mirror of
https://github.com/DarkPlacesEngine/gmqcc.git
synced 2024-11-27 22:22:17 +00:00
36 lines
1.3 KiB
Text
36 lines
1.3 KiB
Text
|
This is a propsal to extend the progs.dat file format without breaking
|
||
|
|
backwards compatability. Currently the progs file format header has a
|
||
|
|
description simaler to this:
|
||
|
|
|
||
|
|
struct {
|
||
|
|
uint32_t version;
|
||
|
|
uint32_t crc16;
|
||
|
|
....
|
||
|
|
uint32_t entfield;
|
||
|
|
}
|
||
|
|
|
||
|
|
The obvious notable issue here is version and crc16 are larger than they
|
||
|
|
essentially need to be, if we made version and crc16 both uint16_t we can
|
||
|
|
give ourselfs 32 bytes (2x16) to store additional data that can be used
|
||
|
|
to make smaller progs.dat files.
|
||
|
|
|
||
|
|
I propose a new structual layout like this:
|
||
|
|
struct {
|
||
|
|
uint16_t version;
|
||
|
|
uint16_t flags; /* contains a skip field */
|
||
|
|
uint16_t crc16;
|
||
|
|
uint16_t skip; /* skiped globals */
|
||
|
|
....
|
||
|
|
uint32_t entfield;
|
||
|
|
}
|
||
|
|
|
||
|
|
about 45% of globals are zero, if we could order them at the top of the
|
||
|
|
globals array we can essentially use the skip field to specify how much
|
||
|
|
zero globals the engine would have to populate (instead of being stored
|
||
|
|
in the actual file itself) flags can specify if the progs.dat file skiped
|
||
|
|
globals on the write of the progs.dat file.
|
||
|
|
|
||
|
|
Of course only one bit in the flags would have to be set to specify if the
|
||
|
|
file contains a skip field. Which lends itself to the fact that flags could
|
||
|
|
later be extended for other things.
|