devkitPro

Posted: **Mon Feb 08, 2010 8:49 pm**

Unfortunately I'm back to portray my stupidity. I am creating an application that I want to base on the "fire and sprites" example under the nds Graphics/sprites directory. I believe I have successfully removed the "fire" part which I do not need. The sprites moving around loaded from external files is ideally what I want to use. I want my sprites to display and move around on the top screen only but my thick head has not allowed me to be successfull after spending the entire weekend trying to understand how to switch engines. I can produce anything from black on top and bottom, white on top and bottom, black on top and white on bottom, but never any sprites. I am absolutely convinced it is something utterly simple the longer I work on it. If anyone is inclined to help I attach my code to expose my expertise. The code changes I made are selected by the define SUB_ENGINE.

--dumber

Code: Select all

/*---------------------------------------------------------------------------------
	$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
#define SUB_ENGINE false	

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) {
//---------------------------------------------------------------------------------
	if(SUB_ENGINE)
		memcpy(OAM_SUB, OAMCopySub, 128 * sizeof(SpriteEntry));
	else
		memcpy(OAM, OAMCopySub, 128 * sizeof(SpriteEntry));
}



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

	Sprite sprites[NUM_SPRITES];

	int i, delta = 0;
	int ix = 0;
	int iy = 0;
	
	/* remove fire
	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);
	*/
	
	if(SUB_ENGINE)
	{
		//set up the sub display
		videoSetModeSub(MODE_0_2D | 
						DISPLAY_SPR_1D_LAYOUT | 
						DISPLAY_SPR_ACTIVE | 
						DISPLAY_BG0_ACTIVE |
						DISPLAY_BG1_ACTIVE );
	}
	else
	{
	//set the main display MAIN ENGINE
	videoSetMode(MODE_0_2D | 
					DISPLAY_SPR_1D_LAYOUT | 
					DISPLAY_SPR_ACTIVE | 
					DISPLAY_BG0_ACTIVE |
					DISPLAY_BG1_ACTIVE );
	}
	
	//vram banks are somewhat complex
	if(SUB_ENGINE)
		vramSetMainBanks(VRAM_A_LCD, VRAM_B_LCD, VRAM_C_SUB_BG, VRAM_D_SUB_SPRITE);
	else
		vramSetMainBanks(VRAM_A_MAIN_BG, VRAM_B_MAIN_SPRITE, VRAM_C_SUB_BG, VRAM_D_SUB_SPRITE);	//MAIN ENGINE	

	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
	if(SUB_ENGINE)
	{
		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];
	}
	else
	{
		for(i = 0; i < 256; i++)
			SPRITE_PALETTE[i] = ball.palette[i];

		for(i = 0; i< 32*16; i++)
			SPRITE_GFX[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;
	}

	/* remove fire
	//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) {
		/* remove fire
		//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]);
		}
		

		/*remove fire
		//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();

		/* remove fire
		//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;
}

Posted: **Mon Mar 01, 2010 9:40 pm**

I decided to study many more examples and go through numerous tutorials. I fixed my problem once the fog cleared by replacing the set memory banks instruction when I want the main engine to support sprites.
Old code:

Code: Select all

		vramSetMainBanks(VRAM_A_MAIN_BG, VRAM_B_MAIN_SPRITE, VRAM_C_SUB_BG, VRAM_D_SUB_SPRITE);	//MAIN ENGINE

New code:

Code: Select all

		vramSetMainBanks(VRAM_A_MAIN_SPRITE, VRAM_B_LCD, VRAM_C_SUB_BG, VRAM_D_LCD);

This seems to work the way I would expect it to and it's also the way the main engine would expect me to set the memory banks, I guess. All these codes make me a little dizzy but reverse engineering always did.

--greybeard

devkitPro

fire and sprites example

fire and sprites example

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