#include <mygba.h>

#define MODE_0 0x0
#define MODE_1 0x1
#define MODE_2 0x2
#define MODE_3 0x3
#define BG2_ENABLE 0x400
#define RGB(r,g,b) (unsigned short)(r + (g << 5) + (b << 10))

MULTIBOOT

unsigned short* videoBuffer = (unsigned short*)0x6000000;

void drawPixel (int x, int y, unsigned short colour);
void rectFill (int startX, int startY, int endX, int endY, unsigned short colour);

void drawPixel (int x, int y, unsigned short colour)
{
    videoBuffer[y * 240 + x] = colour;
}

void rectFill (int startX, int startY, int endX, int endY, unsigned short colour)
{

    int row, col;

    for (row = startX; row <= endX; row++)
    {

        for (col = startY; col <= endY; col++)
        {
            drawPixel(row, col, colour);
        }

    }

}

int main()
{

    int row, col;
    unsigned short colour;
    bool rowFirst = 1, flip = 1;

    REG_DISPCNT = (MODE_3 | BG2_ENABLE);

    for (row = 0; row < 160; row += 20)
    {

        flip = rowFirst;

        for (col = 0; col < 240; col += 20)
        {

            if (flip)
            {
                colour = RGB(0, 0, 255);
            }
            else
            {
                colour = RGB(0, 255, 0);
            }

            rectFill(col, row, (col + 19), (row + 19), colour);
            flip = !flip;

        }

        rowFirst = !rowFirst;

    }

   while (TRUE)
   {

   }

   return 0;

}


/* END OF FILE */