color_map_editor.cxx

#include "color_map_editor.h"
 
#include <cgv/gui/key_event.h>
#include <cgv/gui/mouse_event.h>
#include <cgv/gui/theme_info.h>
#include <cgv/math/ftransform.h>
#include <cgv/utils/advanced_scan.h>
#include <cgv/utils/file.h>
#include <cgv_gl/gl/gl.h>
#include <cgv_g2d/msdf_font.h>
#include <cgv_g2d/msdf_gl_font_renderer.h>
 
namespace cgv {
namespace app {
 
const float color_map_editor::color_point::default_width = 12.0f;
const float color_map_editor::color_point::default_height = 18.0f;
 
const float color_map_editor::opacity_point::default_size = 12.0f;
 
color_map_editor::color_map_editor() {
 
    set_name("Color Scale Editor");
    blocks_events(true);
 
    resolution = (cgv::type::DummyEnum)256;
    opacity_scale_exponent = 1.0f;
    supports_opacity = false;
    use_interpolation = true;
    use_linear_filtering = true;
    range = vec2(0.0f, 1.0f);
 
    layout.padding = padding();
    layout.total_height = supports_opacity ? 200 : 60;
 
    set_size(ivec2(600u, layout.total_height));
    
    mouse_is_on_overlay = false;
    cursor_position = { 0 };
    show_value_label = false;
 
    cmc.color_points.set_constraint(layout.color_handles_rect);
    cmc.color_points.callback = std::bind(&color_map_editor::handle_color_drag, this, std::placeholders::_1);
 
    cmc.opacity_points.set_constraint(layout.opacity_editor_rect);
    cmc.opacity_points.callback = std::bind(&color_map_editor::handle_opacity_drag, this, std::placeholders::_1);
 
    color_handle_renderer = cgv::g2d::generic_2d_renderer(cgv::g2d::shaders::arrow);
    opacity_handle_renderer = cgv::g2d::generic_2d_renderer(cgv::g2d::shaders::rectangle);
    line_renderer = cgv::g2d::generic_2d_renderer(cgv::g2d::shaders::line);
    polygon_renderer = cgv::g2d::generic_2d_renderer(cgv::g2d::shaders::polygon);
}
 
void color_map_editor::clear(cgv::render::context& ctx) {
 
    cgv::g2d::ref_msdf_font_regular(ctx, -1);
    cgv::g2d::ref_msdf_gl_font_renderer_2d(ctx, -1);
 
    canvas_overlay::clear(ctx);
 
    color_handle_renderer.destruct(ctx);
    opacity_handle_renderer.destruct(ctx);
    line_renderer.destruct(ctx);
    polygon_renderer.destruct(ctx);
 
    bg_tex.destruct(ctx);
    preview_tex.destruct(ctx);
    hist_tex.destruct(ctx);
}
 
bool color_map_editor::handle_key_event(cgv::gui::key_event& e) {
    
    switch(e.get_action()) {
    case cgv::gui::KA_PRESS:
        switch(e.get_key()) {
        case cgv::gui::KEY_Left_Ctrl:
            cursor_label = "+";
            post_damage();
            break;
        case cgv::gui::KEY_Left_Alt:
            cursor_label = "-";
            post_damage();
            break;
        default:
            break;
        }
        break;
    case cgv::gui::KA_RELEASE:
        switch(e.get_key()) {
        case cgv::gui::KEY_Left_Ctrl:
        case cgv::gui::KEY_Left_Alt:
            cursor_label = "";
            post_damage();
            break;
        default:
            break;
        }
        break;
    default:
        break;
    }
    return false;
}
 
bool color_map_editor::handle_mouse_event(cgv::gui::mouse_event& e, cgv::ivec2 local_mouse_pos) 
{
    bool capture_event = false;
    switch(e.get_action()) {
    case cgv::gui::MA_ENTER:
        mouse_is_on_overlay = true;
        return true;
    case cgv::gui::MA_LEAVE:
        mouse_is_on_overlay = false;
        post_damage();
        return true;
    case cgv::gui::MA_DRAG:
        capture_event = true;
    case cgv::gui::MA_MOVE:
        if(get_context())
            cursor_position = local_mouse_pos;// ivec2(me.get_x(), get_context()->get_height() - 1 - me.get_y());
        if(!cursor_label.empty())
            post_damage();
        break;
    }
    bool request_clear_selection = false;
    if(e.get_button_state() & cgv::gui::MB_LEFT_BUTTON) {
        if(e.get_action() == cgv::gui::MA_PRESS) {
            request_clear_selection = is_hit_local(local_mouse_pos);
 
            switch(e.get_modifiers()) {
            case cgv::gui::EM_CTRL:
                if(!get_hit_point(local_mouse_pos)) {
                    add_point(local_mouse_pos);
                    request_clear_selection = false;
                }
                break;
            case cgv::gui::EM_ALT:
            {
                cgv::g2d::draggable* hit_point = get_hit_point(local_mouse_pos);
                if(hit_point)
                    remove_point(hit_point);
                break;
            }
            default:
                break;
            }
            capture_event = true;
        }
    }
 
