From dc1bd559fdda8d338d480dd7d9c3d77bb1ec5ac2 Mon Sep 17 00:00:00 2001
From: DaveH355 <101005658+DaveH355@users.noreply.github.com>
Date: Mon, 2 Oct 2023 16:44:42 +0800
Subject: [PATCH] Avoid qsort() in rmodels.c

---
 src/rmodels.c | 24 +++++++++++++-----------
 1 file changed, 13 insertions(+), 11 deletions(-)

diff --git a/src/rmodels.c b/src/rmodels.c
index 2e836b33..f2fab846 100644
--- a/src/rmodels.c
+++ b/src/rmodels.c
@@ -5567,15 +5567,6 @@ static Model LoadVOX(const char *fileName)
 unsigned char *m3d_loaderhook(char *fn, unsigned int *len) { return LoadFileData((const char *)fn, (int *)len); }
 void m3d_freehook(void *data) { UnloadFileData((unsigned char *)data); }
 
-// Comparison function for qsort
-static int m3d_compare_faces(const void *a, const void *b)
-{
-  m3df_t *fa = (m3df_t *)a;
-  m3df_t *fb = (m3df_t *)b;
-
-  return (fa->materialid - fb->materialid);
-}
-
 // Load M3D mesh data
 static Model LoadM3D(const char *fileName)
 {
@@ -5623,8 +5614,19 @@ static Model LoadM3D(const char *fileName)
         // We always need a default material, so we add +1
         model.materialCount++;
 
-        // Sort faces by material.
-        qsort(m3d->face, m3d->numface, sizeof(m3df_t), m3d_compare_faces);
+        // Sort faces by material (insertion)
+        for (i = 1; i < m3d->numface; i++)
+        {
+          m3df_t key = m3d->face[i];
+          j = i - 1;
+    
+          while (j >= 0 && m3d->face[j].materialid > key.materialid)
+          {
+            m3d->face[j+1] = m3d->face[j];
+            j = j - 1;
+          }
+          m3d->face[j+1] = key;
+        }
 
         model.meshes = (Mesh *)RL_CALLOC(model.meshCount, sizeof(Mesh));
         model.meshMaterial = (int *)RL_CALLOC(model.meshCount, sizeof(int));