使用 ImageSharp 放置旋转图像

Question

我正在尝试旋转（围绕它的中心）并将一个图像放在另一个图像之上。

旋转后，我预期的 XY 坐标全错了。

非常感谢有关如何执行此操作的示例

当前正在绘制调试帧而不是图像。

我的坐标系基于展示位置的中心位置，但我可以将 XY 坐标切换到左上角

private static void DrawDebugFrames(List<LogoPlacementContentDto> placements, Image<Rgba32> mutatedImage)
{
    foreach (var placement in placements)
    {
        var width = placement.Width;
        var height = placement.Height;

        using (var logo = new Image<Rgba32>(Configuration.Default, width, height))
        {
            var centerX = placement.X; // center of imagePlacement
            var centerY = placement.Y; // center of imagePlacement

            var affineBuilder = new AffineTransformBuilder();
            affineBuilder.PrependTranslation(new Vector2(centerX, centerY));
            affineBuilder.PrependRotationDegrees(placement.Rotation);

            logo.Mutate(
                x => x
                    .BackgroundColor(Rgba32.Beige).DrawPolygon(
                        Rgba32.HotPink,
                        4,
                        new Vector2(0, 0),
                        new Vector2(width, 0),
                        new Vector2(width, height),
                        new Vector2(0, height)
                    )
                    .Transform(affineBuilder)
            );

            mutatedImage.Mutate(
                x => x
                    .DrawImage(logo, new Point(-(width / 2), -(height / 2)), GraphicsOptions.Default)
            );
        }
    }
}

（图片）Expected result (editor)

（图片）Result

Answer 1

我能够解决这个问题。

问题是客户端从未发送边界框的 XY 坐标。相反，我尝试使用左上角的 XY 或中心位置 XY。

有了这个固定。我稍微调整了代码以反映这一变化。

private static void DrawDebugFrames(List<LogoPlacementContentDto> placements, Image<Rgba32> mutatedImage)
{
    foreach (var placement in placements)
    {
        var width = placement.WidthInt;
        var height = placement.HeightInt;

        using (var logo = new Image<Rgba32>(Configuration.Default, width, height))
        {
            var positionX = placement.Position.X;
            var positionY = placement.Position.Y;

            var affineBuilder = new AffineTransformBuilder();

            affineBuilder.PrependTranslation(new Vector2(positionX, positionY));
            affineBuilder.PrependRotationDegrees(placement.Rotation);
            affineBuilder.AppendTranslation(new Vector2(-positionX, -positionY));

            logo.Mutate(
                x => x
                    .BackgroundColor(Rgba32.Beige).DrawPolygon(
                        Rgba32.HotPink,
                        4,
                    new Vector2(0, 0),
                    new Vector2(width, 0),
                    new Vector2(width, height),
                    new Vector2(0, height)
                    )
                    .Transform(affineBuilder)
            );

            mutatedImage.Mutate(
                x => x
                    .DrawImage(logo, new Point(placement.Position.XInt, placement.Position.YInt), GraphicsOptions.Default)
            );
        }
    }
}

使用 ImageSharp 放置旋转图像

Placing a rotated image with ImageSharp

c#

image-manipulation

imagesharp