C++ ShadingContext类代码示例

OSL_SHADEOP int
osl_regex_impl (void *sg_, const char *subject_, void *results, int nresults,
                const char *pattern, int fullmatch)
{
    ShaderGlobals *sg = (ShaderGlobals *)sg_;
    ShadingContext *ctx = sg->context;
    const std::string &subject (ustring::from_unique(subject_).string());
    match_results<std::string::const_iterator> mresults;
    const regex &regex (ctx->find_regex (USTR(pattern)));
    if (nresults > 0) {
        std::string::const_iterator start = subject.begin();
        int res = fullmatch ? regex_match (subject, mresults, regex)
                            : regex_search (subject, mresults, regex);
        int *m = (int *)results;
        for (int r = 0;  r < nresults;  ++r) {
            if (r/2 < (int)mresults.size()) {
                if ((r & 1) == 0)
                    m[r] = mresults[r/2].first - start;
                else
                    m[r] = mresults[r/2].second - start;
            } else {
                m[r] = USTR(pattern).length();
            }
        }
        return res;
    } else {
        return fullmatch ? regex_match (subject, regex)
                         : regex_search (subject, regex);
    }
}

bool
RendererServices::environment (ustring filename, TextureHandle *texture_handle,
                               TexturePerthread *texture_thread_info,
                               TextureOpt &options, ShaderGlobals *sg,
                               const Vec3 &R, const Vec3 &dRdx, const Vec3 &dRdy,
                               int nchannels, float *result,
                               float *dresultds, float *dresultdt)
{
    ShadingContext *context = sg->context;
    if (! texture_thread_info)
        texture_thread_info = context->texture_thread_info();
    bool status;
    if (texture_handle)
        status = texturesys()->environment (texture_handle, texture_thread_info,
                                            options, R, dRdx, dRdy,
                                            nchannels, result, dresultds, dresultdt);
    else
        status = texturesys()->environment (filename, options, R, dRdx, dRdy,
                                            nchannels, result, dresultds, dresultdt);
    if (!status) {
        std::string err = texturesys()->geterror();
        if (err.size() && sg) {
            sg->context->error ("[RendererServices::environment] %s", err);
        }
    }
    return status;
}

OSL_SHADEOP void osl_luminance_dfdv (void *sg, void *out, void *c)
{
    ShadingContext *ctx = (ShadingContext *)((ShaderGlobals *)sg)->context;
    ((float *)out)[0] = ctx->shadingsys().luminance (((const Color3 *)c)[0]);
    ((float *)out)[1] = ctx->shadingsys().luminance (((const Color3 *)c)[1]);
    ((float *)out)[2] = ctx->shadingsys().luminance (((const Color3 *)c)[2]);
}

void DisneyLayeredBRDF::evaluate_inputs(
    const ShadingContext&       shading_context,
    InputEvaluator&             input_evaluator,
    const ShadingPoint&         shading_point,
    const size_t                offset) const
{
    char* ptr = reinterpret_cast<char*>(input_evaluator.data());
    DisneyBRDFInputValues* values = reinterpret_cast<DisneyBRDFInputValues*>(ptr + offset);
    memset(values, 0, sizeof(DisneyBRDFInputValues));

    Color3d base_color(0.0);

    for (size_t i = 0, e = m_parent->get_layer_count(); i < e; ++i)
    {
        const DisneyMaterialLayer& layer =
            m_parent->get_layer(i, shading_context.get_thread_index());

        layer.evaluate_expressions(
            shading_point,
            shading_context.get_oiio_texture_system(),
            base_color,
            *values);
    }

    // Colors in SeExpr are always in the sRGB color space.
    base_color = srgb_to_linear_rgb(base_color);
    values->m_base_color = Color3f(base_color);
    values->precompute_tint_color();
}

OSL_SHADEOP void
osl_prepend_color_from (void *sg, void *c_, const char *from)
{
    ShadingContext *ctx (((ShaderGlobals *)sg)->context);
    Color3 &c (*(Color3*)c_);
    c = ctx->shadingsys().to_rgb (USTR(from), c[0], c[1], c[2]);
}

