/*

Name:
S3M_IT.C

Description:
Commonfunctions between S3Ms and ITs  (smaller .EXE! :)

Portability:
All systems - all compilers (hopefully)

*/

#include "mikmod.h"

UBYTE  *poslookup=NULL;// S3M/IT fix - removing blank patterns needs a
                       // lookup table to fix position-jump commands
SBYTE   remap[64];     // for removing empty channels
SBYTE   isused[64];    // for removing empty channels


void S3MIT_ProcessCmd(UBYTE cmd,UBYTE inf,BOOL oldeffect)
{
    UBYTE hi,lo;

    lo=inf&0xf;
    hi=inf>>4;

    // process S3M / IT specific command structure

   if(cmd!=255)
   {   switch(cmd)
       {   case 1:                 // Axx set speed to xx
              UniWrite(UNI_S3MEFFECTA);
              UniWrite(inf);
           break;

           case 2:                 // Bxx position jump
              UniPTEffect(0xb,poslookup[inf]);
           break;

           case 3:                 // Cxx patternbreak to row xx
               if(oldeffect & 1)
                   UniPTEffect(0xd,(((inf&0xf0)>>4)*10)+(inf&0xf));
               else
                   UniPTEffect(0xd,inf);
           break;

           case 4:                 // Dxy volumeslide
               UniWrite(UNI_S3MEFFECTD);
               UniWrite(inf);
           break;

           case 5:                 // Exy toneslide down
               UniWrite(UNI_S3MEFFECTE);
               UniWrite(inf);
           break;

           case 6:                 // Fxy toneslide up
               UniWrite(UNI_S3MEFFECTF);
               UniWrite(inf);
           break;
                 
           case 7:                 // Gxx Tone portamento, speed xx
               UniWrite(UNI_ITEFFECTG);
               UniWrite(inf);
           break;

           case 8:                 // Hxy vibrato
               if(oldeffect & 1)
                  UniPTEffect(0x4,inf);
               else
               {   UniWrite(UNI_ITEFFECTH);
                   UniWrite(inf);
               }
           break;

           case 9:                 // Ixy tremor, ontime x, offtime y
               if(oldeffect & 1)
                   UniWrite(UNI_S3MEFFECTI);
               else                     
                   UniWrite(UNI_ITEFFECTI);
               UniWrite(inf);
           break;

           case 0xa:               // Jxy arpeggio
               UniPTEffect(0x0,inf);
           break;

           case 0xb:               // Kxy Dual command H00 & Dxy
               if(oldeffect & 1)
                   UniPTEffect(0x4,0);    
               else
               {   UniWrite(UNI_ITEFFECTH);
                   UniWrite(0);
               }
               UniWrite(UNI_S3MEFFECTD);
               UniWrite(inf);
           break;

           case 0xc:               // Lxy Dual command G00 & Dxy
               if(oldeffect & 1)
                  UniPTEffect(0x3,0);
               else
               {   UniWrite(UNI_ITEFFECTG);
                   UniWrite(0);
               }
               UniWrite(UNI_S3MEFFECTD);
               UniWrite(inf);
           break;

           case 0xd:               // Mxx Set Channel Volume
               UniWrite(UNI_ITEFFECTM);
               UniWrite(inf);
           break;       

           case 0xe:               // Nxy Slide Channel Volume
               UniWrite(UNI_ITEFFECTN);
               UniWrite(inf);
           break;

           case 0xf:               // Oxx set sampleoffset xx00h
               UniPTEffect(0x9,inf);
           break;

           case 0x10:              // Pxy Slide Panning Commands
               UniWrite(UNI_ITEFFECTP);
               UniWrite(inf);
           break;

           case 0x11:              // Qxy Retrig (+volumeslide)
               UniWrite(UNI_S3MEFFECTQ);
               if((inf!=0) && (lo==0) && !(oldeffect & 1))
                   UniWrite(1);
               else
                   UniWrite(inf); 
           break;

           case 0x12:              // Rxy tremolo speed x, depth y
               UniWrite(UNI_S3MEFFECTR);
               UniWrite(inf);
           break;

           case 0x13:              // Sxx special commands
               UniWrite(UNI_ITEFFECTS0);
               UniWrite(inf);
           break;

           case 0x14:      // Txx tempo
               if(inf>0x20)
               {   UniWrite(UNI_S3MEFFECTT);
                   UniWrite(inf);
               }
           break;

           case 0x15:      // Uxy Fine Vibrato speed x, depth y
               if(oldeffect & 1)
                   UniWrite(UNI_S3MEFFECTU);
               else
                   UniWrite(UNI_ITEFFECTU);
               UniWrite(inf);
           break;

           case 0x16:      // Vxx Set Global Volume
               UniWrite(UNI_XMEFFECTG);
               UniWrite(inf);
           break;

           case 0x17:      // Wxy Global Volume Slide
               UniWrite(UNI_ITEFFECTW);
               UniWrite(inf);  
           break;

           case 0x18:      // Xxx amiga command 8xx
               if(oldeffect & 1)
                   UniPTEffect(0x8,((inf<<1) == 256) ? 255 : (inf<<1));
               else
                   UniPTEffect(0x8,inf);                                          
           break;

           case 0x19:      // Yxy Panbrello  speed x, depth y
               UniWrite(UNI_ITEFFECTY);
               UniWrite(inf);
           break;
       }
   }
}