private static BoundingBox DeskewBoundingBoxBase(BoundingBox src, IsometricTransform transform)
{
var cosAngle = Math.Abs(transform.CosAngle);
var sinAngle = Math.Abs(transform.SinAngle);
if (cosAngle > sinAngle)
{
var tmp = sinAngle;
sinAngle = cosAngle;
cosAngle = tmp;
}
var cos2Angle = cosAngle * cosAngle - sinAngle * sinAngle;
var sin2Angle = 2 * sinAngle * cosAngle;
var points = new List <Point>
{
transform.Transform(new Point(src.XMin, src.YMin)),
transform.Transform(new Point(src.XMin, src.YMax)),
transform.Transform(new Point(src.XMax, src.YMax)),
transform.Transform(new Point(src.XMax, src.YMin)),
};
var xMin = points.Select(point => point.x).Min();
var xMax = points.Select(point => point.x).Max();
var yMin = points.Select(point => point.y).Min();
var yMax = points.Select(point => point.y).Max();
var W = xMax - xMin;
var H = yMax - yMin;
var p = ((W * sin2Angle - H) * sin2Angle) / ((sin2Angle * sin2Angle - 1) * 2);
var q = ((H * sin2Angle - W) * sin2Angle) / ((sin2Angle * sin2Angle - 1) * 2);
// var p = 0;
// var q = 0;
var result = new BoundingBox(Floor(xMin + p), Floor(yMin + q), Ceiling(xMax - p), Ceiling(yMax - q));
// Console.Out.WriteLine(@"""{0}"": ({1}) => ({2})", word.Text, src, result);
// if (word.Text == "Óòâåðæäåíà")
// {
// Console.Out.WriteLine("Òðàíñôîðìàöèÿ:");
// Console.Out.WriteLine("xMin: {0:N4}", xMin);
// Console.Out.WriteLine("xMax: {0:N4}", xMax);
// Console.Out.WriteLine("yMin: {0:N4}", yMin);
// Console.Out.WriteLine("yMax: {0:N4}", yMax);
// Console.Out.WriteLine("W: {0:N4}", W);
// Console.Out.WriteLine("H: {0:N4}", H);
// Console.Out.WriteLine("p: {0:N4}", p);
// Console.Out.WriteLine("q: {0:N4}", q);
// Console.Out.WriteLine("result: {0}", result);
// Console.Out.WriteLine("cosAngle: {0:N4}", cosAngle);
// Console.Out.WriteLine("sinAngle: {0:N4}", sinAngle);
// Console.Out.WriteLine("cos2angle: {0:N4}", cos2Angle);
// Console.Out.WriteLine("sin2angle: {0:N4}", sin2Angle);
// foreach (var point in points)
// {
// Console.Out.WriteLine(point);
// }
// Console.Out.WriteLine(@"""{0}"": ({1}) => ({2})", word.Text, src, result);
// }
return(result);
}
/// <summary>
/// Calculates composition of two transformations, i.e. new transformation C(x) = A(B(x))
/// </summary>
/// <param name="trA"></param>
/// <param name="trB"></param>
/// <returns></returns>
public static IsometricTransform Compose(IsometricTransform trA, IsometricTransform trB)
{
var newAngle = Angles.NormalizeRad(trA.AngleRadians + trB.AngleRadians);
var newPreShift = new Point(trB.preShiftX, trB.preShiftY);
var newPostShift = trA.Transform(new Point(trB.postShiftX, trB.postShiftY));
return(new IsometricTransform(newAngle, newPostShift, newPreShift));
}
/// <summary>
/// Rotates given model by given isomorphic transform.
/// Bounding box for an object of the model is transformed in such a way that it is still the minimal rectangle with sides parallel to coordinate axes contaning original box rotated.
