Add support for affine transformations. The key changes are outlined
below.
- Painting/clipping with rectangles is handled by, for complex
transforms, creating clipping paths representing the transformed
rectangle and using a larger bounding box. Cover/Blit shaders updated
correspondingly to correctly map texture cordinates from the new
bounding boxes.
- Since path splitting must happen on CPU the transforms must happen CPU
side as well - offsets removed from shaders.
- Complex transforms will lead to different path splitting which means
that GPU arrays can no longer be cached if the transform has changed.
Thus the current transform is added as a key to the cache.
- Add a public API to op for setting Affine transformations.
There are a number of optimizations that could be explored further but
which are left out now:
- Caching also of CPU operations (e.g path splitting & transforms) and
not only caching the GPU arrays.
- Allow for re-use of cached GPU vertices if the transformation change
is a pure offset / scaling since the splitting is then the same.
Signed-off-by: Viktor <viktor.ogeman@gmail.com>
Converting
macro := op.Record(ops)
...
macro.Stop()
macro.Add()
to
macro := op.Record(ops)
...
call := macro.Stop()
call.Add(ops)
Which is more general (call.Add can take a different ops than the op.Record
that started it), and enforced the order between Stop and the subsequent Add.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
The ability to invoke other operation lists belongs in the new CallOp.
While we're here, make MacroOp.Add use a pointer receiver to match the
other methods.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
We'd like to improve the API of Flex, Stack and similar layouts
that use MacroOps internall. Unfortunately, the
func (m MacroOp) Add(o *Ops)
method causes the MacroOp to be allocated on the heap, ruining the
nice garbage-free property of layouts.
Fortunately, layouts don't need the feature that caused the heap
allocation: invoking operation lists different than the current.
CallOp separates the invoke-different-list semantic from MacroOp,
in preparation for removing the feature from MacroOp.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Viktor