Play around more with text rendering

Assets/Scripts/DecalProjectorTest.cs

@@ -0,0 +1,47 @@
+using UnityEngine;
+
+[ExecuteInEditMode]
+public class DecalProjectorTest : MonoBehaviour
+{
+    public GameObject target = null;
+    public Material targetMaterial = null;
+    public MeshRenderer targetRenderer;
+
+
+    public float aspectRatio = 1.0f;
+    public float size = 1.0f;
+    public float factor = 1.0f;
+
+    private Matrix4x4 _projectionMatrix;
+    private Matrix4x4 _OrthoMatrix;
+
+    private int _matrixID;
+    private int _normalID;
+    public int _tangentID;
+    
+    // Start is called before the first frame update
+    void Awake()
+    {
+        _projectionMatrix = Matrix4x4.identity;
+        _matrixID = Shader.PropertyToID("_ProjectionMatrix");
+        _normalID = Shader.PropertyToID("_DecalNormal");
+        _tangentID= Shader.PropertyToID("_DecalTangent");
+        targetRenderer = target.GetComponent<MeshRenderer>();
+    }
+
+    // Update is called once per frame
+    void Update()
+    {
+        Vector3 pos =new Vector3( 0.5f ,0.5f, 0);
+        Vector3 scale = new Vector3(1 / size, 1 / (aspectRatio * size), 1);
+        _OrthoMatrix.SetTRS(pos, Quaternion.identity, scale);
+        //Debug.Log(_OrthoMatrix);
+        var targetToProjector = transform.worldToLocalMatrix * targetRenderer.localToWorldMatrix;
+        var projectorToTarget = targetRenderer.worldToLocalMatrix * transform.localToWorldMatrix;
+        _projectionMatrix = _OrthoMatrix * targetToProjector;
+        
+        targetMaterial.SetMatrix(_matrixID, _projectionMatrix);
+        targetMaterial.SetVector(_normalID, projectorToTarget.MultiplyVector(Vector3.back).normalized);
+        targetMaterial.SetVector(_tangentID, projectorToTarget.MultiplyVector(Vector3.right).normalized);
+    }
+}

Assets/Scripts/TextRenderTest.cs

@@ -0,0 +1,90 @@
+using System.Collections;
+using System.Collections.Generic;
+using TMPro;
+using UnityEngine;
+using UnityEngine.Rendering;
+
+public class TextRenderTest : MonoBehaviour {
+    //[InspectorButton("go")] public bool button;
+
+    public Camera _camera;
+
+    public GameObject _cameraObject;
+
+    public TextMeshPro _tmp;
+    
+    public Material _blitMaterial;
+
+    public Material _targetMaterial;
+
+    public RenderTexture renderTex;
+    private float pixelDensity = 36;
+    private int MaxTextureSize = 4096;
+
+    public const TextureFormat TextTextureFormat = TextureFormat.RG16;
+    public const RenderTextureFormat TextRenderTextureFormat = RenderTextureFormat.R8;
+    
+    // Start is called before the first frame update
+    void Start() {
+        Debug.Log("starting...");
+
+        StartCoroutine(OnRender());
+    }
+
+    // Update is called once per frame
+    void Update() {
+    }
+
+    private void go() {
+        Debug.Log("starting...");
+    }
+
+    private IEnumerator OnRender() {
+        Debug.Log("starting...2");
+
+        // calculate camera and texture size
+        _tmp.ForceMeshUpdate();
+        var mesh = _tmp.mesh;
+        mesh.RecalculateBounds();
+        var bounds = mesh.bounds;
+        Debug.Log(bounds.size);
+
+        var width = Mathf.NextPowerOfTwo((int) (bounds.size.x * pixelDensity));
+        var height = Mathf.NextPowerOfTwo((int) (bounds.size.y * pixelDensity));
+        
+        Debug.Log($"width = {width}");
+        Debug.Log($"height = {height}");
+        
+        _camera.orthographicSize = height / pixelDensity / 2;
+        _camera.aspect = (float) width / height;
+
+        _cameraObject.transform.localPosition = new Vector3(bounds.center.x, bounds.center.y, -1);
+
+        width = Mathf.Min(width, MaxTextureSize);
+        height = Mathf.Min(height, MaxTextureSize);
+        
+        // setup texture
+        var texture = new Texture2D(width, height, TextTextureFormat, true);
+        _targetMaterial.mainTexture = texture;
+
+        // setup render texture
+        renderTex = RenderTexture.GetTemporary(width, height, 0, TextRenderTextureFormat, RenderTextureReadWrite.Linear, 1);
+        renderTex.autoGenerateMips = true;
+        _camera.targetTexture = renderTex;
+
+        // setup material
+        _blitMaterial.mainTexture = _tmp.font.atlas;
+
+        // draw the mesh
+        Graphics.DrawMesh(mesh, _tmp.renderer.localToWorldMatrix, _blitMaterial, 0, _camera, 0);
+        _camera.Render();
+
+        yield return null;
+
+        RenderTexture.active = renderTex;
+        texture.ReadPixels(new Rect(0, 0, width, height), 0, 0, true);
+        texture.Apply(false, true);
+        
+        RenderTexture.ReleaseTemporary(renderTex);
+    }
+}