#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))
#define WHITE 0xFFFF
#define BLACK 0x0000
#define RED RGB(255, 0, 0)
#define GREEN RGB(0, 255, 0)
#define BLUE RGB(0, 0, 255)

MULTIBOOT

const unsigned short NUM_ROWS = 16, NUM_COLS = 24, CELL_SIZE = 10;
const unsigned short BACKGROUND_PATH = 0, BACKGROUND_WALL = 1;
const unsigned short BACKGROUND_PATH_COLOUR = WHITE, BACKGROUND_WALL_COLOUR = BLACK;
unsigned short* videoBuffer = (unsigned short*)0x6000000;

unsigned short maze[16][24] = {
{1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1},
{1,0,0,0,0,0,0,0,1,0,1,1,1,1,0,0,0,0,1,1,0,0,0,0},
{1,0,1,1,1,1,1,0,0,0,0,1,1,0,0,1,1,0,0,0,0,1,0,1},
{1,0,1,0,0,0,1,0,1,1,0,1,0,0,1,1,1,1,1,1,1,1,0,1},
{1,0,1,0,1,0,1,1,1,1,0,1,0,1,1,0,0,0,0,0,0,1,0,1},
{1,0,1,1,1,0,1,0,0,1,0,0,0,0,1,0,1,0,1,1,1,1,0,1},
{1,0,0,0,0,0,1,0,1,1,1,1,1,1,1,0,1,0,0,0,0,1,1,1},
{1,1,1,1,0,1,1,0,0,0,0,1,0,0,0,0,1,0,1,1,0,0,0,1},
{1,0,0,0,0,0,1,1,1,1,0,1,0,1,1,1,1,1,1,1,1,1,0,1},
{1,0,1,1,1,0,0,0,0,1,0,1,0,1,0,0,0,0,0,0,1,1,0,1},
{1,0,0,0,0,0,1,1,0,0,0,0,0,1,0,1,1,1,1,0,0,0,0,1},
{1,1,1,1,1,0,1,1,1,1,1,1,0,1,0,0,0,0,1,1,1,1,0,1},
{1,0,0,0,0,0,0,1,0,0,1,0,0,1,0,1,0,1,1,1,0,0,0,1},
{1,1,0,1,1,1,0,1,1,0,1,0,1,1,0,1,0,0,0,1,1,1,0,1},
{0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,1,0,1,0,0,1,0,0,1},
{1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1}};

unsigned short gameStartRow = 14, gameStartCol = 0, gameEndRow = 1, gameEndCol = 23;
unsigned short currentRow, currentCol;

void clearScreen ();
void displayEndGame ();
void drawPixel (int x, int y, unsigned short colour);
void drawPlayer ();
void drawTile (int row, int col);
void rectFill (int startX, int startY, int endX, int endY, unsigned short colour);

void clearScreen ()
{
    rectFill(0, 0, 240, 160, WHITE);
}

void displayEndGame ()
{
    clearScreen();
}

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

void drawPlayer ()
{
    rectFill(currentCol * CELL_SIZE, currentRow * CELL_SIZE, ((currentCol + 1) * CELL_SIZE), ((currentRow + 1) * CELL_SIZE), BLUE);
}

void drawTile (int row, int col)
{
    
    unsigned short colour;
    
    if (maze[row][col] == BACKGROUND_PATH)
    {
        colour = BACKGROUND_PATH_COLOUR;
    }
    else
    {
        colour = BACKGROUND_WALL_COLOUR;
    }
    
    rectFill((col * CELL_SIZE), (row * CELL_SIZE), ((col + 1) * CELL_SIZE), ((row + 1) * CELL_SIZE), 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 ()
{
    
    REG_DISPCNT = (MODE_3 | BG2_ENABLE);

    int row, col, lastRow, lastCol;
    int keyPressed = 0, gameWon = 0;
    
    for (row = 0; row < NUM_ROWS; row++)
    {
        
        for (col = 0; col < NUM_COLS; col++)
        {
            drawTile(row, col);
        }
        
    }
    
    currentRow = gameStartRow;
    currentCol = gameStartCol;
    
    drawPlayer();

   while (1)
   {

       if (gameWon)
       {
           continue;
       }
       
       lastRow = currentRow;
       lastCol = currentCol;

       if (F_CTRLINPUT_UP_PRESSED)
       {

           if (!keyPressed && currentRow > 0 && maze[currentRow - 1][currentCol] == BACKGROUND_PATH)
           {
               currentRow--;
           }

       }
       else if (F_CTRLINPUT_DOWN_PRESSED)
       {

           if (!keyPressed && currentRow < (NUM_ROWS - 1) && maze[currentRow + 1][currentCol] == BACKGROUND_PATH)
           {
               currentRow++;
           }

       }
       else if (F_CTRLINPUT_LEFT_PRESSED)
       {

           if (!keyPressed && currentCol > 0 && maze[currentRow][currentCol - 1] == BACKGROUND_PATH)
           {
               currentCol--;
           }

       }
       else if (F_CTRLINPUT_RIGHT_PRESSED)
       {

           if (!keyPressed && currentCol < (NUM_COLS - 1) && maze[currentRow][currentCol + 1] == BACKGROUND_PATH)
           {
               currentCol++;
           }

       }
       else
       {
           keyPressed = 0;
       }

       if (!(lastRow == currentRow && lastCol == currentCol))
       {

           drawTile(lastRow, lastCol);
           drawPlayer();
           keyPressed = 1;
           
           if (currentRow == gameEndRow && currentCol == gameEndCol)
           {
               
               displayEndGame();
               gameWon = 1;
               
           }
           
       }

   }

   return 0;

}

/* END OF FILE */