projects/doodle: doodle/tk/geometry.d annotate

annotate doodle/tk/geometry.d @ 100:a274d16ab6ce

struct initialisers

author	David Bryant <bagnose@gmail.com>
date	Mon, 18 Oct 2010 18:10:02 +1030
parents	535bae7a7305
children	bc5baa585b32

rev	line source
28 1754cb773d41 Part-way through getting to compile with configure/builder. Graham St Jack <graham.stjack@internode.on.net> parents: 25 diff changeset	1 module doodle.tk.geometry;
4 58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	2
16 9e63308b749c * Fix up public/private includes David Bryant <daveb@acres.com.au> parents: 15 diff changeset	3 private {
9e63308b749c * Fix up public/private includes David Bryant <daveb@acres.com.au> parents: 15 diff changeset	4 import std.stdio;
9e63308b749c * Fix up public/private includes David Bryant <daveb@acres.com.au> parents: 15 diff changeset	5 import std.math;
67 31d10176415d Checkpoint daveb parents: 66 diff changeset	6 import doodle.core.misc;
41 f2e4e1d29b98 Bah daveb parents: 40 diff changeset	7 import doodle.core.logging;
16 9e63308b749c * Fix up public/private includes David Bryant <daveb@acres.com.au> parents: 15 diff changeset	8 }
4 58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	9
33 157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	10 // In doodle x and y increase right/east and up/north respectively.
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	11
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	12 // TODO explain the strategy for ensuring numerical stability
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	13 // and the division of responsibility between users of these
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	14 // types and the types themselves.
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	15 //
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	16 // Explain how numerical instability is handled. The current policy
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	17 // is to correct bad user input (eg a gradient with miniscule length) and
34 c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	18 // print warnings rather than have assertions that cause crashes.
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	19 //
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	20 // There are no mutating operations other than opAssign
33 157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	21
34 c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	22 //
33 157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	23 // A location in 2D space
34 c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	24 //
33 157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	25
4 58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	26 struct Point {
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	27 this(in double x, in double y) {
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	28 _x = x;
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	29 _y = y;
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	30 }
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	31
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	32 Point opAdd(in Vector v) const {
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	33 return Point(_x + v._x, _y + v._y);
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	34 }
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	35
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	36 Point opSub(in Vector v) const {
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	37 return Point(_x - v._x, _y - v._y);
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	38 }
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	39
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	40 Vector opSub(in Point p) const {
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	41 return Vector(_x - p._x, _y - p._y);
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	42 }
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	43
62 6c3993f4c3eb Checkpoint daveb parents: 51 diff changeset	44 string toString() {
4 58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	45 return std.string.format("(%f, %f)", _x, _y);
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	46 }
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	47
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	48 double x() const { return _x; }
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	49 double y() const { return _y; }
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	50
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	51 private {
100 a274d16ab6ce struct initialisers David Bryant <bagnose@gmail.com> parents: 79 diff changeset	52 double _x = 0.0, _y = 0.0;
4 58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	53 }
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	54 }
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	55
48 1b4c9ba58673 Stylistic overhaul. daveb parents: 41 diff changeset	56 Point minExtents(in Point a, in Point b) {
4 58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	57 return Point(min(a.x, b.x), min(a.y, b.y));
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	58 }
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	59
48 1b4c9ba58673 Stylistic overhaul. daveb parents: 41 diff changeset	60 Point maxExtents(in Point a, in Point b) {
4 58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	61 return Point(max(a.x, b.x), max(a.y, b.y));
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	62 }
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	63
34 c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	64 //
33 157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	65 // The displacement between two locations in 2D space
34 c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	66 //
33 157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	67
4 58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	68 struct Vector {
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	69 this(in double x, in double y) {
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	70 _x = x;
