void MapPanned(NSPanGestureRecognizer obj)
{
var p = obj.TranslationInView(CanvasView);
var pp = new SKPoint((float)(_canvasSize.Width * p.X / CanvasView.Bounds.Width),
(float)(_canvasSize.Height - (_canvasSize.Height * p.Y / CanvasView.Bounds.Height)));
pp = _im.MapPoint(pp);
if (!_isPanZoom)
{
StartPanZoom(new SKPoint((float)pp.X, (float)pp.Y));
}
if (_isPanZoom)
{
_totalDistance = new SKPoint((float)p.X, 1 - (float)p.Y);
DoPanZoom(_startM, _startAnchorPt, _totalDistance, _totalScale);
}
NSCursor.ClosedHandCursor.Set();
if (obj.State == NSGestureRecognizerState.Ended)
{
NSCursor.ArrowCursor.Set();
_isPanZoom = false;
_m.TryInvert(out _im);
}
}
protected override void OnPaintSurface(SKPaintSurfaceEventArgs args)
{
base.OnPaintSurface(args);
SKImageInfo info = args.Info;
SKSurface surface = args.Surface;
SKCanvas canvas = surface.Canvas;
canvas.Clear(SKColors.Gray);
// Calculate rectangle for displaying bitmap
float scale = Math.Min((float)info.Width / bitmap.Width, (float)info.Height / bitmap.Height);
float x = (info.Width - scale * bitmap.Width) / 2;
float y = (info.Height - scale * bitmap.Height) / 2;
SKRect bitmapRect = new SKRect(x, y, x + scale * bitmap.Width, y + scale * bitmap.Height);
canvas.DrawBitmap(bitmap, bitmapRect);
// Calculate a matrix transform for displaying the cropping rectangle
SKMatrix bitmapScaleMatrix = SKMatrix.MakeIdentity();
bitmapScaleMatrix.SetScaleTranslate(scale, scale, x, y);
// Display rectangle
SKRect scaledCropRect = bitmapScaleMatrix.MapRect(croppingRect.Rect);
canvas.DrawRect(scaledCropRect, edgeStroke);
// Display heavier corners
using (SKPath path = new SKPath())
{
path.MoveTo(scaledCropRect.Left, scaledCropRect.Top + CORNER);
path.LineTo(scaledCropRect.Left, scaledCropRect.Top);
path.LineTo(scaledCropRect.Left + CORNER, scaledCropRect.Top);
path.MoveTo(scaledCropRect.Right - CORNER, scaledCropRect.Top);
path.LineTo(scaledCropRect.Right, scaledCropRect.Top);
path.LineTo(scaledCropRect.Right, scaledCropRect.Top + CORNER);
path.MoveTo(scaledCropRect.Right, scaledCropRect.Bottom - CORNER);
path.LineTo(scaledCropRect.Right, scaledCropRect.Bottom);
path.LineTo(scaledCropRect.Right - CORNER, scaledCropRect.Bottom);
path.MoveTo(scaledCropRect.Left + CORNER, scaledCropRect.Bottom);
path.LineTo(scaledCropRect.Left, scaledCropRect.Bottom);
path.LineTo(scaledCropRect.Left, scaledCropRect.Bottom - CORNER);
canvas.DrawPath(path, cornerStroke);
}
// Invert the transform for touch tracking
bitmapScaleMatrix.TryInvert(out inverseBitmapMatrix);
}
public RotatedGrid(SKMatrix matrix, Rectangle containingRec, int numFrames)
{
GridContainer = containingRec;
CellWidth = (float)dist(containingRec.A, containingRec.B) / numFrames;
CellHeight = (float)dist(containingRec.A, containingRec.D) / numFrames;
