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

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

public class Program
{
    static void NormalsCasting(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 processor. 
            using (Simplygon.spReductionProcessor sgReductionProcessor = sg.CreateReductionProcessor())
            {
                sgReductionProcessor.SetScene( sgScene );

                using (Simplygon.spReductionSettings sgReductionSettings = sgReductionProcessor.GetReductionSettings())
                using (Simplygon.spMappingImageSettings sgMappingImageSettings = sgReductionProcessor.GetMappingImageSettings())
                {
                    // Set reduction target to triangle ratio with a ratio of 50%. 
                    sgReductionSettings.SetReductionTargets( Simplygon.EStopCondition.All, true, false, false, false );
                    sgReductionSettings.SetReductionTargetTriangleRatio( 0.5f );

                    // Generates a mapping image which is used after the reduction to cast new materials to the new 
                    // reduced object. 
                    sgMappingImageSettings.SetGenerateMappingImage( true );
                    sgMappingImageSettings.SetApplyNewMaterialIds( true );
                    sgMappingImageSettings.SetGenerateTangents( true );
                    sgMappingImageSettings.SetUseFullRetexturing( true );

                    using (Simplygon.spMappingImageOutputMaterialSettings sgOutputMaterialSettings = sgMappingImageSettings.GetOutputMaterialSettings(0))
                    {
                        // Setting the size of the output material for the mapping image. This will be the output size of the 
                        // textures when we do material casting in a later stage. 
                        sgOutputMaterialSettings.SetTextureWidth( 2048 );
                        sgOutputMaterialSettings.SetTextureHeight( 2048 );

                    }
                }
                // Start the reduction process. 
                sgReductionProcessor.RunProcessing();

                // Setup and run the normals material casting. 
                string normalsTextureFilePath;
                using (Simplygon.spNormalCaster sgNormalsCaster = sg.CreateNormalCaster())
                {
                    sgNormalsCaster.SetMappingImage( sgReductionProcessor.GetMappingImage() );
                    sgNormalsCaster.SetSourceMaterials( sgScene.GetMaterialTable() );
                    sgNormalsCaster.SetSourceTextures( sgScene.GetTextureTable() );
                    sgNormalsCaster.SetOutputFilePath( "NormalsTexture" );

                    using (Simplygon.spNormalCasterSettings sgNormalsCasterSettings = sgNormalsCaster.GetNormalCasterSettings())
                    {
                        sgNormalsCasterSettings.SetMaterialChannel( "Normals" );
                        sgNormalsCasterSettings.SetGenerateTangentSpaceNormals( true );
                        sgNormalsCasterSettings.SetOutputImageFileFormat( Simplygon.EImageOutputFormat.PNG );
                        sgNormalsCasterSettings.SetOutputPixelFormat( Simplygon.EPixelFormat.R8G8B8 );
                    }

                    sgNormalsCaster.RunProcessing();
                    normalsTextureFilePath = sgNormalsCaster.GetOutputFilePath();
                }

                // Update scene with new casted texture. 
                using (Simplygon.spMaterialTable sgMaterialTable = sg.CreateMaterialTable())
                using (Simplygon.spTextureTable sgTextureTable = sg.CreateTextureTable())
                using (Simplygon.spMaterial sgMaterial = sg.CreateMaterial())
                {
                    using(Simplygon.spTexture sgNormalsTexture = sg.CreateTexture())
                    {
                        sgNormalsTexture.SetName( "Normals" );
                        sgNormalsTexture.SetFilePath( normalsTextureFilePath );
                        sgTextureTable.AddTexture( sgNormalsTexture );
                    }

                    using(Simplygon.spShadingTextureNode sgNormalsTextureShadingNode = sg.CreateShadingTextureNode())
                    {
                        sgNormalsTextureShadingNode.SetTexCoordLevel( 0 );
                        sgNormalsTextureShadingNode.SetTextureName( "Normals" );

                        sgMaterial.AddMaterialChannel( "Normals" );
                        sgMaterial.SetShadingNetwork( "Normals", sgNormalsTextureShadingNode );
                    }

                    sgMaterialTable.AddMaterial( sgMaterial );

                    sgScene.GetTextureTable().Clear();
                    sgScene.GetMaterialTable().Clear();
                    sgScene.GetTextureTable().Copy(sgTextureTable);
                    sgScene.GetMaterialTable().Copy(sgMaterialTable);
                }

            }
            using (Simplygon.spSceneExporter sgSceneExporter = sg.CreateSceneExporter())
            {
                sgSceneExporter.SetScene(sgScene);
                sgSceneExporter.SetExportFilePath( "Output.fbx" );
                if(!sgSceneExporter.RunExport())
                    throw new System.Exception("Failed to save Output.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;
            NormalsCasting(sg);
        }

        return 0;
    }
}