Most properties in Bluepic hold a fixed value, like a colour or a number you type in. An expression lets a property compute its value instead, so it can react to input fields, other elements, or logic you define.
The expression tool, the fx button in the toolbar, is how you open the expression editor: click it, then click the property you want to make dynamic.
The expression editor
The editor opens in a small movable window with two ways to work, switched with the icons in its top corner.
Builder view lets you assemble the expression from blocks. Browse the building blocks under four tabs and click to insert them:
- Functions: operations grouped by purpose, such as Math, Color, Logic, Animation, and Helpers.
- Elements: data from other elements, like their position or size.
- Variables: the values coming from your input fields.
- Static: fixed numbers, text, and colours.
Click Update to apply the expression to the property.
Code view lets you write the expression as text. Prettify reformats it to be easier to read.
For the rules of writing expressions as text, see Syntax.
If you already know the syntax, you can also skip the editor and type an expression straight into a property field, for example
text1.bottom + 20.