1 files changed, 79 insertions, 0 deletions
diff --git a/dep/src/g3dlite/Cone.cpp b/dep/src/g3dlite/Cone.cpp
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index 00000000000..3104b8424a7
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+++ b/dep/src/g3dlite/Cone.cpp
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+/**
+ @file Cone.cpp
+
+ Cone class
+
+ @maintainer Morgan McGuire, http://graphics.cs.williams.edu
+
+ @created 2001-07-09
+ @edited  2006-01-29
+*/
+
+#include "G3D/platform.h"
+#include "G3D/Cone.h"
+#include "G3D/Line.h"
+#include "G3D/Sphere.h"
+#include "G3D/Box.h"
+
+namespace G3D {
+
+Cone::Cone(const Vector3 &tip, const Vector3 &direction, float angle) {
+    this->tip = tip;
+    this->direction = direction.direction();
+    this->angle = angle;
+
+    debugAssert(angle >= 0);
+    debugAssert(angle <= pi());
+}
+
+/**
+ Forms the smallest cone that contains the box.  Undefined if
+ the tip is inside or on the box.
+ */
+Cone::Cone(const Vector3& tip, const Box& box) {
+    this->tip = tip;
+    this->direction = (box.center() - tip).direction();
+
+    // Find the biggest angle
+    float smallestDotProduct = direction.dot((box.corner(0) - tip).direction());
+
+    for (int i = 1; i < 8; ++i) {
+        float dp = direction.dot((box.corner(i) - tip).direction());
+
+        debugAssert(dp > 0);
+
+        if (dp < smallestDotProduct) {
+            smallestDotProduct = dp;
+        }
+    }
+
+    angle = acosf(smallestDotProduct);
+}
+
+
+bool Cone::intersects(const Sphere& b) const {
+    // If the bounding sphere contains the tip, then
+    // they definitely touch.
+    if (b.contains(this->tip)) {
+        return true;
+    }
+
+    // Move the tip backwards, effectively making the cone bigger
+    // to account for the radius of the sphere.
+
+    Vector3 tip = this->tip - direction * b.radius / sinf(angle);
+
+    return Cone(tip, direction, angle).contains(b.center);
+}
+
+
+bool Cone::contains(const Vector3& v) const {
+
+    Vector3 d = (v - tip).direction();
+
+    float x = d.dot(direction);
+
+    return (x > 0) && (x >= cosf(angle));
+}
+
+}; // namespace