GuiGlyph.h

/****************************************************************************
 * libgui
 * Daryl Borth 2026
 * GuiGlyph.h
 ***************************************************************************/
#pragma once
 
#include <vector>
#include <cmath>
#include <algorithm>
#include "GuiElement.h"
#include "GuiPaint.h"
#include "GuiTheme.h"

enum class GLYPH {
    BUTTON,       
    BUMPER,       
    UP,           
    DOWN,
    LEFT,
    RIGHT,
    PLUS,
    MINUS,
    STICK,     
    CAPTURE, 
    HOME
};
 
class GuiText;

class GuiGlyph : public GuiElement
{
    public:
        GuiGlyph(GLYPH kind, const char * letter = "");
        ~GuiGlyph();
        void draw() override;

        static void size(GLYPH kind, float& w, float& h);

        static void build(GuiMesh& mesh, GLYPH kind, float w, float h);
 
    private:
        GLYPH kind;
        GuiText * text;
        GuiMesh mesh;
        float meshFeather;
        std::vector<MeshVertex> scratch;
};
 
inline void GuiGlyph::size(GLYPH kind, float& w, float& h)
{
    switch(kind)
    {
        case GLYPH::BUMPER: w = 30.0f; h = 20.0f; break;
        default: w = 22.0f; h = 22.0f; break;
    }
}
 
inline void GuiGlyph::build(GuiMesh& mesh, GLYPH kind, float w, float h)
{
    const GuiTheme& theme = GuiTheme::current();
    const GuiFill light = GuiFill::solid(theme.text);
    const GuiFill dark = GuiFill::solid(theme.background);
    const GuiRect box = { 0.0f, 0.0f, w, h };
    const float cx = w * 0.5f, cy = h * 0.5f, u = std::min(w, h) / 22.0f; // u = size relative to a 22-pixel glyph
 
    switch(kind)
    {
        case GLYPH::BUMPER:
            mesh.addRoundRect(box, GuiCorners(6.0f * u), light);
            return;
        case GLYPH::CAPTURE:
            mesh.addRoundRect(box, GuiCorners(5.0f * u), light);
            mesh.strokeEllipse(GuiRect{ cx - 6.0f * u, cy - 6.0f * u, 12.0f * u, 12.0f * u }, 1.6f * u, STROKE::INSIDE, dark);
            return;
        default:
            break;
    }
 
    mesh.addEllipse(box, light);
    switch(kind)
    {
        case GLYPH::UP:
        case GLYPH::DOWN:
        case GLYPH::LEFT:
        case GLYPH::RIGHT:
        {
            // a triangle pointing up, turned to face the right way
            const float a = kind == GLYPH::UP ? 0.0f : kind == GLYPH::RIGHT ? 90.0f : kind == GLYPH::DOWN ? 180.0f : 270.0f;
            const float rad = a * 3.14159265f / 180.0f, c = cosf(rad), s = sinf(rad);
            const float pts[3][2] = { { 0.0f, -5.5f * u }, { -5.0f * u, 4.0f * u }, { 5.0f * u, 4.0f * u } };
            std::vector<GuiPoint> tri;
            for(int i = 0; i < 3; i++)
                tri.push_back(GuiPoint{ cx + pts[i][0] * c - pts[i][1] * s, cy + pts[i][0] * s + pts[i][1] * c });
            mesh.addPolygon(tri, dark);
            break;
        }
        case GLYPH::PLUS:
            mesh.addRect(GuiRect{ cx - 5.5f * u, cy - 1.3f * u, 11.0f * u, 2.6f * u }, dark);
            mesh.addRect(GuiRect{ cx - 1.3f * u, cy - 5.5f * u, 2.6f * u, 11.0f * u }, dark);
            break;
        case GLYPH::MINUS:
            mesh.addRect(GuiRect{ cx - 5.5f * u, cy - 1.3f * u, 11.0f * u, 2.6f * u }, dark);
            break;
        case GLYPH::HOME:
        {
            std::vector<GuiPoint> house = { { cx, cy - 6.0f * u }, { cx + 6.5f * u, cy - 0.5f * u }, { cx + 4.8f * u, cy + 5.5f * u },
                { cx - 4.8f * u, cy + 5.5f * u }, { cx - 6.5f * u, cy - 0.5f * u } };
            mesh.addPolygon(house, dark);
            break;
        }
        case GLYPH::STICK:
            mesh.strokeEllipse(GuiRect{ 2.5f * u, 2.5f * u, w - 5.0f * u, h - 5.0f * u }, 1.2f * u, STROKE::INSIDE, dark);
            break;
        default:
            break;
    }
}