From 1e480f6c15d191008abd0a20dd9d72c1795d4369 Mon Sep 17 00:00:00 2001
From: jracek <racek.janek@gmail.com>
Date: Thu, 13 Mar 2025 12:37:23 +0100
Subject: [PATCH] Added PSXMesh, deindexes tris, converts them into primitives
 for the PSX

---
 Runtime/PSXMesh.cs           | 52 +++++++++++++++++++++++++++++++++---
 Runtime/PSXObjectExporter.cs | 12 +++++++++
 2 files changed, 61 insertions(+), 3 deletions(-)

diff --git a/Runtime/PSXMesh.cs b/Runtime/PSXMesh.cs
index 14e52e3..bb234f3 100644
--- a/Runtime/PSXMesh.cs
+++ b/Runtime/PSXMesh.cs
@@ -1,16 +1,62 @@
+using System.Collections.Generic;
 using UnityEngine;
 
 namespace PSXSplash.RuntimeCode
 {
 
+    public struct PSXVertex
+    {
+        public short vx, vy, vz;
+        public byte u, v;
+    }
+
+    public struct Tri
+    {
+        public PSXVertex v0;
+        public PSXVertex v1;
+        public PSXVertex v2;
+    }
+
     [System.Serializable]
     public class PSXMesh
     {
-        public bool TriangulateMesh = true;
+        public List<Tri> Triangles;
 
-        public void Export(GameObject gameObject)
+        public static PSXMesh CreateFromUnityMesh(Mesh mesh, int textureWidth, int textureHeight)
         {
-            Debug.Log($"Export: {this}");
+            PSXMesh psxMesh = new PSXMesh { Triangles = new List<Tri>() };
+
+            Vector3[] vertices = mesh.vertices;
+            Vector2[] uv = mesh.uv;
+            int[] indices = mesh.triangles;
+
+            for (int i = 0; i < indices.Length; i += 3)
+            {
+                int vid0 = indices[i];
+                int vid1 = indices[i + 1];
+                int vid2 = indices[i + 2];
+
+                PSXVertex v0 = ConvertToPSXVertex(vertices[vid0], uv[vid0], textureWidth, textureHeight);
+                PSXVertex v1 = ConvertToPSXVertex(vertices[vid1], uv[vid1], textureWidth, textureHeight);
+                PSXVertex v2 = ConvertToPSXVertex(vertices[vid2], uv[vid2], textureWidth, textureHeight);
+
+                psxMesh.Triangles.Add(new Tri { v0 = v0, v1 = v1, v2 = v2 });
+            }
+
+            return psxMesh;
+        }
+
+        private static PSXVertex ConvertToPSXVertex(Vector3 vertex, Vector2 uv, int textureWidth, int textureHeight)
+        {
+            PSXVertex psxVertex = new PSXVertex
+            {
+                vx = (short)(Mathf.Clamp(vertex.x, -4f, 3.999f) * 4096),
+                vy = (short)(Mathf.Clamp(vertex.y, -4f, 3.999f) * 4096),
+                vz = (short)(Mathf.Clamp(vertex.z, -4f, 3.999f) * 4096),
+                u = (byte)(Mathf.Clamp(uv.x * textureWidth, 0, 255)),
+                v = (byte)(Mathf.Clamp((1.0f - uv.y) * textureHeight, 0, 255))
+            };
+            return psxVertex;
         }
     }
 }
\ No newline at end of file
diff --git a/Runtime/PSXObjectExporter.cs b/Runtime/PSXObjectExporter.cs
index 6ccc31a..53d8099 100644
--- a/Runtime/PSXObjectExporter.cs
+++ b/Runtime/PSXObjectExporter.cs
@@ -9,6 +9,9 @@ namespace PSXSplash.RuntimeCode
         [HideInInspector]
         public PSXTexture2D Texture;
 
+        [HideInInspector]
+        public PSXMesh Mesh;
+
         public void CreatePSXTexture2D()
         {
             Renderer renderer = GetComponent<Renderer>();
@@ -18,6 +21,15 @@ namespace PSXSplash.RuntimeCode
                 Texture.OriginalTexture = texture;
             }
         }
+
+        public void CreatePSXMesh()
+        {
+            MeshFilter meshFilter = gameObject.GetComponent<MeshFilter>();
+            if (meshFilter != null)
+            {
+                Mesh = PSXMesh.CreateFromUnityMesh(meshFilter.mesh, Texture.Width, Texture.Height);
+            }
+        }
     }
 }