Recursive application of group effects

A non-transitory computer readable medium (CRM) storing instructions for rendering a page, the instructions comprising functionality for:

• obtaining an electronic document (ED) comprising:
• a first container object comprising a first member and a second member;
• a plurality of first container shadow parameters defining a shadow of the first container object;
• and
• a first plurality of member shadow parameters defining a shadow of solely the first member;
• determining a main bounding box surrounding the first container object on the page but excluding the shadow of the first member;
• creating a main brush comprising the first container object but excluding the shadow of the first member;
• calculating a shadow bounding box based on the main bounding box surrounding the first container and at least one of the plurality of first container shadow parameters;
• creating a shadow brush by applying a first shadow transformation matrix to the main brush comprising the first container object, wherein the first shadow transformation matrix maps the first container object to the shadow of the first container object;
• outputting the shadow of the first container object to a framebuffer for the page;
• and
• outputting, by processing the first member, the first member and the shadow of the first member to the framebuffer for the page.

A system for rendering a page of an electronic document (ED), comprising:

• a hardware processor;
• a buffer storing the ED, wherein the ED comprises:
• a first container object comprising a first member and a second member;
• a plurality of first container shadow parameters defining a shadow of the first container object;
• and
• a first plurality of member shadow parameters defining a shadow of solely the first member;
• a bounding box calculator executing on the hardware processor and configured to:
• determine a main bounding box surrounding the first container object on the page but excluding the shadow of the first member;
• and
• calculate a shadow bounding box based on the main bounding box surrounding the first container object and at least one of the plurality of first container shadow parameters;
• a transformation matrix generator executing on the hardware processor and configured to calculate a first shadow transformation matrix mapping the first container object to the shadow of the first container object defined by the plurality of first container shadow parameters;
• a brush generator executing on the hardware processor and configured to:
• create a main brush comprising the first container object but excluding the shadow of the first member;
• and
• create a shadow brush by applying the first shadow transformation matrix to the main brush comprising the first container object;
• a framebuffer for the page comprising:
• the shadow of the first container object;
• the first member after processing the first member;
• and
• the shadow of the first member after processing the first member;
• and
• a rasterizing engine.