How can I cross the river?

Hint 1 of 9:

Note that the log followed you when you walked near it.

Hint 2 of 9:

Somehow you need to stop the log long enough to cross it.

Hint 3 of 9:

That rock on the ground is big enough to stop it.

Hint 4 of 9:

Use the rock on the river.

Hint 5 of 9:

Walk to the log to get it to move further.

Hint 6 of 9:

Another log should appear at the top of the screen.

Hint 7 of 9:

You need something to wedge it in place more securely.

Hint 8 of 9:

Pick up the spear from the bushes.