Display device, and method of controlling display device

A method of controlling a display device, comprising:

• generating a composite image including a first image based on a first image signal, a second image based on a second image signal, and a boundary line between the first image and the second image;
• displaying the composite image having been generated on a display surface;
• detecting a position of a pointing body with respect to the display surface;
• and
• re-generating the composite image with the boundary line moved based on the detected position of the pointing body, such that relative sizes of the first image and the second image in the composite image are changed based on the detected position of the pointing body, while the first image is displayed based on the same first image signal and the second image is displayed based on the same second image signal, wherein
• the composite image is re-generated with the boundary line moved based on the detected position of the pointing body without receiving a change in either the first image signal or the second image signal, and
• the first image is displayed based on the same first image signal and the second image is displayed based on the same second image signal before and after the re-generation.

A non-transitory computer readable storage medium storing a program executable by a computer controlling a display device, the program causes the computer to:

• generate a composite image including a first image based on a first image signal, a second image based on a second image signal, and a boundary line between the first image and the second image;
• display the composite image having been generated on a display surface;
• detect a position of a pointing body with respect to the display surface;
• and
• re-generate the composite image with the boundary line moved based on the detected position of the pointing body, such that relative sizes of the first image and the second image in the composite image are changed based on the detected position of the pointing body, while the first image is displayed based on the same first image signal, and the second image is displayed based on the same second image signal, wherein
• the composite image is re-generated with the boundary line moved based on the detected position of the pointing body without receiving a change in either the first image signal or the second image signal, and
• the first image is displayed based on the same first image signal and the second image is displayed based on the same second image signal before and after the re-generation.