ios - IOS 中的图像变形

Question

我是 IOS 图像编辑工作的新手。

我想在 ios 或 swift(任何一个)中实现 Image Warp 的功能。

我搜索了很多谷歌但没有得到我想要的东西

下面的链接我是searf

How can you apply distortions to a UIImage using OpenGL ES?

https://github.com/BradLarson/GPUImage

https://github.com/Ciechan/BCMeshTransformView

这是我想要的图像(当我触摸网格点图像时，我们应该换行，如果我将网格点放在原始位置，它应该是原始的)

Answer 1

我已经为 BCMeshTransformView 编写了一个扩展，允许您应用扭曲变换来响应用户的触摸输入。

extension BCMutableMeshTransform {
    static func warpTransform(from startPoint:CGPoint,
                              to endPoint:CGPoint, in size:CGSize) -> BCMutableMeshTransform {
        let resolution:UInt = 30
        let mesh = BCMutableMeshTransform.identityMeshTransform(withNumberOfRows: resolution,
                                                                numberOfColumns: resolution)!

        let _startPoint = CGPoint(x: startPoint.x/size.width, y: startPoint.y/size.height)
        let _endPoint = CGPoint(x: endPoint.x/size.width, y: endPoint.y/size.height)
        let dragDistance = _startPoint.distance(to: _endPoint)

        for i in 0..<mesh.vertexCount {
            var vertex = mesh.vertex(at: i)
            let myDistance = _startPoint.distance(to: vertex.from)

            let hEdgeDistance = min(vertex.from.x, 1 - vertex.from.x)
            let vEdgeDistance = min(vertex.from.y, 1 - vertex.from.y)
            let hProtection = min(100, pow(hEdgeDistance * 100, 1.5))/100
            let vProtection = min(100, pow(vEdgeDistance * 100, 1.5))/100

            if (myDistance < dragDistance) {
                let maxDistort = CGPoint(x:(_endPoint.x - _startPoint.x) / 2,
                                         y:(_endPoint.y - _startPoint.y) / 2)

                let normalizedDistance = myDistance/dragDistance
                let normalizedImpact = (cos(normalizedDistance * .pi) + 1) / 2

                vertex.to.x += maxDistort.x * normalizedImpact * hProtection
                vertex.to.y += maxDistort.y * normalizedImpact * vProtection

                mesh.replaceVertex(at: i, with: vertex)
            }
        }
        return mesh
    }
}

然后只需将该属性设置为您的 transformView。

fileprivate var startPoint:CGPoint?

    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        guard let touch = touches.first else { return }
        startPoint = touch.location(in: self)
    }

    override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
        guard let startPoint_ = startPoint else { return }
        guard let touch = touches.first else { return }

        let position = touch.location(in: self)
        transformView.meshTransform = BCMutableMeshTransform.warpTransform(from: startPoint_,
                                                                           to: position, in: bounds.size)
    }

warp 代码并不完美，但在我的案例中它完成了工作。您可以使用它，但总体思路保持不变。