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author | 2024-08-02 11:46:41 +0000 | |
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committer | 2024-08-02 12:46:41 +0100 | |
commit | 94e87610c4ce9bbb1c614a61bab29c1422fed11b (patch) | |
tree | 2e06b8ce64212140e796f6077ba841b6cc678501 /vendor/github.com/golang/geo/s2/paddedcell.go | |
parent | [feature] Allow import of following and blocks via CSV (#3150) (diff) | |
download | gotosocial-94e87610c4ce9bbb1c614a61bab29c1422fed11b.tar.xz |
[chore] add back exif-terminator and use only for jpeg,png,webp (#3161)
* add back exif-terminator and use only for jpeg,png,webp
* fix arguments passed to terminateExif()
* pull in latest exif-terminator
* fix test
* update processed img
---------
Co-authored-by: tobi <tobi.smethurst@protonmail.com>
Diffstat (limited to 'vendor/github.com/golang/geo/s2/paddedcell.go')
-rw-r--r-- | vendor/github.com/golang/geo/s2/paddedcell.go | 252 |
1 files changed, 252 insertions, 0 deletions
diff --git a/vendor/github.com/golang/geo/s2/paddedcell.go b/vendor/github.com/golang/geo/s2/paddedcell.go new file mode 100644 index 000000000..ac304a6cc --- /dev/null +++ b/vendor/github.com/golang/geo/s2/paddedcell.go @@ -0,0 +1,252 @@ +// Copyright 2016 Google Inc. All rights reserved. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package s2 + +import ( + "github.com/golang/geo/r1" + "github.com/golang/geo/r2" +) + +// PaddedCell represents a Cell whose (u,v)-range has been expanded on +// all sides by a given amount of "padding". Unlike Cell, its methods and +// representation are optimized for clipping edges against Cell boundaries +// to determine which cells are intersected by a given set of edges. +type PaddedCell struct { + id CellID + padding float64 + bound r2.Rect + middle r2.Rect // A rect in (u, v)-space that belongs to all four children. + iLo, jLo int // Minimum (i,j)-coordinates of this cell before padding + orientation int // Hilbert curve orientation of this cell. + level int +} + +// PaddedCellFromCellID constructs a padded cell with the given padding. +func PaddedCellFromCellID(id CellID, padding float64) *PaddedCell { + p := &PaddedCell{ + id: id, + padding: padding, + middle: r2.EmptyRect(), + } + + // Fast path for constructing a top-level face (the most common case). + if id.isFace() { + limit := padding + 1 + p.bound = r2.Rect{r1.Interval{-limit, limit}, r1.Interval{-limit, limit}} + p.middle = r2.Rect{r1.Interval{-padding, padding}, r1.Interval{-padding, padding}} + p.orientation = id.Face() & 1 + return p + } + + _, p.iLo, p.jLo, p.orientation = id.faceIJOrientation() + p.level = id.Level() + p.bound = ijLevelToBoundUV(p.iLo, p.jLo, p.level).ExpandedByMargin(padding) + ijSize := sizeIJ(p.level) + p.iLo &= -ijSize + p.jLo &= -ijSize + + return p +} + +// PaddedCellFromParentIJ constructs the child of parent with the given (i,j) index. +// The four child cells have indices of (0,0), (0,1), (1,0), (1,1), where the i and j +// indices correspond to increasing u- and v-values respectively. +func PaddedCellFromParentIJ(parent *PaddedCell, i, j int) *PaddedCell { + // Compute the position and orientation of the child incrementally from the + // orientation of the parent. + pos := ijToPos[parent.orientation][2*i+j] + + p := &PaddedCell{ + id: parent.id.Children()[pos], + padding: parent.padding, + bound: parent.bound, + orientation: parent.orientation ^ posToOrientation[pos], + level: parent.level + 1, + middle: r2.EmptyRect(), + } + + ijSize := sizeIJ(p.level) + p.iLo = parent.iLo + i*ijSize + p.jLo = parent.jLo + j*ijSize + + // For each child, one corner of the bound is taken directly from the parent + // while the diagonally opposite corner is taken from middle(). + middle := parent.Middle() + if i == 1 { + p.bound.X.Lo = middle.X.Lo + } else { + p.bound.X.Hi = middle.X.Hi + } + if j == 1 { + p.bound.Y.Lo = middle.Y.Lo + } else { + p.bound.Y.Hi = middle.Y.Hi + } + + return p +} + +// CellID returns the CellID this padded cell represents. +func (p PaddedCell) CellID() CellID { + return p.id +} + +// Padding returns the amount of padding on this cell. +func (p PaddedCell) Padding() float64 { + return p.padding +} + +// Level returns the level this cell is at. +func (p PaddedCell) Level() int { + return p.level +} + +// Center returns the center of this cell. +func (p PaddedCell) Center() Point { + ijSize := sizeIJ(p.level) + si := uint32(2*p.iLo + ijSize) + ti := uint32(2*p.jLo + ijSize) + return Point{faceSiTiToXYZ(p.id.Face(), si, ti).Normalize()} +} + +// Middle returns the rectangle in the middle of this cell that belongs to +// all four of its children in (u,v)-space. +func (p *PaddedCell) Middle() r2.Rect { + // We