/*---------------------------------------------------------------------------*
  Project:  TwlSDK - GX - demos - UnitTours/2D_CharBg_4
  File:     main.c

  Copyright 2003-2008 Nintendo. All rights reserved.

  These coded instructions, statements, and computer programs contain
  proprietary information of Nintendo of America Inc. and/or Nintendo
  Company Ltd., and are protected by Federal copyright law. They may
  not be disclosed to third parties or copied or duplicated in any form,
  in whole or in part, without the prior written consent of Nintendo.

  $Date:: 2008-09-18#$
  $Rev: 8573 $
  $Author: okubata_ryoma $
 *---------------------------------------------------------------------------*/
//---------------------------------------------------------------------------
// A sample that scrolls BG #0 (text mode):
//
// USAGE:
//   UP, DOWN, LEFT, RIGHT      : Scrolls a sphere
//   SELECT     :                Move sphere to the initial position
//
// HOWTO:
// 1. Set up the character/palette/screen data same as 2D_CharBG_1.
// 2. Specify an offset with G2_SetBGxOffset().
//---------------------------------------------------------------------------

#ifdef SDK_TWL
#include <twl.h>
#else
#include <nitro.h>
#endif
#include "DEMO.h"
#include "data.h"

static u16 sScrnBuf[SCREEN_SIZE];      // Buffer for screen data (BG #0)

#ifdef SDK_TWL
void TwlMain(void)
#else
void NitroMain(void)
#endif
{
    int     offset_H = 0, offset_V = 0;

    //---------------------------------------------------------------------------
    // Initialize:
    // Enables IRQ interrupts, initializes VRAM, and sets BG #0 for text mode.
    //---------------------------------------------------------------------------
    DEMOInitCommon();
    DEMOInitVRAM();
    DEMOInitDisplayBG0Only();

    //---------------------------------------------------------------------------
    // Transmitting the character data and the palette data
    //---------------------------------------------------------------------------
    GX_LoadBG0Char(d_64_256_bg_schDT, 0, sizeof(d_64_256_bg_schDT));
    GX_LoadBGPltt(d_64_256_bg_sclDT, 0, sizeof(d_64_256_bg_sclDT));

    {
        int     i, j;
        for (i = 0; i < 8; i++)
        {
            for (j = 0; j < 8; j++)
            {
                sScrnBuf[(i * 32) + j] = (u16)((i * 0x10) + j);
            }
        }
    }

    // Store the data in the main memory, and invalidate the cache.
    DC_FlushRange(sScrnBuf, sizeof(sScrnBuf));
    /* I/O register is accessed using DMA operation, so cache wait is not needed */
    // DC_WaitWriteBufferEmpty();

    // DMA Transfer to BG #0 screen
    GX_LoadBG0Scr(sScrnBuf, 0, sizeof(sScrnBuf));

    DEMOStartDisplay();
    //---------------------------------------------------------------------------
    // Main Loop
    //---------------------------------------------------------------------------
    while (1)
    {
        DEMOReadKey();

        if (DEMO_IS_PRESS(PAD_KEY_UP))
            offset_V += 2;
        if (DEMO_IS_PRESS(PAD_KEY_DOWN))
            offset_V -= 2;
        if (DEMO_IS_PRESS(PAD_KEY_RIGHT))
            offset_H -= 2;
        if (DEMO_IS_PRESS(PAD_KEY_LEFT))
            offset_H += 2;
        if (DEMO_IS_TRIG(PAD_BUTTON_SELECT))
        {
            offset_H = 0;
            offset_V = 0;
        }

#ifdef SDK_AUTOTEST
        offset_H = 10;
        offset_V = 15;                 // default params for testing.
        GX_SetBankForLCDC(GX_VRAM_LCDC_C);
        EXT_TestSetVRAMForScreenShot(GX_VRAM_LCDC_C);
        EXT_TestScreenShot(100, 0xAF23A638);
        EXT_TestTickCounter();
#endif //SDK_AUTOTEST

        OS_WaitVBlankIntr();           // Waiting for the end of the VBlank interrupt

        // Setting the offset for BG #0 plane
        G2_SetBG0Offset(offset_H, offset_V);
    }
}

//---------------------------------------------------------------------------
// VBlank interrupt function:
//
// Interrupt handlers are registered on the interrupt table by OS_SetIRQFunction.
// OS_EnableIrqMask selects IRQ interrupts to enable, and
// OS_EnableIrq enables IRQ interrupts.
// Notice that you have to call 'OS_SetIrqCheckFlag' to check a VBlank interrupt.
//---------------------------------------------------------------------------
void VBlankIntr(void)
{
    OS_SetIrqCheckFlag(OS_IE_V_BLANK); // Checking VBlank interrupt
}