    if(cmc.color_points.handle(e, get_viewport_size(), get_rectangle()))
        return true;
    if(cmc.opacity_points.handle(e, get_viewport_size(), get_rectangle()))
        return true;
 
    if(request_clear_selection) {
        cmc.color_points.clear_selected();
        cmc.opacity_points.clear_selected();
        handle_drag_end();
    }
    if (capture_event)
        return true;
    return false;
}
 
void color_map_editor::handle_member_change(const cgv::utils::pointer_test& m) {
 
    if(m.is(layout.total_height)) {
        ivec2 size = get_rectangle().size;
        size.y() = layout.total_height;
        set_size(size);
    }
 
    if(m.is(opacity_scale_exponent)) {
        opacity_scale_exponent = cgv::math::clamp(opacity_scale_exponent, 1.0f, 5.0f);
 
        update_point_positions();
        sort_points();
        update_geometry();
    }
 
    if(m.is(resolution)) {
        cgv::render::context* ctx_ptr = get_context();
        if(cmc.cm)
            cmc.cm->set_resolution(resolution);
        update_color_map(false);
    }
 
    if(m.is(use_interpolation)) {
        cgv::render::context* ctx_ptr = get_context();
        if(cmc.cm)
            cmc.cm->enable_interpolation(use_interpolation);
        update_color_map(false);
    }
 
    if(m.is(use_linear_filtering)) {
        cgv::render::context* ctx_ptr = get_context();
        if(cmc.cm) {
            cgv::render::gl_color_map* gl_cm = cmc.get_gl_color_map();
            if(gl_cm)
                gl_cm->enable_linear_filtering(use_linear_filtering);
        }
        update_color_map(false);
    }
 
    for(unsigned i = 0; i < cmc.color_points.size(); ++i) {
        if(m.is(cmc.color_points[i].col)) {
            update_color_map(true);
            break;
        }
    }
 
    for(unsigned i = 0; i < cmc.opacity_points.size(); ++i) {
        if(m.is(cmc.opacity_points[i].val[1])) {
            cmc.opacity_points[i].update_pos(layout, opacity_scale_exponent);
            update_color_map(true);
            break;
        }
    }
    
    if(m.is(supports_opacity)) {
        layout.total_height = supports_opacity ? 200 : 60;
        on_set(&layout.total_height);
 
        if(supports_opacity) {
            layout.total_height = 200;
        } else {
            layout.total_height = 60;
            if(cmc.cm) {
                cmc.cm->clear_opacity_points();
                cmc.opacity_points.clear();
 
                update_point_positions();
                update_color_map(false);
            }
        }
 
        post_recreate_layout();
        post_recreate_gui();
    }
}
 
bool color_map_editor::init(cgv::render::context& ctx) {
    
    cgv::g2d::ref_msdf_font_regular(ctx, 1);
    cgv::g2d::ref_msdf_gl_font_renderer_2d(ctx, 1);
    
    register_shader("rectangle", cgv::g2d::shaders::rectangle);
    register_shader("circle", cgv::g2d::shaders::circle);
    register_shader("histogram", "heightfield1d.glpr");
    register_shader("background", "color_map_editor_bg.glpr");
 
    bool success = canvas_overlay::init(ctx);
 
    success &= color_handle_renderer.init(ctx);
    success &= opacity_handle_renderer.init(ctx);
    success &= line_renderer.init(ctx);
    success &= polygon_renderer.init(ctx);
    
    init_preview_texture(ctx);
    update_color_map(false);
 
    rgb a(0.75f);
    rgb b(0.9f);
    std::vector<rgb> bg_data = { a, b, b, a };
    
    bg_tex.destruct(ctx);
    cgv::data::data_view bg_dv = cgv::data::data_view(new cgv::data::data_format(2, 2, cgv::type::info::TI_FLT32, cgv::data::CF_RGB), bg_data.data());
    bg_tex = cgv::render::texture("flt32[R,G,B]", cgv::render::TF_NEAREST, cgv::render::TF_NEAREST, cgv::render::TW_REPEAT, cgv::render::TW_REPEAT);
    success &= bg_tex.create(ctx, bg_dv, 0);
 
    return success;
}
 
void color_map_editor::init_frame(cgv::render::context& ctx) {
 
    if(ensure_layout(ctx)) {
        ivec2 container_size = get_rectangle().size;
        layout.update(container_size, supports_opacity);
 
        auto& bg_prog = content_canvas.enable_shader(ctx, "background");
        float width_factor = static_cast<float>(layout.opacity_editor_rect.w()) / static_cast<float>(layout.opacity_editor_rect.h());
        bg_style.texcoord_scaling = vec2(5.0f * width_factor, 5.0f);
        bg_style.apply(ctx, bg_prog);
        content_canvas.disable_current_shader(ctx);
 
        update_point_positions();
        sort_points();
        update_geometry();
        cmc.color_points.set_constraint(layout.color_handles_rect);
        cmc.opacity_points.set_constraint(layout.opacity_editor_rect);
    }
}
 
void color_map_editor::draw_content(cgv::render::context& ctx) {
    
    begin_content(ctx);
    
