1 files changed, 39 insertions, 0 deletions
diff --git a/WebCore/platform/graphics/FloatQuad.cpp b/WebCore/platform/graphics/FloatQuad.cpp
index a32d8ab..427230d 100644
--- a/WebCore/platform/graphics/FloatQuad.cpp
+++ b/WebCore/platform/graphics/FloatQuad.cpp
@@ -46,6 +46,34 @@ static inline float max4(float a, float b, float c, float d)
     return max(max(a, b), max(c, d));
 }
 
+inline float dot(const FloatSize& a, const FloatSize& b)
+{
+    return a.width() * b.width() + a.height() * b.height();
+}
+
+inline bool isPointInTriangle(const FloatPoint& p, const FloatPoint& t1, const FloatPoint& t2, const FloatPoint& t3)
+{
+    // Compute vectors        
+    FloatSize v0 = t3 - t1;
+    FloatSize v1 = t2 - t1;
+    FloatSize v2 = p - t1;
+    
+    // Compute dot products
+    float dot00 = dot(v0, v0);
+    float dot01 = dot(v0, v1);
+    float dot02 = dot(v0, v2);
+    float dot11 = dot(v1, v1);
+    float dot12 = dot(v1, v2);
+
+    // Compute barycentric coordinates
+    float invDenom = 1.0f / (dot00 * dot11 - dot01 * dot01);
+    float u = (dot11 * dot02 - dot01 * dot12) * invDenom;
+    float v = (dot00 * dot12 - dot01 * dot02) * invDenom;
+
+    // Check if point is in triangle
+    return (u >= 0) && (v >= 0) && (u + v <= 1);
+}
+
 FloatRect FloatQuad::boundingBox() const
 {
     float left   = min4(m_p1.x(), m_p2.x(), m_p3.x(), m_p4.x());
@@ -57,4 +85,15 @@ FloatRect FloatQuad::boundingBox() const
     return FloatRect(left, top, right - left, bottom - top);
 }
 
+bool FloatQuad::containsPoint(const FloatPoint& p) const
+{
+    return isPointInTriangle(p, m_p1, m_p2, m_p3) || isPointInTriangle(p, m_p1, m_p3, m_p4);
+} 
+
+// Note that we only handle convex quads here.
+bool FloatQuad::containsQuad(const FloatQuad& other) const
+{
+    return containsPoint(other.p1()) && containsPoint(other.p2()) && containsPoint(other.p3()) && containsPoint(other.p4());
+}
+
 } // namespace WebCore