cenotaph/src/treasure.h

#define TREASURE_OFF 16


void spawnTreasure(u8 zone){
	s16 i = -1;
	for(s16 j = 0; j < TREASURE_COUNT; j++) if(!treasures[j].active) { i = j; break; }
	if(i == -1) return;

	treasures[i].active = TRUE;
	treasures[i].state = TREASURE_WALKING;
	treasures[i].carriedBy = -1;

	fix32 zoneStart = FIX32(zone * 512);
	treasures[i].pos.x = zoneStart + FIX32(random() % 512);
	treasures[i].pos.y = GAME_H_F - FIX32(24);

	fix32 speeds[] = { FIX32(0.3), FIX32(0.4), FIX32(0.5) };
	treasures[i].vel.x = (random() % 2 == 0) ? speeds[random() % 3] : -speeds[random() % 3];
	treasures[i].vel.y = (random() % 2 == 0) ? FIX32(0.1) : FIX32(-0.1);

	treasures[i].image = SPR_addSprite(&treasureSprite,
		getScreenX(treasures[i].pos.x, player.camera) - TREASURE_OFF, fix32ToInt(treasures[i].pos.y) - TREASURE_OFF,
		TILE_ATTR(PAL0, 0, 0, 0));
	if(!treasures[i].image){
		treasures[i].active = FALSE;
		return;
	}
	SPR_setVisibility(treasures[i].image, HIDDEN);
	treasures[i].type = random() % 4;
	SPR_setAnim(treasures[i].image, treasures[i].type);
}

static void updateTreasure(u8 i){
	switch(treasures[i].state){
		case TREASURE_WALKING:
			// Y bounce: bob 4px around ground level
			if(treasures[i].pos.y >= GAME_H_F - FIX32(20) || treasures[i].pos.y <= GAME_H_F - FIX32(28))
				treasures[i].vel.y *= -1;

			// X wrap
			if(treasures[i].pos.x >= GAME_WRAP)
				treasures[i].pos.x -= GAME_WRAP;
			if(treasures[i].pos.x < 0)
				treasures[i].pos.x += GAME_WRAP;

			treasures[i].pos.x += treasures[i].vel.x;
			treasures[i].pos.y += treasures[i].vel.y;
			break;

		case TREASURE_CARRIED:
			// follow carrier enemy position
			if(treasures[i].carriedBy >= 0 && enemies[treasures[i].carriedBy].active){
				treasures[i].pos.x = enemies[treasures[i].carriedBy].pos.x;
				treasures[i].pos.y = enemies[treasures[i].carriedBy].pos.y + FIX32(16);
			} else {
				// carrier died (shouldn't normally reach here, killEnemy handles it)
				treasures[i].state = TREASURE_FALLING;
				treasures[i].carriedBy = -1;
				treasures[i].vel.x = 0;
				treasures[i].vel.y = FIX32(3);
				treasureBeingCarried = FALSE;
			}
			break;

		case TREASURE_FALLING:
			treasures[i].pos.y += treasures[i].vel.y;
			// land on ground
			if(treasures[i].pos.y >= GAME_H_F - FIX32(24)){
				treasures[i].pos.y = GAME_H_F - FIX32(24);
				treasures[i].state = TREASURE_WALKING;
				fix32 speeds[] = { FIX32(0.3), FIX32(0.4), FIX32(0.5) };
				treasures[i].vel.x = (random() % 2 == 0) ? speeds[random() % 3] : -speeds[random() % 3];
				treasures[i].vel.y = (random() % 2 == 0) ? FIX32(0.1) : FIX32(-0.1);
			}
			break;

		case TREASURE_COLLECTED: {
			fix32 targetX, targetY;
			if(treasures[i].trailIndex == 0){
				targetX = player.pos.x;
				targetY = player.pos.y + FIX32(24);
			} else {
				// find the treasure ahead in the chain
				targetX = player.pos.x;
				targetY = player.pos.y + FIX32(24);
				for(s16 j = 0; j < TREASURE_COUNT; j++){
					if(treasures[j].active && treasures[j].state == TREASURE_COLLECTED
						&& treasures[j].trailIndex == treasures[i].trailIndex - 1){
						targetX = treasures[j].pos.x;
						targetY = treasures[j].pos.y + FIX32(8);
						break;
					}
				}
			}
			fix32 deltaX = getWrappedDelta(targetX, treasures[i].pos.x);
			treasures[i].pos.x += deltaX >> 2;
			treasures[i].pos.y += (targetY - treasures[i].pos.y) >> 2;
			// X wrap
			if(treasures[i].pos.x >= GAME_WRAP)
				treasures[i].pos.x -= GAME_WRAP;
			if(treasures[i].pos.x < 0)
				treasures[i].pos.x += GAME_WRAP;
			break;
		}
	}

	// collect: check overlap with player (walking or falling only)
	fix32 dx = getWrappedDelta(treasures[i].pos.x, player.pos.x);
	if(treasures[i].state != TREASURE_CARRIED && treasures[i].state != TREASURE_COLLECTED){
		fix32 dy = treasures[i].pos.y - player.pos.y;
		if(dx >= FIX32(-32) && dx <= FIX32(32) && dy >= FIX32(-32) && dy <= FIX32(32)){
			score += (treasures[i].state == TREASURE_FALLING) ? 2000 : 1000;
			sfxPickup();
			treasureCollectedType = treasures[i].type;
			treasureCollectedClock = 120;
			// only add to trail if this type isn't already collected
			bool duplicate = FALSE;
			for(s16 j = 0; j < TREASURE_COUNT; j++){
				if(treasures[j].active && treasures[j].state == TREASURE_COLLECTED
					&& treasures[j].type == treasures[i].type){
					duplicate = TRUE;
					break;
				}
			}
			if(duplicate){
				killTreasure(i);
			} else {
				treasures[i].state = TREASURE_COLLECTED;
				treasures[i].trailIndex = collectedCount++;
			}
			return;
		}
	}

	s16 sx = getScreenX(treasures[i].pos.x, player.camera);
	s16 sy = fix32ToInt(treasures[i].pos.y);
	bool visible = (treasures[i].state == TREASURE_COLLECTED) || (dx >= -CULL_LIMIT && dx <= CULL_LIMIT);
	if(visible && treasures[i].state == TREASURE_COLLECTED){
		if(player.respawnClock > 0)
			visible = FALSE;
		else if(player.recoveringClock > 0)
			visible = (player.recoveringClock % 20 > 10);
	}
	SPR_setVisibility(treasures[i].image, visible ? VISIBLE : HIDDEN);
	SPR_setPosition(treasures[i].image, sx - TREASURE_OFF, sy - TREASURE_OFF);
	// frame 0 = normal, frame 1 = flash, frame 2 = collected/faded
	if(treasures[i].state == TREASURE_WALKING || treasures[i].state == TREASURE_FALLING)
		SPR_setFrame(treasures[i].image, (clock / 15) & 1);
	else if(treasures[i].state == TREASURE_COLLECTED)
		SPR_setFrame(treasures[i].image, 2);
	else
		SPR_setFrame(treasures[i].image, 0);
}

void updateTreasures(){
	for(s16 i = 0; i < TREASURE_COUNT; i++)
		if(treasures[i].active)
			updateTreasure(i);
}