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	71 _y = y;
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	72 }
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	73
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	74 Vector opAdd(in Vector v) const {
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	75 return Vector(_x + v._x, _y + v._y);
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	76 }
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	77
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	78 Vector opSub(in Vector v) const {
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	79 return Vector(_x - v._x, _y - v._y);
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	80 }
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	81
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	82 Vector opNeg() const {
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	83 return Vector(-_x, -_y);
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	84 }
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	85
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	86 Vector opMul_r(in double d) const {
41 f2e4e1d29b98 Bah daveb parents: 40 diff changeset	87 assert(!isnan(d));
4 58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	88 return Vector(d * _x, d * _y);
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	89 }
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	90
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	91 Vector opDiv(in double d) const {
41 f2e4e1d29b98 Bah daveb parents: 40 diff changeset	92 assert(!isnan(d));
4 58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	93 return Vector(_x / d, _y / d);
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	94 }
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	95
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	96 double length() const {
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	97 return sqrt(_x * _x + _y * _y);
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	98 }
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	99
62 6c3993f4c3eb Checkpoint daveb parents: 51 diff changeset	100 string toString() {
4 58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	101 return std.string.format("[%f, %f]", _x, _y);
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	102 }
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	103
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	104 double x() const { return _x; }
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	105 double y() const { return _y; }
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	106
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	107 private {
100 a274d16ab6ce struct initialisers David Bryant <bagnose@gmail.com> parents: 79 diff changeset	108 double _x = 0.0, _y = 0.0;
4 58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	109 }
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	110 }
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	111
79 535bae7a7305 Checkpoint "David Bryant <bagnose@gmail.com>" parents: 78 diff changeset	112 /*
535bae7a7305 Checkpoint "David Bryant <bagnose@gmail.com>" parents: 78 diff changeset	113 Vector normal(in Vector v) {
34 c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	114 double l = v.length;
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	115
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	116 if (l < 1e-9) { // TODO consolidate numerical stability constants
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	117 writefln("Warning: normalising tiny vector. Length: %f", l);
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	118 return Vector(1.0, 0.0);
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	119 }
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	120 else {
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	121 return v / l;
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	122 }
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	123 }
79 535bae7a7305 Checkpoint "David Bryant <bagnose@gmail.com>" parents: 78 diff changeset	124 */
34 c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	125
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	126 //
33 157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	127 // A rectangle in 2D space.
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	128 // Internally represented by:
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	129 // a point defining the bottom left corner
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	130 // a vector defining the displacement to the upper right corner
34 c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	131 //
33 157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	132
4 58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	133 struct Rectangle {
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	134 /*
66 43cc2135ced0 Some code cleanups "David Bryant <bagnose@gmail.com>" parents: 62 diff changeset	135 static Rectangle from_arbitrary_corners(in Point corner1, in Point corner) {
43cc2135ced0 Some code cleanups "David Bryant <bagnose@gmail.com>" parents: 62 diff changeset	136 }
43cc2135ced0 Some code cleanups "David Bryant <bagnose@gmail.com>" parents: 62 diff changeset	137 */
4 58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	138
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	139 this(in Point position, in Vector size) {
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	140 this(position.x, position.y, size.x, size.y);
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	141 }
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	142
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	143 this(in Point corner1, in Point corner) {
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	144 this(corner1.x, corner1.y, corner.x - corner1.x, corner.y - corner1.y);
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	145 }
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	146
