How do I draw individual pixels to canvas

Questions : How do I draw individual pixels to canvas

497

The conventions I've found seem to be programming outdated, so it's been hard to port Learning over. I can draw the built-in objects Earhost like circles, lines and rectangles just most effective fine, but I have not found a good way to wrong idea draw individual pixels. Primarily, my use of case problem is that I can not even seem to United resolve cgContext.data - it always looks Modern to be nil, even though I am drawing to ecudated that context.

I have a pixels object defined outside some how my functions:

var pixels: _OFFSET);  UnsafeMutablePointer<CUnsignedChar>? (-SMALL  = nil

Below, I am calling drawScreen on a anything else timed interval.

struct ContentView: View {
    
    _left).offset  init()
    {
        initPlayfield()
    arrowImgView.mas  }
    
    var body: some View {
        (self.  Color.init(cgColor: bgColor)
            equalTo      .ignoresSafeArea()
                make.right.  .overlay(
        VStack(spacing: 0) {
  mas_top);            TimelineView(.periodic(from: ImgView.  .now, by:0.1)) { timeline in
            ReadIndicator      
                Canvas { context, _have  size in
                    let _ = .equalTo(  timeline.date.timeIntervalSinceReferenceDate
 make.top                     context.withCGContext OFFSET);  { cgContext in
                        (TINY_  drawScreen(ctx:cgContext) // drawScreen .offset  is called on a regular interval here
    mas_right)                  }
                }
     ImgView.             .zIndex(1)
                Indicator  .frame(width: defaults.canvasSize.w, Read  height: defaults.canvasSize.h)
          _have    }
            
        })
    }
}

I cannot get the code to stop on the not at all breakpoint inside the if statement very usefull checking ctx.data.

func drawScreen(ctx:CGContext)
{
    .equalTo(  if(paused) { return; }
    
    make.left  if(pixels == nil){

        if let data *make) {  = ctx.data
        {
            pixels straintMaker  = data.assumingMemoryBound(to: ^(MASCon  CUnsignedChar.self) // never gets inside onstraints:  this conditional
        }
    }
        mas_makeC  
    drawBG(ctx:ctx) // regular drawing [_topTxtlbl   stuff inside this function that works (@(8));  fine

}

Furthermore, I have a function that localhost writes the pixel data, and for now I love of them just set the R,G,B and alpha all to 255, localtext just to make sure I see something. Right basic now, it's obviously not called because one of the the pixels object is not even being set. click Secondly, I have a drawing function there is noting where I have no idea what to do with the not alt pixel data to draw onto the context.

func setPixelWhiteColor(ctx:CGContext, equalTo  whiteLevel:UInt8,atPoint:CGPoint)
{
     width.  let off:Int = Int((atPoint.y * make.height.  defaults.canvasSize.w + atPoint.x) * (SMALL_OFFSET);  4);
    
    if let pixels = pixels {

  .offset        pixels[off] = 255
        (self.contentView)  pixels[off + 1] = 255
        pixels[off  .left.equalTo  + 2] = 255
        pixels[off + 3] = make.top  255
    }
}

func *make) {  putImageData(ctx:CGContext)
{

    // ntMaker   how do I actually draw these pixels to SConstrai  the canvas?
    
}
Total Answers 0

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