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Progress Report - January 2025

· 4 min read
Hat Kid
Hat Kid

Decompiler improvements, custom actor support for Jak 2 and 3 and more.

Release Info​

This month's OpenGOAL Tooling (jak-project repo) release is 0.2.22.

General Changes​

Decompiler Improvements​

Add More VF Macros ​

The PS2's Vector Units had a lot of instructions for vector operations that let you define a mask to only operate on specific parts of a vector. Our macros for this were a bit lackluster and required you to manually define the mask as a bitfield. This adds extra convenience macros for every mask combination, cleaning up the code a bit.

- (.add.w.vf vf2 vf0 vf5 :mask #b0001)
- (.add.z.vf vf2 vf0 vf5 :mask #b0010)
- (.sub.y.vf vf2 vf0 vf5 :mask #b0100)
- (.sub.w.vf vf2 vf0 vf0 :mask #b1000)
+ (.add.w.vf.x vf2 vf0 vf5)
+ (.add.z.vf.y vf2 vf0 vf5)
+ (.sub.y.vf.z vf2 vf0 vf5)
+ (.sub.w.vf.w vf2 vf0 vf0)

Detect vector*! And More ​

In Jak 2 and 3, the vector*! function was inlined, which the decompiler now detects. Along with this, some other common operations are now also detected:

  • new-stack-matrix0
- (let ((s4-2 (new 'stack-no-clear 'matrix)))
-   (set! (-> s4-2 rvec quad) (the-as uint128 0))
-   (set! (-> s4-2 uvec quad) (the-as uint128 0))
-   (set! (-> s4-2 fvec quad) (the-as uint128 0))
-   (set! (-> s4-2 trans quad) (the-as uint128 0))
-   (let ((f30-0 (-> arg0 bounds w)))
-     (matrix-4x4-inverse! s4-2 (-> arg1 data 0 bone transform))
-     (set! (-> arg0 bounds w) 1.0)
-     (vector-matrix*! (-> arg0 bounds) (-> arg0 bounds) s4-2)
-     (set! (-> arg0 bounds w) f30-0)
-     )
+ (let ((s4-2 (new-stack-matrix0))
+       (f30-0 (-> arg0 bounds w))
+       )
+   (matrix-4x4-inverse! s4-2 (-> arg1 data 0 bone transform))
+   (set! (-> arg0 bounds w) 1.0)
+   (vector-matrix*! (-> arg0 bounds) (-> arg0 bounds) s4-2)
+   (set! (-> arg0 bounds w) f30-0)
+   )
  • matrix-copy!
- (let* ((a3-0 (-> this parent 0 node-list data a0-6 bone transform))
-        (a2-0 (-> s3-0 mat))
-        (v1-9 (-> a3-0 rvec quad))
-        (a0-8 (-> a3-0 uvec quad))
-        (a1-4 (-> a3-0 fvec quad))
-        (a3-1 (-> a3-0 trans quad))
-        )
-   (set! (-> a2-0 rvec quad) v1-9)
-   (set! (-> a2-0 uvec quad) a0-8)
-   (set! (-> a2-0 fvec quad) a1-4)
-   (set! (-> a2-0 trans quad) a3-1)
+ (let ((a3-0 (-> this parent 0 node-list data a0-6 bone transform)))
+   (matrix-copy! (-> s3-0 mat) a3-0)
+   )
  • vector-copy!
- (set! (-> s5-1 trans quad) (-> self sphere quad))
+ (vector-copy! (-> s5-1 trans) (-> self sphere))

as-type Macro and Font Inline Method Detection ​

Another very common operation in Jak 2 and 3 is to check if an object is of a specific type and then cast it to that type, similar to dynamic_cast in C++.

(let* ((s4-0 (-> this process))
       (a0-15 (if (type? s4-0 process-focusable) s4-0)))
  ...)

This operation is now detected and will use the as-type macro:

- (let* ((s4-0 (-> this process))
-        (a0-15 (if (type? s4-0 process-focusable) s4-0)))
-   ...)
+ (let ((a0-15 (as-type (-> this process) process-focusable))) ...)

Additionally, font-context methods that were previously inlined are now properly detected:

- (let ((v1-14 gp-0))
-   (set! (-> v1-14 width) (the float 440))
-   )
- (let ((v1-15 gp-0))
-   (set! (-> v1-15 height) (the float 140))
-   )
+ (set-width! gp-0 440)
+ (set-height! gp-0 140)

Custom Levels​

Support Enviroment Mapping in Jak 2 and 3 ​

The environment mapping support that was added recently for Jak 1 now also works in Jak 2 and 3.

Custom Actor Support in Jak 2 and 3 ​

Jak 2 and 3 have received support for custom actors! Previously only available for Jak 1, this allows you to create a model in Blender with animations and import it into the game to create your own game objects with custom behavior.

You can find a guide on how to make your own custom actors here if interested.

Jak 1​

Fix TIE Wind Regression ​

The camera code improvements from last month's release have caused a regression that made objects using wind, such as trees, vanish.

Jak 2​

Fix camera-other Regression ​

Along with wind, there was another regression in Jak 2/3 that broke levels like the Palace Throne, which uses the camera-other effect to rotate parts of the level.

Jak 3​

Enemy Code Cleanup ​

The code for enemy types has been cleaned up to make it a lot more readable.