CODEWITHSUNDEEP
iosswiftimageself
Mattman85208
Mattman85208

Reputation: 2110

Swift self image creation and change

In Swift I have an image: (but {I think} the problem is how the 'self' is implemented) (in my viewDidLoad)

let colorSpace       = CGColorSpaceCreateDeviceRGB()
let bytesPerPixel    = 4
let bitsPerComponent = 8
let bytesPerRow      = bytesPerPixel * self.cols // width
let bitmapInfo       = RGBA32.bitmapInfo
let minimapContext = CGContext(data: nil, width: self.cols, height: self.rows, bitsPerComponent: bitsPerComponent, bytesPerRow: bytesPerRow, space: colorSpace, bitmapInfo: bitmapInfo)
let buffer = minimapContext!.data
self.pixelBuffer = buffer!.bindMemory(to: RGBA32.self, capacity: self.cols * self.rows) // was let

var pixelIndex = 1

Then I loop over an array of like:

self.pixelBuffer[pixelIndex] = .blue

This all works fine without the 'self'.

I want to change some of the pixels, so I added the 'self' and defined it at the top of the ViewController class

Now change the pixels like:

self.pixelBuffer[newPixelIndex] = .lightblue

But I get a variety of errors: Cannot assign value of type 'UnsafeMutablePointer' to type 'RGBA32'

Cannot infer contextual base in reference to member 'lightblue'

Value of type 'RGBA32?' has no subscripts

Don't know if this helps but the pixelBuffer is defined ike:

var pixelBuffer: RGBA32? = nil

and here is RGBA32:

struct RGBA32: Equatable {
private var color: UInt32

init(red: UInt8, green: UInt8, blue: UInt8, alpha: UInt8) {
    color = (UInt32(red) << 24) | (UInt32(green) << 16) | (UInt32(blue) << 8) | (UInt32(alpha) << 0)
}

static let bitmapInfo = CGImageAlphaInfo.premultipliedLast.rawValue | CGBitmapInfo.byteOrder32Little.rawValue

static func ==(lhs: RGBA32, rhs: RGBA32) -> Bool {
    return lhs.color == rhs.color
}

static let black = RGBA32(red: 0, green: 0, blue: 0, alpha: 255)
static let red   = RGBA32(red: 255, green: 0, blue: 0, alpha: 255)
static let green = RGBA32(red: 24, green: 183, blue: 3, alpha: 255)
static let darkgreen = RGBA32(red: 70, green: 105, blue: 35, alpha: 255)
static let blue  = RGBA32(red: 0, green: 127, blue: 255, alpha: 255)
static let lightblue = RGBA32(red: 33, green: 255, blue: 255, alpha: 255)
static let brown = RGBA32(red: 127, green: 63, blue: 0, alpha: 255)

}

THANKS!!

Upvotes: 0

Views: 150

Answers (1)

matt
matt

Reputation: 536027

The main problem is that you have declared self.pixelBuffer to be an Optional RGBA32. But that is not what pixelBuffer was before. It was a UnsafeMutablePointer<RGBA32>. Here is the declaration you need:

var pixelBuffer : UnsafeMutablePointer<RGBA32>!

All your issues will then go away, I think. Your

self.pixelBuffer[newPixelIndex] = .lightblue

then compiles for me.

Upvotes: 1

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