79 535bae7a7305 Checkpoint "David Bryant <bagnose@gmail.com>" parents: 78 diff changeset	147 double x0() const { return _position.x; }
535bae7a7305 Checkpoint "David Bryant <bagnose@gmail.com>" parents: 78 diff changeset	148 double y0() const { return _position.y; }
535bae7a7305 Checkpoint "David Bryant <bagnose@gmail.com>" parents: 78 diff changeset	149 double w() const { return _size.x; }
535bae7a7305 Checkpoint "David Bryant <bagnose@gmail.com>" parents: 78 diff changeset	150 double h() const { return _size.y; }
535bae7a7305 Checkpoint "David Bryant <bagnose@gmail.com>" parents: 78 diff changeset	151 double x1() const { return x0 + w; }
535bae7a7305 Checkpoint "David Bryant <bagnose@gmail.com>" parents: 78 diff changeset	152 double y1() const { return y0 + h; }
70 0e61702c6ea6 Checkpoint "David Bryant <bagnose@gmail.com>" parents: 67 diff changeset	153
0e61702c6ea6 Checkpoint "David Bryant <bagnose@gmail.com>" parents: 67 diff changeset	154 alias position corner0;
33 157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	155 Point position() const { return _position; }
4 58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	156
33 157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	157 Vector size() const { return _size; }
4 58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	158
70 0e61702c6ea6 Checkpoint "David Bryant <bagnose@gmail.com>" parents: 67 diff changeset	159 Point corner1() const { return _position + _size; }
4 58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	160
41 f2e4e1d29b98 Bah daveb parents: 40 diff changeset	161 bool valid() const { return _size.x > 0.0 && _size.y > 0.0; }
4 58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	162
33 157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	163 bool invalid() const { return !valid(); }
4 58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	164
33 157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	165 double area() const { return _size.x * _size.y; }
4 58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	166
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	167 // Intersection
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	168 Rectangle opAnd(in Rectangle r) const {
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	169 if (invalid() \|\| r.invalid()) {
100 a274d16ab6ce struct initialisers David Bryant <bagnose@gmail.com> parents: 79 diff changeset	170 return Rectangle();
4 58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	171 }
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	172 else {
70 0e61702c6ea6 Checkpoint "David Bryant <bagnose@gmail.com>" parents: 67 diff changeset	173 Point max = minExtents(corner1(), r.corner1());
0e61702c6ea6 Checkpoint "David Bryant <bagnose@gmail.com>" parents: 67 diff changeset	174 Point min = maxExtents(corner0(), r.corner0());
4 58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	175
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	176 if (max.x < min.x \|\| max.y < min.y) {
100 a274d16ab6ce struct initialisers David Bryant <bagnose@gmail.com> parents: 79 diff changeset	177 return Rectangle();
4 58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	178 }
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	179 else {
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	180 return Rectangle(min, max);
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	181 }
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	182 }
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	183 }
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	184
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	185 // Union
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	186 Rectangle opOr(in Rectangle r) const {
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	187 if (invalid()) {
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	188 return r;
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	189 }
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	190 else if (r.invalid()) {
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	191 return this;
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	192 }
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	193 else {
70 0e61702c6ea6 Checkpoint "David Bryant <bagnose@gmail.com>" parents: 67 diff changeset	194 return Rectangle(minExtents(corner0(), r.corner0()),
0e61702c6ea6 Checkpoint "David Bryant <bagnose@gmail.com>" parents: 67 diff changeset	195 maxExtents(corner1(), r.corner1()));
4 58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	196 }
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	197 }
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	198
33 157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	199 //
15 2f79aab4d385 Checkpoint "David Bryant <bagnose@gmail.com>" parents: 13 diff changeset	200
34 c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	201 // FIXME this method is all about pixels. Not sure it belongs in
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	202 // this file, let alone this class.
48 1b4c9ba58673 Stylistic overhaul. daveb parents: 41 diff changeset	203 void getQuantised(out int x, out int y, out int w, out int h) const {
17 c643c04e3f5e Checkpoint David Bryant <daveb@acres.com.au> parents: 16 diff changeset	204 x = cast(int)floor(_position.x);
c643c04e3f5e Checkpoint David Bryant <daveb@acres.com.au> parents: 16 diff changeset	205 y = cast(int)floor(_position.y);
c643c04e3f5e Checkpoint David Bryant <daveb@acres.com.au> parents: 16 diff changeset	206 w = cast(int)ceil(_position.x + _size.x) - x;
c643c04e3f5e Checkpoint David Bryant <daveb@acres.com.au> parents: 16 diff changeset	207 h = cast(int)ceil(_position.y + _size.y) - y;
c643c04e3f5e Checkpoint David Bryant <daveb@acres.com.au> parents: 16 diff changeset	208 }
c643c04e3f5e Checkpoint David Bryant <daveb@acres.com.au> parents: 16 diff changeset	209
c643c04e3f5e Checkpoint David Bryant <daveb@acres.com.au> parents: 16 diff changeset	210 //
c643c04e3f5e Checkpoint David Bryant <daveb@acres.com.au> parents: 16 diff changeset	211
33 157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	212 Point centre() const { return _position + _size / 2.0; }