    // draw inner border
    ivec2 container_size = get_rectangle().size;
    content_canvas.enable_shader(ctx, "rectangle");
    content_canvas.set_style(ctx, border_style);
    content_canvas.draw_shape(ctx, ivec2(layout.padding - 1) + ivec2(0, 10), container_size - 2 * layout.padding + 2 - ivec2(0, 10));
    
    if(cmc.cm) {
        // draw color scale texture
        content_canvas.set_style(ctx, color_map_style);
        preview_tex.enable(ctx, 0);
        content_canvas.draw_shape(ctx, layout.color_editor_rect);
        preview_tex.disable(ctx);
        //content_canvas.disable_current_shader(ctx);
 
        if(supports_opacity) {
            // draw opacity editor checkerboard background
            auto& bg_prog = content_canvas.enable_shader(ctx, "background");
            bg_style.apply(ctx, bg_prog);
            bg_prog.set_uniform(ctx, "scale_exponent", opacity_scale_exponent);
            bg_tex.enable(ctx, 0);
            content_canvas.draw_shape(ctx, layout.opacity_editor_rect);
            bg_tex.disable(ctx);
            content_canvas.disable_current_shader(ctx);
 
            // draw histogram
            if(histogram_type != (cgv::type::DummyEnum)0 && hist_tex.is_created()) {
                auto& hist_prog = content_canvas.enable_shader(ctx, "histogram");
                hist_prog.set_uniform(ctx, "max_value", hist_norm_ignore_zero ? hist_max_non_zero : hist_max);
                hist_prog.set_uniform(ctx, "norm_gamma", hist_norm_gamma);
                hist_prog.set_uniform(ctx, "sampling_type", cgv::math::clamp(static_cast<unsigned>(histogram_type) - 1, 0u, 2u));
                hist_style.apply(ctx, hist_prog);
 
                hist_tex.enable(ctx, 1);
                content_canvas.draw_shape(ctx, layout.opacity_editor_rect);
                hist_tex.disable(ctx);
                content_canvas.disable_current_shader(ctx);
            }
 
            preview_tex.enable(ctx, 0);
            // draw transfer function area polygon
            polygon_renderer.render(ctx, content_canvas, cgv::render::PT_TRIANGLE_STRIP, cmc.triangles, polygon_style);
 
            // draw transfer function lines
            line_renderer.render(ctx, content_canvas, cgv::render::PT_LINE_STRIP, cmc.lines, line_style);
            preview_tex.disable(ctx);
 
            // draw separator line
            content_canvas.enable_shader(ctx, "rectangle");
            content_canvas.set_style(ctx, border_style);
            content_canvas.draw_shape(ctx,
                ivec2(layout.color_editor_rect.x(), layout.color_editor_rect.y1()),
                ivec2(container_size.x() - 2 * layout.padding, 1)
            );
            content_canvas.disable_current_shader(ctx);
        }
 
        // draw control points
        // color handles
        color_handle_renderer.render(ctx, content_canvas, cgv::render::PT_LINES, cmc.color_handles, color_handle_style);
 
        // opacity handles
        if(supports_opacity) {
            auto& opacity_handle_prog = opacity_handle_renderer.enable_prog(ctx);
            opacity_handle_prog.set_attribute(ctx, "size", vec2(opacity_point::default_size)); // size is constant for all points
            opacity_handle_renderer.render(ctx, content_canvas, cgv::render::PT_POINTS, cmc.opacity_handles, opacity_handle_style);
        }
    } else {
        content_canvas.disable_current_shader(ctx);
    }
 
    auto& font = cgv::g2d::ref_msdf_font_regular(ctx);
    auto& font_renderer = cgv::g2d::ref_msdf_gl_font_renderer_2d(ctx);
    cgv::g2d::msdf_gl_font_renderer::text_render_info text_render_info;
 
    if(show_value_label) {
        cgv::g2d::irect rectangle = value_label_rectangle;
        rectangle.translate(0, 5);
        rectangle.size += ivec2(10, 6);
 
        content_canvas.enable_shader(ctx, "rectangle");
        content_canvas.set_style(ctx, label_box_style);
        content_canvas.draw_shape(ctx, rectangle);
        content_canvas.disable_current_shader(ctx);
 
        text_render_info.alignment = cgv::render::TextAlignment::TA_BOTTOM;
        font_renderer.render(ctx, content_canvas, font, value_label, value_label_rectangle.position, text_render_info, value_label_style);
    }
 
