55 lines
2.1 KiB
C++
55 lines
2.1 KiB
C++
#pragma once
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#include <array>
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#include <glm/glm.hpp>
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#include <utility>
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struct AABB
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{
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glm::vec3 min = glm::vec3(std::numeric_limits<float>::max());
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glm::vec3 max = glm::vec3(std::numeric_limits<float>::lowest());
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float surfaceArea() const
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{
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glm::vec3 d = glm::vec3(max.x - min.x, max.y - min.y, max.z - min.z);
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return 2.0f * (d.x * d.y + d.y * d.z + d.z * d.x);
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}
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void adjust(glm::vec3 pos)
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{
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min.x = std::min(min.x, pos.x);
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min.y = std::min(min.y, pos.y);
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min.z = std::min(min.z, pos.z);
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max.x = std::max(max.x, pos.x);
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max.y = std::max(max.y, pos.y);
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max.z = std::max(max.z, pos.z);
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}
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void transform(glm::mat4 transform)
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{
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std::array<glm::vec3, 8> corners;
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corners[0] = glm::vec3(min.x, min.y, min.z);
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corners[1] = glm::vec3(min.x, min.y, max.z);
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corners[2] = glm::vec3(min.x, max.y, min.z);
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corners[3] = glm::vec3(min.x, max.y, max.z);
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corners[4] = glm::vec3(max.x, min.y, min.z);
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corners[5] = glm::vec3(max.x, min.y, max.z);
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corners[6] = glm::vec3(max.x, max.y, min.z);
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corners[7] = glm::vec3(max.x, max.y, max.z);
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min = glm::vec3(std::numeric_limits<float>::max());
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max = glm::vec3(std::numeric_limits<float>::lowest());
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for (int i = 0; i < 8; ++i)
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{
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glm::vec4 transformed = transform * glm::vec4(corners[i].x, corners[i].y, corners[i].z, 1.0f);
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min = glm::vec3(std::min(min.x, transformed.x), std::min(min.y, transformed.y), std::min(min.z, transformed.z));
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max = glm::vec3(std::max(max.x, transformed.x), std::max(max.y, transformed.y), std::max(max.z, transformed.z));
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}
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}
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static AABB combine(AABB lhs, AABB rhs)
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{
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AABB result = {
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.min = glm::vec3(std::min(lhs.min.x, rhs.min.x), std::min(lhs.min.y, rhs.min.y), std::min(lhs.min.z, rhs.min.z)),
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.max = glm::vec3(std::max(lhs.max.x, rhs.max.x), std::max(lhs.max.y, rhs.max.y), std::max(lhs.max.z, rhs.max.z)),
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};
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return result;
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}
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};
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