display the specified message at the top row */

   fg_setcolor(15);
   length = strlen(message);
   fg_locate(0,20-length/2);
   fg_text(message,length);

   /* scroll the message to the center of the screen */

   fg_setcolor(0);

   for (y = 0; y < 96; y+=4)
   {
      fg_scroll(0,319,y,y+7,4,1);
      fg_stall(scroll_delay);
   }

   /* wait 1.5 seconds */

   fg_waitfor(27);
}

/****************************************************************************\
*                                                                            *
*  irandom                                                                   *
*                                                                            *
*  Random number generator used in some of the effects.  It returns an       *
*  integer between min and max inclusive.                                    *
*                                                                            *
\****************************************************************************/

int irandom(min,max)
int min, max;
{
   return(rand() % (max-min+1) + min);
}

/****************************************************************************\
*                                                                            *
*  curtain                                                                   *
*                                                                            *
*  Reveal each row, one at a time, starting from the bottom and proceeding   *
*  to the top.  This gives the effect of a curtain rising, hence the name.   *
*                                                                            *
\****************************************************************************/

void curtain(delay)
int delay;
{
   register int y;

   for (y = 199; y >= 0; y--)
   {
      fg_restore(0,319,y,y);
      fg_stall(delay);
   }
}

/****************************************************************************\
*                                                                            *
*  diagonal_fade                                                             *
*                                                                            *
*  This reveals the hidden page in two diagonal segments, separated by an    *
*  imaginary line extending from the lower left corner to the upper right    *
*  corner of the screen.  We start with the top line of the left segment and *
*  the bottom line of the right segment, and continue until the entire       *
*  screen is revealed.                                                       *
*                                                                            *
\****************************************************************************/

void diagonal_fade(delay)
int delay;
{
   int xmin, xmax;
   int ymin, ymax;

   xmin = 0;
   xmax = 319;
   ymin = 0;
   ymax = 199;

   while (xmax > 0)
   {
      fg_restore(0,xmax,ymin,ymin+4);
      fg_restore(xmin,319,ymax-4,ymax);
      fg_stall(delay);

      xmin += 8;
      xmax -= 8;
      ymin += 5;
      ymax -= 5;
   }
}

/****************************************************************************\
*                                                                            *
*  horizontal_random_fade                                                    *
*                                                                            *
*  In this effect, the screen is divided into a series of two-pixel high     *
*  rows.  Each row is revealed in random parts from left to right.  This     *
*  process repeats 20 times, once for each row.  At the end, a call to the   *
*  fg_restore routine guarantees that all rows are transferred.              *
*                                                                            *
\****************************************************************************/

void horizontal_random_fade(delay)
int delay;
{
   register int i, j;
   int xwidth;
   int xmin, xmax;
   int y;
   int xpos[100];

   for (j = 0; j < 100; j++)
      xpos[j] = 0;

   for (i = 0; i < 20; i++)
   {
      for (j = 0; j < 100; j++)
      {
         xmin = xpos[j];
         if (xmin < 320)
         {
            xmax = xmin + irandom(1,10) * 8;
            if (xmax > 320) xmax = 320;
            y = j * 2;
            fg_restore(xmin,xmax-1,y,y+1);
            xpos[j] = xmax;
         }
      }
      fg_stall(delay);
   }

   /* make sure we got them all */

   fg_restore(0,319,0,199);
}

/****************************************************************************\
*                                                                            *
*  inward_tunnel_effect                                                      *
*                                                                            *
*  Starting at the screen edges, reveal the screen through a series of       *
*  concentric hollow rectangles.                                             *
*                                                                            *
\****************************************************************************/

void inward_tunnel_effect(delay)
int delay;
{
   int xmin, xmax;
   int ymin, ymax;

   xmin = 0;
   xmax = 319;
   ymin = 0;
   ymax = 199;

   while (xmin < xmax)
   {
      fg_restore(0,319,ymin,ymin+4);
      fg_restore(xmax-7,xmax,0,199);
      fg_restore(0,319,ymax-4,ymax);
      fg_restore(xmin,xmin+7,0,199);
      fg_stall(delay);

      xmin += 8;
      xmax -= 8;
      ymin += 5;
      ymax -= 5;
   }
}

/****************************************************************************\
*                                                                            *
*  outward_tunnel_effect                                                     *
*                                                                            *
*  Starting at the screen center, reveal the screen through a series of      *
*  concentric hollow rectangles.                                             *
*                                                                            *
\****************************************************************************/

void outward_tunnel_effect(delay)
int delay;
{
   int xmin, xmax;
   int ymin, ymax;

   xmin = 152;
   xmax = 167;
   ymin = 95;
   ymax = 104;

   while (xmin >= 0)
   {
      fg_restore(xmin,xmax,ymin,ymin+5);
      fg_restore(xmax-7,xmax,ymin,ymax);
      fg_restore(xmin,xmax,ymax-4,ymax);
      fg_restore(xmin,xmin+7,ymin,ymax);
      fg_stall(delay);

      xmin -= 8;
      xmax += 8;
      ymin -= 5;
      ymax += 5;
   }
}

/****************************************************************************\
*                                                                            *
*  spiral_dual                                                               *
*                                                                            *
*  In this effect, we reveal the screen through two spirals.  One spiral     *
*  emanates clockwise from the screen edges to the screen center, while the  *
*  other emanates counterclockwise from the center to the screen edges.      *
*                                                                            *
\****************************************************************************/

void spiral_dual(delay)
int delay;
{
   int xmin_outer, xmax_outer;
   int ymin_outer, ymax_outer;
   int xmin_inner, xmax_inner;
   int ymin_inner, ymax_inner;

