Fix warning during build with lvgl https://github.com/lvgl/lvgl/pull/6081/
error: a function declaration without a prototype is deprecated in all versions of C [-Werror,-Wstrict-prototypes]
Signed-off-by: Xu Xingliang <xuxingliang@xiaomi.com>
sw_engine: radial gradient
[issues 2014: radial gradient](#2014)
Radial gradient results in a corrupted image when the focal point is outside the circle on Apple Silicon.
This happens because some compilers use FMA to optimize the a = dr² - dx² - dy² calculation,
which cause loss of precision.
We rely on temporary variables to prevent FMA.
We could also use compiler specific float contraction control pragmas to avoid this if this doesn't work in the future
This would fail building with Visual Studio 2017, at least downstream in Godot
where we undefine old Windows compilers' non-standard `min`/`max` macros (see
`minmax.h`/`NOMINMAX`).
Introduce project skeleton such as build envrionment and interfaces
to build up code further cooperatively.
Change-Id: Ie9ac38991f609d33637283134906d7cc3f2ac19e