main.c

// Simple citro2d sprite drawing example
// Images borrowed from:
//   https://kenney.nl/assets/space-shooter-redux
#include <citro2d.h>

#include <assert.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>

#define MAX_SPRITES   768
#define SCREEN_WIDTH  400
#define SCREEN_HEIGHT 240

// Simple sprite struct
typedef struct
{
	C2D_Sprite spr;
	float z;
	float dx, dy; // velocity
} Sprite;

static C2D_SpriteSheet spriteSheet;
static Sprite sprites[MAX_SPRITES];
static size_t numSprites = MAX_SPRITES/2;

float depth = 100;
bool rotation = false;

//---------------------------------------------------------------------------------
static void initSprites() {
//---------------------------------------------------------------------------------
	size_t numImages = C2D_SpriteSheetCount(spriteSheet);
	srand(time(NULL));

	for (size_t i = 0; i < MAX_SPRITES; i++)
	{
		Sprite* sprite = &sprites[i];

		// Random image, position, rotation and speed
		C2D_SpriteFromSheet(&sprite->spr, spriteSheet, rand() % numImages);
		C2D_SpriteSetCenter(&sprite->spr, 0.5f, 0.5f);
		C2D_SpriteSetPos(&sprite->spr, rand() % SCREEN_WIDTH, rand() % SCREEN_HEIGHT);
		// C2D_SpriteSetRotation(&sprite->spr, C3D_Angle(rand()/(float)RAND_MAX));
		sprite->dx = rand()*4.0f/RAND_MAX - 2.0f;
		sprite->dy = rand()*4.0f/RAND_MAX - 2.0f;
		sprite->z  = (MAX_SPRITES-i) / depth;
		// sprite->z  = -(rand()*10.0f/RAND_MAX - 5.0f);
	}
}

//---------------------------------------------------------------------------------
static void moveSprites() {
//---------------------------------------------------------------------------------
	for (size_t i = 0; i < numSprites; i++)
	{
		Sprite* sprite = &sprites[i];
		C2D_SpriteMove(&sprite->spr, sprite->dx, sprite->dy);

		if (rotation) {
			C2D_SpriteRotateDegrees(&sprite->spr, 1.0f);
		}

		// Check for collision with the screen boundaries
		if ((sprite->spr.params.pos.x < sprite->spr.params.pos.w / 2.0f && sprite->dx < 0.0f) ||
			(sprite->spr.params.pos.x > (SCREEN_WIDTH-(sprite->spr.params.pos.w / 2.0f)) && sprite->dx > 0.0f))
			sprite->dx = -sprite->dx;

		if ((sprite->spr.params.pos.y < sprite->spr.params.pos.h / 2.0f && sprite->dy < 0.0f) ||
			(sprite->spr.params.pos.y > (SCREEN_HEIGHT-(sprite->spr.params.pos.h / 2.0f)) && sprite->dy > 0.0f))
			sprite->dy = -sprite->dy;

		sprite->z  = (MAX_SPRITES-i) / depth;
	}
}

//---------------------------------------------------------------------------------
int main(int argc, char* argv[]) {
//---------------------------------------------------------------------------------
	// Init libs
	romfsInit();
	gfxInitDefault();
	gfxSet3D(true); // Enable stereoscopic 3D
	C3D_Init(C3D_DEFAULT_CMDBUF_SIZE);
	C2D_Init(C2D_DEFAULT_MAX_OBJECTS);
	C2D_Prepare();
	consoleInit(GFX_BOTTOM, NULL);

	// Create screens
	C3D_RenderTarget* topLeft = C2D_CreateScreenTarget(GFX_TOP, GFX_LEFT);
	C3D_RenderTarget* topRight = C2D_CreateScreenTarget(GFX_TOP, GFX_RIGHT);

	// Load graphics
	spriteSheet = C2D_SpriteSheetLoad("romfs:/gfx/sprites.t3x");
	if (!spriteSheet) svcBreak(USERBREAK_PANIC);

	// Initialize sprites
	initSprites();

	printf("\x1b[8;1HPress Up to increment sprites");
	printf("\x1b[9;1HPress Down to decrement sprites");

	// Main loop
	while (aptMainLoop())
	{
		hidScanInput();

		// Respond to user input
		u32 kDown = hidKeysDown();
		if (kDown & KEY_START)
			break; // break in order to return to hbmenu

		if (kDown & KEY_X)
			rotation = !rotation;

		u32 kHeld = hidKeysHeld();
		if ((kHeld & KEY_UP) && numSprites < MAX_SPRITES)
			numSprites++;
		if ((kHeld & KEY_DOWN) && numSprites > 1)
			numSprites--;

		if ((kHeld & KEY_LEFT))
			depth--;
		if ((kHeld & KEY_RIGHT))
			depth++;

		moveSprites();

		printf("\x1b[1;1HSprites: %zu/%u\x1b[K", numSprites, MAX_SPRITES);
		printf("\x1b[2;1HCPU:     %6.2f%%\x1b[K", C3D_GetProcessingTime()*6.0f);
		printf("\x1b[3;1HGPU:     %6.2f%%\x1b[K", C3D_GetDrawingTime()*6.0f);
		printf("\x1b[4;1HCmdBuf:  %6.2f%%\x1b[K", C3D_GetCmdBufUsage()*100.0f);
		printf("\x1b[5;1Hdepth:   %6.2f%%\x1b[K", depth);

		// Render the scene
		C3D_FrameBegin(C3D_FRAME_SYNCDRAW);
		C2D_TargetClear(topLeft, C2D_Color32f(0.0f, 0.0f, 0.0f, 1.0f));
		C2D_SceneBegin(topLeft);
		for (size_t i = 0; i < numSprites; i ++) {
			float oldX = sprites[i].spr.params.pos.x;
			sprites[i].spr.params.pos.x -= sprites[i].z;
			C2D_DrawSprite(&sprites[i].spr);
			sprites[i].spr.params.pos.x = oldX;
		}


		C2D_TargetClear(topRight, C2D_Color32f(0.0f, 0.0f, 0.0f, 1.0f));
		C2D_SceneBegin(topRight);
		for (size_t i = 0; i < numSprites; i ++) {
			float oldX = sprites[i].spr.params.pos.x;
			sprites[i].spr.params.pos.x += sprites[i].z;
			C2D_DrawSprite(&sprites[i].spr);
			sprites[i].spr.params.pos.x = oldX;
		}

		C3D_FrameEnd(0);
	}

	// Delete graphics
	C2D_SpriteSheetFree(spriteSheet);

	// Deinit libs
	C2D_Fini();
	C3D_Fini();
	gfxExit();
	romfsExit();
	return 0;
}