intro.c

/* Allegro port Copyright (C) 2014 Gavin Smith. */
// Intro [c] Alpha-Helix 1992
// written by Dany Schoch

#include <allegro.h>

#include "xmode.h"
#include "sound.h"
#include "fileman.h"
#include "baller.h"


#define SCROLLY			311

#define BYTESPERLINE		80
#define SCREENSIZE		28000

static int loadEGA(char *file)
{
   BITMAP *bmp;

   unsigned char  *data;
   int   dataptr;
   int   count, i, page;
   int x, x2, y, p;

   bmp = create_bitmap (640, 350);
   clear_bitmap (bmp);

   data = loadfile(datapool, file);
   dataptr = 0;

   count = 0;
   int inc = 0;

   int r, g, b, br, pal = 0;
   /* Set EGA 3-bit palette. */
   for (br = 0; br <= 1; br++) {
   for (r = 0; r <= 1; r++) {
   for (g = 0; g <= 1; g++) {
   for (b = 0; b <= 1; b++) {
     RGB rgb;
     rgb.r = r ? 32 : 0;
     rgb.g = g ? 32 : 0;
     rgb.b = b ? 32 : 0;

     if (br) {
       rgb.r += 31;
       rgb.g += 31;
       rgb.b += 31;
     }

     set_color (8 * br + 4 * r + 2 * g + b, &rgb);
   }
   }
   }
   }

   RGB rgb = {15, 15, 15};
   set_color (8, &rgb); /* High-intensity black - dark grey */

   for (p = 1; p <= 8; p *= 2) {
     y = 0;
     x = 0;
     while (y <= 349) {
       if (count == 0) {
           count = data[dataptr++];
           if (count < 128)
             {
               /* Output count pixels the same. */
               inc = 0;
             }
           else
             {
               count -= 128;
               inc = 1; /* Read and output count pixels. */
             }
           count += 1;
           continue;
       }
       
       /* Each byte has info for 8 pixels. */
       for (x2 = 7; x2 >= 0; x2--)
         {
           putpixel (bmp, x + (7-x2), y,
             ((data[dataptr] & (1 << x2)) >> x2) /* 0 or 1 */
             * p + getpixel (bmp, x + (7-x2), y));
         }


       count--;
       dataptr += inc;
       if (count == 0 && inc == 0)
         dataptr++;

       x += 8;
       if (x >= 640) {
           x = 0;
           y++;
       }
     }
   }

   blit (bmp, screen, 0, 0, 0, 0, bmp->w, bmp->h);
   destroy_bitmap (bmp);
   unloadfile(data);

   return 0;
}


/* C is the character. S the column / 8.  PAPER is the font glyphs. */
static void putpaper(int c, int s, char *paper)
{
   int   i;
   char  *ptr;
   char  *data;

   c -= 32;
   data = &paper[(c*5+s)*40];

   /* Each character is 32 pixels wide (4 x 8). */
   /* Not full EGA data - only has one byte (for brightness) instead of 4. */
   for (i = 0; i < 40; i++) { /* Forty rows */
      int col;

      for (col = 7; col >= 0; col --)
        {
          int pixel = (*data & (1 << col)) >> col; /* 0 or 1 */
          putpixel (screen, 632 + (7-col), 310 + i, pixel * 15);
        }
      data++;
   }
}

static void paperscroll(void)
{
   /* Move left eight pixels. */
   blit (screen, screen, 8, 310, 0, 310,
       screen->w - 8, 40);
}


void intro(void)
{
   char   *paper;

   struct sndstrc snd;
   void *ptr;
   SAMPLE *s;

   // Switch to 640x350 mode.
   set_gfx_mode (GFX_AUTODETECT_WINDOWED,
                 640,
                 350, 0, 0);

   //setvanillapalette(0);
   loadEGA("BLICK.PAK");
   paper = loadfile(datapool, "PAPER.FNT");

   ptr = loadfile(datapool, "BLICK.SND");
   create_sndstrc (&snd, ptr);
   s = create_SAMPLE (&snd);
   playloop(s);

   //glowto(63, 63, 63);
   //glowin(1);

   {
      int  l, c;
      char text[] =
	 " . . . ALPHA HELIX PRODUCTION. (C) COPYRIGHT 1993.   "
	 "PROGRAMMING, SOUND FX AND LEVEL DESIGN BY TRITONE.   "
	 "GRAPHICS AND FONTS BY TWEETY.   "
	 "ADDITIONAL PROGRAMMING AND MUSIC BY ZYNAX OF DARK SYSTEM.   ";

      c = 0; l = 0;

      clear_keybuf();
      do {
	 putpaper(text[c], l, paper);
	 if (++l > 4) { l = 0; c++; }
	 if (text[c] == 0) c = 0;
         vsync();
	 paperscroll();
      } while (!keypressed());
   }

   stop_sample (s);
   //haltsound();
   unloadfile(ptr);

   unloadfile(paper);

   glowout();

// All this mode switching is a little bit a 'murks'. I know.
   setxmode();				// Switch back to X mode.
   setstandardpalette();
}