/*---------------------------------------------------------------------------*
  Project:  TwlSDK - GX - demos - UnitTours/Sub_CharBg_7
  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 blends two text BG planes
//
// USAGE:
//   UP, DOWN, LEFT, RIGHT: Controls blending coefficients
//
// HOWTO:
// 1. Set up the character/palette/screen data the same as Sub_CharBg_1
// 2. Specify the planes blended and blend ratio with G2S_SetBlendAlpha
// 3. You can also control the blend ratio with G2S_ChangeBlendAlpha
//---------------------------------------------------------------------------

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

static u16 sScrnBuf1[SCREEN_SIZE];     // Buffer for screen data (BG #0)
static u16 sScrnBuf2[SCREEN_SIZE];     // Buffer for screen data (BG #1)

#ifdef SDK_TWL
void TwlMain(void)
#else
void NitroMain(void)
#endif
{

    int     eva = 0, evb = 0;

    //---------------------------------------------------------------------------
    // Initialize:
    // Enables IRQ interrupts, initializes VRAM, and sets BG #0 for text mode
    //---------------------------------------------------------------------------
    DEMOInitCommon();
    DEMOInitVRAM();
    DEMOInitDisplaySubBG0Only();

    //---------------------------------------------------------------------------
    // Setting up BG #0 controls
    //---------------------------------------------------------------------------
    G2S_SetBG0Control(GX_BG_SCRSIZE_TEXT_256x256,
                      GX_BG_COLORMODE_256,
                      GX_BG_SCRBASE_0x0000, GX_BG_CHARBASE_0x04000, GX_BG_EXTPLTT_01);
    G2S_SetBG0Priority(0);
    G2S_BG0Mosaic(FALSE);

    //---------------------------------------------------------------------------
    // Setting up BG #1 controls
    //---------------------------------------------------------------------------
    G2S_SetBG1Control(GX_BG_SCRSIZE_TEXT_256x256,
                      GX_BG_COLORMODE_256,
                      GX_BG_SCRBASE_0x0800, GX_BG_CHARBASE_0x0c000, GX_BG_EXTPLTT_01);

    G2S_SetBG1Priority(1);
    G2S_BG1Mosaic(FALSE);

    //---------------------------------------------------------------------------
    // Transmitting the character data and the palette data
    //---------------------------------------------------------------------------
    GXS_LoadBG0Char(d_al_1_schDT, 0, sizeof(d_al_1_schDT));
    GXS_LoadBG1Char(d_al_2_schDT, 0, sizeof(d_al_2_schDT));
    GXS_LoadBGPltt(d_al_1_sclDT, 0, sizeof(d_al_1_sclDT));

    GXS_SetVisiblePlane(GX_PLANEMASK_BG0 | GX_PLANEMASK_BG1);   // Displays BG #0 and BG #1

    {
        int     i, j;

        for (i = 0; i < 18; i++)
        {
            for (j = 0; j < 12; j++)
            {
                sScrnBuf1[((i + 3) * 32) + (j + 11)] = (u16)((i * 0x10) + j);
            }
        }
        // Store the data in main memory, and invalidate the cache
        DC_FlushRange(sScrnBuf1, sizeof(sScrnBuf1));

        MI_CpuFill16(sScrnBuf2, 0xffff, SCREEN_SIZE * sizeof(u16));

        for (i = 0; i < 13; i++)
        {
            for (j = 0; j < 16; j++)
            {
                sScrnBuf2[((i + 6) * 32) + (j + 9)] = (u16)((i * 0x10) + j);
            }
        }
        // Store the data in main memory, and invalidate the cache
        DC_FlushRange(sScrnBuf2, sizeof(sScrnBuf2));
    }

    // DMA Transfer to BG0 and BG1 screen
    /* I/O register is accessed using DMA operation, so cache wait is not needed */
    // DC_WaitWriteBufferEmpty();
    GXS_LoadBG0Scr(sScrnBuf1, 0, sizeof(sScrnBuf1));
    GXS_LoadBG1Scr(sScrnBuf2, 0, sizeof(sScrnBuf2));

    //---------------------------------------------------------------------------
    // Setting up alpha blending
    //
    // The first plane is BG #0 and the second one is BG #1.
    // Alpha blending occurs if and only if BG #1 is just behind BG #0.
    //---------------------------------------------------------------------------
    G2S_SetBlendAlpha(GX_BLEND_PLANEMASK_BG0,   // Specifies only BG #0
                      GX_BLEND_PLANEMASK_BG1,   // Specifies only BG #1
                      0,               // eva
                      0                // evb
        );

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

        if (DEMO_IS_PRESS(PAD_KEY_UP))
            eva++;
        if (DEMO_IS_PRESS(PAD_KEY_DOWN))
            eva--;
        if (DEMO_IS_PRESS(PAD_KEY_RIGHT))
            evb++;
        if (DEMO_IS_PRESS(PAD_KEY_LEFT))
            evb--;
        if (eva < 0x00)
            eva = 0x00;
        if (eva > 0x10)
            eva = 0x10;
        if (evb < 0x00)
            evb = 0x00;
        if (evb > 0x10)
            evb = 0x10;

        OS_WaitVBlankIntr();           // Waiting for the end of the V-Blank interrupt

        //---------------------------------------------------------------------------
        // Change the coefficients for alpha blending
        //---------------------------------------------------------------------------
        G2S_ChangeBlendAlpha(eva, evb);
    }

}

//---------------------------------------------------------------------------
// V-Blank 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 V-Blank interrupt
//---------------------------------------------------------------------------
void VBlankIntr(void)
{
    OS_SetIrqCheckFlag(OS_IE_V_BLANK); // Checking V-Blank interrupt
}