Graphics/Sprites/fire_and_sprites/source/main.cpp

/*---------------------------------------------------------------------------------
    $Id: main.cpp,v 1.16 2008-11-29 22:58:58 wntrmute Exp $

    -- dovoto

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

#include <stdlib.h>
#include <string.h>
#include <nds.h>

//include our ball pcx file (auto generated)
#include "ball_pcx.h"

#define NUM_SPRITES 128 

SpriteEntry OAMCopySub[128];

//simple sprite struct
typedef struct {
    int x,y;            // screen co-ordinates 
    int dx, dy;         // velocity
    SpriteEntry* oam;   // pointer to the sprite attributes in OAM
    int gfxID;          // graphics lovation
}Sprite;


//---------------------------------------------------------------------------------
void MoveSprite(Sprite* sp) {
//---------------------------------------------------------------------------------
    int x = sp->x >> 8;
    int y = sp->y >> 8;

    sp->oam->x = x;
    sp->oam->y = y;

} 



//---------------------------------------------------------------------------------
void initOAM(void) {
//---------------------------------------------------------------------------------
    int i;

    for(i = 0; i < 128; i++) {
        OAMCopySub[i].attribute[0] = ATTR0_DISABLED;
    }   
}

//---------------------------------------------------------------------------------
void updateOAM(void) {
//---------------------------------------------------------------------------------
    memcpy(OAM_SUB, OAMCopySub, 128 * sizeof(SpriteEntry));
}



//---------------------------------------------------------------------------------
int main(void) {
//---------------------------------------------------------------------------------
    
    uint16* back = VRAM_A;
    uint16* front = VRAM_B;

    Sprite sprites[NUM_SPRITES];

    int i, delta = 0;
    int ix = 0;
    int iy = 0;
    int screen = 1;
    uint16* map0 = (uint16*)SCREEN_BASE_BLOCK_SUB(1);
    uint16* map1 = (uint16*)SCREEN_BASE_BLOCK_SUB(2);
    uint16 red;

    //set main display to render directly from the frame buffer
    videoSetMode(MODE_FB1);
    
    //set up the sub display
    videoSetModeSub(MODE_0_2D | 
                    DISPLAY_SPR_1D_LAYOUT | 
                    DISPLAY_SPR_ACTIVE | 
                    DISPLAY_BG0_ACTIVE |
                    DISPLAY_BG1_ACTIVE );
    
    //vram banks are somewhat complex
    vramSetMainBanks(VRAM_A_LCD, VRAM_B_LCD, VRAM_C_SUB_BG, VRAM_D_SUB_SPRITE); 

    sImage ball;

    //load our ball pcx file into an image
    loadPCX((u8*)ball_pcx, &ball);
    
    //tile it so it is usefull as sprite data
    imageTileData(&ball);

    // Sprite initialisation
    for(i = 0; i < 256; i++)
        SPRITE_PALETTE_SUB[i] = ball.palette[i];

    for(i = 0; i< 32*16; i++)
        SPRITE_GFX_SUB[i] = ball.image.data16[i];
    
    //turn off sprites
    initOAM();

    for(i = 0; i < NUM_SPRITES; i++) {
        //random place and speed
        sprites[i].x = rand() & 0xFFFF;
        sprites[i].y = rand() & 0x7FFF;
        sprites[i].dx = (rand() & 0xFF) + 0x100;
        sprites[i].dy = (rand() & 0xFF) + 0x100;
    
        if(rand() & 1)
            sprites[i].dx = -sprites[i].dx;
        if(rand() & 1)
            sprites[i].dy = -sprites[i].dy;
    
        sprites[i].oam = &OAMCopySub[i];
        sprites[i].gfxID = 0;
    
        //set up our sprites OAM entry attributes
        sprites[i].oam->attribute[0] = ATTR0_COLOR_256 | ATTR0_SQUARE;  
        sprites[i].oam->attribute[1] = ATTR1_SIZE_32;
        sprites[i].oam->attribute[2] = sprites[i].gfxID;
    }

    //set up two backgrounds to scroll around
    REG_BG0CNT_SUB = BG_COLOR_256 | (1 << MAP_BASE_SHIFT);
    REG_BG1CNT_SUB = BG_COLOR_256 | (2 << MAP_BASE_SHIFT);

    BG_PALETTE_SUB[0] = RGB15(10,10,10);
    BG_PALETTE_SUB[1] = RGB15(0,16,0);
    BG_PALETTE_SUB[2] = RGB15(0,0,31);
    
    //load the maps with alternating tiles (0,1 for bg0 and 0,2 for bg1)
    for(iy = 0; iy < 32; iy++) {
        for(ix = 0; ix <32; ix++) {
            map0[iy * 32 + ix] = (ix ^ iy) & 1;
            map1[iy * 32 + ix] = ((ix ^ iy) & 1)<<1;
        }
    }    

    //fill 2 tiles with different colors
    for(i = 0; i < 64 / 2; i++) {
        BG_GFX_SUB[i+32] = 0x0101;
        BG_GFX_SUB[i+32+32] = 0x0202;
    }   

    while (1) {
        //scroll the background
        REG_BG0HOFS = delta ;
        REG_BG0VOFS = delta++ ;
        
        //move the sprites
        for(i = 0; i < NUM_SPRITES; i++) {
            sprites[i].x += sprites[i].dx;
            sprites[i].y += sprites[i].dy;
            
            //check for collision with the screen boundries
            if(sprites[i].x < (1<<8) || sprites[i].x > (247 << 8))
                sprites[i].dx = -sprites[i].dx;

            if(sprites[i].y < (1<<8) || sprites[i].y > (182 << 8))
                sprites[i].dy = -sprites[i].dy;
            
            //reposition the sprites
            MoveSprite(&sprites[i]);
        }
        

    
        //do the plasma/fire
        for(ix = 0; ix < SCREEN_WIDTH; ix++) {
            back[ix + SCREEN_WIDTH * (SCREEN_HEIGHT - 1)] = rand()& 0xFFFF;
            back[ix + SCREEN_WIDTH * (SCREEN_HEIGHT - 2)] = rand()& 0xFFFF;
        }

        back++;
        
        for(iy = 1; iy < SCREEN_HEIGHT - 2 ; iy++) {
            for(ix = 1; ix < SCREEN_WIDTH - 1; ix++)  {
                red = 0;

                red += front[0];
                red += front[2];
    
                front += SCREEN_WIDTH;

                red += front[0];
                red += front[1];
                red += front[2];
                
                front += SCREEN_WIDTH;

                red += front[0];
                red += front[1];
                red += front[2];

                front -= (2 * SCREEN_WIDTH) - 1;    

                back[0] =  (red >> 3);  
                back++;
            }
            back += 2;
            front += 2;
        
        }

        swiWaitForVBlank();
        
        updateOAM();

        //flip screens
        if(screen) {
            videoSetMode(MODE_FB1);
            front = VRAM_B;
            back = VRAM_A;
            screen = 0;
        } else {
            videoSetMode(MODE_FB0); 
            front = VRAM_A;
            back = VRAM_B;
            screen = 1;
        }
    }    
    return 0;
}