color_selector.h

#pragma once
 
#include <cgv/render/texture.h>
#include <cgv_g2d/draggable_collection.h>
#include <cgv_g2d/msdf_text_geometry.h>
#include <cgv_g2d/shape2d_styles.h>
#include <cgv_overlay/themed_canvas_overlay.h>
 
#include "lib_begin.h"
 
namespace cgv {
namespace overlay {
 
class CGV_API color_selector : public themed_canvas_overlay {
protected:
    struct layout_attributes {
        int padding;
        int size = 280;
 
        // dependent members
        cgv::g2d::irect border_rect;
        cgv::g2d::irect color_rect;
        cgv::g2d::irect hue_rect;
        cgv::g2d::irect opacity_rect;
        cgv::g2d::irect preview_rect;
 
        cgv::g2d::irect hue_constraint;
        cgv::g2d::irect opacity_constraint;
    } layout;
    
    struct selector_handle : public cgv::g2d::draggable {
        vec2 val = vec2(0.0f);
        bool is_rectangular = false;
 
        selector_handle() {
            size = vec2(10.0f);
            position_is_center = true;
            constraint_reference = cgv::g2d::ConstraintReference::kCenter;
        }
 
        void update_val() {
            if(constraint) {
                const cgv::g2d::irect& c = *constraint;
                vec2 p = position - static_cast<vec2>(c.position);
                ivec2 size = c.size;
                val = p / static_cast<vec2>(size);
                if(size.x() == 0) val.x() = 0.0f;
                if(size.y() == 0) val.y() = 0.0f;
                val = cgv::math::clamp(val, 0.0f, 1.0f);
            }
        }
 
        void update_pos() {
            if(constraint) {
                const cgv::g2d::irect& c = *constraint;
                val = cgv::math::clamp(val, 0.0f, 1.0f);
                position = static_cast<vec2>(c.position) + val * c.size;
            }
        }
 
        bool contains(const vec2& mp) const override {
            if(is_rectangular) {
                return draggable::contains(mp);
            } else {
                const auto dist = length(mp - center());
                return dist <= 0.5f*size.x();
            }
        }
    };
 
    bool has_opacity = false;
    bool auto_show = true;
 
    cgv::g2d::msdf_text_geometry text_geometry;
 
    cgv::g2d::shape2d_style border_style, color_texture_style, hue_texture_style, opacity_color_style, color_handle_style, hue_handle_style;
    cgv::g2d::text2d_style text_style;
    cgv::g2d::grid2d_style opacity_bg_style;
 
    cgv::g2d::draggable_collection<selector_handle> selector_handles;
 
    cgv::render::texture color_tex = { "uint8[R,G,B]", cgv::render::TF_LINEAR, cgv::render::TF_LINEAR };
    cgv::render::texture hue_tex = { "uint8[R,G,B]", cgv::render::TF_LINEAR, cgv::render::TF_LINEAR };
 
    rgb rgb_color = rgb(0.0f);
    rgba rgba_color = rgba(0.0f);
 
    void update_layout(const ivec2& parent_size);
 
    void init_styles() override;
    bool create_hue_texture(cgv::render::context& ctx);
    bool create_color_texture(cgv::render::context& ctx);
    void update_color();
    void update_texts();
 
    void handle_selector_drag(cgv::g2d::DragAction action);
 
    void set_color(rgba color, bool opacity, bool init = false);
 
    std::function<void(rgb)> on_change_rgb_callback;
    std::function<void(rgba)> on_change_rgba_callback;
 
    void create_gui_impl() override;
    
public:
    color_selector();
    std::string get_type_name() const override { return "color_selector"; }
 
    void clear(cgv::render::context& ctx) override;
 
    bool handle_mouse_event(cgv::gui::mouse_event& e, cgv::ivec2 local_mouse_pos) override;
    void handle_member_change(cgv::data::informed_ptr ptr) override;
 
    bool init(cgv::render::context& ctx) override;
    void init_frame(cgv::render::context& ctx) override;
    void draw_content(cgv::render::context& ctx) override;

    void set_auto_show(bool enabled) { auto_show = enabled; }
 
    void set_rgb_color(rgb color);
    void set_rgba_color(rgba color);
    rgb get_rgb_color() const { return rgb_color; }
    rgba get_rgba_color() const { return rgba_color; }
 
    void set_on_change_rgb_callback(std::function<void(rgb)> cb) { on_change_rgb_callback = cb; }
    void set_on_change_rgba_callback(std::function<void(rgba)> cb) { on_change_rgba_callback = cb; }
};
 
typedef cgv::data::ref_ptr<color_selector> color_selector_ptr;
 
} // namespace overlay
} // namespace cgv
 
#include <cgv/config/lib_end.h>