hit_metrics.hpp

Go to the documentation of this file.

#pragma once

 
#include <pulp/view/input_events.hpp>
 
#include <algorithm>
 
namespace pulp::view {

struct HitMetrics {
    PointerType pointer_type = PointerType::mouse;
    float min_target_pt = 0.0f;

    static constexpr float default_min_target_pt(PointerType type) noexcept {
        switch (type) {
        case PointerType::touch: return 44.0f;
        case PointerType::pen:   return 12.0f;
        case PointerType::mouse: break;
        }
        return 8.0f;
    }

    static constexpr HitMetrics for_pointer(PointerType type) noexcept {
        return HitMetrics{type, default_min_target_pt(type)};
    }

    [[nodiscard]] constexpr float effective_target_pt() const noexcept {
        return min_target_pt > 0.0f ? min_target_pt : default_min_target_pt(pointer_type);
    }

    [[nodiscard]] constexpr float tolerance_px(float pixels_per_point = 1.0f) const noexcept {
        const float scale = pixels_per_point > 0.0f ? pixels_per_point : 1.0f;
        return effective_target_pt() * 0.5f * scale;
    }
};
 
} // namespace pulp::view