    // draw cursor decorators to show interaction hints
    if(mouse_is_on_overlay && !cursor_label.empty()) {
        vec2 position = static_cast<vec2>(cursor_position + ivec2(12, 6));
        text_render_info.alignment = cgv::render::TextAlignment::TA_NONE;
        font_renderer.render(ctx, content_canvas, font, cursor_label, vec3(position, 0.0f), text_render_info, cursor_label_style);
    }
 
    end_content(ctx);
}
 
void color_map_editor::handle_theme_change(const cgv::gui::theme_info& theme) {
 
    themed_canvas_overlay::handle_theme_change(theme);
    update_geometry();
    post_recreate_gui();
}
 
void color_map_editor::create_gui_impl() {
 
    if(begin_tree_node("Settings", layout, false)) {
        align("\a");
        std::string height_options = "min=";
        height_options += supports_opacity ? "80" : "40";
        height_options += ";max=500;step=10;ticks=true";
        add_member_control(this, "Height", layout.total_height, "value_slider", height_options);
        add_member_control(this, "Opacity Scale Exponent", opacity_scale_exponent, "value_slider", "min=1.0;max=5.0;step=0.001;ticks=true");
        add_member_control(this, "Resolution", resolution, "dropdown", "enums='2=2,4=4,8=8,16=16,32=32,64=64,128=128,256=256,512=512,1024=1024,2048=2048';w=106", " ");
        add_member_control(this, "Interpolate", use_interpolation, "check", "w=82");
        
        if(cmc.cm && cmc.cm->has_texture_support()) {
            add_member_control(this, "Linear Filtering (Texture)", use_linear_filtering, "check");
        }
        align("\b");
        end_tree_node(layout);
 
        add_decorator("Histogram", "heading", "level=4");
        add_member_control(this, "Type", histogram_type, "dropdown", "enums='None,Nearest,Linear,Smooth'");
        add_member_control(this, "Ignore Zero for Normalization", hist_norm_ignore_zero, "check");
        add_member_control(this, "Gamma", hist_norm_gamma, "value_slider", "min=0.001;max=2;step=0.001;ticks=true");
        add_member_control(this, "Fill Color", hist_style.fill_color);
        add_member_control(this, "Border Color", hist_style.border_color);
        add_member_control(this, "Border Width", hist_style.border_width, "value_slider", "min=0;max=10;step=0.5;ticks=true");
    }
 
    if(begin_tree_node("Color Points", cmc.color_points, true)) {
        align("\a");
        auto& points = cmc.color_points;
        for(unsigned i = 0; i < points.size(); ++i) {
            std::string label_prefix = "";
            std::string options = "w=48";
            if(&points[i] == cmc.color_points.get_selected()) {
                label_prefix = "> ";
                options += ";label_color=" + highlight_color_hex;
            }
 
            add_view(label_prefix + std::to_string(i), points[i].val, "", options, " ");
            add_member_control(this, "", points[i].col, "", "w=140");
        }
        align("\b");
        end_tree_node(cmc.color_points);
    }
 
    if(supports_opacity) {
        if(begin_tree_node("Opacity Points", cmc.opacity_points, true)) {
            align("\a");
            auto& points = cmc.opacity_points;
            for(unsigned i = 0; i < points.size(); ++i) {
                std::string label_prefix = "";
                std::string options = "w=48";
                if(&points[i] == cmc.opacity_points.get_selected()) {
                    label_prefix = "> ";
                    options += ";label_color=" + highlight_color_hex;
                }
 
                add_view(label_prefix + std::to_string(i), points[i].val[0], "", options, " ");
                add_member_control(this, "", points[i].val[1], "value", "w=140");
            }
            align("\b");
            end_tree_node(cmc.opacity_points);
        }
    }
}
 
void color_map_editor::set_opacity_support(bool flag) {
    
    supports_opacity = flag;
    set_color_map(cmc.cm);
    on_set(&supports_opacity);
}
 
void color_map_editor::set_color_map(cgv::render::color_map* cm) {
    cmc.reset();
    cmc.cm = cm;
 
    if(cmc.cm) {
        auto& cm = *cmc.cm;
        auto& cp = cmc.cm->ref_color_points();
        
        for(size_t i = 0; i < cp.size(); ++i) {
            color_point p;
            p.val = cgv::math::clamp(cp[i].first, 0.0f, 1.0f);
            p.col = cp[i].second;
            cmc.color_points.add(p);
        }
 
        if(supports_opacity) {
            auto& op = cmc.cm->ref_opacity_points();
            for(size_t i = 0; i < op.size(); ++i) {
                opacity_point p;
                p.val.x() = cgv::math::clamp(op[i].first, 0.0f, 1.0f);
                p.val.y() = cgv::math::clamp(op[i].second, 0.0f, 1.0f);
                cmc.opacity_points.add(p);
            }
        }
 
        use_interpolation = cm.is_interpolation_enabled();
        use_linear_filtering = true;
        
        cgv::render::gl_color_map* gl_cm = cmc.get_gl_color_map();
        if(gl_cm)
            use_linear_filtering = gl_cm->is_linear_filtering_enabled();
 
        update_point_positions();
        update_color_map(false);
 
        post_recreate_gui();
    }
}
 
void color_map_editor::set_histogram_data(const std::vector<unsigned> data) {
    histogram = data;
 
    std::vector<float> float_data(histogram.size(), 0.0f);
    hist_max = 1;
    hist_max_non_zero = 1;
    for(size_t i = 0; i < histogram.size(); ++i) {
        unsigned count = histogram[i];
        hist_max = std::max(hist_max, count);
        if(i > 0)
            hist_max_non_zero = std::max(hist_max_non_zero, count);
        float_data[i] = static_cast<float>(count);
    }
 
