GlyphMetrics.hpp

// Copyright 2019, 2020 Pokitec
// All rights reserved.
 
#pragma once
 
#include "TTauri/Foundation/required.hpp"
#include "TTauri/Foundation/vec.hpp"
#include "TTauri/Foundation/mat.hpp"
#include "TTauri/Foundation/aarect.hpp"
 
namespace tt {
 
struct GlyphMetrics {
    aarect boundingBox = {};
 
    float leftSideBearing = 0.0f;
 
    float rightSideBearing = 0.0f;
 
    float ascender = 0.0f;
 
    float descender = 0.0f;
 
    float lineGap = 0.0f;
 
    float capHeight = 0.0f;
 
    float xHeight = 0.0f;
 
    vec advance = {0.0f, 0.0f};
 
    int numberOfGraphemes = 1;
 
    GlyphMetrics() noexcept = default;
    GlyphMetrics(GlyphMetrics const &) noexcept = default;
    GlyphMetrics(GlyphMetrics &&) noexcept = default;
    GlyphMetrics &operator=(GlyphMetrics const &) noexcept = default;
    GlyphMetrics &operator=(GlyphMetrics &&) noexcept = default;
 
    vec advanceForGrapheme(int index) const noexcept {
        ttlet ligatureRatio = vec{1.0f / numberOfGraphemes};
 
        return advance * ligatureRatio * vec{index};
    }
 
    GlyphMetrics &scale(float rhs) noexcept
    {
        auto S = mat::S(rhs, rhs);
 
        boundingBox = S * boundingBox;
        leftSideBearing *= rhs; 
        rightSideBearing *= rhs;
        advance = S * advance;
        ascender *= rhs;
        descender *= rhs;
        lineGap *= rhs;
        capHeight *= rhs;
        xHeight *= rhs;
        return *this;
    }
};
 
 
 
}