从Texture2D创建UI图像 [英] Creating UI Image from Texture2D

问题描述

我正在开发一个实时流应用，该应用接收 JPEG 图像作为字节数组，并显示它在屏幕上和UI.Image. 工作很好，但是我正在进行优化，并且有几个问题.目前，我在下面的代码将字节数组转换为Texture2D，然后从Texture2D 创建一个Sprite，然后将Sprite分配给UI.Iamge在屏幕上显示.

I working on a live stream App that receives JPEG image as arrays of bytes and displays it on the screen with UI.Image. It works fine but I am making optimization and have few questions. Currently, the code I have below converts arrays of bytes to Texture2D then creates a Sprite from the Texture2D then assign that Sprite to UI.Iamge to display on the screen.

Texture2D camTexture;
Image screenDisplay;
public byte[] JPEG_VIDEO_STREAM;
bool updateScreen = false;

//正在初始化

JPEG_VIDEO_STREAM = new byte[20000];
camTexture = new Texture2D(Screen.width, Screen.height, TextureFormat.RGB24, false);

//在更新功能中运行的主代码

//Main Code that runs in the Update function

if(updateScreen){
camTexture.LoadImage(JPEG_VIDEO_STREAM);
Sprite tempSprite = Sprite.Create(camTexture, new Rect(0, 0, camTexture.width, camTexture.height), Vector2.zero, 0);
screenDisplay.sprite = tempSprite;
updateScreen = false;
}

上面的代码当前仅执行3个步骤即可将图像显示到屏幕上.

The code above currently perform 3 steps just to display image to screen.

byte array -> Texture2D -> Sprite -> UI.Image.

但是我希望它看起来像byte array -> Texture2D -> UI.Image.

but I want it to look like byte array -> Texture2D-> UI.Image.

我想直接将Texture2D写到UI.Image 而无需创建新Sprite ，因为我相信Sprite.Create(camTexture, new Rect(0, 0, camTexture.width, camTexture.height), Vector2.zero, 0); 分配新内存每次Sprite.Create调用.我看了看Unity文档，找不到其他方法.

I want to write Texture2D directly to UI.Image without creating new Sprite because I believe that Sprite.Create(camTexture, new Rect(0, 0, camTexture.width, camTexture.height), Vector2.zero, 0); allocates new memory each time Sprite.Create called. I looked at the Unity Documentation and couldn't find any other way to do this.

我的问题是:

1. 如何在不首先将camTexture(Texture2D)转换为Sprite的情况下将camTexture(Texture2D)分配到屏幕screenDisplay(UI.Image)?

1. How can I assign camTexture(Texture2D) to the screen screenDisplay(UI.Image) without converting camTexture(Texture2D) to Sprite first?

Sprite.Create调用时是否分配新的内存?

Does Sprite.Create allocate new memory when called?

如果对此有一个解决方案，那么该解决方案是否比我目前在性能和内存管理?

If there is a solution to this, is that solution better than what I currently have in terms of performance and memory management?

注意:我没有没有计划使用OnGUI绘制Texture2D.我想用新的Unity UI来做到这一点.谢谢.

Note: I have no plans on using OnGUI to draw Texture2D. I want to do this with the new Unity UI. Thanks.

修改: 有了Joe对RawImage的回答，最终代码如下:

With Joe's answer of RawImage, the final code looks like this:

RawImage screenDisplay;
if(updateScreen){
camTexture.LoadImage(JPEG_VIDEO_STREAM);
screenDisplay.texture = camTexture;
updateScreen = false;
}

不再需要Sprite.

No more Sprite needed.

推荐答案

我认为，通过专门使用RawImage而不是Image，可以做到这一点.

I think that by specifically using a RawImage rather than Image, one can do this.

我广泛使用RawImage，因为我们必须显示PNG"，而且更容易.

I use RawImage extensively, because, we have to "display PNGs" and it's easier.

考虑非常方便的把戏:

仅 以 开头，您已经导入了一个普通的灰色PNG.. 然后对其进行修改 .而不是尝试从头开始构建?

just start with a trivial gray PNG which you have imported .. and then modify that .. rather than try to build from scratch?

我发现一个有趣的好奇心是:通常要镜像图像，您只需将x或y缩放为-1.除非已修复，否则Unity会出现一个问题，该问题不适用于RawImage.

An interesting curiosity I found is: normally to mirror an image, you just simply scale of x or y to -1. Unless it's been fixed, Unity has a problem where this won't work for RawImage.

    // currently in Unity, the ONLY way to mirror a RAW image is by fooling with
    // the uvRect. changing the scale is completely broken.

    if ( shouldWeMirror )
      rawImage.uvRect = new Rect(1,0,-1,1); // means mirror
    else
      rawImage.uvRect = new Rect(0,0,1,1);  // means no flip

另一个有趣的因素.因此，许多Unity项目仍使用(甚至是2017年)最高级的 2dToolkit .它可以立即解决诸如此类的问题.

Another interesting factor. For this reason, many Unity projects still use (even 2017) the superlative 2dToolkit. It instantly solves issues such as this.

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