34 lines
791 B
C++
34 lines
791 B
C++
#pragma once
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#include <glm/glm.hpp>
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#include <glm/gtc/matrix_access.hpp>
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#include <array>
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/* extracts frustum from projection matrix */
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static std::array<glm::vec4, 6> frustum(const glm::mat4& mat) {
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/* Left, Right, Top, Bottom, Back, Front */
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std::array<glm::vec4, 6> ret;
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for (size_t i = 0; i < 3; i++)
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for (size_t j = 0; j < 4; j++)
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ret[i * 2][j] = mat[j].w + mat[j][i],
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ret[i * 2 + 1][j] = mat[j].w - mat[j][i];
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return ret;
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}
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static bool box_in_frustum(const std::array<glm::vec4, 6>& frustum, const glm::vec3 box_verts[8]) {
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for (const auto& plane : frustum) {
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for (size_t i = 0; i < 8; i++) {
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const auto& vert = box_verts[i];
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if (glm::dot(glm::vec4(vert, 1.0), plane) > 0)
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goto double_continue;
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}
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return false;
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double_continue:;
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}
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return true;
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} |