Glossary

local coordinates

The local coordinate system is the coordinate system of the current group or layer, with the X coordinate increasing towards the right and the Y coordinate increasing towards the bottom. Without any transforms, the point $(0,0)$ corresponds with the top-left corner of the viewport.

render stack

A render stack is a list if rendering primitive to be drawn in inverse stack order. A render stack can contain child stacks.

stacking order

The order in which objects appear in the render stack.

collected shapes

When collecting shapes for a rendering operation, implementations MUST traverse the render stack in reverse order. All Shapes encountered in the stack traversal MUST be included, until the beginning of the stack is reached or a Modifier is encountered. If a Modifier is found, it MUST be applied to its own collected shapes and the output added to the shape collection.