4 58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	213
62 6c3993f4c3eb Checkpoint daveb parents: 51 diff changeset	214 string toString() {
4 58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	215 return std.string.format("{%s, %s}", _position, _size);
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	216 }
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	217
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	218 private {
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	219 this(double x, double y, double w, double h) {
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	220 if (w < 0.0) { x += w; w = -w; }
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	221 if (h < 0.0) { y += h; h = -h; }
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	222 _position = Point(x, y);
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	223 _size = Vector(w, h);
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	224 }
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	225
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	226 Point _position;
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	227 Vector _size;
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	228 }
58a8ad20b228 Ooops, this got left out of previous commit David Bryant <daveb@acres.com.au> parents: diff changeset	229 }
25 8f58a8f88735 Checkpoint "David Bryant <bagnose@gmail.com>" parents: 19 diff changeset	230
79 535bae7a7305 Checkpoint "David Bryant <bagnose@gmail.com>" parents: 78 diff changeset	231 Rectangle growCentre(in Rectangle r, in Vector amount) {
535bae7a7305 Checkpoint "David Bryant <bagnose@gmail.com>" parents: 78 diff changeset	232 return Rectangle(r.x0 - amount.x / 2, r.y0 - amount.y / 2, r.w + amount.x, r.h + amount.y);
535bae7a7305 Checkpoint "David Bryant <bagnose@gmail.com>" parents: 78 diff changeset	233 }
535bae7a7305 Checkpoint "David Bryant <bagnose@gmail.com>" parents: 78 diff changeset	234
535bae7a7305 Checkpoint "David Bryant <bagnose@gmail.com>" parents: 78 diff changeset	235 Rectangle growCentre(in Rectangle r, in double amount) {
535bae7a7305 Checkpoint "David Bryant <bagnose@gmail.com>" parents: 78 diff changeset	236 return Rectangle(r.x0 - amount / 2, r.y0 - amount / 2, r.w + amount, r.h + amount);
535bae7a7305 Checkpoint "David Bryant <bagnose@gmail.com>" parents: 78 diff changeset	237 }
535bae7a7305 Checkpoint "David Bryant <bagnose@gmail.com>" parents: 78 diff changeset	238
34 c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	239 // TODO review these functions.
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	240 // Want a clear and simple set.
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	241
79 535bae7a7305 Checkpoint "David Bryant <bagnose@gmail.com>" parents: 78 diff changeset	242 /+
34 c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	243 Rectangle move(in Rectangle r, in Vector displacement) {
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	244 return Rectangle(r.position + displacement, r.size);
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	245 }
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	246
66 43cc2135ced0 Some code cleanups "David Bryant <bagnose@gmail.com>" parents: 62 diff changeset	247 Rectangle reposition(in Rectangle r, in Point newPosition) {
43cc2135ced0 Some code cleanups "David Bryant <bagnose@gmail.com>" parents: 62 diff changeset	248 return Rectangle(newPosition, r.size);
34 c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	249 }
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	250
41 f2e4e1d29b98 Bah daveb parents: 40 diff changeset	251 Rectangle resize(in Rectangle r, in Vector new_size) {
f2e4e1d29b98 Bah daveb parents: 40 diff changeset	252 return Rectangle(r.position, new_size);
f2e4e1d29b98 Bah daveb parents: 40 diff changeset	253 }
f2e4e1d29b98 Bah daveb parents: 40 diff changeset	254
34 c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	255 // Operations about the bottom left corner
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	256
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	257 Rectangle expand(in Rectangle r, in Vector expand_amount) {
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	258 return Rectangle(r.position, r.size + expand_amount);
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	259 }
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	260
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	261 Rectangle shrink(in Rectangle r, in Vector shrink_amount) {
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	262 return Rectangle(r.position, r.size - shrink_amount);
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	263 }
79 535bae7a7305 Checkpoint "David Bryant <bagnose@gmail.com>" parents: 78 diff changeset	264 +/
34 c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	265
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	266 // Operations about the centre
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	267
79 535bae7a7305 Checkpoint "David Bryant <bagnose@gmail.com>" parents: 78 diff changeset	268 /+
78 024a5608087f Meh "David Bryant <bagnose@gmail.com>" parents: 70 diff changeset	269 Rectangle feather(in Rectangle r, double amount) { // feather isn't the right name
34 c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	270 assert(amount >= 0.0);
41 f2e4e1d29b98 Bah daveb parents: 40 diff changeset	271 assert(!isnan(amount));
34 c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	272 return Rectangle(Point(r.position.x - amount, r.position.y - amount),
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	273 Vector(r.size.x + 2.0 * amount, r.size.y + 2.0 * amount));
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	274 }
79 535bae7a7305 Checkpoint "David Bryant <bagnose@gmail.com>" parents: 78 diff changeset	275 +/
34 c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	276
33 157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	277 private {
41 f2e4e1d29b98 Bah daveb parents: 40 diff changeset	278 // This function computes the intersection of two lines.
