Dump IW4 xmodels as obj

src/Common/Utils/Pack.cpp

@@ -0,0 +1,57 @@
+#include "Pack.h"
+
+#include <cassert>
+
+union PackUtil32
+{
+    uint32_t u;
+    int32_t i;
+    float f;
+    int8_t c[4];
+    uint8_t uc[4];
+};
+
+uint32_t Pack32::Vec2PackTexCoords(const float* in)
+{
+    // TODO
+    return 0;
+}
+
+uint32_t Pack32::Vec3PackUnitVec(const float* in)
+{
+    // TODO
+    return 0;
+}
+
+void Pack32::Vec2UnpackTexCoords(const uint32_t in, float* out)
+{
+    PackUtil32 packTemp{};
+
+    const auto inHiDw = (in >> 16) & UINT16_MAX;
+    const auto inLoDw = in & UINT16_MAX;
+
+    if (inHiDw)
+        packTemp.u = ((inHiDw << 16) & 0x80000000) | (((((inHiDw << 14) & 0xFFFC000)
+            - (~(inHiDw << 14) & 0x10000000)) ^ 0x80000000) >> 1);
+    else
+        packTemp.f = 0.0f;
+    out[0] = packTemp.f;
+
+    if (inLoDw)
+        packTemp.u = ((inLoDw << 16) & 0x80000000) | (((((inLoDw << 14) & 0xFFFC000)
+            - (~(inLoDw << 14) & 0x10000000)) ^ 0x80000000) >> 1);
+    else
+        packTemp.f = 0.0f;
+    out[1] = packTemp.f;
+}
+
+void Pack32::Vec3UnpackUnitVec(const uint32_t in, float* out)
+{
+    assert(out != nullptr);
+
+    PackUtil32 _in{in};
+    const float decodeScale = (static_cast<float>(_in.uc[3]) - -192.0f) / 32385.0f;
+    out[0] = (static_cast<float>(_in.uc[0]) + -127.0f) * decodeScale;
+    out[1] = (static_cast<float>(_in.uc[1]) + -127.0f) * decodeScale;
+    out[2] = (static_cast<float>(_in.uc[2]) + -127.0f) * decodeScale;
+}

src/Common/Utils/Pack.h

@@ -0,0 +1,12 @@
+#pragma once
+
+#include <cstdint>
+
+class Pack32
+{
+public:
+    static uint32_t Vec2PackTexCoords(const float* in);
+    static uint32_t Vec3PackUnitVec(const float* in);
+    static void Vec2UnpackTexCoords(uint32_t in, float* out);
+    static void Vec3UnpackUnitVec(uint32_t in, float* out);
+};