Simplify the TextureResizer

[ZeevAbrams]

Hi,
Thanks for posting the code for tfLite - but it's massive overkill. Though I tried many ways to go around it, the best was just to copy the code within the TextureResizer into a new Script file, and just use it directly. It has almost no dependencies on the tfLite package - except for the Dispose - which I remarked out below:
(Also - I copied the required Shader to a new Shader file under Custom/ResizeShader - it's easy to find

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class TextureResizer : MonoBehaviour
{
// taking the code from : https://github.com/paulorenanmelo/MonocularDepthSensing/blob/master/Assets/Scripts/tf-lite-unity-sample/Common/TextureResizer.cs
// and redoing it

RenderTexture resizeTexture;
Material _blitMaterial;

static readonly int _VertTransform = Shader.PropertyToID("_VertTransform");
static readonly int _UVRect = Shader.PropertyToID("_UVRect");


public enum AspectMode
{
    None,
    Fit,
    Fill,
}
public struct ResizeOptions
{
    public int width;
    public int height;
    public float rotationDegree;
    public bool flipX;
    public bool flipY;
    public AspectMode aspectMode;
}

public Material material
{
    get
    {
        if (_blitMaterial == null)
        {
            _blitMaterial = new Material(Shader.Find("Custom/ResizeShader"));  //changed
        }
        return _blitMaterial;
    }
}

public Vector4 UVRect
{
    get => material.GetVector(_UVRect);
    set => material.SetVector(_UVRect, value);
}

public Matrix4x4 VertexTransfrom
{
    get => material.GetMatrix(_VertTransform);
    set => material.SetMatrix(_VertTransform, value);
}

public TextureResizer()
{

}

//public void Dispose()
//{
//    DisposeUtil.TryDispose(resizeTexture);
//    DisposeUtil.TryDispose(_blitMaterial);
//}
public ResizeOptions ModifyOptionForWebcam(ResizeOptions options, WebCamTexture texture)
{
    options.rotationDegree += texture.videoRotationAngle;
    if (texture.videoVerticallyMirrored)
    {
        options.flipX = !options.flipX;
    }
    return options;
}


public RenderTexture Resize(Texture texture, ResizeOptions options)
{
    // Set options
    if (texture is WebCamTexture)
    {
        options = ModifyOptionForWebcam(options, (WebCamTexture)texture);
    }

    VertexTransfrom = GetVertTransform(options.rotationDegree, options.flipX, options.flipY);
    UVRect = GetTextureST(texture, options);
    return ApplyResize(texture, options.width, options.height);
}


public RenderTexture ApplyResize(Texture texture, int width, int height)
{
    if (resizeTexture == null
        || resizeTexture.width != width
        || resizeTexture.height != height)
    {
        //DisposeUtil.TryDispose(resizeTexture);
        resizeTexture = new RenderTexture(width, height, 0, RenderTextureFormat.ARGB32);
    }
    Graphics.Blit(texture, resizeTexture, material, 0);
    return resizeTexture;
}

public static Vector4 GetTextureST(float srcAspect, float dstAspect, AspectMode mode)
{
    switch (mode)
    {
        case AspectMode.None:
            return new Vector4(1, 1, 0, 0);
        case AspectMode.Fit:
            if (srcAspect > dstAspect)
            {
                float s = srcAspect / dstAspect;
                return new Vector4(1, s, 0, (1 - s) / 2);
            }
            else
            {
                float s = dstAspect / srcAspect;
                return new Vector4(s, 1, (1 - s) / 2, 0);
            }
        case AspectMode.Fill:
            if (srcAspect > dstAspect)
            {
                float s = dstAspect / srcAspect;
                return new Vector4(s, 1, (1 - s) / 2, 0);
            }
            else
            {
                float s = srcAspect / dstAspect;
                return new Vector4(1, s, 0, (1 - s) / 2);
            }
    }
    throw new System.Exception("Unknown aspect mode");
}

public static Vector4 GetTextureST(Texture sourceTex, ResizeOptions options)
{
    return GetTextureST(
        (float)sourceTex.width / (float)sourceTex.height, // src
        (float)options.width / (float)options.height, // dst
        options.aspectMode);
}

private static readonly Matrix4x4 PUSH_MATRIX = Matrix4x4.Translate(new Vector3(0.5f, 0.5f, 0));
private static readonly Matrix4x4 POP_MATRIX = Matrix4x4.Translate(new Vector3(-0.5f, -0.5f, 0));
public static Matrix4x4 GetVertTransform(float rotation, bool invertX, bool invertY)
{
    Vector3 scale = new Vector3(
        invertX ? -1 : 1,
        invertY ? -1 : 1,
        1);
    Matrix4x4 trs = Matrix4x4.TRS(
        Vector3.zero,
        Quaternion.Euler(0, 0, rotation),
        scale
    );
    return PUSH_MATRIX * trs * POP_MATRIX;
}

}