Pre-Loading Screen Images

Commands:

LI Load off-screen image

TI Transfer screen image

SI Save screen image

These commands allow you to render images into an off-screen canvas and then use them a later point in time for instant presentation.

By default, direct-rendering mode is used which means the images are rendered into the visible screen image. With today’s power of graphics cards, this mode is usually good enough to achieve a single page switch, but larger pictures or screen images composed of multiple pictures may benefit from pre-loading into off-screen canvas.

You can activate off-screen image with the LI command. This trial activates or de-activates off-screen rendering for subsequent visual presentation commands like SP and FP. The resulting image can be transferred into the visible canvas with the TI trial command or saved as a picture and then used like any other picture definition.

To save a screen image as a picture, the picture definition must already exist. We recommend defining pictures of type ‘N’ for each image you want to dynamically save during trials. Those pictures have their name as the initial content which will be overwritten by the SI trial command with the new screen image.