Description
The paragraph does not state to which coordinate space "currPt"(Current point) and "lnfPt"(Last new figure point) belong. The same goes with "mtx"(Path transformation matrix) - the paragraph does not specify the purpose of the transformation. This makes it hard to understand the meaning of certain statements, for instance:
figure_items::abs_new_figure p
Creates a new figure. Sets currPt to mtx.transform_pt({ 0.0f, 0.0f}) + p.at(). Sets lnfPt to currPt.
So, does now currPt belong to the surface's coordinate system and its value can be used "as is", or it has to be transformed before actually passing into backend's API?
The next figure's description implies an actual transformation, which confuses and makes an impression that coordinate systems are being mixed up here:
Let mm equal mtx. Let mm.m20 equal 0.0f. Let mm.m21 equal 0.0f. Creates a new figure. Sets currPt to currPt + p.at() * mm. Sets lnfPt to currPt.
It would be nice to have a clearer definition of figures' transformations. Possibly a single example of a transformation can help a lot, for instance drawing of a rotated&scaled&translated rectangle with an image of an expected result.