OSL_SHADEOP void osl_wavelength_color_vf (void *sg, void *out, float lambda)
{
    ShadingContext *ctx = (ShadingContext *)((ShaderGlobals *)sg)->context;
    Color3 rgb = ctx->shadingsys().XYZ_to_RGB (wavelength_color_XYZ (lambda));
//    constrain_rgb (rgb);
    rgb *= 1.0/2.52;    // Empirical scale from lg to make all comps <= 1
//    norm_rgb (rgb);
    clamp_zero (rgb);
    *(Color3 *)out = rgb;
}

void ShadingEngine::shade_environment(
    SamplingContext&        sampling_context,
    const ShadingContext&   shading_context,
    const ShadingPoint&     shading_point,
    ShadingResult&          shading_result) const
{
    // Retrieve the environment shader of the scene.
    const EnvironmentShader* environment_shader =
        shading_point.get_scene().get_environment()->get_environment_shader();

    if (environment_shader)
    {
        // There is an environment shader: execute it.
        InputEvaluator input_evaluator(shading_context.get_texture_cache());
        const ShadingRay& ray = shading_point.get_ray();
        const Vector3d direction = normalize(ray.m_dir);
        environment_shader->evaluate(
            input_evaluator,
            direction,
            shading_result);

        // Set environment shader AOV.
        shading_result.set_entity_aov(*environment_shader);
    }
    else
    {
        // No environment shader: shade as transparent black.
        shading_result.set_main_to_transparent_black_linear_rgba();
        shading_result.set_aovs_to_transparent_black_linear_rgba();
    }
}

    void do_compute_lighting(
        SamplingContext&        sampling_context,
        const ShadingContext&   shading_context,
        const ShadingPoint&     shading_point,
        Spectrum&               radiance,               // output radiance, in W.sr^-1.m^-2
        SpectrumStack&          aovs)
    {
        PathVisitor path_visitor(
            m_params,
            m_light_sampler,
            sampling_context,
            shading_context,
            shading_point.get_scene(),
            radiance,
            aovs);

        PathTracer<PathVisitor, false> path_tracer(     // false = not adjoint
            path_visitor,
            m_params.m_rr_min_path_length,
            m_params.m_max_path_length,
            shading_context.get_max_iterations());

        const size_t path_length =
            path_tracer.trace(
                sampling_context,
                shading_context,
                shading_point);

        // Update statistics.
        ++m_path_count;
        m_path_length.insert(path_length);
    }

void PathVertex::compute_emitted_radiance(
    const ShadingContext&   shading_context,
    TextureCache&           texture_cache,
    Spectrum&               radiance) const
{
    assert(m_edf);

    // No radiance if we're too close to the light.
    if (m_shading_point->get_distance() < m_edf->get_light_near_start())
    {
        radiance.set(0.0f);
        return;
    }

    if (const ShaderGroup* sg = get_material()->get_render_data().m_shader_group)
        shading_context.execute_osl_emission(*sg, *m_shading_point);

    // Evaluate the EDF inputs.
    InputEvaluator input_evaluator(texture_cache);
    m_edf->evaluate_inputs(input_evaluator, *m_shading_point);

    // Compute the emitted radiance.
    m_edf->evaluate(
        input_evaluator.data(),
        Vector3f(m_shading_point->get_geometric_normal()),
        Basis3f(m_shading_point->get_shading_basis()),
        Vector3f(m_outgoing.get_value()),
        radiance);
}

ShadingContext *ShadingApi
  ::context(Gotham::AttributeMap &attr,
            const boost::shared_ptr<MaterialList> &materials,
            const boost::shared_ptr<TextureList> &textures)
{
  ShadingContext *result = 0;

  result = new ShadingContext();

  // give the materials to the ShadingContext
  result->setMaterials(materials);

  // give the textures to the ShadingContext
  result->setTextures(textures);

  return result;
} // end context()

 void evaluate_osl_background(
     const ShadingContext&   shading_context,
     const Vector3f&         local_outgoing,
     Spectrum&               value) const
 {
     if (m_shader_group)
         shading_context.execute_osl_background(*m_shader_group, local_outgoing, value);
     else value.set(0.0f);
 }

        void add_back_lighting(
            const InputValues&      values,
            SamplingContext&        sampling_context,
            const PixelContext&     pixel_context,
            const ShadingContext&   shading_context,
            const ShadingPoint&     shading_point,
            Spectrum&               radiance,
            SpectrumStack&          aovs) const
        {
            const Vector3d& p = shading_point.get_point();
            const Vector3d& n = shading_point.get_original_shading_normal();
            const Vector3d& d = shading_point.get_ray().m_dir;

