Added opacity setter/getter to CAPI. They will be useful to simplify
code responsible for set visiblility of paint.
@API Additions:
Tvg_Result tvg_paint_set_opacity(Tvg_Paint* paint, uint8_t opacity)
Tvg_Result tvg_paint_get_opacity(Tvg_Paint* paint, uint8_t* opacity)
The algorithm erroneously treated some shapes (like isosceles trapezoids
and specifically arranged zero width parallelograms) as rectangles,
which causes the whole bbox to be filled.
We introduced separate opacity interface to adjust alpha value by paint.
This opacity will affect to whole paint image if paint is a group of paints.
Also, this opacity is to multipy with fill/stroke alpha values.
This means if the opacity is valid, the paint might deal with a composition step,
which is very expensive due to additional rendering step.
One tip is, if you want to toggle on/off for a certian paint,
you can set opacity to 255 or 0.
@API Additions:
Result Paint::opacity(uint8_t o) noexcept;
uint8_t Paint::opacity() const noexcept;
@Examples: examples/Opacity
@Issues: 94
Fill rule is used to select how paths are filled.
For both fill rules, wheter or not a point is included in the fill is determined by taking a ray
from that point to infinity and looking at intersections with the path. The ray can be in any
direction, as long as it doens't pass through the end point of a segment or have a tricky
intersection such as intersecting tangent to the path.
@API Addtions:
enum class TVG_EXPORT FillRule { Winding = 0, EvenOdd };
Result Fill::rule(FillRule r) noexcept;
FillRule Fill::rule() const noexcept;
@Examples:
shape->rule(FillRule::EvenOdd);
@issue: 97
If viewer calls load() with a data which does not have size changes of both
viewbox and canvas, then load() does not set a scale value.
This makes incorrect result on viewer side.
So thorvg wasm should set a scale value, whenever load() is called.
It missed to update shape data if visilibity is changed from false to true by alpha.
Also, it needs to update engine shape data for every requests.
There scenario can be allowed,
1. update shape
2. change shape property
3. update shape
4. draw
previously engine could skip step 3, its result was not properly expected.
@fix #84
When using <use> node, do atrribute copy.
At that time, when target(url) is polygon or polyline,
points array is not copied, causing a problem in output.
So, add missing array copy.
