public void TestShapeTwist()
{
const double edgeLength = 50;
const double startAngle = Math.PI * 0.5;
ShapeModel shapeModel = TestHelper.CreateTestShapeModelWith2Edges(Math.PI * 0.5, 1);
List <Vector> vertices = new List <Vector>();
vertices.Add(new Vector(0, 0));
vertices.Add(new Vector(Math.Cos(startAngle) * edgeLength, Math.Sin(startAngle) * edgeLength));
vertices.Add(new Vector());
List <double> edgeWidths = new List <double> {
10, 10
};
const int iterationCount = 10;
const double angleStep = 2 * Math.PI / iterationCount;
Shape lastShape = null;
for (int i = 0; i < iterationCount; ++i)
{
double angle = startAngle + Math.PI * 0.5 + angleStep * i;
vertices[2] = new Vector(vertices[1].X + edgeLength * Math.Cos(angle), vertices[1].Y + edgeLength * Math.Sin(angle));
Shape shape = new Shape(shapeModel.Structure, vertices, edgeWidths);
// Test if energy is increasing/decreasing properly
if (i <= iterationCount / 2)
{
Assert.IsTrue(lastShape == null || shapeModel.CalculateEnergy(lastShape) < shapeModel.CalculateEnergy(shape));
}
else
{
Assert.IsTrue(shapeModel.CalculateEnergy(lastShape) > shapeModel.CalculateEnergy(shape));
}
TestShapeEnergyCalculationApproachesImpl(shapeModel, vertices, edgeWidths, new Size(51, 51), 2001, 2001, 0.01);
lastShape = shape;
}
}
private static double TestShapeEnergyCalculationApproachesImpl(
ShapeModel model,
IEnumerable <Vector> vertices,
IEnumerable <double> edgeWidths,
Size imageSize,
int lengthGridSize,
int angleGridSize,
double eps)
{
// Create shape model and calculate energy in normal way
Shape shape = new Shape(model.Structure, vertices, edgeWidths);
double energy1 = model.CalculateEnergy(shape);
// Calculate energy via generalized distance transforms
ShapeConstraints constraints = ShapeConstraints.CreateFromShape(shape);
ShapeEnergyLowerBoundCalculator calculator = new ShapeEnergyLowerBoundCalculator(lengthGridSize, angleGridSize);
double energy2 = calculator.CalculateLowerBound(imageSize, model, constraints);
Assert.AreEqual(energy1, energy2, eps);
return(energy1);
}
private static double TestShapeEnergyCalculationApproachesImpl(
ShapeModel model,
IEnumerable<Vector> vertices,
IEnumerable<double> edgeWidths,
Size imageSize,
int lengthGridSize,
int angleGridSize,
double eps)
{
// Create shape model and calculate energy in normal way
Shape shape = new Shape(model.Structure, vertices, edgeWidths);
double energy1 = model.CalculateEnergy(shape);
// Calculate energy via generalized distance transforms
ShapeConstraints constraints = ShapeConstraints.CreateFromShape(shape);
ShapeEnergyLowerBoundCalculator calculator = new ShapeEnergyLowerBoundCalculator(lengthGridSize, angleGridSize);
double energy2 = calculator.CalculateLowerBound(imageSize, model, constraints);
Assert.AreEqual(energy1, energy2, eps);
return energy1;
}
