Method update

examples/keyboard/Keyboard.cpp:374–413

    }

    void update(sf::Time frameTime)
    {
        // Animate m_moveFactors values linearly towards zero
        static constexpr sf::Time transitionDuration = sf::milliseconds(200);
        for (float& factor : m_moveFactors)
        {
            const float absoluteChange = std::min(std::abs(factor), frameTime / transitionDuration);
            factor += factor > 0.f ? -absoluteChange : absoluteChange;
        }

        // Update vertices positions from m_moveFactors and opacity from real-time keyboard state
        forEachKey(
            [this](sf::Keyboard::Scancode scancode, const sf::FloatRect& rect)
            {
                const auto scancodeIndex = static_cast<std::size_t>(scancode);

                static constexpr std::array square = {
                    sf::Vector2f(0.f, 0.f),
                    sf::Vector2f(1.f, 0.f),
                    sf::Vector2f(1.f, 1.f),
                    sf::Vector2f(0.f, 1.f),
                };
                static constexpr std::array cornerIndexes = {0u, 1u, 3u, 3u, 1u, 2u};

                const float        moveFactor = m_moveFactors[scancodeIndex];
                const sf::Vector2f move(0.f, 2.f * moveFactor * (1.f - std::abs(moveFactor)) * padding);

                const bool pressed = sf::Keyboard::isKeyPressed(scancode);

                for (std::size_t vertexIndex = 0u; vertexIndex < 6u; ++vertexIndex)
                {
                    sf::Vertex&                   vertex = m_triangles[6u * scancodeIndex + vertexIndex];
                    const sf::Vector2f&           corner = square[cornerIndexes[vertexIndex]];
                    static constexpr sf::Vector2f pad(padding, padding);
                    vertex.position = rect.position + pad + (rect.size - 2.f * pad).componentWiseMul(corner) + move;
                    vertex.color.a  = pressed ? 96 : 48;
                }
                m_labels[scancodeIndex].setPosition(rect.position + rect.size / 2.f + move);
            });
    }

private:
    void draw(sf::RenderTarget& target, sf::RenderStates states) const override