compute this field lazily because it is not needed the majority of the + // time (i.e., for cells where the recursion terminates). + if p.middle.IsEmpty() { + ijSize := sizeIJ(p.level) + u := stToUV(siTiToST(uint32(2*p.iLo + ijSize))) + v := stToUV(siTiToST(uint32(2*p.jLo + ijSize))) + p.middle = r2.Rect{ + r1.Interval{u - p.padding, u + p.padding}, + r1.Interval{v - p.padding, v + p.padding}, + } + } + return p.middle +} + +// Bound returns the bounds for this cell in (u,v)-space including padding. +func (p PaddedCell) Bound() r2.Rect { + return p.bound +} + +// ChildIJ returns the (i,j) coordinates for the child cell at the given traversal +// position. The traversal position corresponds to the order in which child +// cells are visited by the Hilbert curve. +func (p PaddedCell) ChildIJ(pos int) (i, j int) { + ij := posToIJ[p.orientation][pos] + return ij >> 1, ij & 1 +} + +// EntryVertex return the vertex where the space-filling curve enters this cell. +func (p PaddedCell) EntryVertex() Point { + // The curve enters at the (0,0) vertex unless the axis directions are + // reversed, in which case it enters at the (1,1) vertex. + i := p.iLo + j := p.jLo + if p.orientation&invertMask != 0 { + ijSize := sizeIJ(p.level) + i += ijSize + j += ijSize + } + return Point{faceSiTiToXYZ(p.id.Face(), uint32(2*i), uint32(2*j)).Normalize()} +} + +// ExitVertex returns the vertex where the space-filling curve exits this cell. +func (p PaddedCell) ExitVertex() Point { + // The curve exits at the (1,0) vertex unless the axes are swapped or + // inverted but not both, in which case it exits at the (0,1) vertex. + i := p.iLo + j := p.jLo + ijSize := sizeIJ(p.level) + if p.orientation == 0 || p.orientation == swapMask+invertMask { + i += ijSize + } else { + j += ijSize + } + return Point{faceSiTiToXYZ(p.id.Face(), uint32(2*i), uint32(2*j)).Normalize()} +} + +// ShrinkToFit returns the smallest CellID that contains all descendants of this +// padded cell whose bounds intersect the given rect. For algorithms that use +// recursive subdivision to find the cells that intersect a particular object, this +// method can be used to skip all of the initial subdivision steps where only +// one child needs to be expanded. +// +// Note that this method is not the same as returning the smallest cell that contains +// the intersection of this cell with rect. Because of the padding, even if one child +// completely contains rect it is still possible that a neighboring child may also +// intersect the given rect. +// +// The provided Rect must intersect the bounds of this cell. +func (p *PaddedCell) ShrinkToFit(rect r2.Rect) CellID { + // Quick rejection test: if rect contains the center of this cell along + // either axis, then no further shrinking is possible. + if p.level == 0 { + // Fast path (most calls to this function start with a face cell). + if rect.X.Contains(0) || rect.Y.Contains(0) { + return p.id + } + } + + ijSize := sizeIJ(p.level) + if rect.X.Contains(stToUV(siTiToST(uint32(2*p.iLo+ijSize)))) || + rect.Y.Contains(stToUV(siTiToST(uint32(2*p.jLo+ijSize)))) { + return p.id + } + + // Otherwise we expand rect by the given padding on all sides and find + // the range of coordinates that it spans along the i- and j-axes. We then + // compute the highest bit position at which the min and max coordinates + // differ. This corresponds to the first cell level at which at least two + // children intersect rect. + + // Increase the padding to compensate for the error in uvToST. + // (The constant below is a provable upper bound on the additional error.) + padded := rect.ExpandedByMargin(p.padding + 1.5*dblEpsilon) + iMin, jMin := p.iLo, p.jLo // Min i- or j- coordinate spanned by padded + var iXor, jXor int // XOR of the min and max i- or j-coordinates + + if iMin < stToIJ(uvToST(padded.X.Lo)) { + iMin = stToIJ(uvToST(padded.X.Lo)) + } + if a, b := p.iLo+ijSize-1, stToIJ(uvToST(padded.X.Hi)); a <= b { + iXor = iMin ^ a + } else { + iXor = iMin ^ b + } + + if jMin < stToIJ(uvToST(padded.Y.Lo)) { + jMin = stToIJ(uvToST(padded.Y.Lo)) + } + if a, b := p.jLo+ijSize-1, stToIJ(uvToST(padded.Y.Hi)); a <= b { + jXor = jMin ^ a + } else { + jXor = jMin ^ b + } + + // Compute the highest bit position where the two i- or j-endpoints differ, + // and then choose the cell level that includes both of these endpoints. So + // if both pairs of endpoints are equal we choose maxLevel; if they differ + // only at bit 0, we choose (maxLevel - 1), and so on. + levelMSB := uint64(((iXor | jXor) << 1) + 1) + level := maxLevel - findMSBSetNonZero64(levelMSB) + if level <= p.level { + return p.id + } + + return cellIDFromFaceIJ(p.id.Face(), iMin, jMin).Parent(level) +} |