megacart/megacart.c

/*---------------------------------------------------------------------------------


    megacart demo with 3 banks
    images from Amy Purple post (newcoleco) here:
        https://atariage.com/forums/topic/268244-data-compression-benchmark-dan-pletter-zx7-exomizer-pucrunch-megalz/
    -- alekmaul


---------------------------------------------------------------------------------*/
#include "megacart.h"

#include "gfxsb1.h"                                 // to add definition of graphics
#include "gfxsb2.h"                                 // to add definition of graphics
#include "gfxsb3.h"                                 // to add definition of graphics

// Switch of the banks
#define SWITCH_IN_BANK1     { dummy=(*(volatile unsigned char*) 0xFFF8); } // b1 with 16k
#define SWITCH_IN_BANK2     { dummy=(*(volatile unsigned char*) 0xFFF9); } // b2 with 16k
#define SWITCH_IN_BANK3     { dummy=(*(volatile unsigned char*) 0xFFFA); } // b3 with 16k
#define SWITCH_IN_BANK4     { dummy=(*(volatile unsigned char*) 0xFFFB); } // b4 with 16k
#define SWITCH_IN_BANK5     { dummy=(*(volatile unsigned char*) 0xFFFC); } // b5 with 16k
#define SWITCH_IN_BANK6     { dummy=(*(volatile unsigned char*) 0xFFFD); } // b6 with 16k
#define SWITCH_IN_BANK7     { dummy=(*(volatile unsigned char*) 0xFFFE); } // b7 with 16k
#define SWITCH_IN_BANK8     { dummy=(*(volatile unsigned char*) 0xFFFF); } // b8 with 16k

// var for bank switching
unsigned char dummy;

//---------------------------------------------------------------------------------
// The NMI routine. Gets called 50 or 60 times per second 
// nothing to update for bitmap example
void nmi (void) {
}

//---------------------------------------------------------------------------------
void initvramIMG1(void) {
    // Disable Interrupt 
    vdp_waitvblank(1);
    vdp_disablescr();
    
    SWITCH_IN_BANK1;
    
    // Put image in vram  
    vdp_dan2vram (TILimage1, chrgen); // characters
    vdp_dan2vram (COLimage1, coltab); // colors
    vdp_dan2vram (MAPimage1, chrtab); // map

    // enable interrupt
    vdp_enablescr(); 
}

//---------------------------------------------------------------------------------
void initvramIMG2(void) {
    // Disable Interrupt 
    vdp_waitvblank(1);
    vdp_disablescr();
    
    SWITCH_IN_BANK2;
    
    // Put image in vram  
    vdp_dan2vram (TILimage2, chrgen); // characters
    vdp_dan2vram (COLimage2, coltab); // colors
    vdp_dan2vram (MAPimage2, chrtab); // map

    // enable interrupt
    vdp_enablescr(); 
}

//---------------------------------------------------------------------------------
void initvramIMG3(void) {
    // Disable Interrupt 
    vdp_waitvblank(1);
    vdp_disablescr();
    
    SWITCH_IN_BANK3;
    
    // Put image in vram  
    vdp_dan2vram (TILimage3, chrgen); // characters
    vdp_dan2vram (COLimage3, coltab); // colors
    vdp_dan2vram (MAPimage3, chrtab); // map

    // enable interrupt
    vdp_enablescr(); 
}

//---------------------------------------------------------------------------------
void main (void) {
    // Put screen in bitmapmode 2
    vdp_disablescr();
    
    vdp_setmode2bmp();
    
    vdp_enablescr();
    
    // Put 1st image
    initvramIMG1();
    
    // Wait for nothing :P
    while(1) {
        // change image regarding joypad
        if ( (joypad_1 & PAD_RIGHT) ) initvramIMG1();
        if ( (joypad_1 & PAD_LEFT) ) initvramIMG2();
        if ( (joypad_1 & PAD_FIRE1) ) initvramIMG3();

        // Wait Vblank
        while (joypad_1) { vdp_waitvblank(1); }
        vdp_waitvblank(1);
    }
    // startup module will issue a soft reboot if it comes here 
}