    if(auto ctx_ptr = get_context()) {
        auto& ctx = *ctx_ptr;
        hist_tex.destruct(ctx);
 
        cgv::data::data_view dv = cgv::data::data_view(new cgv::data::data_format(unsigned(histogram.size()), cgv::type::info::TI_FLT32, cgv::data::CF_R), float_data.data());
        hist_tex = cgv::render::texture("flt32[R]");
        hist_tex.create(ctx, dv, 0);
 
        post_damage();
    }
}
 
void color_map_editor::set_selected_color(rgb color) {
    
    auto selected_point = cmc.color_points.get_selected();
    if(selected_point) {
        selected_point->col = color;
        update_color_map(true);
        update_member(&selected_point->col);
        post_damage();
    }
}
 
void color_map_editor::init_styles() {
    auto& theme = cgv::gui::theme_info::instance();
    handle_color = rgba(theme.text(), 1.0f);
    highlight_color = rgba(theme.highlight(), 1.0f);
    highlight_color_hex = theme.highlight_hex();
 
    // configure style for the border rectangles
    border_style.fill_color = theme.border();
    border_style.border_width = 0.0f;
    border_style.feather_width = 0.0f;
    
    // configure style for the color scale rectangle
    color_map_style = border_style;
    color_map_style.use_texture = true;
 
    // configure style for background
    bg_style.use_texture = true;
    bg_style.feather_width = 0.0f;
 
    // configure style for histogram
    hist_style.use_blending = true;
    hist_style.feather_width = 1.0f;
    hist_style.feather_origin = 0.0f;
    hist_style.fill_color = rgba(rgb(0.5f), 0.666f);
    hist_style.border_color = rgba(rgb(0.0f), 0.666f);
    hist_style.border_width = 1.0f;
 
    // configure style for color handles
    color_handle_style.use_blending = true;
    color_handle_style.use_fill_color = false;
    color_handle_style.position_is_center = true;
    color_handle_style.border_color = theme.border();
    color_handle_style.border_width = 1.5f;
    color_handle_style.border_radius = 2.0f;
    color_handle_style.stem_width = color_point::default_width;
    color_handle_style.head_width = color_point::default_width;
 
    label_box_style.position_is_center = true;
    label_box_style.use_blending = true;
    label_box_style.fill_color = handle_color;
    label_box_style.border_color = theme.border();
    label_box_style.border_width = 1.5f;
    label_box_style.border_radius = 4.0f;
 
    // configure style for opacity handles
    opacity_handle_style.use_blending = true;
    opacity_handle_style.use_fill_color = false;
    opacity_handle_style.position_is_center = true;
    opacity_handle_style.border_color = theme.border();
    opacity_handle_style.border_width = 1.5f;
 
    // configure style for the lines and polygon
    line_style.use_blending = true;
    line_style.use_fill_color = false;
    line_style.use_texture = true;
    line_style.use_texture_alpha = false;
    line_style.width = 3.0f;
 
    polygon_style = static_cast<cgv::g2d::shape2d_style>(line_style);
    polygon_style.use_texture_alpha = true;
 
    // label style
    cursor_label_style.fill_color = rgb(0.0f);
    cursor_label_style.font_size = 16.0f;
 
    value_label_style.fill_color = theme.group();
    value_label_style.font_size = 12.0f;
}
 
void color_map_editor::setup_preview_texture(cgv::render::context& ctx) {
 
    if(preview_tex.is_created())
        preview_tex.destruct(ctx);
 
    cgv::render::TextureFilter filter = use_linear_filtering ? cgv::render::TF_LINEAR : cgv::render::TF_NEAREST;
    preview_tex = cgv::render::texture("uint8[R,G,B,A]", filter, filter);
}
 
void color_map_editor::init_preview_texture(cgv::render::context& ctx) {
 
    std::vector<uint8_t> data(resolution * 4 * 2, 0u);
 
    setup_preview_texture(ctx);
    cgv::data::data_view tf_dv = cgv::data::data_view(new cgv::data::data_format(resolution, 2, cgv::type::info::TI_UINT8, cgv::data::CF_RGBA), data.data());
    preview_tex.create(ctx, tf_dv, 0);
}
 
void color_map_editor::add_point(const vec2& pos) {
 
    if(cmc.cm) {
        ivec2 test_pos = static_cast<ivec2>(pos);
 
        if(layout.color_editor_rect.contains(test_pos)) {
            // color point
            color_point p;
            p.position = ivec2(int(pos.x()), layout.color_handles_rect.y());
            p.update_val(layout);
            p.col = cmc.cm->interpolate_color(p.val);
            size_t index = cmc.color_points.add(p);
            cmc.color_points.set_selected(index);
            handle_drag_end();
        } else if(supports_opacity && layout.opacity_editor_rect.contains(test_pos)) {
            // opacity point
            opacity_point p;
            p.position = pos;
            p.update_val(layout, opacity_scale_exponent);
            size_t index = cmc.opacity_points.add(p);
            cmc.opacity_points.set_selected(index);
            handle_drag_end();
        }
        
