XTE1 is not developed anymore, and XTE2 doesn't have a real demo yet. @ketmar will post when it will be ready. thank you!
The XTE source code repository link there: http://ketmar.no-ip.org/fossil/xtengine/.
the optimisation topic created by @Joefish finally made me to finish my old idea about "universal platform engine". so, here it is, XT-Engine Tech Preview Demo v0.0.2!
what is XT-Engine exactly, you may ask? let me quote readme file:
Spoiler
It is currently oriented at assembler users, but can easily be adapted to
use with Z88DK, or any other compiler.
The code of the engine is heavily commented, and the engine has clean
public API.
some engine features:
* the core rendering engine is about 2kb of machine code
* uses about 1.5kb of working area (including framebuffer, and room tilemap)
* can render the whole 32x24 screen area (or smaller, if you want that)
* internal tilemap is 32x24 bytes, so tilemap address calculation is easy
* doesn't use IY (so it is possible to run it in IM 1)
* supports masked sprites, each sprite is 24x16 pixels
* supports 4 graphics set for each sprite (for easy using of 16x16 preshifted sprite gfx)
* sprites will not flicker even if the engine is interrupted (but may be teared)
* updates only changed tiles
* automatically erases sprites at old positions when the sprite is moved
* no need to do anything special for sprite moving, just change the coords
* has IM 2-driven sound engine from Steve Turner as a bonus ;-)
* works at ~18-20 FPS with 10 24x16 sprites moving, and with simple platforming logic
* simple platforming game demo included
* 48K-compatible
* per-tile "always on top" flag; not per tile index, but per tile on a tilemap!
this means that you can make any room tile "on top"; but there is no way
do dynamically change this yet (TODO)
* NO NFTs ATTACHED!
you can use up to 63 8x8 tiles in your rooms, any individual tile can have "tile always on top" flag (any room tile, not the whole tile type!), and the engine has support for several sprite attr modes ("don't change", "always change", "change only on tile #0"). also, all the sprites are properly masked sprites, not a cheating "xor-print" ones! and of course, the sprites can freely overlap without any flickering.
WARNING! this is not "game creator" a-la AGD! XT-Engine is assembler library which you can use to skip writing things like screen rendering, collision detection, sound fx, input management, and such. i.e. it is a set of assembler routines to include in your own asm projects.
this is prerelease tech demo. while it is already usable, i am planning to better optimise the code, and add some more features for the release (sprites of different sizes, more utility API, documentation, and better demo game).
screenshot from the included demo:
Spoiler
Link removed. the code is under WTFPL license.
have fun, and happy hacking!