From c76d6277a8a631740119f3bb219bba61f4e1ea98 Mon Sep 17 00:00:00 2001
From: Sonic Dreamcaster <alejandro.asenjo88@gmail.com>
Date: Tue, 18 Feb 2025 20:12:11 -0300
Subject: [PATCH] Float precision rendering

---
 .vscode/c_cpp_properties.json |  3 ++-
 CMakeLists.txt                |  1 +
 src/engine/fox_bg.c           |  3 ++-
 src/libultra/gu/mtxutil.c     | 24 ++++++++++++++++++------
 src/sys/sys_matrix.c          |  2 +-
 5 files changed, 24 insertions(+), 9 deletions(-)

diff --git a/.vscode/c_cpp_properties.json b/.vscode/c_cpp_properties.json
index d2f8dd83..a8bccffc 100644
--- a/.vscode/c_cpp_properties.json
+++ b/.vscode/c_cpp_properties.json
@@ -17,7 +17,8 @@
                 "_LANGUAGE_C",
                 "__sgi",
                 "_MIPS_SZLONG=32",
-                "F3DEX_GBI"
+                "F3DEX_GBI",
+                "GBI_FLOATS"
             ],
             "cStandard": "gnu89", // C89 + some GNU extensions from C99 like C++ comments
             "cppStandard": "${default}"
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 525123b7..f949fa0b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -85,6 +85,7 @@ add_compile_definitions(
     NON_MATCHING=1
     NON_EQUIVALENT=1
 	AVOID_UB=1
+    GBI_FLOATS=1
 )
 
 # Find necessary libraries
diff --git a/src/engine/fox_bg.c b/src/engine/fox_bg.c
index 9af4f76c..983b5ca4 100644
--- a/src/engine/fox_bg.c
+++ b/src/engine/fox_bg.c
@@ -1249,6 +1249,7 @@ void AllRangeGround_Draw(void) {
 
         Matrix_Push(&gGfxMatrix);
 
+        // @port: Tag the transform.
         FrameInterpolation_RecordOpenChild("360Ground", i);
 
         Matrix_Translate(gGfxMatrix, sGroundPositions360x_FIX[i], 0.0f, sGroundPositions360z_FIX[i], MTXF_APPLY);
@@ -1287,7 +1288,7 @@ void AllRangeGround_Draw(void) {
         }
         Matrix_Pop(&gGfxMatrix);
 
-        // @port: Tag the transform.
+        // @port: Pop the transform.
         FrameInterpolation_RecordCloseChild();
     }
 }
diff --git a/src/libultra/gu/mtxutil.c b/src/libultra/gu/mtxutil.c
index e2da48e8..d68fc103 100644
--- a/src/libultra/gu/mtxutil.c
+++ b/src/libultra/gu/mtxutil.c
@@ -12,8 +12,13 @@
 
 #include <libultraship.h>
 
+#ifdef GBI_FLOATS
+#include <string.h>
+#endif
+
+#ifndef GBI_FLOATS
 void guMtxF2L(float mf[4][4], Mtx* m) {
-    unsigned int r, c;
+    int r, c;
     s32 tmp1;
     s32 tmp2;
     s32* m1 = &m->m[0][0];
@@ -29,7 +34,7 @@ void guMtxF2L(float mf[4][4], Mtx* m) {
 }
 
 void guMtxL2F(float mf[4][4], Mtx* m) {
-    unsigned int r, c;
+    int r, c;
     u32 tmp1;
     u32 tmp2;
     u32* m1;
@@ -48,9 +53,14 @@ void guMtxL2F(float mf[4][4], Mtx* m) {
         }
     }
 }
+#else
+void guMtxF2L(float mf[4][4], Mtx* m) {
+    memcpy(m, mf, sizeof(Mtx));
+}
+#endif
 
-void guMtxIdentF(f32 mf[4][4]) {
-    unsigned int r, c;
+void guMtxIdentF(float mf[4][4]) {
+    int r, c;
     for (r = 0; r < 4; r++) {
         for (c = 0; c < 4; c++) {
             if (r == c) {
@@ -63,9 +73,11 @@ void guMtxIdentF(f32 mf[4][4]) {
 }
 
 void guMtxIdent(Mtx* m) {
+#ifndef GBI_FLOATS
     float mf[4][4];
-
     guMtxIdentF(mf);
-
     guMtxF2L(mf, m);
+#else
+    guMtxIdentF(m->mf);
+#endif
 }
diff --git a/src/sys/sys_matrix.c b/src/sys/sys_matrix.c
index 6be1ea62..52c39180 100644
--- a/src/sys/sys_matrix.c
+++ b/src/sys/sys_matrix.c
@@ -493,7 +493,7 @@ void Matrix_ToMtx(Mtx* dest) {
 // Converts the Mtx src to a Matrix, putting the result in dest
 void Matrix_FromMtx(Mtx* src, Matrix* dest) {
     FrameInterpolation_RecordMatrixMtxFToMtx(src, dest);
-    guMtxF2L(src->m, dest->m);
+    guMtxF2L(src->mf, dest->m);
 }
 
 // Applies the transform matrix mtx to the vector src, putting the result in dest