        update_color_map(true);
    }
}
 
void color_map_editor::remove_point(const cgv::g2d::draggable* ptr) {
 
    int color_point_idx = -1;
    int opacity_point_idx = -1;
 
    for(unsigned i = 0; i < cmc.color_points.size(); ++i) {
        if(&cmc.color_points[i] == ptr) {
            color_point_idx = i;
            break;
        }
    }
 
    for(unsigned i = 0; i < cmc.opacity_points.size(); ++i) {
        if(&cmc.opacity_points[i] == ptr) {
            opacity_point_idx = i;
            break;
        }
    }
 
    bool removed = false;
 
    if(color_point_idx > -1) {
        if(cmc.color_points.size() > 1) {
            cmc.color_points.ref_draggables().erase(cmc.color_points.ref_draggables().begin() + color_point_idx);
            removed = true;
        }
    }
 
    if(opacity_point_idx > -1) {
        if(cmc.opacity_points.size() > 1) {
            cmc.opacity_points.ref_draggables().erase(cmc.opacity_points.ref_draggables().begin() + opacity_point_idx);
            removed = true;
        }
    }
 
    if(removed)
        update_color_map(true);
}
 
cgv::g2d::draggable* color_map_editor::get_hit_point(const vec2& pos) {
 
    cgv::g2d::draggable* hit = nullptr;
 
    for(unsigned i = 0; i < cmc.color_points.size(); ++i) {
        color_point& p = cmc.color_points[i];
        if(p.contains(pos))
            hit = &p;
    }
 
    for(unsigned i = 0; i < cmc.opacity_points.size(); ++i) {
        opacity_point& p = cmc.opacity_points[i];
        if(p.contains(pos))
            hit = &p;
    }
 
    return hit;
}
 
void color_map_editor::update_value_label_rectangle(vec2 position, const cgv::g2d::rect& parent_rectangle) {
 
    value_label_rectangle.position = position;
 
    if(auto ctx = get_context()) {
        auto& font = cgv::g2d::ref_msdf_font_regular(*get_context());
        value_label_rectangle.size = font.compute_render_size(value_label, value_label_style.font_size);
    }
 
    float padding = std::ceil(0.5f * value_label_rectangle.w()) + 4.0f;
    float min_x = layout.color_editor_rect.x() + padding;
    float max_x = layout.color_editor_rect.x1() - padding;
    value_label_rectangle.position.x() = cgv::math::clamp(value_label_rectangle.position.x(), min_x, max_x);
}
 
void color_map_editor::handle_color_drag(cgv::g2d::DragAction action) {
 
    switch(action) {
    case cgv::g2d::DragAction::kDrag:
    {
        color_point* dragged_point = cmc.color_points.get_dragged();
        if(dragged_point) {
            dragged_point->update_val(layout);
            update_color_map(true);
 
            show_value_label = true;
            value_label = value_to_string(dragged_point->val);
            update_value_label_rectangle(dragged_point->position, layout.color_editor_rect);
            value_label_rectangle.position.y() += 25.0f;
 
            if(dragged_point && on_color_point_select_callback)
                on_color_point_select_callback(dragged_point->col);
 
            post_damage();
        }
        break;
    }
    case cgv::g2d::DragAction::kDragEnd:
    case cgv::g2d::DragAction::kSelect:
        handle_drag_end();
        break;
    default:
        break;
    }
}
 
void color_map_editor::handle_opacity_drag(cgv::g2d::DragAction action) {
 
    switch(action) {
    case cgv::g2d::DragAction::kDrag:
    {
        opacity_point* dragged_point = cmc.opacity_points.get_dragged();
        if(dragged_point) {
            dragged_point->update_val(layout, opacity_scale_exponent);
            update_color_map(true);
 
            show_value_label = true;
            std::string x_label = value_to_string(dragged_point->val.x());
            std::string y_label = cgv::utils::to_string(dragged_point->val.y(), -1, 3u);
            value_label = x_label + ", " + y_label;
 
            update_value_label_rectangle(dragged_point->position, layout.opacity_editor_rect);
            value_label_rectangle.position.y() = std::min(value_label_rectangle.position.y() + 10.0f, static_cast<float>(layout.opacity_editor_rect.y1() - 6));
 
            post_damage();
        }
        break;
    }
    case cgv::g2d::DragAction::kDragEnd:
    case cgv::g2d::DragAction::kSelect:
        handle_drag_end();
        break;
    default:
        break;
    }
}
 