FromGrid = matrix;
//try to invert, if unsucessful ToGrid will be all 0's
if (!FromGrid.TryInvert(out toGrid))
{
toGrid = new SKMatrix();
}
}
private SKMatrix ComputeMatrix(SKSize size, SKPoint ptUL, SKPoint ptUR, SKPoint ptLL, SKPoint?ptLR = null)
{
// Scale transform
SKMatrix S = SKMatrix.CreateScale(1 / size.Width, 1 / size.Height);
// Affine transform
SKMatrix A = new SKMatrix
{
ScaleX = ptUR.X - ptUL.X,
SkewY = ptUR.Y - ptUL.Y,
SkewX = ptLL.X - ptUL.X,
ScaleY = ptLL.Y - ptUL.Y,
TransX = ptUL.X,
TransY = ptUL.Y,
Persp2 = 1
};
// Non-Affine transform
SKMatrix N = SKMatrix.CreateIdentity();
if (ptLR.HasValue)
{
SKMatrix inverseA;
A.TryInvert(out inverseA);
SKPoint abPoint = inverseA.MapPoint(ptLR.Value);
float a = abPoint.X;
float b = abPoint.Y;
float scaleX = a / (a + b - 1);
float scaleY = b / (a + b - 1);
N = new SKMatrix
{
ScaleX = scaleX,
ScaleY = scaleY,
Persp0 = scaleX - 1,
Persp1 = scaleY - 1,
Persp2 = 1
};
}
// Multiply S * N * A
SKMatrix result = SKMatrix.CreateIdentity();
SKMatrix.PostConcat(ref result, S);
SKMatrix.PostConcat(ref result, N);
SKMatrix.PostConcat(ref result, A);
return(result);
}
public void MoveByVector(SKPoint vector)
{
SKMatrix invertedMatrix;
if (!Matrix.TryInvert(out invertedMatrix))
{
return;
}
var resultPoint = invertedMatrix.MapVector(vector.X, vector.Y);
SKMatrix.PreConcat(ref Matrix, SKMatrix.MakeTranslation(resultPoint.X, resultPoint.Y));
if (CenterBoundary.IsEmpty)
{
return;
}
var center = GetCenter();
if (!CenterBoundary.Contains(center))
{
//rollback
SKMatrix.PreConcat(ref Matrix, SKMatrix.MakeTranslation(-resultPoint.X, -resultPoint.Y));
}
}
protected override void OnPaintSurface(SKPaintSurfaceEventArgs args)
{
base.OnPaintSurface(args);
SKImageInfo info = args.Info;
SKSurface surface = args.Surface;
SKCanvas canvas = surface.Canvas;
canvas.Clear(SkiaHelper.backgroundColor);
// 计算显示位图的矩形
var rect = SkiaHelper.CalculateRectangle(new SKRect(0, 0, info.Width, info.Height), bitmap);
canvas.DrawBitmap(bitmap, rect.rect);
// 计算用于显示裁剪矩形的矩阵变换
SKMatrix bitmapScaleMatrix = SKMatrix.CreateIdentity();
SKMatrix.CreateScaleTranslation(rect.scaleX, rect.scaleX, rect.rect.Left, rect.rect.Top);
// 显示矩形
SKRect scaledCropRect = bitmapScaleMatrix.MapRect(croppingRect.Rect);
using (SKPaint edgeStroke = new SKPaint())
{
edgeStroke.Style = SKPaintStyle.Stroke;
edgeStroke.Color = SKColors.White;
edgeStroke.StrokeWidth = 3;
edgeStroke.IsAntialias = true;
canvas.DrawRect(scaledCropRect, edgeStroke);
}
canvas.DrawSurrounding(rect.rect, scaledCropRect, SKColors.Gray.WithAlpha(190));
// Display heavier corners
using (SKPaint cornerStroke = new SKPaint())
using (SKPath path = new SKPath())
{
cornerStroke.Style = SKPaintStyle.Stroke;
