Como eu salvaria um CGContext em um nsundomanager
-
20-09-2019 - |
Pergunta
Eu quero ser capaz de salvar um CGContext
em meu NSUndoManager
usando esses métodos
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
CGPoint currentPoint = [touch locationInView:self.view];
currentPoint.x = currentPoint.x;
currentPoint.y = currentPoint.y;
mouseSwiped = YES;
UIGraphicsBeginImageContext(self.view.frame.size);
[drawImage.image drawInRect:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height)];
CGContextSetShouldAntialias(UIGraphicsGetCurrentContext(), YES);
CGContextSetLineCap(UIGraphicsGetCurrentContext(), kCGLineCapRound);
CGContextSetLineWidth(UIGraphicsGetCurrentContext(), brushSizeVal);
CGContextSetAlpha(UIGraphicsGetCurrentContext(), drawingColorAlpha);
CGContextSaveGState(UIGraphicsGetCurrentContext()); //Probably right here
CGContextSetRGBStrokeColor(UIGraphicsGetCurrentContext(),
drawingColorRed,
drawingColorGreen,
drawingColorBlue,
drawingColorAlpha);
CGContextBeginPath(UIGraphicsGetCurrentContext());
CGContextMoveToPoint(UIGraphicsGetCurrentContext(),
lastPoint.x,
lastPoint.y);
CGContextAddLineToPoint(UIGraphicsGetCurrentContext(),
currentPoint.x,
currentPoint.y);
CGContextStrokePath(UIGraphicsGetCurrentContext());
drawImage.image = UIGraphicsGetImageFromCurrentImageContext(); //drawImage is the UIImageView that I am drawing my context to
NSLog(@"current point x: %d current point y: %d",currentPoint.x, currentPoint.y); //Used for my purposes
lastPoint = currentPoint;
mouseMoved++;
e
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
if (!optionsDisplayerVisible && canDraw)
{
if(!mouseSwiped)
{
UIGraphicsBeginImageContext(self.view.frame.size);
[drawImage.image drawInRect:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height)];
CGContextSetShouldAntialias(UIGraphicsGetCurrentContext(), YES);
CGContextSetLineCap(UIGraphicsGetCurrentContext(), kCGLineCapRound);
CGContextSetLineWidth(UIGraphicsGetCurrentContext(), brushSizeVal);
CGContextSetRGBStrokeColor(UIGraphicsGetCurrentContext(),
drawingColorRed,
drawingColorGreen,
drawingColorBlue,
drawingColorAlpha);
CGContextMoveToPoint(UIGraphicsGetCurrentContext(), lastPoint.x, lastPoint.y);
CGContextAddLineToPoint(UIGraphicsGetCurrentContext(), lastPoint.x, lastPoint.y);
CGContextStrokePath(UIGraphicsGetCurrentContext());
CGContextFlush(UIGraphicsGetCurrentContext());
drawImage.image = UIGraphicsGetImageFromCurrentImageContext(); //drawImage is the UIImageView that I am drawing to
UIGraphicsEndImageContext();
}
}
}
A propósito, se você quiser saber que tenho meu nsundomanager chamado Undodrawing
Solução
Eu não acredito que você queira salvar o CGContext
, pois faz parte de uma pilha que não será válida quando você precisar mais tarde. Em vez disso, basta salvar a própria imagem. Primeiro, não crie o contexto em todo o quadro. Você só precisa do retângulo entre o Currentpoint e o LastPoint. Então, antes de começar a desenhar, pegue a imagem do contexto atual (UIGRAPHICSGETIMAGEFROMCURINGIMAGECONTEXT ()) e salve isso junto com o quadro no NSundomanager.
Se você não estiver familiarizado em otimizar seu desenho apenas para o retângulo sujo, comece com a versão mais simples disso e salve a imagem inteira no Undomanager antes de desenhar nele.