testGraphics.c

#include <stdio.h>
#include <string.h>
#include <3ds.h>

#define GFX_TOP_WIDTH     400
#define GFX_TOP_HEIGHT    240
#define GFX_BOTTOM_WIDTH  320
#define GFX_BOTTOM_HEIGHT 240

u32 kDown;        // keys down
u32 kHeld;        // keys pressed
u32 kUp;          // keys up
u8* fbTopLeft;    // top left screen's framebuffer
u8* fbTopRight;   // top right screen's framebuffer
u8* fbBottom;     // bottom screen's framebuffer
u8* sprites;

void resetBuffers()
{
  fbTopLeft = gfxGetFramebuffer(GFX_TOP, GFX_LEFT, NULL, NULL);
  fbTopRight = gfxGetFramebuffer(GFX_TOP, GFX_RIGHT, NULL, NULL);
  fbBottom = gfxGetFramebuffer(GFX_BOTTOM, 0, NULL, NULL);
  memset(fbTopLeft, 0, 240 * 400 * 3);
  memset(fbTopRight, 0, 240 * 400 * 3);
  memset(fbBottom, 0, 240 * 320 * 3);
}

void init()
{
  srvInit();        // services
  aptInit();        // applets
  hidInit(NULL);    // input
  gfxInitDefault(); // graphics
  gfxSet3D(false);  // stereoscopy (true == on / false == off)
  resetBuffers();
}

void quit()
{
  gfxExit();
  hidExit();
  aptExit();
  srvExit();
}

void setPixelRGB(u8* buffer, int w, int h, int x, int y, int r, int g, int b)
{
  if((x < w) && (y < h))
  {
    buffer[((h * x) + (h - y)) * 3] = b;
    buffer[(((h * x) + (h - y)) * 3) + 1] = g;
    buffer[(((h * x) + (h - y)) * 3) + 2] = r;
  }
}

void setPixelBGR(u8* buffer, int w, int h, int x, int y, int b, int g, int r)
{
  if((x < w) && (y < h))
  {
    buffer[((h * x) + (h - y)) * 3] = b;
    buffer[(((h * x) + (h - y)) * 3) + 1] = g;
    buffer[(((h * x) + (h - y)) * 3) + 2] = r;
  }
}

int main()
{
  init();
  // Main loop
  while (aptMainLoop())
  {
    // Wait for next frame
    gspWaitForVBlank();

    // Read which buttons are currently pressed or not
    hidScanInput();
    kDown = hidKeysDown();
    kHeld = hidKeysHeld();
    kUp = hidKeysUp();

    // If START button is pressed, break loop and quit
    if (kDown & KEY_START)
    {
      break;
    }

    //resetBuffers();

    setPixelRGB(fbTopLeft, GFX_TOP_WIDTH, GFX_TOP_HEIGHT, 0, 0, 255, 0, 0);

    // Flush and swap framebuffers
    gfxFlushBuffers();
    gfxSwapBuffers();
  }

  quit();

  // Return to hbmenu
  return 0;
}