            // Construct a ray perpendicular to the other side of the surface.
            ShadingRay back_ray(shading_point.get_ray());
            back_ray.m_tmax *= norm(d);
            back_ray.m_dir = dot(d, n) > 0.0 ? -n : n;
            back_ray.m_org = p - back_ray.m_tmax * back_ray.m_dir;

            ShadingPoint back_shading_point(shading_point);
            back_shading_point.set_ray(back_ray);

            Spectrum back_radiance(0.0f);
            SpectrumStack back_aovs(aovs.size(), 0.0f);

            // Compute back lighting.
            for (size_t i = 0; i < m_back_lighting_samples; ++i)
            {
                shading_context.get_lighting_engine()->compute_lighting(
                    sampling_context,
                    pixel_context,
                    shading_context,
                    back_shading_point,
                    back_radiance,
                    back_aovs);
            }

            // Apply translucency factor.
            back_radiance *= values.m_translucency;
            back_aovs *= values.m_translucency;

            // Divide by the number of samples.
            const float rcp_sample_count = 1.0f / static_cast<float>(m_back_lighting_samples);
            back_radiance *= rcp_sample_count;
            back_aovs *= rcp_sample_count;

            // Add back lighting contribution.
            radiance += back_radiance;
            aovs += back_aovs;
        }

        void apply_aerial_perspective(
            const InputValues&      values,
            const ShadingContext&   shading_context,
            const PixelContext&     pixel_context,
            const ShadingPoint&     shading_point,
            ShadingResult&          shading_result) const
        {
            Spectrum sky_color;

            if (m_aerial_persp_mode == AerialPerspSkyColor)
                sky_color = values.m_aerial_persp_sky_color;
            else
            {
                // Retrieve the environment shader of the scene.
                const Scene& scene = shading_point.get_scene();
                const EnvironmentShader* environment_shader =
                    scene.get_environment()->get_environment_shader();

                if (environment_shader)
                {
                    // Execute the environment shader to obtain the sky color in the direction of the ray.
                    InputEvaluator input_evaluator(shading_context.get_texture_cache());
                    const ShadingRay& ray = shading_point.get_ray();
                    const Vector3d direction = normalize(ray.m_dir);
                    ShadingResult sky;
                    environment_shader->evaluate(
                        shading_context,
                        pixel_context,
                        input_evaluator,
                        direction,
                        sky);
                    sky_color = sky.m_main.m_color;
                }
                else sky_color.set(0.0f);
            }

            // Compute the blend factor.
            const double d = shading_point.get_distance() * m_aerial_persp_rcp_distance;
            const double k = m_aerial_persp_intensity * exp(d);
            const double blend = min(k, 1.0);

            // Blend the shading result and the sky color.
            sky_color *= static_cast<float>(blend);
            shading_result.m_main.m_color *= static_cast<float>(1.0 - blend);
            shading_result.m_main.m_color += sky_color;
        }

void compute_ibl_bsdf_sampling(
    SamplingContext&        sampling_context,
    const ShadingContext&   shading_context,
    const EnvironmentEDF&   environment_edf,
    const ShadingPoint&     shading_point,
    const Dual3d&           outgoing,
    const BSDF&             bsdf,
    const void*             bsdf_data,
    const int               bsdf_sampling_modes,
    const size_t            bsdf_sample_count,
    const size_t            env_sample_count,
    Spectrum&               radiance)
{
    assert(is_normalized(outgoing.get_value()));

    radiance.set(0.0f);

    for (size_t i = 0; i < bsdf_sample_count; ++i)
    {
        // Sample the BSDF.
        // todo: rendering will be incorrect if the BSDF value returned by the sample() method
        // includes the contribution of a specular component since these are explicitly rejected
        // afterward. We need a mechanism to indicate that we want the contribution of some of
        // the components only.
        BSDFSample sample(shading_point, outgoing);
        bsdf.sample(
            sampling_context,
            bsdf_data,
            false,              // not adjoint
            true,               // multiply by |cos(incoming, normal)|
            sample);

