8.1.6 VCL Properties

A common leaf node represents just an area and its border. Its visual appearance is defined by properties. There is a special node for setting properties – the non-leaf property node. A property set in that node applies to all its descendants until set to another value by another property node.

A property is a pair (key, value), where key is an integer constant and value is a byte sequence.

The list of defined property constants and byte sequence interpretations is as follows:

VCL_PROP_FILL_COLOR

u32 – packed RGBA color data, used for area filling

VCL_PROP_STROKE_COLOR

u32 – packed RGBA color data, used for stroke border

VCL_PROP_STROKE_WIDTH

double – the width of a border in local coords

VCL_PROP_STROKE_CAP_STYLE

u8 constant – cap style

VCL_PROP_STROKE_JOIN_STYLE

u8 constant – join style

Values of cap and join styles are these (the meaning of cap style and join style is traditional, so we will not explain it):

• VCL_CAP_BUTT
• VCL_CAP_ROUND
• VCL_CAP_PROJECTING

• VCL_JOIN_MITER
• VCL_JOIN_ROUND
• VCL_JOIN_BEVEL