我正在ios中开发绘图功能,我有3种类型的线
问题在于 DOTTED lines ,当我快速绘制时它绘制得很好,但是当我慢慢绘制它时会画出实线
Bellow是代码片段,请指导我问题在哪里。
- (void)drawingLayerMoved:(UIPanGestureRecognizer *)recognizer {
//MOVE START
if (recognizer.state == UIGestureRecognizerStateBegan) {
dw_mouseSwiped = NO;
dw_lastPoint = [recognizer locationInView:self.tempDrawImage];
UIGraphicsBeginImageContext(self.tempDrawImage.frame.size);
[self.tempDrawImage.image drawInRect:CGRectMake(0, 0, self.tempDrawImage.frame.size.width, self.tempDrawImage.frame.size.height)];
}
//MOVING
else if (recognizer.state == UIGestureRecognizerStateChanged) {
dw_mouseSwiped = YES;
CGPoint currentPoint = [recognizer locationInView:self.tempDrawImage];
CGContextRef dw_context = UIGraphicsGetCurrentContext();
if( [dw_brushType isEqual: DRAWING_DOTTED_LINE] ) {
CGContextSetLineCap(dw_context, kCGLineCapRound);
}
else if( [dw_brushType isEqual: DRAWING_DASHED_LINE] ) {
CGContextSetLineCap(dw_context, kCGLineCapSquare);
}
else if( [dw_brushType isEqual: DRAWING_PLANE_LINE] ) {
CGContextSetLineCap(dw_context, kCGLineCapRound);
}
// ADD FEW SPACES B/W DOTS OF LINE
if( [dw_brushType isEqual: DRAWING_DASHED_LINE] || [dw_brushType isEqual: DRAWING_DOTTED_LINE] ) {
CGFloat dw_dash[] = {2,dw_brush*3,dw_brush*2,dw_brush};
CGContextSetLineDash(dw_context, 1, dw_dash, 4);
}
//BRUSH WIDTH ( we have devided it on 3 )
CGContextSetLineWidth(dw_context, (dw_brush/3));
if( [dw_drawingLayerMode isEqualToString:DRAWING_LAYER_MODE_ERASER] ){
//BRUSH CLEAR COLOR
CGContextSetFillColorWithColor( dw_context, [UIColor clearColor].CGColor );
//CLEAR DRAWING
CGContextSetBlendMode(dw_context, kCGBlendModeClear);
} else{
// BRUSH RGB COLOR
CGContextSetRGBStrokeColor(dw_context, dw_red, dw_green, dw_blue, dw_opacity);
//NORMAL DRAWING
CGContextSetBlendMode(dw_context,kCGBlendModeNormal);
}
CGContextMoveToPoint(dw_context, dw_lastPoint.x, dw_lastPoint.y);
CGContextAddLineToPoint(dw_context, currentPoint.x, currentPoint.y);
CGContextStrokePath(dw_context);
//SAVE CURRENT MOVE INFO IN TEMP IMG
self.tempDrawImage.image = UIGraphicsGetImageFromCurrentImageContext();
//SAVE CURRENT MOVE POINT AS dw_lastPoint
dw_lastPoint = currentPoint;
}
//MOVE END
else if (recognizer.state == UIGestureRecognizerStateEnded) {
UIGraphicsEndImageContext();
}
}
我的问题是simmiler喜欢这个问题,但没有找到解决方案: Drawing a dashed line with CGContextSetLineDash
答案 0 :(得分:3)
我解决了这个问题, 我用自定义逻辑更新了移动代码,
//MOVING
else if (recognizer.state == UIGestureRecognizerStateChanged) {
dw_mouseSwiped = YES;
CGPoint currentPoint = [recognizer locationInView:self.tempDrawImage];
BOOL dw_addThisPointInLine = YES;
if( ([dw_brushType isEqual: DRAWING_DASHED_LINE] || [dw_brushType isEqual: DRAWING_DOTTED_LINE]) && !([dw_drawingLayerMode isEqualToString:DRAWING_LAYER_MODE_ERASER]) ) {
CGFloat dw_points_distance = 0.0;
dw_points_distance = [self distanceBtwPoints:currentPoint p2:dw_lastPoint];
if( dw_points_distance < dw_brush)
dw_addThisPointInLine = NO;
if( !(dw_addThisPointInLine) ) {
if( dw_points_distance > 30 && dw_brush < 50)
dw_addThisPointInLine = YES;
else if( dw_points_distance > 40 && dw_brush < 80)
dw_addThisPointInLine = YES;
else if( dw_points_distance > 50 && dw_brush < 100)
dw_addThisPointInLine = YES;
}
}
if( dw_addThisPointInLine ) {
//shif the code of move inside this condition.
}
}//move code end