IntroWML
From The Battle for Wesnoth Wiki
The [story] tag
The [story] tag is a series of images and text to display as the first part of the intro screen.
The only tag recognized for [story] is [part]. Each [part] represents one image and text. The part is displayed until the user clicks on the "Next>>>" button.
The following key/tags are recognized for [part]:
- background the image to display. Story images are usually created specially for this purpose, except for the map.
- story (translatable) the text to display below the image.
- show_title whether to display the title of the scenario at the top
- music change to this music
- [image] an image to display.
- x, y the location in pixels to draw the image. The x,y pixel location is relative to the image specified in background, but not in a normal way. The background image is scaled up or down to fill the screen resolution, but images are never scaled in size. Their coordinates, however, are scaled. It's basically a big pain in the rear. Example: I have a background image at 640x480 and an overlay at 640x480. To horizontally center the overlay on a 1024x768 screen, I want to position it at x=192. This is because 1024-640 = 384 total extra pixel space, then 384/2 = 192. This results in equal space on both sides of the overlay. However, now you have to account for the background scaling. The background image at 640 is scaled up to 1024, a scaling factor of 1.6. All image locations are also scaled up, so the overlay is not drawn at x=192, rather it is drawn at x=192*1.6 or x=307! To compensate for this, divide the desired pixel location by the scaling factor. In the example, x_compensated=192/1.6 or x_compensated=120.
- file the image to display.
- delay the time to delay drawing this image.
See also the DOT and CROSS macros, in UtilWML