// Copyright (c) Microsoft Corporation. 
// Licensed under the MIT license. 

using System;
using System.IO;
using System.Threading.Tasks;

public class Program
{
    static void RunReduction(Simplygon.ISimplygon sg)
    {
        using (Simplygon.spSceneImporter sgSceneImporter = sg.CreateSceneImporter())
        {
            sgSceneImporter.SetImportFilePath( "../Assets/SimplygonMan/SimplygonMan.obj" );
            if(!sgSceneImporter.RunImport())
                throw new System.Exception("Failed to load SimplygonMan/SimplygonMan.obj.");
            Simplygon.spScene sgScene = sgSceneImporter.GetScene();

            // Create the reduction pipeline. 
            using (Simplygon.spReductionPipeline sgReductionPipeline = sg.CreateReductionPipeline())
            {
                using (Simplygon.spReductionSettings sgReductionSettings = sgReductionPipeline.GetReductionSettings())
                using (Simplygon.spNormalCalculationSettings sgNormalCalculationSettings = sgReductionPipeline.GetNormalCalculationSettings())
                {
                    // Set reduction target to triangle ratio with a ratio of 50%. 
                    sgReductionSettings.SetReductionTargets( Simplygon.EStopCondition.All, true, false, false, false );
                    sgReductionSettings.SetReductionTargetTriangleRatio( 0.5f );

                    // The angle in degrees determing the normal smoothness. 
                    sgNormalCalculationSettings.SetHardEdgeAngle( 75 );

                    // Reorthogonalize the tangentspace after the reduction. 
                    sgNormalCalculationSettings.SetReorthogonalizeTangentSpace( true );

                    // Repair invalid normals. 
                    sgNormalCalculationSettings.SetRepairInvalidNormals( true );

                    // Don't generate new normals. However invalid normals will still be repaired. 
                    sgNormalCalculationSettings.SetReplaceNormals( false );

                    // Don't generate new tangents and bitangents. 
                    sgNormalCalculationSettings.SetReplaceTangents( false );

                    // Scale the vertex normal based on the triangle area. 
                    sgNormalCalculationSettings.SetScaleByAngle( false );
                    sgNormalCalculationSettings.SetScaleByArea( true );

                    // Don't snap the normal to flat surfaces. 
                    sgNormalCalculationSettings.SetSnapNormalsToFlatSurfaces( false );

                }
                // Start the reduction pipeline. 
                sgReductionPipeline.RunScene(sgScene, Simplygon.EPipelineRunMode.RunInThisProcess);

                // Get the processed scene. 
                using (Simplygon.spScene sgProcessedScene = sgReductionPipeline.GetProcessedScene())
                {
                    using (Simplygon.spSceneExporter sgSceneExporter = sg.CreateSceneExporter())
                    {
                        sgSceneExporter.SetScene(sgProcessedScene);
                        sgSceneExporter.SetExportFilePath( "ReductionOutput.fbx" );
                        if(!sgSceneExporter.RunExport())
                            throw new System.Exception("Failed to save ReductionOutput.fbx.");

                    }
                }
            }
        }
    }
    static int Main(string[] args)
    {
        using (var sg = Simplygon.Loader.InitSimplygon(out var errorCode, out var errorMessage))
        {
            if (errorCode != Simplygon.EErrorCodes.NoError)
                return (int)errorCode;
            RunReduction(sg);
        }

        return 0;
    }
}