Reconstruct readable C++ and organize cohesive source subsystems

Administrative source import: native x86 compilation passed for 423 authored units. Source placement and submission states are migrated separately; this commit does not imply peer acceptance.

Previous head: 35d2a8cb36
Payload SHA256: 592f016d2730c5593bb653aa054c1e5f76a6df72c8f5a09e66f74876e2e33dee

Source/Contents/Models/ModelTextureAnimation.cpp

@@ -0,0 +1,34 @@
+#include "Contents/Models/ModelNode.h"
+
+// OFFSET: 0x00540EA0
+// FUNCTION: fn_01727
+void SampleModelTexture(const ModelTextureChannels& channels, float frame, ModelTextureTransform& output) {
+  for (int channel = 0; channel < 5; ++channel) {
+    const auto found = channels.find(channel);
+
+    if (found == channels.end()) {
+      continue;
+    }
+
+    const auto& keys = found->second;
+    const int last = keys.back().frame;
+
+    if (frame >= static_cast<float>(last)) {
+      output.values[channel] = keys.back().value;
+      continue;
+    }
+
+    unsigned next = 1;
+
+    while (next < keys.size() && !(static_cast<float>(keys[next].frame) > frame)) {
+      ++next;
+    }
+
+    const int previous = keys[next - 1].frame;
+    const int difference = keys[next].frame - keys[next - 1].frame;
+    const float amount = (frame - static_cast<float>(previous)) / static_cast<float>(difference);
+    const float first = (1.0f - amount) * keys[next - 1].value;
+    const float second = amount * keys[next].value;
+    output.values[channel] = first + second;
+  }
+}