Port a Unity Game to Your Own Engine: Part 19

A concrete look into a data-oriented approach to engine development.

Hero Bullets

Extract hero bullet data from Unity project into xlsx. Hero bullet format matches enemy bullets, so rename the common format source_bullets. Patch up references to enemy_bullets.

010 Editor Template (bt)

In addition to Kaitai (ksy) files, also generate templates for 010 Editor (bt). They’re basically equivalent here.

Prepare for schema map

Quick rename of source_bullets to bullets. Change sheet counts to be offset into data segment instead of directly in header. Which will allow for a mapped schema type to point to specific columns and along with the counts.

Add map to bin and ksy

Change export_bin to add any maps. Update ksy to inspect the data. Todo: update bt and c_header outputs.

First test for maps

Create the C header for maps and fix up issues with bin export. Maps are the first thing exported, so that all offsets are positive relative to a given map. First test case: Use bullet_source_instances instead of enemy_instances for bullets schema. This is the first step in removing dependency on enemy data in bullets update, so hero and enemy will use the same bullet system. Todo: Update export_bt, remove enemy_instances_update dependency.

Indirect values

Make values in schema types indirect. Patch up existing code. Now maps can also remap values. Add bullet_source_instances_update map to enemy_instances_update. Bullets no longer have any direct references to enemies.

Next: Port a Unity Game to Your Own Engine: Part 20

Links to files below for paid subscribers.