        // Filter scattering modes.
        if (!(bsdf_sampling_modes & sample.m_mode))
            continue;

        // Discard occluded samples.
        const float transmission =
            shading_context.get_tracer().trace(
                shading_point,
                Vector3d(sample.m_incoming.get_value()),
                VisibilityFlags::ShadowRay);
        if (transmission == 0.0f)
            continue;

        // Evaluate the environment's EDF.
        InputEvaluator input_evaluator(shading_context.get_texture_cache());
        Spectrum env_value;
        float env_prob;
        environment_edf.evaluate(
            shading_context,
            input_evaluator,
            sample.m_incoming.get_value(),
            env_value,
            env_prob);

        // Apply all weights, including MIS weight.
        if (sample.m_mode == ScatteringMode::Specular)
            env_value *= transmission;
        else
        {
            const float mis_weight =
                mis_power2(
                    bsdf_sample_count * sample.m_probability,
                    env_sample_count * env_prob);
            env_value *= transmission / sample.m_probability * mis_weight;
        }

        // Add the contribution of this sample to the illumination.
        env_value *= sample.m_value;
        radiance += env_value;
    }

    if (bsdf_sample_count > 1)
        radiance /= static_cast<float>(bsdf_sample_count);
}

void DiagnosticSurfaceShader::evaluate(
    SamplingContext&        sampling_context,
    const PixelContext&     pixel_context,
    const ShadingContext&   shading_context,
    const ShadingPoint&     shading_point,
    ShadingResult&          shading_result) const
{
    switch (m_shading_mode)
    {
      case Color:
        {
            shading_result.set_main_to_opaque_pink_linear_rgba();

            const Material* material = shading_point.get_material();
            if (material)
            {
                const Material::RenderData& material_data = material->get_render_data();

#ifdef APPLESEED_WITH_OSL
                // Execute the OSL shader if there is one.
                if (material_data.m_shader_group)
                {
                    shading_context.execute_osl_shading(
                        *material_data.m_shader_group,
                        shading_point);
                }
#endif

                if (material_data.m_bsdf)
                {
                    InputEvaluator input_evaluator(shading_context.get_texture_cache());
                    material_data.m_bsdf->evaluate_inputs(
                        shading_context,
                        input_evaluator,
                        shading_point);

                    const Vector3d direction = -normalize(shading_point.get_ray().m_dir);
                    material_data.m_bsdf->evaluate(
                        input_evaluator.data(),
                        false,
                        false,
                        shading_point.get_geometric_normal(),
                        shading_point.get_shading_basis(),
                        direction,
                        direction,
                        ScatteringMode::All,
                        shading_result.m_main.m_color);

                    shading_result.m_color_space = ColorSpaceSpectral;
                }
            }
        }
        break;

      case Coverage:
        shading_result.set_main_to_linear_rgb(Color3f(1.0f));
        break;

      case Barycentric:
        shading_result.set_main_to_linear_rgb(
            vector2_to_color(shading_point.get_bary()));
        break;

      case UV:
        shading_result.set_main_to_linear_rgb(
            uvs_to_color(shading_point.get_uv(0)));
        break;

      case Tangent:
      case Bitangent:
      case ShadingNormal:
        {
#ifdef APPLESEED_WITH_OSL
            const Material* material = shading_point.get_material();
            if (material)
            {
                const Material::RenderData& material_data = material->get_render_data();

                // Execute the OSL shader if there is one.
                if (material_data.m_shader_group)
                {
                    sampling_context.split_in_place(2, 1);
                    shading_context.execute_osl_bump(
                        *material_data.m_shader_group,
                        shading_point,
                        sampling_context.next_vector2<2>());
                }
            }
#endif

            const Vector3d v =
                m_shading_mode == ShadingNormal ? shading_point.get_shading_basis().get_normal() :
                m_shading_mode == Tangent ? shading_point.get_shading_basis().get_tangent_u() :
                shading_point.get_shading_basis().get_tangent_v();

            shading_result.set_main_to_linear_rgb(vector3_to_color(v));
        }
        break;

      case GeometricNormal:
//.........这里部分代码省略.........