[Vm-dev] Byte ordering in Form (urgent)

tim Rowledge tim at rowledge.org
Thu Oct 11 18:34:29 UTC 2018

> On 2018-10-11, at 11:27 AM, Bert Freudenberg <bert at freudenbergs.de> wrote:
> No, positive depth means big endian on all platforms.
> Until Andreas added little endian support to bitblt, everything was done in big endian, and only reversed on copying to the OS window. That byte reversal was expensive, so that's why the little endian support was added, to be able to keep forms in native order on little endian platforms. Little endian is indicated by negative depth, also in the platform support code (e.g. supportsDepth).

IIRC from far too long ago I concluded that the littleendian stuff Andreas added was very specifically Windows weird idea of littleendian, which involved some strange stuff for less than 32bpp forms. It certainly didn't work on RISC OS.

tim Rowledge; tim at rowledge.org; http://www.rowledge.org/tim
Useful random insult:- Calls people to ask them their phone number.

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