#include "Application1.h"

void Application1::initScene() {
    Data_Constructor(&data, 1, 8);

    /* select scene here */
    standardScene();
    // standardScenewithAreaLight();
}

void Application1::standardScene() {
    FileName file = workingDir + FileName("Framework/scenes/cornell_box.obj");

    /* set default camera */
    camera.from = Vec3fa(278, 273, -800);
    camera.to = Vec3fa(278, 273, 0);

    Ref<SceneGraph::GroupNode> sceneGraph = loadOBJ(file, false).cast<SceneGraph::GroupNode>();
    sceneGraph->add(new SceneGraph::LightNodeImpl<SceneGraph::PointLight>(
        SceneGraph::PointLight(Vec3fa(213, 300, 227), Vec3fa(100000, 100000, 100000))));

    Ref<SceneGraph::GroupNode> flattened_scene = SceneGraph::flatten(sceneGraph, SceneGraph::INSTANCING_NONE);
    Scene* scene = new Scene;
    scene->add(flattened_scene);
    sceneGraph = nullptr;
    flattened_scene = nullptr;

    auto renderScene = new RenderScene(g_device, scene);
    g_render_scene = renderScene;
    data.scene = renderScene;
    scene = nullptr;
}

void Application1::standardScenewithAreaLight() {
    FileName file = workingDir + FileName("Framework/scenes/cornell_box.obj");

    /* set default camera */
    camera.from = Vec3fa(278, 273, -800);
    camera.to = Vec3fa(278, 273, 0);

    Ref<SceneGraph::GroupNode> sceneGraph = loadOBJ(file, false).cast<SceneGraph::GroupNode>();
    sceneGraph->add(new SceneGraph::LightNodeImpl<SceneGraph::QuadLight>(
        SceneGraph::QuadLight(Vec3fa(343.0, 548.0, 227.0), Vec3fa(343.0, 548.0, 332.0), Vec3fa(213.0, 548.0, 332.0),
                              Vec3fa(213.0, 548.0, 227.0), Vec3fa(100000, 100000, 100000))));

    Ref<SceneGraph::GroupNode> flattened_scene = SceneGraph::flatten(sceneGraph, SceneGraph::INSTANCING_NONE);
    Scene* scene = new Scene;
    scene->add(flattened_scene);
    sceneGraph = nullptr;
    flattened_scene = nullptr;

    auto renderScene = new RenderScene(g_device, scene);
    g_render_scene = renderScene;
    data.scene = renderScene;
    scene = nullptr;
}

/* task that renders a single screen tile */
Vec3fa Application1::renderPixel(float x, float y, const ISPCCamera& camera, RayStats& stats, RandomSampler& sampler) {
    /* radiance accumulator and weight */
    Vec3fa L = Vec3fa(0.0f);
    Vec3fa Lw = Vec3fa(1.0f);

    /* initialize ray */
    Ray ray(Vec3fa(camera.xfm.p), Vec3fa(normalize(x * camera.xfm.l.vx + y * camera.xfm.l.vy + camera.xfm.l.vz)), 0.0f,
            inf);

    /* intersect ray with scene */
    RTCIntersectArguments iargs;
    rtcInitIntersectArguments(&iargs);
    iargs.feature_mask = RTC_FEATURE_FLAG_TRIANGLE;
    rtcIntersect1(data.g_scene, RTCRayHit_(ray), &iargs);
    RayStats_addRay(stats);

    const Vec3fa wo = neg(ray.dir);

    /* shade pixels */
    if (ray.geomID != RTC_INVALID_GEOMETRY_ID) {
        Vec3fa Ns = normalize(ray.Ng);
        Sample sample;
        sample.P = ray.org + ray.tfar * ray.dir;
        sample.Ng = ray.Ng;
        sample.Ns = Ns;
        int matId = data.scene->geometries[ray.geomID]->materialID;
        sample.Ng = face_forward(ray.dir, normalize(sample.Ng));
        sample.Ns = face_forward(ray.dir, normalize(sample.Ns));

        /* calculate BRDF */
        BRDF brdf;
        std::vector<Material *> material_array = data.scene->materials;
        Material__preprocess(material_array, matId, brdf, wo, sample);

        /* sample BRDF at hit point */
        Sample3f wi1;
        Material__sample(material_array, matId, brdf, Lw, wo, sample, wi1, RandomSampler_get2D(sampler));

        const Light* l = data.scene->lights[0];
        Light_SampleRes ls = Lights_sample(l, sample, RandomSampler_get2D(sampler));
        Vec3f lightColor = {colorLight[0], colorLight[1], colorLight[2]};

        Vec3fa diffuse = Material__eval(material_array, matId, brdf, wo, sample, ls.dir);
        L += diffuse;

        /* initialize shadow ray */
        Ray shadow(sample.P, ls.dir, 0.001f, ls.dist, 0.0f);

        /* trace shadow ray */
        RTCOccludedArguments sargs;
        rtcInitOccludedArguments(&sargs);
        sargs.feature_mask = RTC_FEATURE_FLAG_TRIANGLE;
        rtcOccluded1(data.g_scene, RTCRay_(shadow), &sargs);
        RayStats_addShadowRay(stats);

        /* add light contribution if not occluded */
        if (shadow.tfar >= 0.0f) {
            L += ls.weight * lightColor * 0.1f;
        }
    }

    return L;
}