From d0e016e5684ab66c29a1bbe688f05fc33b08dad0 Mon Sep 17 00:00:00 2001
From: Joshua Goins <josh@redstrate.com>
Date: Sat, 16 Apr 2022 16:38:29 -0400
Subject: [PATCH] Move float utility functions into utility.h

---
 include/utility.h | 33 +++++++++++++++++++++++++++++-
 src/mdlparser.cpp | 51 ++++++++++++-----------------------------------
 2 files changed, 45 insertions(+), 39 deletions(-)

diff --git a/include/utility.h b/include/utility.h
index 9b19d6e..33fce94 100644
--- a/include/utility.h
+++ b/include/utility.h
@@ -4,6 +4,37 @@
 
 template <class T>
 void endianSwap(T *objp) {
-    auto memp = reinterpret_cast<unsigned char*>(objp);
+    auto memp = reinterpret_cast<uint8_t*>(objp);
     std::reverse(memp, memp + sizeof(T));
+}
+
+// ported from lumina.halfextensions
+static float half_to_float(const uint16_t value) {
+    unsigned int num3;
+    if ((value & -33792) == 0) {
+        if ((value & 0x3ff) != 0) {
+            auto num2 = 0xfffffff2;
+            auto num = (unsigned int) (value & 0x3ff);
+            while ((num & 0x400) == 0) {
+                num2--;
+                num <<= 1;
+            }
+
+            num &= 0xfffffbff;
+            num3 = ((unsigned int) (value & 0x8000) << 0x10) | ((num2 + 0x7f) << 0x17) | (num << 13);
+        } else {
+            num3 = (unsigned int) ((value & 0x8000) << 0x10);
+        }
+    } else {
+        num3 = (unsigned int)
+                (((value & 0x8000) << 0x10) |
+                 ((((value >> 10) & 0x1f) - 15 + 0x7f) << 0x17) |
+                 ((value & 0x3ff) << 13));
+    }
+
+    return *(float *)&num3;
+}
+
+static float byte_to_float(const uint8_t value) {
+    return static_cast<float>(value) / 255.0f;
 }
\ No newline at end of file
diff --git a/src/mdlparser.cpp b/src/mdlparser.cpp
index d9ccc0c..b07efdf 100644
--- a/src/mdlparser.cpp
+++ b/src/mdlparser.cpp
@@ -1,4 +1,5 @@
 #include "mdlparser.h"
+#include "utility.h"
 
 #include <cstdio>
 #include <stdexcept>
@@ -7,37 +8,6 @@
 #include <fstream>
 #include <algorithm>
 
-using ushort = unsigned short;
-using uint = unsigned int;
-
-// from lumina.halfextensions
-static float Unpack(ushort value) {
-    uint num3;
-    if ((value & -33792) == 0) {
-        if ((value & 0x3ff) != 0) {
-            auto num2 = 0xfffffff2;
-            auto num = (uint) (value & 0x3ff);
-            while ((num & 0x400) == 0) {
-                num2--;
-                num <<= 1;
-            }
-
-            num &= 0xfffffbff;
-            num3 = ((uint) (value & 0x8000) << 0x10) | ((num2 + 0x7f) << 0x17) | (num << 13);
-        } else {
-            num3 = (uint) ((value & 0x8000) << 0x10);
-        }
-    } else {
-        num3 =
-                (uint)
-                        (((value & 0x8000) << 0x10) |
-                         ((((value >> 10) & 0x1f) - 15 + 0x7f) << 0x17) |
-                         ((value & 0x3ff) << 13));
-    }
-
-    return *(float *) &num3;
-}
-
 Model parseMDL(const std::string_view path) {
     FILE* file = fopen(path.data(), "rb");
     if(file == nullptr) {
@@ -384,22 +354,27 @@ Model parseMDL(const std::string_view path) {
                             fseek(file, sizeof(uint8_t) * 4, SEEK_CUR);
                             break;
                         case VertexType::ByteFloat4:
-                            fseek(file, sizeof(uint8_t) * 4, SEEK_CUR);
+                            uint8_t values[4];
+                            fread(values, sizeof(uint8_t) * 4, 1, file);
+                            floatData[0] = byte_to_float(values[0]);
+                            floatData[1] = byte_to_float(values[1]);
+                            floatData[2] = byte_to_float(values[2]);
+                            floatData[3] = byte_to_float(values[3]);
                             break;
                         case VertexType::Half2: {
                             uint16_t values[2];
                             fread(values, sizeof(uint16_t) * 2, 1, file);
-                            floatData[0] = Unpack(values[0]);
-                            floatData[1] = Unpack(values[1]);
+                            floatData[0] = half_to_float(values[0]);
+                            floatData[1] = half_to_float(values[1]);
                         }
                             break;
                         case VertexType::Half4: {
                             uint16_t values[4];
                             fread(values, sizeof(uint16_t) * 4, 1, file);
-                            floatData[0] = Unpack(values[0]);
-                            floatData[1] = Unpack(values[1]);
-                            floatData[2] = Unpack(values[2]);
-                            floatData[3] = Unpack(values[3]);
+                            floatData[0] = half_to_float(values[0]);
+                            floatData[1] = half_to_float(values[1]);
+                            floatData[2] = half_to_float(values[2]);
+                            floatData[3] = half_to_float(values[3]);
                         }
                             break;
                     }