volume_renderer.cxx

#include "volume_renderer.h"
#include <random>
#include <cgv/math/ftransform.h>
#include <cgv_gl/gl/gl.h>
#include <cgv_gl/gl/gl_tools.h>
 
namespace cgv {
    namespace render {
        volume_renderer& ref_volume_renderer(context& ctx, int ref_count_change)
        {
            static int ref_count = 0;
            static volume_renderer r;
            r.manage_singleton(ctx, "volume_renderer", ref_count, ref_count_change);
            return r;
        }
 
        void volume_renderer::init_noise_texture(context& ctx)
        {
            if(noise_texture.is_created())
                noise_texture.destruct(ctx);
 
            unsigned size = 64;
            std::vector<uint8_t> noise_data(size*size);
 
            std::default_random_engine rng(42);
            std::uniform_int_distribution<unsigned> dist(0u, 255u);
 
            for(size_t i = 0; i < noise_data.size(); ++i)
                noise_data[i] = static_cast<uint8_t>(dist(rng));
 
            cgv::data::data_view dv = cgv::data::data_view(new cgv::data::data_format(size, size, cgv::type::info::TI_UINT8, cgv::data::CF_R), noise_data.data());
            noise_texture.create(ctx, dv, 0);
        }
 
        bool volume_renderer::validate_attributes(const context& ctx) const
        {
            // validate set attributes
            const volume_render_style& vrs = get_style<volume_render_style>();
            bool res = renderer::validate_attributes(ctx);
            res = res && (volume_texture != nullptr);
            return res;
        }
        void volume_renderer::update_shader_program_options(shader_compile_options& options) const
        {
            const volume_render_style& vrs = get_style<volume_render_style>();
 
            options.define_macro_if_not_default("NUM_STEPS", vrs.integration_quality, VolumeIntegrationQuality::k128);
            options.define_macro_if_not_default("INTERPOLATION_MODE", vrs.interpolation_mode, VolumeInterpolationMode::kLinear);
            options.define_macro_if_true(vrs.enable_noise_offset, "ENABLE_NOISE_OFFSET");
            options.define_macro_if_not_default("SHOW_VOLUME", vrs.show_volume, true);
            options.define_macro_if_true(vrs.enable_lighting, "ENABLE_LIGHTING");
            options.define_macro_if_true(vrs.use_gradient_texture, "USE_GRADIENT_TEXTURE");
            options.define_macro_if_true(vrs.enable_gradient_modulation, "ENABLE_GRADIENT_MODULATION");
            options.define_macro_if_true(vrs.enable_depth_test, "ENABLE_DEPTH_TEST");
            
            options.define_macro_if_not_default("ISOSURFACE_MODE", vrs.isosurface_mode, VolumeIsosurfaceMode::kNone);
            options.define_macro_if_not_default("ISOSURFACE_COLOR_MODE", vrs.isosurface_color_from_transfer_function, false);
 
            options.define_macro_if_not_default("SLICE_MODE", vrs.slice_mode, VolumeSliceMode::kNone);
 
            options.define_macro_if_not_default("COMPOSITING_MODE", vrs.compositing_mode, VolumeCompositingMode::kBlend);
            if(transfer_function_texture)
                options.define_macro_if_not_default("TRANSFER_FUNCTION_SAMPLER_DIMENSIONS", transfer_function_texture->get_nr_dimensions(), 1u);
        }
        bool volume_renderer::init(cgv::render::context& ctx)
        {
            bool res = renderer::init(ctx);
            res = res && position_aam.init(ctx);
            enable_attribute_array_manager(ctx, position_aam);
 
            // use a single optimized triangle strip to define a cube
            std::vector<vec3> positions = {
                { -0.5f, +0.5f, -0.5f },
                { +0.5f, +0.5f, -0.5f },
                { -0.5f, -0.5f, -0.5f },
                { +0.5f, -0.5f, -0.5f },
                { +0.5f, -0.5f, +0.5f },
                { +0.5f, +0.5f, -0.5f },
                { +0.5f, +0.5f, +0.5f },
                { -0.5f, +0.5f, -0.5f },
                { -0.5f, +0.5f, +0.5f },
                { -0.5f, -0.5f, -0.5f },
                { -0.5f, -0.5f, +0.5f },
                { +0.5f, -0.5f, +0.5f },
                { -0.5f, +0.5f, +0.5f },
                { +0.5f, +0.5f, +0.5 }
            };
            set_position_array(ctx, positions);
            
