diff --git a/src/EngineSharp.Core/EngineSharp.Core/Rendering/Mesh.cs b/src/EngineSharp.Core/EngineSharp.Core/Rendering/Mesh.cs new file mode 100644 index 0000000..0e624e1 --- /dev/null +++ b/src/EngineSharp.Core/EngineSharp.Core/Rendering/Mesh.cs @@ -0,0 +1,45 @@ +using Silk.NET.Maths; + +namespace EngineSharp.Core.Rendering; + +public class Mesh +{ + public Vector3D[] Vertices { get; set; } + public Vector3D[] Normals { get; set; } + public uint[] Indices { get; set; } + + // TODO: Add uv textures but make them nullable; MeshRenderer should then only send uv data to shader if specified + + /// + /// Overwrites the values of + /// + public void CalculateNormals() + { + if (Normals.Length != Vertices.Length) + { + Normals = new Vector3D[Vertices.Length]; + } + + for (var i = 0; i < Indices.Length; i += 3) + { + var i0 = Indices[i]; + var i1 = Indices[i+1]; + var i2 = Indices[i+2]; + var v0 = Vertices[i0]; + var v1 = Vertices[i1]; + var v2 = Vertices[i2]; + + var normal = Vector3D.Cross(v1-v0, v2-v0); + // Commenting this out, will result in the normals being weighted based on the triangle area + normal = Vector3D.Normalize(normal); + Normals[i0] += normal; + Normals[i1] += normal; + Normals[i2] += normal; + } + + for (var i = 0; i < Normals.Length; i++) + { + Normals[i] = Vector3D.Normalize(Normals[i]); // smoothing for shared vertices + } + } +} \ No newline at end of file diff --git a/src/EngineSharp.Core/EngineSharp.Core/Rendering/MeshRenderer.cs b/src/EngineSharp.Core/EngineSharp.Core/Rendering/MeshRenderer.cs new file mode 100644 index 0000000..ecaf096 --- /dev/null +++ b/src/EngineSharp.Core/EngineSharp.Core/Rendering/MeshRenderer.cs @@ -0,0 +1,53 @@ +using Silk.NET.OpenGL; + +namespace EngineSharp.Core.Rendering; + +public class MeshRenderer +{ + public Mesh Mesh { get; set; } + + private uint vao, vbo, ebo; + + internal void Render(GL gl) + { + GenerateRenderableMesh(gl); + gl.BindVertexArray(vao); + gl.DrawElements(PrimitiveType.Triangles, (uint)Mesh.Indices.Length, DrawElementsType.UnsignedInt, 0); + } + + private void GenerateRenderableMesh(GL gl) + { + if(vao == 0) { vao = gl.CreateVertexArray(); } + gl.BindVertexArray(vao); + + if(vbo == 0) { vbo = gl.GenBuffer(); } + if(ebo == 0) { ebo = gl.GenBuffer(); } + + var meshData = new float[Mesh.Vertices.Length * 3 + Mesh.Indices.Length * 3]; + for (int i = 0, insert = 0; i < Mesh.Vertices.Length; i++, insert += 6) + { + meshData[insert] = Mesh.Vertices[i].X; + meshData[insert + 1] = Mesh.Vertices[i].Y; + meshData[insert + 2] = Mesh.Vertices[i].Z; + + meshData[insert + 3] = Mesh.Normals[i].X; + meshData[insert + 4] = Mesh.Normals[i].Y; + meshData[insert + 5] = Mesh.Normals[i].Z; + } + + gl.BindBuffer(BufferTargetARB.ArrayBuffer, vbo); + var meshDataSpan = new ReadOnlySpan(meshData); + gl.BufferData(BufferTargetARB.ArrayBuffer, meshDataSpan, BufferUsageARB.StaticDraw); + + gl.BindBuffer(BufferTargetARB.ArrayBuffer, ebo); + var indicesSpan = new ReadOnlySpan(Mesh.Indices); + gl.BufferData(BufferTargetARB.ArrayBuffer, indicesSpan, BufferUsageARB.StaticDraw); + + // vertices + gl.EnableVertexAttribArray(0); + gl.VertexAttribPointer(0, 3, VertexAttribPointerType.Float, false, 6 * sizeof(float), 0); + // normals + gl.EnableVertexAttribArray(1); + gl.VertexAttribPointer(1, 3, VertexAttribPointerType.Float, false, 6 * sizeof(float), 3*sizeof(float)); + } +} \ No newline at end of file