e

Program.cs

           // TODO: for model replacement just delete the old elements and make a new one
            var element0 = drawCalls[0];
            var vertexBuffer = element0._graphicsVertexBuffer._vertexBuffer;
            var indexBuffer = element0._graphicsIndexBuffer._indexBuffer;
            
            var replacementModel = new Model("C:/Users/hydos/Desktop/skibidiToilet/tarclop.gltf");
            var mesh = replacementModel.Meshes[0]; // TODO: in future we will support > 1 mesh. for now just do 1 mesh

            using var newVertexBytes = new MemoryStream();
            using (var writer = new EndianAwareBinaryWriter(newVertexBytes, Endianness.BigEndian)) {
                foreach (var vert in mesh.vertices) {
                    writer.Write(vert.pos.X);
                    writer.Write(vert.pos.Y);
                    writer.Write(vert.pos.Z);
                    writer.Write((Half) vert.uv.X);
                    writer.Write((Half) vert.uv.Y);
                }
            }
            
            using var newIndexBytes = new MemoryStream();
            using (var writer = new EndianAwareBinaryWriter(newIndexBytes, Endianness.BigEndian)) {
                foreach (var idx in mesh.indices) {
                    writer.Write((ushort) idx);
                }
            }

            vertexBuffer._format._vertexSize = 4 * 3 + 4 * 2 ; // float3(pos) + float2(uv)
            vertexBuffer._format._enableSoftwareBlending = false; // this requires an extra vertex format. nuh-uh
            vertexBuffer._format._elements.Realloc(2);
            vertexBuffer._format._elements[0] = new igVertexElementMetaField {
                _count = 0,
                _freq = 0,
                _offset = 0,
                _stream = 0,
                _type = 3,
                _usage = 0,
                _usageIndex = 0,
                _mapToElement = 0,
                _packDataOffset = 0,
                _packTypeAndFracHint = 0
            };
            
            vertexBuffer._format._elements[1] = new igVertexElementMetaField {
                _count = 0,
                _freq = 0,
                _offset = 12,
                _stream = 0,
                _type = 42,
                _usage = 5,
                _usageIndex = 0,
                _mapToElement = 0,
                _packDataOffset = 0,
                _packTypeAndFracHint = 0
            };
            
            indexBuffer._vertexFormat._vertexSize = 4 * 3 + 4 * 2 ; // float3(pos) + float2(uv)
            indexBuffer._vertexFormat._enableSoftwareBlending = false; // this requires an extra vertex format. nuh-uh
            indexBuffer._vertexFormat._elements.Realloc(2);
            indexBuffer._vertexFormat._elements[0] = new igVertexElementMetaField {
                _count = 0,
                _freq = 0,
                _offset = 0,
                _stream = 0,
                _type = 3,
                _usage = 0,
                _usageIndex = 0,
                _mapToElement = 0,
                _packDataOffset = 0,
                _packTypeAndFracHint = 0
            };
            
            indexBuffer._vertexFormat._elements[1] = new igVertexElementMetaField {
                _count = 0,
                _freq = 0,
                _offset = 12,
                _stream = 0,
                _type = 42,
                _usage = 5,
                _usageIndex = 0,
                _mapToElement = 0,
                _packDataOffset = 0,
                _packTypeAndFracHint = 0
            };

            var newData = newVertexBytes.ToArray();
            vertexBuffer._data.Realloc(newData.Length);
            for (var i = 0; i < newData.Length; i++) vertexBuffer._data[i] = newData[i];
            vertexBuffer._vertexCount = (uint)mesh.vertices.Count;
            vertexBuffer._vertexCountArray[0] = (uint)mesh.vertices.Count;
            
            newData = newIndexBytes.ToArray();
            indexBuffer._data.Realloc(newData.Length);
            for (var i = 0; i < newData.Length; i++) indexBuffer._data[i] = newData[i];
            indexBuffer._indexCount = (uint)mesh.indices.Count;
            indexBuffer._indexCountArray[0] = (uint)mesh.indices.Count;
            Save(directory);