The assets for the Tiberian Dawn HD mod are much larger than assets for the default mods, causing a lot of load time to be spent in Util.FastCopyIntoChannel.
We can provide a special case for the SpriteFrameType.Bgra32 format, which is the same format as the destination buffer. In this scenario we can just perform memory copies between the source and destination. Additionally, whilst the default mods require all their assets to get their alpha premultiplied, many of the Tiberian Dawn assets are already premultiplied. Being able to skip this step for these assets saves us having to interpret the bytes into colors and back again.
For the default mods, there isn't a noticeable timing difference. For Tiberian Dawn HD or other mods with modern assets sizes, a large speedup is achieved.
This is a more natural representation than int that allows removal of casts in many places that require uint. Additionally, we can change the internal representation from long to uint, making the Color struct smaller. Since arrays of colors are common, this can save on memory.
- Enforce SA1604 ElementDocumentationShouldHaveSummary.
- Enforce SA1629 DocumentationTextShouldEndWithAPeriod.
- Turn off some rules covered by IDExxxx rules.
- Remaining rules are treated as part of OpenRA style.
Our SpriteFrameType names refer to the byte channel order rather than
the bit order, meaning that SpriteFrameType.BGRA corresponds to the
standard Color.ToArgb() etc byte order when the (little-endian) integer
is read as 4 individual bytes.
The previous code did not account for the fact that non-indexed Png
uses big-endian storage for its RGBA colours, and that SheetBuilder
had the color channels incorrectly swapped to match and cancel this out.
New SpriteFrameType enums are introduced to distinguish between BGRA
(little-endian) and RGBA (big-endian) formats, and also for 24bit data
without alpha. The channel swizzling / alpha creation is now handled
when copying into the texture atlas, removing the need for non-png
ISpriteLoader implementations to allocate an additional temporary array
and reorder the channels during load.
