* Adjustment: Initial CMake reworking.

Engine/lib/bullet/Extras/InverseDynamics/IDRandomUtil.cpp

@@ -0,0 +1,71 @@
+#include <cmath>
+#include <cstdlib>
+#include <ctime>
+
+#include "BulletInverseDynamics/IDConfig.hpp"
+#include "BulletInverseDynamics/IDMath.hpp"
+#include "IDRandomUtil.hpp"
+
+
+namespace btInverseDynamics {
+
+// constants for random mass and inertia generation
+// these are arbitrary positive values.
+static const float mass_min = 0.001;
+static const float mass_max = 1.0;
+
+void randomInit() { srand(time(NULL)); }
+void randomInit(unsigned seed) { srand(seed); }
+
+int randomInt(int low, int high) { return rand() % (high + 1 - low) + low; }
+
+float randomFloat(float low, float high) {
+    return low + static_cast<float>(rand()) / RAND_MAX * (high - low);
+}
+
+float randomMass() { return randomFloat(mass_min, mass_max); }
+
+vec3 randomInertiaPrincipal() {
+    vec3 inertia;
+    do {
+        inertia(0) = randomFloat(mass_min, mass_max);
+        inertia(1) = randomFloat(mass_min, mass_max);
+        inertia(2) = randomFloat(mass_min, mass_max);
+    } while (inertia(0) + inertia(1) < inertia(2) || inertia(0) + inertia(2) < inertia(1) ||
+             inertia(1) + inertia(2) < inertia(0));
+    return inertia;
+}
+
+mat33 randomInertiaMatrix() {
+    // generate random valid inertia matrix by first getting valid components
+    // along major axes and then rotating by random amount
+    vec3 principal = randomInertiaPrincipal();
+    mat33 rot(transformX(randomFloat(-BT_ID_PI, BT_ID_PI)) * transformY(randomFloat(-BT_ID_PI, BT_ID_PI)) *
+              transformZ(randomFloat(-BT_ID_PI, BT_ID_PI)));
+    mat33 inertia;
+    inertia(0, 0) = principal(0);
+    inertia(0, 1) = 0;
+    inertia(0, 2) = 0;
+    inertia(1, 0) = 0;
+    inertia(1, 1) = principal(1);
+    inertia(1, 2) = 0;
+    inertia(2, 0) = 0;
+    inertia(2, 1) = 0;
+    inertia(2, 2) = principal(2);
+    return rot * inertia * rot.transpose();
+}
+
+vec3 randomAxis() {
+    vec3 axis;
+    idScalar length;
+    do {
+        axis(0) = randomFloat(-1.0, 1.0);
+        axis(1) = randomFloat(-1.0, 1.0);
+        axis(2) = randomFloat(-1.0, 1.0);
+
+        length = std::sqrt(std::pow(axis(0), 2) + std::pow(axis(1), 2) + std::pow(axis(2), 2));
+    } while (length < 0.01);
+
+    return axis / length;
+}
+}