/*
void color_map_editor::handle_color_point_drag() {
 
    auto dragged_point = cmc.color_points.get_dragged();
    dragged_point->update_val(layout);
    update_color_map(true);
 
    show_value_label = true;
    value_label = value_to_string(dragged_point->val);
    update_value_label_rectangle(dragged_point->position, layout.color_editor_rect);
    value_label_rectangle.position.y() += 25.0f;
 
    if(dragged_point && on_color_point_select_callback)
        on_color_point_select_callback(dragged_point->col);
 
    post_damage();
}
 
void color_map_editor::handle_opacity_point_drag() {
 
    auto dragged_point = cmc.opacity_points.get_dragged();
    dragged_point->update_val(layout, opacity_scale_exponent);
    update_color_map(true);
 
    show_value_label = true;
    std::string x_label = value_to_string(dragged_point->val.x());
    std::string y_label = cgv::utils::to_string(dragged_point->val.y(), -1, 3u);
    value_label = x_label + ", " + y_label;
    
    update_value_label_rectangle(dragged_point->position, layout.opacity_editor_rect);
    value_label_rectangle.position.y() = std::min(value_label_rectangle.position.y() + 10.0f, static_cast<float>(layout.opacity_editor_rect.y1() - 6));
 
    post_damage();
}
*/
 
void color_map_editor::handle_drag_end() {
    
    show_value_label = false;
    update_geometry();
 
    auto selected_point = cmc.color_points.get_selected();
    if(selected_point) {
        if(on_color_point_select_callback)
            on_color_point_select_callback(selected_point->col);
    } else {
        if(on_color_point_deselect_callback)
            on_color_point_deselect_callback();
    }
 
    post_recreate_gui();
    post_damage();
}
 
std::string color_map_editor::value_to_string(float value) {
 
    float display_value = cgv::math::lerp(range.x(), range.y(), value);
 
    float total = range.y() - range.x();
    if(total < 100.0f) {
        // show as float
        return cgv::utils::to_string(display_value, -1, 3u);
    } else {
        // show as int
        int display_value_int = static_cast<int>(round(display_value));
        return std::to_string(display_value_int);
    }
}
 
void color_map_editor::sort_points() {
    sort_color_points();
    if(supports_opacity)
        sort_opacity_points();
}
 
void color_map_editor::sort_color_points() {
 
    auto& points = cmc.color_points;
 
    if(points.size() > 1) {
        int dragged_point_idx = -1;
        int selected_point_idx = -1;
 
        const color_point* dragged_point = points.get_dragged();
        const color_point* selected_point = points.get_selected();
 
        std::vector<std::pair<color_point, int>> sorted(points.size());
 
        for(unsigned i = 0; i < points.size(); ++i) {
            sorted[i].first = points[i];
            sorted[i].second = i;
 
            if(dragged_point == &points[i])
                dragged_point_idx = i;
            if(selected_point == &points[i])
                selected_point_idx = i;
        }
 
        std::sort(sorted.begin(), sorted.end(),
            [](const auto& a, const auto& b) -> bool {
                return a.first.val < b.first.val;
            }
        );
 
        int new_dragged_point_idx = -1;
        int new_selected_point_idx = -1;
 
        for(unsigned i = 0; i < sorted.size(); ++i) {
            points[i] = sorted[i].first;
            if(dragged_point_idx == sorted[i].second) {
                new_dragged_point_idx = i;
            }
            if(selected_point_idx == sorted[i].second) {
                new_selected_point_idx = i;
            }
        }
 
        points.set_dragged(new_dragged_point_idx);
        points.set_selected(new_selected_point_idx);
    }
}
 
void color_map_editor::sort_opacity_points() {
 
    auto& points = cmc.opacity_points;
 
    if(points.size() > 1) {
        int dragged_point_idx = -1;
        int selected_point_idx = -1;
 
        const opacity_point* dragged_point = points.get_dragged();
        const opacity_point* selected_point = points.get_selected();
 
        std::vector<std::pair<opacity_point, int>> sorted(points.size());
 
        for(unsigned i = 0; i < points.size(); ++i) {
            sorted[i].first = points[i];
            sorted[i].second = i;
 
            if(dragged_point == &points[i])
                dragged_point_idx = i;
            if(selected_point == &points[i])
                selected_point_idx = i;
        }
 
        std::sort(sorted.begin(), sorted.end(),
            [](const auto& a, const auto& b) -> bool {
                return a.first.val.x() < b.first.val.x();
            }
        );
 
        int new_dragged_point_idx = -1;
        int new_selected_point_idx = -1;
 
        for(unsigned i = 0; i < sorted.size(); ++i) {
            points[i] = sorted[i].first;
            if(dragged_point_idx == sorted[i].second) {
                new_dragged_point_idx = i;
            }
            if(selected_point_idx == sorted[i].second) {
                new_selected_point_idx = i;
            }
        }
 
        points.set_dragged(new_dragged_point_idx);
        points.set_selected(new_selected_point_idx);
    }
}
 
void color_map_editor::update_point_positions() {
 
    for(unsigned i = 0; i < cmc.color_points.size(); ++i)
        cmc.color_points[i].update_pos(layout);
 
    for(unsigned i = 0; i < cmc.opacity_points.size(); ++i)
        cmc.opacity_points[i].update_pos(layout, opacity_scale_exponent);
}
 
void color_map_editor::update_color_map(bool is_data_change) {
    
    cgv::render::context* ctx_ptr = get_context();
    if(!ctx_ptr || !cmc.cm) return;
    cgv::render::context& ctx = *ctx_ptr;
 
