在Unity5中缩放PNG？ - Bountie

Question

令人惊讶的团结,多年来只有这样简单地缩放实际PNG是使用非常真棒库http://wiki.unity3d.com/index.php/TextureScale

以下示例

如何使用Unity5功能缩放PNG？现在必须有一种新的UI等方式.

因此,缩放实际像素(例如in Color[])或字面上的PNG文件,可能是从网上下载的.

(顺便说一下,如果你是Unity新手,那么这个Resize电话是无关的.它只会改变一个数组的大小.)

public WebCamTexture wct;

public void UseFamousLibraryToScale()
    {
    // take the photo. scale down to 256
    // also  crop to a central-square

    WebCamTexture wct;
    int oldW = wct.width; // NOTE example code assumes wider than high
    int oldH = wct.height;

    Texture2D photo = new Texture2D(oldW, oldH,
          TextureFormat.ARGB32, false);
    //consider WaitForEndOfFrame() before GetPixels
    photo.SetPixels( 0,0,oldW,oldH, wct.GetPixels() );
    photo.Apply();

    int newH = 256;
    int newW = Mathf.FloorToInt(
           ((float)newH/(float)oldH) * oldW );

    // use a famous Unity library to scale
    TextureScale.Bilinear(photo, newW,newH);

    // crop to central square 256.256
    int startAcross = (newW - 256)/2;
    Color[] pix = photo.GetPixels(startAcross,0, 256,256);
    photo = new Texture2D(256,256, TextureFormat.ARGB32, false);
    photo.SetPixels(pix);
    photo.Apply();
    demoImage.texture = photo;

    // consider WriteAllBytes(
    //   Application.persistentDataPath+"p.png",
    //   photo.EncodeToPNG()); etc
    }

只是BTW它发生在我身上我可能只是在谈论缩小这里(因为你经常要发布图像,动态创建或其他任何东西.)我猜,通常不需要扩大规模大小的图像; 质量毫无意义.

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Answer 1

如果您可以接受拉伸缩放，实际上有更简单的方法，即使用临时 RenderTexture 和 Graphics.Blit。如果你需要它是Texture2D，暂时交换RenderTexture.active并将其像素读取到Texture2D应该可以解决问题。例如：

public Texture2D ScaleTexture(Texture src, int width, int height){
    RenderTexture rt = RenderTexture.GetTemporary(width, height);
    Graphics.Blit(src, rt);

    RenderTexture currentActiveRT = RenderTexture.active;
    RenderTexture.active = rt;
    Texture2D tex = new Texture2D(rt.width,rt.height); 

    tex.ReadPixels(new Rect(0, 0, tex.width, tex.height), 0, 0);
    tex.Apply();

    RenderTexture.ReleaseTemporary(rt);
    RenderTexture.active = currentActiveRT;

    return tex;
}