            if(!noise_texture.is_created())
                init_noise_texture(ctx);
 
            return res;
        }
        void volume_renderer::clear (const context& ctx) {
            disable_attribute_array_manager(ctx, position_aam);
            position_aam.destruct(ctx);
            noise_texture.destruct(ctx);
            renderer::clear(ctx); // perform upstream actions
        }
 
        bool volume_renderer::set_volume_texture(texture* tex) {
            if(!tex || tex->get_nr_dimensions() != 3)
                return false;
            volume_texture = tex;
            return true;
        }
 
        bool volume_renderer::set_transfer_function_texture(texture* tex) {
            if(!tex || tex->get_nr_dimensions() > 2)
                return false;
            transfer_function_texture = tex;
            return true;
        }
 
        bool volume_renderer::set_gradient_texture(texture* tex) {
            if(!tex || tex->get_nr_dimensions() != 3)
                return false;
            gradient_texture = tex;
            return true;
        }
 
        bool volume_renderer::set_depth_texture(texture* tex) {
            if(!tex || tex->get_nr_dimensions() != 2)
                return false;
            depth_texture = tex;
            return true;
        }
        
        void volume_renderer::set_bounding_box(const box3& bbox)
        {
            bounding_box = bbox;
        }
        
        void volume_renderer::transform_to_bounding_box(bool flag)
        {
            apply_bounding_box_transformation = flag;
        }
        
        void volume_renderer::set_noise_offset(const vec2& offset)
        {
            noise_offset = offset;
        }
 
        bool volume_renderer::enable(context& ctx) {
            const volume_render_style& vrs = get_style<volume_render_style>();
            if(!renderer::enable(ctx))
                return false;
            int vp[4];
            glGetIntegerv(GL_VIEWPORT, vp);
            ref_prog().set_uniform(ctx, "viewport_dims", vec2(float(vp[2] - vp[0]), float(vp[3] - vp[1])));
            ref_prog().set_uniform(ctx, "noise_offset", noise_offset);
 
            ref_prog().set_uniform(ctx, "picking_opacity_threshold", vrs.picking_opacity_threshold);
            ref_prog().set_uniform(ctx, "scale_adjustment_factor", vrs.scale_adjustment_factor);
 
            ref_prog().set_uniform(ctx, "light_local_to_eye", vrs.light_local_to_eye);
            ref_prog().set_uniform(ctx, "light_direction", normalize(vrs.light_direction));
            float specular_exponent = cgv::math::lerp(128.0f, 1.0f, cgv::math::clamp(vrs.roughness, 0.0f, 1.0f));
            ref_prog().set_uniform(ctx, "ambient_strength", vrs.ambient_strength);
            ref_prog().set_uniform(ctx, "diffuse_strength", vrs.diffuse_strength);
            ref_prog().set_uniform(ctx, "specular_strength", vrs.specular_strength);
            ref_prog().set_uniform(ctx, "specular_exponent", specular_exponent);
            ref_prog().set_uniform(ctx, "specular_color_mix", vrs.specular_color_mix);
 
            ref_prog().set_uniform(ctx, "gradient_lambda", std::max(vrs.gradient_lambda, 0.001f));
 
            ref_prog().set_uniform(ctx, "isovalue", vrs.isovalue);
            ref_prog().set_uniform(ctx, "isosurface_color", vrs.isosurface_color);
 
            ref_prog().set_uniform(ctx, "slice_axis", vrs.slice_axis);
            ref_prog().set_uniform(ctx, "slice_coordinate", vrs.slice_coordinate);
            ref_prog().set_uniform(ctx, "slice_opacity", vrs.slice_opacity);
 
            ref_prog().set_uniform(ctx, "clip_box_min", vrs.clip_box.get_min_pnt());
 
            ref_prog().set_uniform(ctx, "clip_box_max", vrs.clip_box.get_max_pnt());
 
            ctx.push_depth_test_state();
            ctx.set_depth_func(CF_ALWAYS);
            ctx.push_blend_state();
            ctx.enable_blending();
            ctx.set_blend_func_back_to_front();
            ctx.push_cull_state();
            ctx.set_cull_state(CM_FRONTFACE);
            
