Hi I was going through Sample of analog watch.In onDraw method I came across this logic
@Override
public void onDraw(Canvas canvas, Rect bounds) {
mTime.setToNow();
// Draw the background.
if (isInAmbientMode()) {
canvas.drawColor(Color.BLACK);
} else {
canvas.drawRect(0, 0, canvas.getWidth(), canvas.getHeight(), mBackgroundPaint);
}
// Find the center. Ignore the window insets so that, on round watches with a
// "chin", the watch face is centered on the entire screen, not just the usable
// portion.
float centerX = bounds.width() / 2f;
float centerY = bounds.height() / 2f;
float secRot = (mTime.second / 30f) * (float) Math.PI;
int minutes = mTime.minute;
float minRot = minutes / 30f * (float) Math.PI;
float hrRot = ((mTime.hour + (minutes / 60f)) / 6f) * (float) Math.PI;
float secLength = centerX - 20;
float minLength = centerX - 40;
float hrLength = centerX - 80;
if (!mAmbient) {
float secX = (float) Math.sin(secRot) * secLength;
float secY = (float) -Math.cos(secRot) * secLength;
canvas.drawLine(centerX, centerY, centerX + secX, centerY + secY, mHandPaint);
}
float minX = (float) Math.sin(minRot) * minLength;
float minY = (float) -Math.cos(minRot) * minLength;
canvas.drawLine(centerX, centerY, centerX + minX, centerY + minY, mHandPaint);
float hrX = (float) Math.sin(hrRot) * hrLength;
float hrY = (float) -Math.cos(hrRot) * hrLength;
canvas.drawLine(centerX, centerY, centerX + hrX, centerY + hrY, mHandPaint);
}
I am not understanding what is exact meaning of these line
float secRot = (mTime.second / 30f) * (float) Math.PI;
int minutes = mTime.minute;
float minRot = minutes / 30f * (float) Math.PI;
float hrRot = ((mTime.hour + (minutes / 60f)) / 6f) * (float) Math.PI;
