AABB.hpp

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#pragma once
 
namespace Cori {
    namespace Utility {
        struct AABB {
            glm::vec2 m_Min;
            glm::vec2 m_Max;
        };

        [[nodiscard]] inline AABB CalculateAABB(const glm::mat3& transform, const glm::vec2 halfSize) {
            const glm::vec2 corners[4]{
                    {transform * glm::vec3{-halfSize.x, -halfSize.y, 1.0f}},
                    {transform * glm::vec3{halfSize.x, -halfSize.y, 1.0f}},
                    {transform * glm::vec3{halfSize.x, halfSize.y, 1.0f}},
                    {transform * glm::vec3{-halfSize.x, halfSize.y, 1.0f}},
                };
            AABB bounds { corners[0], corners[0] };
 
            for (int32_t i = 1; i < 4; ++i) {
                bounds.m_Min.x = std::min(bounds.m_Min.x, corners[i].x);
                bounds.m_Min.y = std::min(bounds.m_Min.y, corners[i].y);
                bounds.m_Max.x = std::max(bounds.m_Max.x, corners[i].x);
                bounds.m_Max.y = std::max(bounds.m_Max.y, corners[i].y);
            }
 
            return bounds;
        }

        [[nodiscard]] inline bool AABBOverlapCheck(const AABB& a, const AABB& b) {
            return (a.m_Min.x <= b.m_Max.x && a.m_Max.x >= b.m_Min.x) &&
                   (a.m_Min.y <= b.m_Max.y && a.m_Max.y >= b.m_Min.y);
        }
    }
}