            if(volume_texture) volume_texture->enable(ctx, 0);
            if(transfer_function_texture) transfer_function_texture->enable(ctx, 1);
            noise_texture.enable(ctx, 2);
            if(gradient_texture) gradient_texture->enable(ctx, 3);
            if(depth_texture) depth_texture->enable(ctx, 4);
            return true;
        }
        bool volume_renderer::disable(context& ctx)
        {
            if(volume_texture) volume_texture->disable(ctx);
            if(transfer_function_texture) transfer_function_texture->disable(ctx);
            noise_texture.disable(ctx);
            if(gradient_texture) gradient_texture->disable(ctx);
            if(depth_texture) depth_texture->disable(ctx);
 
            ctx.pop_cull_state();
            ctx.pop_blend_state();
            ctx.pop_depth_test_state();
            
            return renderer::disable(ctx);
        }
        void volume_renderer::draw(context& ctx, size_t start, size_t count, bool use_strips, bool use_adjacency, uint32_t strip_restart_index)
        {
            ctx.push_modelview_matrix();
 
            if(apply_bounding_box_transformation) {
                const volume_render_style& vrs = get_style<volume_render_style>();
                cgv::box3 clipped_box(
                    bounding_box.get_min_pnt() + bounding_box.get_extent() * vrs.clip_box.get_min_pnt(),
                    bounding_box.get_min_pnt() + bounding_box.get_extent() * vrs.clip_box.get_max_pnt()
                );
                ctx.mul_modelview_matrix(cgv::math::translate4(clipped_box.get_center()));
                ctx.mul_modelview_matrix(cgv::math::scale4(clipped_box.get_extent()));
            }
 
            glDrawArrays(GL_TRIANGLE_STRIP, 0, (GLsizei)14);
 
            ctx.pop_modelview_matrix();
        }
    }
}
 
#include <cgv/gui/provider.h>
 
namespace cgv {
    namespace gui {
 
        struct volume_render_style_gui_creator : public gui_creator {
            bool create(provider* p, const std::string& label,
                void* value_ptr, const std::string& value_type,
                const std::string& gui_type, const std::string& options, bool*) {
                if(value_type != cgv::type::info::type_name<cgv::render::volume_render_style>::get_name())
                    return false;
                cgv::render::volume_render_style* vrs_ptr = reinterpret_cast<cgv::render::volume_render_style*>(value_ptr);
                cgv::base::base* b = dynamic_cast<cgv::base::base*>(p);
 
                p->add_member_control(b, "Quality", vrs_ptr->integration_quality, "dropdown", "w=114;enums='8=8,16=16,32=32,64=64,128=128,256=256,512=512,1024=1024,2048=2048,4096=4096'", " ");
                p->add_member_control(b, "Use Noise", vrs_ptr->enable_noise_offset, "check", "w=74");
                p->add_member_control(b, "Interpolation", vrs_ptr->interpolation_mode, "dropdown", "enums=Nearest,Smoothed,Linear,Cubic");
 
                p->add_member_control(b, "Depth Test", vrs_ptr->enable_depth_test, "check");
                p->add_member_control(b, "Opacity Threshold", vrs_ptr->picking_opacity_threshold, "value_slider", "min=0.0;max=1.0;step=0.001;tooltip='Opacity threshold used for focus picking'");
 
                p->add_member_control(b, "Show Volume", vrs_ptr->show_volume, "toggle");
                p->add_member_control(b, "Compositing Mode", vrs_ptr->compositing_mode, "dropdown", "enums='Maximum Intensity Projection, Average, Blend'");
 
                p->add_member_control(b, "Scale Adjustment", vrs_ptr->scale_adjustment_factor, "value_slider", "min=0.0;step=0.001;max=1000.0;log=true;ticks=true");
                
                if(p->begin_tree_node("Lighting", vrs_ptr->enable_lighting, false)) {
                    p->align("/a");
                    p->add_member_control(b, "Enable", vrs_ptr->enable_lighting, "check", "w=88", " ");
                    p->add_member_control(b, "Local to Eye", vrs_ptr->light_local_to_eye, "check", "w=100");
                    p->add_member_control(b, "Normals from Gradient Texture", vrs_ptr->use_gradient_texture, "check");
                    p->add_member_control(b, "Direction", vrs_ptr->light_direction[0], "value", "w=58;min=-1;max=1", " ");
                    p->add_member_control(b, "", vrs_ptr->light_direction[1], "value", "w=58;min=-1;max=1", " ");
                    p->add_member_control(b, "", vrs_ptr->light_direction[2], "value", "w=58;min=-1;max=1");
                    p->add_member_control(b, "", vrs_ptr->light_direction[0], "slider", "w=58;min=-1;max=1;step=0.0001;ticks=true", " ");
                    p->add_member_control(b, "", vrs_ptr->light_direction[1], "slider", "w=58;min=-1;max=1;step=0.0001;ticks=true", " ");
                    p->add_member_control(b, "", vrs_ptr->light_direction[2], "slider", "w=58;min=-1;max=1;step=0.0001;ticks=true");
 
