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Format

New lines are significant, each item must be on a separate line but initial whitespace is ignored.

Comment lines start with hash or are enclosed by /* */.

Directives

• scene <name> - starts a new scene (and ends previous one)
• end scene - ends current scene
• finish - stop processing commands (everything else ignored)
• end file - same as above
• include <file> - read file as if inserted at this point
• display height/width <value> - sets window dimensions
• display fullscreen - full screen window

Triggers

• begin - runs on scene load (or file load if at top level)
• after <duration> - runs after duration has elapsed from scene start
• on key <key> -runs when key is pressed
• on click - runs when any mouse key is pressed
• at time <timecode> - runs when time of day matches the timecode
• each time <timecode> - runs when time of day matches timecode (including wild cards)
• every <duration> - runs after duration has elapsed from scene start and repeats
• when (expression) - Evaluated once per second, runs once when the Python expression becomes truthy
• while (expression) - Evaluated once per second, runs every time the Python expression is truthy

Commands

In most cases unnecessary words can be omitted, the minimum phrasing is shown in bold

Resource Management

• from <folder> - take all resources from the named folder
• load <file> named <r-tag> [split <cols> by <rows>] - load resource of any type
• unload <r-tag…> - remove resources from memory

Scene Management

• start <scene> - start scene operating
• stop [<scene>] - stop current scene or named scene (removes all images)

Sprite Placement

• place <r-tag> [named <s-tag>] at <x>,<y> depth <z> [size

  scale <w>,<h>] - place an image on to the screen

• put <r-tag> [named <s-tag>] as background

  top

  bottom

  left

  right

  ground

  sky [depth <z>] - place an image on to the screen in a fixed location

• raise/lower <s-tag> to <value> - set depth of image on screen to value
• raise/lower <s-tag> by <value> - change depth of image on screen up or down the set of images
• show/hide <s-tag> - reveal or remove images from screens, but still update changes
• show/hide <s-tag> for <duration>- reveal or remove images from screens just for a set length of time
• remove <s-tag…> - remove images from the screen

Animated Sprite Management

• window <s-tag> at <ix>,<iy>,<iw>,<ih> - define a window on the source image centered at ix,iy of size iw,ih
• zoom window <s-tag> to <iw>,<ih> [in <duration>]- set new window size on source image
• move window of <s-tag> to <ix>,<iy> [in <duration>]- set new window centre on source image

• scroll window of <s-tag> up

  down

  left

  right [at <speed>] - move window centre continuously at speed pixels per minute

• set animation rate of <s-tag> to <value> - if image is sprite, update the frame every <value> seconds
• advance <s-tag> to <number> - switch sprite to the given frame (set rate to zero to use)
• advance/reverse <s-tag> by <number> - advance or reverse sprite by the given number of frames

(Movie image sources can only advance)

Sprite Movement

• move <s-tag> to <x>,<y> [in <duration>] - Move image to a new location on screen in a given time
• move <s-tag> to <x>,<y> [at <speed>] - Move image to a new location on screen at a given speed
• move <s-tag> by <x>,<y> [in <duration>] - Move image relative to current position a given time
• move <s-tag> by <x>,<y> [at <speed>] - Move image relative to current position at a given speed
• set speed of <s-tag> to <speed> [in <duration>] - set the speed of image (acclerate/slow if duration given)
• rotate <s-tag> to <value> - turn image on screen to the given angle (degrees clockwise, 0 at top)
• rotate <s-tag> by <value> - turn image on screen by given angle (degrees clockwise)
• pause/resume <s-tag> - pause or resume all current changes to an image (does not change visibility)

Sprite Sizing

• resize <s-tag> to <w>,<h> [in <duration>] - change size of image on screen to given dimensions
• scale <s-tag> to <x%>,<y%> [in <duration>] - change size of image on screen by given proportions of the original image size
• scale <s-tag> by <x%>,<y%> [in <duration>] - change size of image on screen by given proportions of the current image size

Sprite Appearance

• set transparency of <s-tag> to <value> [in <duration>] - set image transparency (0 = solid, 100 = transparent)
• darken <s-tag> to <value> [in <duration>] - make image darker (0 = no change, 100 = solid black)
• lighten <s-tag> to <value> [in <duration>] - make image lighter (0 = no change, 100 = solid white)
• blur <s-tag> to <value> [in <duration>] - make blurry (0 = unchanged, 100 = very blurry)

Text Commands

• create text <t-name:> - create a named text item
• set content of <t-name> to text…. - sets the text to display

• set style of <t-name> to bold

  italic

  underline - sets text style

• set color of <t-name> to [named web color] - sets text foreground color
• set background of <t-name> to [named web color] - sets text background color
• set size of <t-name> to number - sets the point size of the text

Once created a text item be used as a source image for a sprite to which all the comands above can be applied.

Sounds

• play <r-tag> - play a sound resource
• set volume of <r-tag> to <value> - set volume of sound resource (0-100)

Group Management

• create group <name> - create a named group of sprites.
• add to group <name> <s-tags…> - add named sprites to the group (removes them from scene)

The named group can now be used as an image source for sprites, e.g. “place named-group at x,y,z” and all sprite commands operate on the whole image, however individual sprites within the group can still be operated on by name.

System Commands

• log <args…> - write arguments to the console
• let <var> be (expression) - set the value of a variable
• exit - ends program

Conditionals

Any command may be prefixed with a conditional, of the form:

if (expression) command...

Depending on system configuration, expression can be any valid python code, or a limited arithmetic expression. In either case the command is executed if the expression evaluates to a truthy value. Slow-glass variables are expanded each time the expression is evaluated.

Variables

All variables start with $. Unset variables evaluate to “???”.

Variables are local to scenes, to access variables in other scenes use $<scene-name>:variable.

Create / update variables with the make command, e.g.

make COUNT be 1
make COUNT be ($COUNT + 1)

Variables in commands are evaluated every time the command is invoked, variables in triggers are expanded when the trigger is created (i.e. when the scene is started).

Built-in Variables

• $SECOND - current second (0 - 59)
• $MINUTE - current minute (0 - 59)
• $HOUR - current hour (0 - 23)
• $DAY - day of month (1-31)
• $DAYNAME - name of day as a string
• $MONTH - month of year (1-12)
• $MONTHNAME - name of the month as a string
• $YEAR - year as a 4 digit number
• $SEASON - season as lower case string (needs $HEMISPHERE set correctly)
• $WIDTH - width of the display in pixels
• $HEIGHT - height of the display in pixels
• $FRAMERATE - update rate of display (for Pygame, not the physical device)
• $CENTREX, CENTREY - x, y coordinates of the centre of the display
• $MOUSEX, $MOUSEY - current x & y coordinates of mouse
• $PERCENT - random value from 0 to 100, set on use
• $CHANCE - random value from 0.0 to 1.0, set on use
• $RANDOMX, $RANDOMY - random values somewhere within the current window
• $KEY - key currently being pressed (None if none pressed)
• $LASTKEY - last key that was pressed
• $CLICKX, $CLICKY - x & y coordinates of the last time the mouse was clicked

Sprite properties

Some sprite properties are available as variables, using the sprite tag as the variable name, followed by a ‘.’ and one of the following:

• x - current x coordinate
• y - current y coordinate
• w - current width
• h - current height
• s - current speed (pixels per second)

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