/// </summary>
/// <param name="model">The model to process</param>
/// <param name="transform">The transform to apply</param>
/// <param name="targetWidth">Target model width</param>
/// <param name="targetHeight">Target model height</param>
/// <returns></returns>
public static TextGeometryModel RotateModel(this TextGeometryModel model, IsometricTransform transform, int targetWidth, int targetHeight)
{
var targetModel = new TextGeometryModel(new BoundingBox(0, 0, targetWidth, targetHeight), model.GridUnit);
ModelGeometryTransformer.TransformModelGeometry(model, targetModel,
box => RotateBoundingBox(box, transform));
return(targetModel);
}
private static BoundingBox RotateBoundingBox(BoundingBox src, IsometricTransform transform)
{
var points = new List <Point>
{
transform.Transform(new Point(src.XMin, src.YMin)),
transform.Transform(new Point(src.XMin, src.YMax)),
transform.Transform(new Point(src.XMax, src.YMax)),
transform.Transform(new Point(src.XMax, src.YMin)),
};
var xMin = points.Select(point => point.x).Min();
var xMax = points.Select(point => point.x).Max();
var yMin = points.Select(point => point.y).Min();
var yMax = points.Select(point => point.y).Max();
return(new BoundingBox(Floor(xMin), Floor(yMin), Ceiling(xMax), Ceiling(yMax)));
}
private void CalculateTransformationParams()
{
var rotation = new IsometricTransform(angleRadians, 0, 0, 0, 0);
var points = new List <Point>
{
rotation.Transform(new Point(0, 0)),
rotation.Transform(new Point(0, sourceHeight)),
rotation.Transform(new Point(sourceWidth, 0)),
rotation.Transform(new Point(sourceWidth, sourceHeight))
};
var maxX = points.Select(point => point.x).Max();
var minX = points.Select(point => point.x).Min();
var maxY = points.Select(point => point.y).Max();
var minY = points.Select(point => point.y).Min();
transform = new IsometricTransform(angleRadians, -minX, -minY, 0, 0);
targetWidth = (int)Math.Round(maxX - minX);
targetHeight = (int)Math.Round(maxY - minY);
}
private static BoundingBox DeskewBoundingBox(BoundingBox src, IsometricTransform transform)
{
var cosAngle = Math.Abs(transform.CosAngle);
var sinAngle = Math.Abs(transform.SinAngle);
if (cosAngle > sinAngle)
{
var tmp = sinAngle;
sinAngle = cosAngle;
cosAngle = tmp;
}
var sin2Angle = 2 * sinAngle * cosAngle;
var sin2AngleSq = sin2Angle * sin2Angle;
var cos2AngleSq = 1 - sin2AngleSq;
var points = new List <Point>
{
transform.Transform(new Point(src.XMin, src.YMin)),
transform.Transform(new Point(src.XMin, src.YMax)),
transform.Transform(new Point(src.XMax, src.YMax)),
transform.Transform(new Point(src.XMax, src.YMin)),
};
var xMin = points.Select(point => point.x).Min();
var xMax = points.Select(point => point.x).Max();
var yMin = points.Select(point => point.y).Min();
var yMax = points.Select(point => point.y).Max();
// Here we have a rectangle that is a bounding one for original bounding rectangle rotated
// The problem here is that this rectangle is not the bounding one for the word itself (due to rotation)
// so we have to updte it (if possible) to reduce its size
var W = xMax - xMin;
var H = yMax - yMin;
var xCnt = (xMin + xMax) / 2;
var yCnt = (yMin + yMax) / 2;
var w = (W - sin2Angle * H) / cos2AngleSq;
var h = (H - sin2Angle * W) / cos2AngleSq;
// According to formulas, values of w and h should be positive
// but under some circumstances (line contains words in fonts of different sizes) they can become negative (as desckew formulas
// are obtained under assumption that line contains words of the same vertical size). So in this case we just make the values non-negative
// (although the result will not be quite good - according to the resulting sizes words will be higher than the line itself)
w = Math.Abs(w);
h = Math.Abs(h);
// New height and width are suitable for the case when rotation angle was chosen correctly to deskew the model
// (i.e. the words have been aligned horizontally). Unfortunately, the can be the cases when the angle is a wrong one
// and words are not aligned properly. In such cases we have to limit new bounding rectangle dimensions by the ones obtained
// by rotation of original bounding rectangle (without any correction). Otherwise there is a risk that new bounding rectangle
// will lay outside of the page (and its coordinates get negative)
if (w > W)
{
w = W;
}
if (h > H)
{
h = H;
}
var w2 = w / 2;
var h2 = h / 2;
return(new BoundingBox(Floor(xCnt - w2), Floor(yCnt - h2), Ceiling(xCnt + w2), Ceiling(yCnt + h2)));
}
