From f1dcfe1294a609a66215fcf0f68b7b1595023fec Mon Sep 17 00:00:00 2001
From: ChrisDill <chris.rj.dill@gmail.com>
Date: Sat, 9 Sep 2023 20:12:37 +0100
Subject: [PATCH] Add MeshDemo example using the new Mesh utils

---
 Examples/Models/MeshDemo.cs | 116 ++++++++++++++++++++++++++++++++++++
 Examples/Program.cs         |   1 +
 2 files changed, 117 insertions(+)
 create mode 100644 Examples/Models/MeshDemo.cs

diff --git a/Examples/Models/MeshDemo.cs b/Examples/Models/MeshDemo.cs
new file mode 100644
index 0000000..922327e
--- /dev/null
+++ b/Examples/Models/MeshDemo.cs
@@ -0,0 +1,116 @@
+using System.Numerics;
+using static Raylib_cs.Raylib;
+
+namespace Examples.Models;
+
+public class MeshDemo
+{
+    public unsafe static int Main()
+    {
+        // Initialization
+        //--------------------------------------------------------------------------------------
+        const int screenWidth = 800;
+        const int screenHeight = 450;
+
+        InitWindow(screenWidth, screenHeight, "raylib [models] example - mesh demo");
+
+        // Define the camera to look into our 3d world
+        Camera3D camera = new();
+        camera.Position = Vector3.One * 1.5f;
+        camera.Target = Vector3.Zero;
+        camera.Up = Vector3.UnitY;
+        camera.FovY = 60.0f;
+        camera.Projection = CameraProjection.CAMERA_PERSPECTIVE;
+
+        // Generate a mesh using utils to allocate/access mesh attribute data
+        Mesh tetrahedron = new(4, 4);
+        tetrahedron.AllocVertices();
+        tetrahedron.AllocTexCoords();
+        tetrahedron.AllocColors();
+        tetrahedron.AllocIndices();
+        Span<Vector3> vertices = tetrahedron.VerticesAs<Vector3>();
+        Span<Vector2> texcoords = tetrahedron.TexCoordsAs<Vector2>();
+        Span<Color> colors = tetrahedron.ColorsAs<Color>();
+        Span<ushort> indices = tetrahedron.IndicesAs<ushort>();
+
+        // Coordinates for a regular tetrahedron
+        vertices[0] = new(MathF.Sqrt(8f / 9f), 0f, -1f / 3f);
+        vertices[1] = new(-MathF.Sqrt(2f / 9f), MathF.Sqrt(2f / 3f), -1f / 3f);
+        vertices[2] = new(-MathF.Sqrt(2f / 9f), -MathF.Sqrt(2f / 3f), -1f / 3f);
+        vertices[3] = Vector3.UnitZ;
+
+        texcoords[0] = Vector2.Zero;
+        texcoords[1] = Vector2.UnitX;
+        texcoords[2] = Vector2.UnitY;
+        texcoords[3] = Vector2.One;
+
+        colors[0] = Color.PINK;
+        colors[1] = Color.LIME;
+        colors[2] = Color.SKYBLUE;
+        colors[3] = Color.VIOLET;
+
+        indices[0] = 2;
+        indices[1] = 1;
+        indices[2] = 0;
+
+        indices[3] = 1;
+        indices[4] = 3;
+        indices[5] = 0;
+
+        indices[6] = 2;
+        indices[7] = 3;
+        indices[8] = 1;
+
+        indices[9] = 0;
+        indices[10] = 3;
+        indices[11] = 2;
+
+        float rotationAngle = 0f;
+        Raylib.UploadMesh(ref tetrahedron, false);
+        Model model = Raylib.LoadModelFromMesh(tetrahedron);
+
+        Image image = Raylib.GenImagePerlinNoise(16, 16, 0, 0, 1000f);
+        Raylib.ImageBlurGaussian(ref image, 2);
+        Raylib.ImageColorBrightness(ref image, 100);
+        Raylib.ImageDither(ref image, 4, 4, 4, 4);
+        Texture2D texture = Raylib.LoadTextureFromImage(image);
+        Raylib.UnloadImage(image);
+
+        Raylib.SetMaterialTexture(ref model, 0, MaterialMapIndex.MATERIAL_MAP_DIFFUSE, ref texture);
+
+        SetTargetFPS(60);
+        //--------------------------------------------------------------------------------------
+
+        // Main game loop
+        while (!WindowShouldClose())
+        {
+            // Update
+            //----------------------------------------------------------------------------------
+            UpdateCamera(ref camera, CameraMode.CAMERA_FREE);
+            rotationAngle = Raymath.Wrap(rotationAngle += 1f, 0f, 360f);
+            //----------------------------------------------------------------------------------
+
+            // Draw
+            //----------------------------------------------------------------------------------
+            BeginDrawing();
+            ClearBackground(Color.RAYWHITE);
+
+            BeginMode3D(camera);
+            Raylib.DrawModelEx(model, Vector3.Zero, Vector3.UnitX, rotationAngle, Vector3.One, Color.WHITE);
+            EndMode3D();
+
+            EndDrawing();
+            //----------------------------------------------------------------------------------
+        }
+
+        // De-Initialization
+        //--------------------------------------------------------------------------------------
+        UnloadTexture(texture);
+        UnloadModel(model);
+
+        CloseWindow();
+        //--------------------------------------------------------------------------------------
+
+        return 0;
+    }
+}
diff --git a/Examples/Program.cs b/Examples/Program.cs
index 4d9def5..fbb310d 100644
--- a/Examples/Program.cs
+++ b/Examples/Program.cs
@@ -117,6 +117,7 @@ public class ExampleList
         new ExampleInfo("FirstPersonMaze", FirstPersonMaze.Main),
         new ExampleInfo("GeometricShapes", GeometricShapes.Main),
         new ExampleInfo("HeightmapDemo", HeightmapDemo.Main),
+        new ExampleInfo("MeshDemo", MeshDemo.Main),
         new ExampleInfo("ModelLoading", ModelLoading.Main),
         new ExampleInfo("MeshGeneration", MeshGeneration.Main),
         new ExampleInfo("MeshPicking", MeshPicking.Main),