cornerStroke.Color = SKColors.White;
cornerStroke.StrokeWidth = 7;
path.MoveTo(scaledCropRect.Left, scaledCropRect.Top + corner);
path.LineTo(scaledCropRect.Left, scaledCropRect.Top);
path.LineTo(scaledCropRect.Left + corner, scaledCropRect.Top);
path.MoveTo(scaledCropRect.Right - corner, scaledCropRect.Top);
path.LineTo(scaledCropRect.Right, scaledCropRect.Top);
path.LineTo(scaledCropRect.Right, scaledCropRect.Top + corner);
path.MoveTo(scaledCropRect.Right, scaledCropRect.Bottom - corner);
path.LineTo(scaledCropRect.Right, scaledCropRect.Bottom);
path.LineTo(scaledCropRect.Right - corner, scaledCropRect.Bottom);
path.MoveTo(scaledCropRect.Left + corner, scaledCropRect.Bottom);
path.LineTo(scaledCropRect.Left, scaledCropRect.Bottom);
path.LineTo(scaledCropRect.Left, scaledCropRect.Bottom - corner);
canvas.DrawPath(path, cornerStroke);
}
// 反转变换以进行触摸跟踪
bitmapScaleMatrix.TryInvert(out inverseBitmapMatrix);
}
public void Invert()
{
//// copied from SkMatrix::invertNonIdentity
//// see: https://github.com/google/skia/blob/master/src/core/SkMatrix.cpp
//if (IsIdentity)
// return;
//var m = _m;
//bool isScaleMatrix = m.ScaleX != 1f || m.ScaleY != 1f;
//bool isTranslateMatrix = m.TransX != 0f || m.TransY != 0f;
//bool isRotateMatrix = m.SkewX != 0f || m.SkewX != 0f;
//if (!isRotateMatrix && isScaleMatrix && isTranslateMatrix)
//{
// var invX = m.ScaleX;
// var invY = m.ScaleY;
// if (invX == 0 || invY == 0)
// {
// // not invertible
// return;
// }
// invX = 1/invX;
// invY = 1/invY;
// m.SkewX = 0;
// m.SkewY = 0;
// m.Persp0 = 0;
// m.Persp1 = 0;
// m.ScaleX = invX;
// m.ScaleY = invY;
// m.Persp2 = 1;
// m.TransX = -m.TransX*invX;
// m.TransY = -m.TransY*invY;
// _m = m;
// return;
//}
//else if (!isRotateMatrix && isTranslateMatrix)
//{
// m.TransX = -m.TransX;
// m.TransY = -m.TransY;
// _m = m;
// return;
//}
//var m = _m;
//float det = m.ScaleX * (m.ScaleY * m.Persp2 - m.Persp1 * m.TransY) -
// m.SkewX * (m.SkewY * m.Persp2 - m.TransY * m.Persp0) +
// m.TransX * (m.SkewY * m.Persp1 - m.ScaleY * m.Persp0);
//float invdet = 1 / det;
//var m1 = new SKMatrix();
//m1.ScaleX = (m.ScaleY * m.Persp2 - m.Persp1 * m.TransY) * invdet;
//m1.SkewX = (m.TransX * m.Persp1 - m.SkewX * m.Persp2) * invdet;
//m1.TransX = (m.SkewX * m.TransY - m.TransX * m.ScaleY) * invdet;
//m1.SkewY = (m.TransY * m.Persp0 - m.SkewY * m.Persp2) * invdet;
//m1.ScaleY = (m.ScaleX * m.Persp2 - m.TransX * m.Persp0) * invdet;
//m1.TransY = (m.SkewY * m.TransX - m.ScaleX * m.TransY) * invdet;
//m1.Persp0 = (m.SkewY * m.Persp1 - m.Persp0 * m.ScaleY) * invdet;
//m1.Persp1 = (m.Persp0 * m.SkewX - m.ScaleX * m.Persp1) * invdet;
//m1.Persp2 = (m.ScaleX * m.ScaleY - m.SkewY * m.SkewX) * invdet;
//_m = m1;
SKMatrix m;
if (_m.TryInvert(out m))
{
_m = m;
}
}