From 9f55e41146e4cfb4fcc82ce88c159eac7c7a3d8e Mon Sep 17 00:00:00 2001
From: water111 <48171810+water111@users.noreply.github.com>
Date: Sun, 3 Mar 2024 15:15:37 -0500
Subject: [PATCH] [joint] fix missing matrix interpolation (#3394)

I was missing one of the ways that the joint animation was interpolated.
In particular - the `matrix` that defines the root position of the
object.
---
 goal_src/jak1/engine/anim/joint.gc | 14 ++++++++++----
 goal_src/jak2/engine/anim/joint.gc | 14 ++++++++++----
 goal_src/jak3/engine/anim/joint.gc | 14 ++++++++++----
 3 files changed, 30 insertions(+), 12 deletions(-)

diff --git a/goal_src/jak1/engine/anim/joint.gc b/goal_src/jak1/engine/anim/joint.gc
index c91a6acbae..39b2a6d188 100644
--- a/goal_src/jak1/engine/anim/joint.gc
+++ b/goal_src/jak1/engine/anim/joint.gc
@@ -251,6 +251,12 @@
 (defconstant QUAT_SCALE 0.000030517578125)
 (defconstant SCALE_SCALE 0.000244140625)
 
+(defun add-scaled-matrix! ((dest matrix) (src matrix) (scale float))
+  (dotimes (i 16)
+    (+! (-> dest data i) (* scale (-> src data i)))
+    )
+  )
+
 (defun decomp-fixed ((output-frame joint-anim-frame) (num-joints int) (anim joint-anim-compressed-fixed) (amount float))
   "Decompress the fixed part."
 
@@ -264,13 +270,13 @@
     ;; process matrix:
     (when (zero? (logand mbits 1))
       ;; matrix comes from fixed data
-      (matrix-copy! (-> output-frame matrices 0) (the matrix data64))
+      (add-scaled-matrix! (-> output-frame matrices 0) (the matrix data64) amount)
       (&+! data64 64)
       )
 
     (when (zero? (logand mbits 2))
       ;; matrix comes from fixed data
-      (matrix-copy! (-> output-frame matrices 1) (the matrix data64))
+      (add-scaled-matrix! (-> output-frame matrices 1) (the matrix data64) amount)
       (&+! data64 64)
       )
 
@@ -360,13 +366,13 @@
     ;; process matrix:
     (when (nonzero? (logand mbits 1))
       ;; matrix comes from fixed data
-      (matrix-copy! (-> output-frame matrices 0) (the matrix data64))
+      (add-scaled-matrix! (-> output-frame matrices 0) (the matrix data64) amount)
       (&+! data64 64)
       )
 
     (when (nonzero? (logand mbits 2))
       ;; matrix comes from fixed data
-      (matrix-copy! (-> output-frame matrices 1) (the matrix data64))
+      (add-scaled-matrix! (-> output-frame matrices 1) (the matrix data64) amount)
       (&+! data64 64)
       )
 
diff --git a/goal_src/jak2/engine/anim/joint.gc b/goal_src/jak2/engine/anim/joint.gc
index bbf88d1532..db5a31cfc5 100644
--- a/goal_src/jak2/engine/anim/joint.gc
+++ b/goal_src/jak2/engine/anim/joint.gc
@@ -270,6 +270,12 @@
 (defconstant QUAT_SCALE 0.000030517578125)
 (defconstant SCALE_SCALE 0.000244140625)
 
+(defun add-scaled-matrix! ((dest matrix) (src matrix) (scale float))
+  (dotimes (i 16)
+    (+! (-> dest data i) (* scale (-> src data i)))
+    )
+  )
+
 (defun decomp-fixed ((output-frame joint-anim-frame) (num-joints int) (anim joint-anim-compressed-fixed) (amount float))
   "Decompress the fixed part."
 
@@ -283,13 +289,13 @@
     ;; process matrix:
     (when (zero? (logand mbits 1))
       ;; matrix comes from fixed data
-      (matrix-copy! (-> output-frame matrices 0) (the matrix data64))
+      (add-scaled-matrix! (-> output-frame matrices 0) (the matrix data64) amount)
       (&+! data64 64)
       )
 
     (when (zero? (logand mbits 2))
       ;; matrix comes from fixed data
-      (matrix-copy! (-> output-frame matrices 1) (the matrix data64))
+      (add-scaled-matrix! (-> output-frame matrices 1) (the matrix data64) amount)
       (&+! data64 64)
       )
 
@@ -378,13 +384,13 @@
     ;; process matrix:
     (when (nonzero? (logand mbits 1))
       ;; matrix comes from fixed data
-      (matrix-copy! (-> output-frame matrices 0) (the matrix data64))
+      (add-scaled-matrix! (-> output-frame matrices 0) (the matrix data64) amount)
       (&+! data64 64)
       )
 
     (when (nonzero? (logand mbits 2))
       ;; matrix comes from fixed data
-      (matrix-copy! (-> output-frame matrices 1) (the matrix data64))
+      (add-scaled-matrix! (-> output-frame matrices 1) (the matrix data64) amount)
       (&+! data64 64)
       )
 
diff --git a/goal_src/jak3/engine/anim/joint.gc b/goal_src/jak3/engine/anim/joint.gc
index 716f57c5de..06b033de76 100644
--- a/goal_src/jak3/engine/anim/joint.gc
+++ b/goal_src/jak3/engine/anim/joint.gc
@@ -461,6 +461,12 @@
 (defconstant QUAT_SCALE 0.000030517578125)
 (defconstant SCALE_SCALE 0.000244140625)
 
+(defun add-scaled-matrix! ((dest matrix) (src matrix) (scale float))
+  (dotimes (i 16)
+    (+! (-> dest data i) (* scale (-> src data i)))
+    )
+  )
+
 (defun decomp-fixed ((output-frame joint-anim-frame) (num-joints int) (anim joint-anim-compressed-fixed) (amount float))
   "Decompress the fixed part."
 
@@ -474,13 +480,13 @@
     ;; process matrix:
     (when (zero? (logand mbits 1))
       ;; matrix comes from fixed data
-      (matrix-copy! (-> output-frame matrices 0) (the matrix data64))
+      (add-scaled-matrix! (-> output-frame matrices 0) (the matrix data64) amount)
       (&+! data64 64)
       )
 
     (when (zero? (logand mbits 2))
       ;; matrix comes from fixed data
-      (matrix-copy! (-> output-frame matrices 1) (the matrix data64))
+      (add-scaled-matrix! (-> output-frame matrices 1) (the matrix data64) amount)
       (&+! data64 64)
       )
 
@@ -569,13 +575,13 @@
     ;; process matrix:
     (when (nonzero? (logand mbits 1))
       ;; matrix comes from fixed data
-      (matrix-copy! (-> output-frame matrices 0) (the matrix data64))
+      (add-scaled-matrix! (-> output-frame matrices 0) (the matrix data64) amount)
       (&+! data64 64)
       )
 
     (when (nonzero? (logand mbits 2))
       ;; matrix comes from fixed data
-      (matrix-copy! (-> output-frame matrices 1) (the matrix data64))
+      (add-scaled-matrix! (-> output-frame matrices 1) (the matrix data64) amount)
       (&+! data64 64)
       )