/**
* Display a single character right to left
*
* @param character The character to be displayed
*/
public void displayCharacterBackward(char character) {
try {
dots = font.getChar(character);
for (int i = dots.length - 1; i >= 0; i--) {
bltLEDs(dots[i]);
// System.out.print(character);
Thread.sleep(1);
}
bltLEDs(0);
Thread.sleep(1);
} catch (InterruptedException ex) {
ex.printStackTrace();
}
}
/**
* Scroll a string across the swinging display
*
* @param string The string to display
* @param scrollrate The speed to scroll at. To be readable, this should be a value from 1 to 10.
*/
public void scroll(String string, int scrollrate) {
long start = System.currentTimeMillis();
long left = start;
long right = start;
int overhead = 140; // The magic values of overhead and gap
int gap = 170; // were set empirically
int i, j, offset = overhead;
int len = string.length();
int mapSize = 0;
int[] bitmap;
boolean lefting = false; // debug
System.out.println("start scrolling " + string);
// find the length of the bitmap
for (i = 0; i < len; i++) {
mapSize += (font.getCharWidth(string.charAt(i))) + 1;
}
// create a custom length array to hold the bitmap
bitmap = new int[mapSize + (2 * overhead)];
for (i = 0; i < bitmap.length; i++) bitmap[i] = 0;
// preload the bitmap for the whole string
// this is probably a bad idea memory-wse, but I'm in a hurry
for (i = 0; i < len; i++) {
int[] character = font.getChar(string.charAt(i));
for (j = 0; j < character.length; j++) {
bitmap[offset++] = character[j];
}
bitmap[offset++] = 0;
}
System.out.println("bitmap inited");
offset = overhead - (gap - overhead);
double threshold = 1.0;
try {
while (offset < bitmap.length - gap) {
// wait for motion
double acceleration = accelerometer.getAccelY();
if (acceleration > threshold) {
while (acceleration > threshold) {
Thread.sleep(10);
acceleration = accelerometer.getAccelY();
}
bltBitmapForward(bitmap, offset, gap - overhead);
offset += scrollrate;
} else if (acceleration < -threshold) {
while (acceleration < -threshold) {
Thread.sleep(10);
acceleration = accelerometer.getAccelY();
}
bltBitmapBackward(bitmap, offset, gap - overhead);
offset += scrollrate;
}
try {
Thread.sleep(100);
} catch (InterruptedException ex) {
ex.printStackTrace();
}
}
System.out.println(" finished scrolling " + gap);
} catch (IOException ex) {
ex.printStackTrace();
} catch (InterruptedException ex) {
ex.printStackTrace();
}
}
