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Merge pull request #9168 from jherico/cpu_opt_aabb

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Optimized method for transforming axis aligned bounding boxes
This commit is contained in:
Brad Hefta-Gaub 2016-12-08 13:45:16 -08:00 committed by GitHub
commit 6edd3a9338
1 changed files with 13 additions and 39 deletions
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52
libraries/shared/src/AABox.cpp
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@ -568,46 +568,20 @@ void AABox::transform(const Transform& transform) {
translate(transform.getTranslation());
}
// Logic based on http://clb.demon.fi/MathGeoLib/nightly/docs/AABB.cpp_code.html#471
void AABox::transform(const glm::mat4& matrix) {
auto minimum = _corner;
auto maximum = _corner + _scale;
auto halfSize = _scale * 0.5f;
auto center = _corner + halfSize;
halfSize = abs(halfSize);
auto newCenter = transformPoint(matrix, center);
glm::vec3 bottomLeftNear(minimum.x, minimum.y, minimum.z);
glm::vec3 bottomRightNear(maximum.x, minimum.y, minimum.z);
glm::vec3 bottomLeftFar(minimum.x, minimum.y, maximum.z);
glm::vec3 bottomRightFar(maximum.x, minimum.y, maximum.z);
glm::vec3 topLeftNear(minimum.x, maximum.y, minimum.z);
glm::vec3 topRightNear(maximum.x, maximum.y, minimum.z);
glm::vec3 topLeftFar(minimum.x, maximum.y, maximum.z);
glm::vec3 topRightFar(maximum.x, maximum.y, maximum.z);
auto mm = glm::transpose(glm::mat3(matrix));
vec3 newDir = vec3(
glm::dot(glm::abs(vec3(mm[0])), halfSize),
glm::dot(glm::abs(vec3(mm[1])), halfSize),
glm::dot(glm::abs(vec3(mm[2])), halfSize)
);
glm::vec3 bottomLeftNearTransformed = transformPoint(matrix, bottomLeftNear);
glm::vec3 bottomRightNearTransformed = transformPoint(matrix, bottomRightNear);
glm::vec3 bottomLeftFarTransformed = transformPoint(matrix, bottomLeftFar);
glm::vec3 bottomRightFarTransformed = transformPoint(matrix, bottomRightFar);
glm::vec3 topLeftNearTransformed = transformPoint(matrix, topLeftNear);
glm::vec3 topRightNearTransformed = transformPoint(matrix, topRightNear);
glm::vec3 topLeftFarTransformed = transformPoint(matrix, topLeftFar);
glm::vec3 topRightFarTransformed = transformPoint(matrix, topRightFar);
minimum = glm::min(bottomLeftNearTransformed,
glm::min(bottomRightNearTransformed,
glm::min(bottomLeftFarTransformed,
glm::min(bottomRightFarTransformed,
glm::min(topLeftNearTransformed,
glm::min(topRightNearTransformed,
glm::min(topLeftFarTransformed,
topRightFarTransformed)))))));
maximum = glm::max(bottomLeftNearTransformed,
glm::max(bottomRightNearTransformed,
glm::max(bottomLeftFarTransformed,
glm::max(bottomRightFarTransformed,
glm::max(topLeftNearTransformed,
glm::max(topRightNearTransformed,
glm::max(topLeftFarTransformed,
topRightFarTransformed)))))));
_corner = minimum;
_scale = maximum - minimum;
_corner = newCenter - newDir;
_scale = newDir * 2.0f;
}