/*
 * images.c
 * this program demonstrates image files
 */

/* the width and height of the screen */
#define WIDTH 240
#define HEIGHT 160

/* include the actual image file data */
#include "image.h"

/* the screen is simply a pointer into memory at a specific address this
 *  * pointer points to 16-bit colors of which there are 240x160 */
volatile unsigned short* screen = (volatile unsigned short*) 0x6000000;

/* the display control pointer points to the gba graphics register */
volatile unsigned long* display_control = (volatile unsigned long*) 0x4000000;

/* these identifiers define different bit positions of the display control */
#define MODE3 0x0003
#define BG2 0x0400

/* place a pixel of a given color on the screen */
void put_pixel(int row, int col, unsigned short color) {
    /* set the screen location to this color */
    screen[row * WIDTH + col] = color;
}

/* the main function */
int main() { 
    /* we set the mode to mode 3 with bg2 on */
    *display_control = MODE3 | BG2;

    /* loop through each column of the screen */
    for (int row = 0; row < HEIGHT; row++) { 
        for (int col = 0; col < WIDTH; col++) {
            put_pixel(row, col, image_data[row * WIDTH + col]);
        }
    }

    /* we now loop forever displaying the image */
    while (1) {
        /* do nothing */
    }
}