Make Marker

A drawing over the map that the player sees: a circle over a point, a caption, an arrow, a line

mediumYou need: What a world processor is, The first picture

steptick 0

Jump -> 90

if not

Make Marker1

typeid #xyreplace?

Set Marker2

typecolorid #color

Set Marker3

typeradiusid #radius

Make Marker4

typeid #xyreplace?

Print5

Set Marker6

typeflush textid #fetch?

Make Marker7

typeid #xyreplace?

Set8

=

Set Marker9

typerotationid #rotation

@counter0number

wasPlacednullnull

makemarker shape 1 8 7 1
makemarker text 2 8 3 1
makemarker line 3 4 5 1

Three markers: a shape, a caption and a line. They appear on the map itself — not on a display but over the world, and the player sees them.

Field	What is in it
first	the kind of marker
second	the id: what it is found by later
third and fourth	coordinates in tiles
fifth	whether to replace a marker with that id if one already exists

A marker lives on its own

That is the main difference from drawing on a display. A display has to be redrawn every time; a marker is placed once and stays on the map until it is removed.

setmarker remove 1 0 0 0

Hence the fifth field: makemarker with the same id and replace = 0 does nothing if the marker already exists. That is exactly how it is placed inside a loop — the program calls makemarker every iteration and the marker does not multiply.

Silent failure

Marker ids are not handed out automatically. The program assigns them, and if two parts of a script take the same id, the second silently overwrites the first.

So ids are allocated in advance and in blocks: traps get their own hundred, hints another.

What kinds there are

Kind	What it draws
shape	a polygon: a circle, a triangle, a square
text	text on the map
shapeText	a shape with a caption under it
line	a segment between two points
texture	a picture — one of the game’s sprites
quad	a quadrilateral given by four corners
point	a point visible only on the minimap

All of them are configured by one instruction — setmarker: colour, radius, rotation, text, drawing layer. Right after creation a marker is plain: a white quadrilateral at the given point.

Note

A marker’s text is not set in makemarker. It is printed into the buffer with an ordinary print and then handed to the marker: setmarker flushText 2 0 0 0 — the same motion as printflush into a message block.

Remember

• makemarker kind id x y replace puts a marker on the map.
• A marker lives until it is removed — it does not need redrawing.
• The program assigns the id; the same id is needed to edit and delete it.
• The fifth field protects against re-creating it in a loop.
• setmarker configures a marker, and text is handed over through the print buffer.

Task

Change the first marker’s kind in the example from shape to shapeText: a place for a caption appears above the shape — empty, though, until text is handed to it.

Then set the fifth field of makemarker text 2 8 3 to zero instead of one and move the marker to other coordinates: it stays where it was — with a zero no replacement happens.