   xmin_outer = 0;
   xmax_outer = 319;
   ymin_outer = 0;
   ymax_outer = 199;

   xmin_inner = 152;
   xmax_inner = 167;
   ymin_inner = 95;
   ymax_inner = 104;

   while (xmin_outer < xmin_inner)
   {
      fg_restore(xmin_outer,xmax_outer,ymin_outer,ymin_outer+4);
      fg_stall(delay);
      fg_restore(xmin_inner,xmax_inner,ymax_inner-4,ymax_inner);
      fg_stall(delay);
      fg_restore(xmax_outer-7,xmax_outer,ymin_outer,ymax_outer);
      fg_stall(delay);
      fg_restore(xmax_inner+1,xmax_inner+8,ymin_inner,ymax_inner);
      fg_stall(delay);
      fg_restore(xmin_outer,xmax_outer,ymax_outer-4,ymax_outer);
      fg_stall(delay);
      fg_restore(xmin_inner-8,xmax_inner,ymin_inner,ymin_inner+4);
      fg_stall(delay);
      fg_restore(xmin_outer,xmin_outer+7,ymin_outer,ymax_outer);
      fg_stall(delay);
      fg_restore(xmin_inner-8,xmin_inner-1,ymin_inner,ymax_inner+5);
      fg_stall(delay);

      xmin_outer += 8;
      xmax_outer -= 8;
      ymin_outer += 5;
      ymax_outer -= 5;

      xmin_inner -= 8;
      xmax_inner += 8;
      ymin_inner -= 5;
      ymax_inner += 5;
   }
}

/****************************************************************************\
*                                                                            *
*  spiral_layered                                                            *
*                                                                            *
*  This effect is similar to the normal spiral.  Instead of revealing the    *
*  screen in one iteration, this effect does so in four iterations (layers), *
*  each moving more toward the screen center.                                *
*                                                                            *
\****************************************************************************/

void spiral_layered(delay)
int delay;
{
   register int i;
   int xmin, xmax;
   int ymin, ymax;

   for (i = 0; i < 4; i++)
   {
      xmin = i * 8;
      xmax = 319 - xmin;
      ymin = i * 5;
      ymax = 199 - ymin;

      while (xmin < xmax)
      {
         fg_restore(xmin,xmax,ymin,ymin+4);
         fg_stall(delay);
         fg_restore(xmax-7,xmax,ymin,ymax);
         fg_stall(delay);
         fg_restore(xmin,xmax,ymax-4,ymax);
         fg_stall(delay);
         fg_restore(xmin,xmin+7,ymin,ymax);
         fg_stall(delay);

         xmin += 32;
         xmax -= 32;
         ymin += 20;
         ymax -= 20;
      }
   }
}

/****************************************************************************\
*                                                                            *
*  spiral_normal                                                             *
*                                                                            *
*  This is a spiral effect in which we reveal the screen as a series of      *
*  rectangles, emanating from the screen edges and proceeding clockwise to   *
*  the center of the screen.                                                 *
*                                                                            *
\****************************************************************************/

void spiral_normal(delay)
int delay;
{
   int xmin, xmax;
   int ymin, ymax;

   xmin = 0;
   xmax = 319;
   ymin = 0;
   ymax = 199;

   while (xmin < xmax)
   {
      fg_restore(xmin,xmax,ymin,ymin+19);
      fg_stall(delay);
      fg_restore(xmax-31,xmax,ymin,ymax);
      fg_stall(delay);
      fg_restore(xmin,xmax,ymax-19,ymax);
      fg_stall(delay);
      fg_restore(xmin,xmin+31,ymin,ymax);
      fg_stall(delay);

      xmin += 32;
      xmax -= 32;
      ymin += 20;
      ymax -= 20;
   }
}

/****************************************************************************\
*                                                                            *
*  split_screen                                                              *
*                                                                            *
*  Reveal the top half of from left to right while revealing the bottom half *
*  from right to left.                                                       *
*                                                                            *
\****************************************************************************/

void split_screen(delay)
int delay;
{
   register int xmin, xmax;

   xmin = 0;
   xmax = 319;

   while (xmax > 0)
   {
      fg_restore(xmin,xmin+7,0,99);
      fg_restore(xmax-7,xmax,100,199);
      fg_stall(delay);
      xmin += 8;
      xmax -= 8;
   }
}

/****************************************************************************\
*                                                                            *
*  unveil                                                                    *
*                                                                            *
*  Starting at the center, reveal the screen in small horizontal increments  *
*  until we reach the left and right edges.                                  *
*                                                                            *
\****************************************************************************/

void unveil(delay)
int delay;
{
   register int xmin, xmax;

   xmin = 152;
   xmax = 167;

   while (xmin >= 0)
   {
      fg_restore(xmin,xmin+7,0,199);
      fg_restore(xmax-7,xmax,0,199);
      fg_stall(delay);
      xmin -= 8;
      xmax += 8;
   }
}

/****************************************************************************\
*                                                                            *
*  venetian_blind                                                            *
*                                                                            *
*  Reveal the screen in four iterations, each revealing every fourth row.    *
*  The effect produced resembles opening a Venetian blind.                   *
*                                                                            *
\****************************************************************************/

void venetian_blind(delay)
int delay;
{
   register int y;

   for (y = 0; y < 200; y += 4)
      fg_restore(0,319,y,y);
   fg_stall(delay);

   for (y = 1; y < 200; y += 4)
      fg_restore(0,319,y,y);
   fg_stall(delay);

   for (y = 2; y < 200; y += 4)
      fg_restore(0,319,y,y);
   fg_stall(delay);

   for (y = 3; y < 200; y += 4)
      fg_restore(0,319,y,y);
}