synsvga.cpp

Yet another mp3 player, but this time using SVGALib under Linux. The idea was to use a 320x240 disp

/* Synaesthesia - program to display sound graphically
   Copyright (C) 1997  Paul Francis Harrison

  This program is free software; you can redistribute it and/or modify it
  under the terms of the GNU General Public License as published by the
  Free Software Foundation; either version 2 of the License, or (at your
  option) any later version.

  This program is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  General Public License for more details.

  You should have received a copy of the GNU General Public License along
  with this program; if not, write to the Free Software Foundation, Inc.,
  675 Mass Ave, Cambridge, MA 02139, USA.

  The author may be contacted at:
    [e-mail]
  or
    27 Bond St., Mt. Waverley, 3149, Melbourne, Australia
*/

#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <fcntl.h>
#include <termios.h>
#include <errno.h>
#include "syna.h"
#include "synvis.h"

static unsigned char scr[320*200];
static int mmfile;

void screenInit(int xHint,int yHint,int widthHint,int heightHint) {

  // SMH: Write to a virtual buffer in a memmapped file. 
  //mmfile = open( "/tmp/vis_screen", O_RDWR | O_CREAT );
  //if (mmfile!=-1) {
  //   scr = (unsigned char*)mmap( 0, 320*200, PROT_READ | PROT_WRITE, MAP_SHARED, mmfile,0); 
  //   if (((int)scr)>0) {
  //      printf( "Visualisation module mapped.\n" );    
  //   } else {
  //      perror( "Failed to map visualisation module" );
  //      exit(1);
  //   }
  //} else {
  //   scr = NULL;
  //   perror( "Error opening /tmp/vis_screen" );
  //}

  outWidth = 320;
  outHeight = 200;
}

unsigned char* GetVisualisationRAM()
{
   return scr;
}

void screenClose()
{
   //delete [] scr;
   //int r = munmap( scr, 320*200 );
   //if (r!=0) {
   //  printf( "error closing memory mapping for visualisation.\n" );
   //}
   //if (mmfile) close( mmfile );
}


int sizeUpdate() {
  return 0;
}

void screenShow(void) {
  if (!scr) return;
  register unsigned long *ptr2 = (unsigned long*)output;
  unsigned long *ptr1 = (unsigned long*)scr;
  int i = 320*200/4;
  // Asger Alstrup Nielsen's ([e-mail])
  // optimized 32 bit screen loop
  do {
    //Original bytewize version:
    //unsigned char v = (*(ptr2++)&15*16);
    //*(ptr1++) = v|(*(ptr2++)>>4);
    register unsigned int const r1 = *(ptr2++);
    register unsigned int const r2 = *(ptr2++);

    //Fade will continue even after value > 16
    //thus black pixel will be written when values just > 0
    //thus no need to write true black
    //if (r1 || r2) {
#ifdef LITTLEENDIAN
      register unsigned int const v = 
          ((r1 & 0x000000f0ul) >> 4)
        | ((r1 & 0x0000f000ul) >> 8)
        | ((r1 & 0x00f00000ul) >> 12)
        | ((r1 & 0xf0000000ul) >> 16);
      *(ptr1++) = v | 
        ( ((r2 & 0x000000f0ul) << 12)
        | ((r2 & 0x0000f000ul) << 8)
        | ((r2 & 0x00f00000ul) << 4)
        | ((r2 & 0xf0000000ul)));
#else
      register unsigned int const v = 
          ((r2 & 0x000000f0ul) >> 4)
        | ((r2 & 0x0000f000ul) >> 8)
        | ((r2 & 0x00f00000ul) >> 12)
        | ((r2 & 0xf0000000ul) >> 16);
      *(ptr1++) = v | 
        ( ((r1 & 0x000000f0ul) << 12)
        | ((r1 & 0x0000f000ul) << 8)
        | ((r1 & 0x00f00000ul) << 4)
        | ((r1 & 0xf0000000ul)));
#endif
    //} else {
    //  ptr1++;
    //}  
  } while (--i); 
}