    auto& cm = *cmc.cm;
    auto& color_points = cmc.color_points;
    auto& opacity_points = cmc.opacity_points;
    
    sort_points();
 
    cm.clear();
 
    for(unsigned i = 0; i < color_points.size(); ++i) {
        const color_point& p = color_points[i];
        cm.add_color_point(p.val, p.col);
    }
 
    if(supports_opacity) {
        for(unsigned i = 0; i < opacity_points.size(); ++i) {
            const opacity_point& p = opacity_points[i];
            cm.add_opacity_point(p.val.x(), p.val.y());
        }
    } else {
        // add one fully opaque point that will be removed later on
        cm.add_opacity_point(0.0f, 1.0f);
    }
 
    size_t size = static_cast<size_t>(resolution);
    std::vector<rgba> cs_data = cm.interpolate(size);
 
    std::vector<uint8_t> data(4 * 2 * size);
    for(size_t i = 0; i < size; ++i) {
        rgba col = cs_data[i];
        uint8_t r = static_cast<uint8_t>(255.0f * col.R());
        uint8_t g = static_cast<uint8_t>(255.0f * col.G());
        uint8_t b = static_cast<uint8_t>(255.0f * col.B());
        uint8_t a = static_cast<uint8_t>(255.0f * col.alpha());
 
        size_t idx = 4 * i;
        data[idx + 0] = r;
        data[idx + 1] = g;
        data[idx + 2] = b;
        data[idx + 3] = a;
        idx += 4*size;
        data[idx + 0] = r;
        data[idx + 1] = g;
        data[idx + 2] = b;
        data[idx + 3] = a;
    }
 
    setup_preview_texture(ctx);
    cgv::data::data_view dv = cgv::data::data_view(new cgv::data::data_format(unsigned(size), 2, cgv::type::info::TI_UINT8, cgv::data::CF_RGBA), data.data());
    preview_tex.create(ctx, dv, 0);
 
    if(!supports_opacity)
        cm.clear_opacity_points();
 
    update_geometry();
 
    if(on_change_callback)
        on_change_callback();
 
    post_damage();
}
 
bool color_map_editor::update_geometry() {
 
    cgv::render::context* ctx_ptr = get_context();
    if(!ctx_ptr || !cmc.cm) return false;
    cgv::render::context& ctx = *ctx_ptr;
 
    auto& cm = *cmc.cm;
    auto& color_points = cmc.color_points;
    auto& opacity_points = cmc.opacity_points;
    auto& color_handles = cmc.color_handles;
    auto& opacity_handles = cmc.opacity_handles;
    auto& lines = cmc.lines;
    auto& triangles = cmc.triangles;
 
    color_handles.clear();
    opacity_handles.clear();
    lines.clear();
    triangles.clear();
 
    bool success = color_points.size() > 0 && opacity_points.size() > 0;
 
    // create color handles
    vec2 pos_offset = vec2(0.0f, 0.5f * color_point::default_height);
 
    for(unsigned i = 0; i < color_points.size(); ++i) {
        const auto& p = color_points[i];
        vec2 pos = p.center();
        rgba col = color_points.get_selected() == &p ? highlight_color : handle_color;
        color_handles.add(pos - pos_offset, col);
        color_handles.add(pos + pos_offset, col);
    }
 
    // create opacity handles
    for(unsigned i = 0; i < opacity_points.size(); ++i) {
        const auto& p = opacity_points[i];
        vec2 pos = p.center();
        rgba col = opacity_points.get_selected() == &p ? highlight_color : handle_color;
        opacity_handles.add(pos, col);
    }
 
    if(opacity_points.size() > 0) {
        const auto& pl = opacity_points[0];
 
        vec2 tex_coord(0.0f, 0.5f);
 
        lines.add(vec2(float(layout.opacity_editor_rect.x()), pl.center().y()), tex_coord);
        
        triangles.add(vec2(float(layout.opacity_editor_rect.x()), pl.center().y()), tex_coord);
        triangles.add(layout.opacity_editor_rect.position, tex_coord);
 
        for(unsigned i = 0; i < opacity_points.size(); ++i) {
            const auto& p = opacity_points[i];
            vec2 pos = p.center();
 
            tex_coord.x() = p.val.x();
 
            lines.add(pos, tex_coord);
 
            triangles.add(pos, tex_coord);
            triangles.add(vec2(pos.x(), (float)layout.opacity_editor_rect.y()), tex_coord);
        }
 
        const auto& pr = opacity_points[opacity_points.size() - 1];
        vec2 max_pos = layout.opacity_editor_rect.position + vec2(1.0f, 0.0f) * layout.opacity_editor_rect.size;
 
        tex_coord.x() = 1.0f;
 
        lines.add(vec2(max_pos.x(), pr.center().y()), tex_coord);
 
        triangles.add(vec2(max_pos.x(), pr.center().y()), tex_coord);
        triangles.add(max_pos, tex_coord);
    } else {
        success = false;
    }
 
    return success;
}
 
}
}