                    p->add_decorator("Light Parameters", "heading", "level=3");
                    p->add_member_control(b, "Ambient", vrs_ptr->ambient_strength, "value_slider", "min=0;max=1;step=0.001;ticks=true");
                    p->add_member_control(b, "Diffuse", vrs_ptr->diffuse_strength, "value_slider", "min=0;max=1;step=0.001;ticks=true");
                    p->add_member_control(b, "Specular", vrs_ptr->specular_strength, "value_slider", "min=0;max=1;step=0.001;ticks=true");
                    p->add_member_control(b, "Roughness", vrs_ptr->roughness, "value_slider", "min=0;max=1;step=0.001;ticks=true");
                    p->add_member_control(b, "Specular Color", vrs_ptr->specular_color_mix, "value_slider", "min=0;max=1;step=0.001;ticks=true");
                    p->align("/b");
                    p->end_tree_node(vrs_ptr->enable_lighting);
                }
 
                if(p->begin_tree_node("Gradient Modulation", vrs_ptr->enable_gradient_modulation, false)) {
                    p->align("\a");
                    p->add_member_control(b, "Enable", vrs_ptr->enable_gradient_modulation, "check");
                    p->add_member_control(b, "Lambda", vrs_ptr->gradient_lambda, "value_slider", "min=0.001;max=10;step=0.001;ticks=true;log=true");
                    p->align("\b");
                    p->end_tree_node(vrs_ptr->enable_gradient_modulation);
                }
                if (p->begin_tree_node("Orthogonal Slicing", vrs_ptr->slice_mode, false)) {
                    p->align("\a");
                    p->add_member_control(b, "Mode", vrs_ptr->slice_mode, "dropdown", "enums='Disabled,Opaque,Transparent'");
                    p->add_member_control(b, "Axis", vrs_ptr->slice_axis, "value_slider", "min=0;max=2;ticks=true");
                    p->add_member_control(b, "Coordinate", vrs_ptr->slice_coordinate, "value_slider", "min=0;max=1;ticks=true");
                    p->add_member_control(b, "Opacity", vrs_ptr->slice_opacity, "value_slider", "min=0;max=1;ticks=true");
                    p->align("\b");
                    p->end_tree_node(vrs_ptr->slice_mode);
                }
 
                if(p->begin_tree_node("Isosurface (Blend only)", vrs_ptr->isosurface_mode, false)) {
                    p->align("\a");
                    p->add_member_control(b, "", vrs_ptr->isosurface_mode, "dropdown", "enums='Disabled,Isovalue,Alpha Threshold'");
 
                    p->add_member_control(b, "Value", vrs_ptr->isovalue, "value_slider", "min=0.0;max=1.0;step=0.001;ticks=true");
                    p->add_member_control(b, "Color", vrs_ptr->isosurface_color, "", "w=42", " ");
                    p->add_member_control(b, "From Transfer Function", vrs_ptr->isosurface_color_from_transfer_function, "check", "w=146");
                    p->align("\b");
                    p->end_tree_node(vrs_ptr->isosurface_mode);
                }
                
                if(p->begin_tree_node("Clip Box", vrs_ptr->clip_box, false)) {
                    p->align("\a");
                    p->add_gui("Clipping Box", vrs_ptr->clip_box, "",
                        "options='w=100;min=0;max=1;step=0.01;ticks=true;align=\"BL\"';align_col=' '");
                    p->align("\b");
                    p->end_tree_node(vrs_ptr->clip_box);
                }
 
                return true;
            }
        };
 
#include "gl/lib_begin.h"
 
        CGV_API cgv::gui::gui_creator_registration<volume_render_style_gui_creator> volume_rs_gc_reg("volume_render_style_gui_creator");
 
    }
}