Method for gesture manipulation on a display and host

A host, comprising:

• a storage circuit, configured to store a program code;
• and
• a processor, coupled to the storage circuit and configured to access the program code to execute:
• obtaining, through a camera, a hand image of a hand of a user;
• performing a hand tracking of the hand based on the hand image;
• performing a ray casting based on the hand tracking;
• obtaining a casting point on a screen of a display based on the ray casting;
• rendering a rendered point on the screen of the display based on the casting point and a projection matrix;
• storing, in the storage circuit, a relative position between the casting point and the rendered point as history manipulation information;
• and
• updating the projection matrix based on the relative position between the casting point and the rendered point.