Puyo Puyo Tsu/Pair Lateral Movement

Lateral pair movement is handled from the main puyo's callback routine. It is the first movement that gets accounted for when the game deals with gamepad input.

The routine itself is pretty simple:

Here's the sequence going on here:

• ends if the pair is already undergoing lateral movement (the shift value is not null), clearing this shift value;
• ends if the pair is locked;
• ends if no right or left arrow is pressed;
• prepares coordinate displacement values according to direction;
• ends if the target cells are blocked;
• updates the pairs coordinates on the board;
• updates shift value to have a smooth transition animation;
• plays the relevant sound effect and exits.

The shift value is an on-screen displacement measured in pixels, and is set to 8 (half the width of a cell).

Notable facts

• The column change is acknowledged immediately on the same frame the input is detected.
• The animation takes 2 frames to complete.
• Lateral movement is subject to input repeat, and cannot be entered in two consecutive frames, even in opposite directions (due to the first check of the routine). See Puyo Puyo Tsu/Gamepad Input for more information on possible input tricks and Puyo Puyo Tsu/Frame Data Tables for input repeat timings.