c# - 如何翻转内存中的图像？

Question

我想翻转图像并为该翻转图像创建一个新的 Texture2D。

我做了一些研究，发现这段代码会创建一个新的 Texture2D；

RenderTarget2D newTarget = new RenderTarget2D(GraphicsDevice, partWidth, partHeight)

GraphicsDevice.SetRenderTarget(newTarget);

SpriteBatch.Draw(original, Vector2.Zero, partSourceRectangle, ... )

GraphicsDevice.SetRenderTarget(null);

Texture2D newTexture = (Texture2D)newTarget;

我知道 newTexture 很容易从内存中删除，所以我被告知我需要使用 getData/SetData 来创建更永久的纹理。谁能告诉我执行此操作的具体语法？

Answer 1

下一个方法将翻转的纹理保存到新的 texture2D:

    public Texture2D SaveAsFlippedTexture2D(Texture2D input, bool vertical, bool horizontal)
    {
        Texture2D flipped = new Texture2D(input.GraphicsDevice, input.Width, input.Height);
        Color[] data = new Color[input.Width * input.Height];
        Color[] flipped_data = new Color[data.Length];

        input.GetData<Color>(data);

        for (int x = 0; x < input.Width; x++)
        {
            for (int y = 0; y < input.Height; y++)
            {
                int index = 0;
                if (horizontal && vertical)
                    index = input.Width - 1 - x + (input.Height - 1 - y) * input.Width;
                else if (horizontal && !vertical)
                    index = input.Width - 1 - x + y * input.Width;
                else if (!horizontal && vertical)
                    index = x + (input.Height - 1 - y) * input.Width;
                else if (!horizontal && !vertical)
                    index = x + y * input.Width;

                flipped_data[x + y * input.Width] = data[index];
            }
        }

        flipped.SetData<Color>(flipped_data);

        return flipped;
    }  

例子: 加载我们的纹理然后使用该方法，将我们的纹理作为参数传递以将新的翻转纹理返回到另一个纹理。您也可以在游戏 Update() 方法中加载您的内容。

    Texture2D texture;
    Texture2D flippedTextureHorizontal;
    Texture2D flippedTextureVertical;
    Texture2D flippedTextureVerticalHorizontal;
    protected override void LoadContent()
    {
        // Create a new SpriteBatch, which can be used to draw textures.
        spriteBatch = new SpriteBatch(GraphicsDevice);
        texture = Content.Load<Texture2D>("kitty-cat");
        flippedTextureHorizontal = SaveAsFlippedTexture2D(texture, false, true);
        flippedTextureVertical = SaveAsFlippedTexture2D(texture, true, false);
        flippedTextureVerticalHorizontal = SaveAsFlippedTexture2D(texture, true, true);
    }

绘制方法:

    protected override void Draw(GameTime gameTime)
    {
        GraphicsDevice.Clear(Color.CornflowerBlue);
        spriteBatch.Begin(SpriteSortMode.Deferred, BlendState.AlphaBlend, SamplerState.LinearWrap, DepthStencilState.None, RasterizerState.CullCounterClockwise);
        spriteBatch.Draw(texture, Vector2.Zero, null, Color.White, 0.0f, Vector2.Zero, 1.0f, SpriteEffects.None, 0);
        spriteBatch.Draw(flippedTextureHorizontal, new Vector2(texture.Width + offset, 0), null, Color.White, 0.0f, Vector2.Zero, 1.0f, SpriteEffects.None, 0);
        spriteBatch.Draw(flippedTextureVertical, new Vector2(texture.Width * 2 + offset * 2, 0), null, Color.White, 0.0f, Vector2.Zero, 1.0f, SpriteEffects.None, 0);
        spriteBatch.Draw(flippedTextureVerticalHorizontal, new Vector2(texture.Width * 3 + offset * 3, 0), null, Color.White, 0.0f, Vector2.Zero, 1.0f, SpriteEffects.None, 0);
        spriteBatch.End();
        base.Draw(gameTime);
    }

输出:

可以找到算法Here以及。 通过使用下面的代码同时进行水平和垂直翻转可以实现与上述相同的结果: 但不确定它会 100% 正确

test = new Texture2D(GraphicsDevice, texture.Width, texture.Height);
int size = texture.Width * texture.Height;
Color[] data = new Color[size];
texture.GetData<Color>(data);
Array.Reverse(data, texture.Width, size - texture.Width);
test.SetData<Color>(data);