f2e4e1d29b98 Bah daveb parents: 40 diff changeset	279 // The lines are defined by a start point and an end point, however they
f2e4e1d29b98 Bah daveb parents: 40 diff changeset	280 // notionally extend infinitely in each direction.
f2e4e1d29b98 Bah daveb parents: 40 diff changeset	281 // The out parameters specify the fraction along the line-segment at which
f2e4e1d29b98 Bah daveb parents: 40 diff changeset	282 // intersection occurred.
f2e4e1d29b98 Bah daveb parents: 40 diff changeset	283 //
f2e4e1d29b98 Bah daveb parents: 40 diff changeset	284 // This is a commmon building block for computing intersection between lines, segments,
f2e4e1d29b98 Bah daveb parents: 40 diff changeset	285 // rectangles, etc.
f2e4e1d29b98 Bah daveb parents: 40 diff changeset	286 //
f2e4e1d29b98 Bah daveb parents: 40 diff changeset	287 // The function returns false if the lines are parallel or nearly so.
f2e4e1d29b98 Bah daveb parents: 40 diff changeset	288 //
33 157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	289 // Influenced by http://ozviz.wasp.uwa.edu.au/~pbourke/geometry/lineline2d/
48 1b4c9ba58673 Stylistic overhaul. daveb parents: 41 diff changeset	290 bool computeIntersection(in Point pa1, in Point pa2, out double ua,
66 43cc2135ced0 Some code cleanups "David Bryant <bagnose@gmail.com>" parents: 62 diff changeset	291 in Point pb1, in Point pb2, out double ub) {
33 157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	292 double den = (pb2.y - pb1.y) * (pa2.x - pa1.x) - (pb2.x - pb1.x) * (pa2.y - pa1.y);
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	293
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	294 if (abs(den) < 1e-9) { // TODO consolidate constants used for numerical stability
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	295 // Lines are parallel or nearly so
41 f2e4e1d29b98 Bah daveb parents: 40 diff changeset	296 warning("Warning, parallel lines!");
33 157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	297 return false;
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	298 }
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	299 else {
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	300 // It will be safe to divide by den
66 43cc2135ced0 Some code cleanups "David Bryant <bagnose@gmail.com>" parents: 62 diff changeset	301 double numA = (pb2.x - pb1.x) * (pa1.y - pb1.y) - (pb2.y - pb1.y) * (pa1.x - pb1.x);
43cc2135ced0 Some code cleanups "David Bryant <bagnose@gmail.com>" parents: 62 diff changeset	302 double numB = (pa2.x - pa1.x) * (pa1.y - pb1.y) - (pa2.y - pa1.y) * (pa1.x - pb1.x);
33 157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	303
66 43cc2135ced0 Some code cleanups "David Bryant <bagnose@gmail.com>" parents: 62 diff changeset	304 ua = numA / den;
43cc2135ced0 Some code cleanups "David Bryant <bagnose@gmail.com>" parents: 62 diff changeset	305 ub = numB / den;
33 157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	306
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	307 return true;
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	308 }
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	309 }
41 f2e4e1d29b98 Bah daveb parents: 40 diff changeset	310
f2e4e1d29b98 Bah daveb parents: 40 diff changeset	311 /+
66 43cc2135ced0 Some code cleanups "David Bryant <bagnose@gmail.com>" parents: 62 diff changeset	312 double compute_angle(in Point p1, in Point p2) {
43cc2135ced0 Some code cleanups "David Bryant <bagnose@gmail.com>" parents: 62 diff changeset	313 }
41 f2e4e1d29b98 Bah daveb parents: 40 diff changeset	314 +/
33 157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	315 }
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	316
34 c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	317 //
33 157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	318 // A line (notionally infinitely extending in both directions) in 2D space.
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	319 // Internally represented by:
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	320 // a point at an arbitrary location along the line
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	321 // a vector defining the gradient of the line
34 c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	322 //
33 157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	323
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	324 struct Line {
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	325 this(in Point p, in Vector g) {
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	326 _point = p;
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	327 _gradient = g;
34 c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	328 // FIXME should we normalise (make unit length) the gradient?
33 157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	329 assert(_gradient.length > 1e-6); // FIXME how to best deal with this
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	330 }
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	331
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	332 this(in Point a, in Point b) {
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	333 _point = a;
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	334 _gradient = b - a;
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	335 assert(_gradient.length > 1e-6); // FIXME as above
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	336 }
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	337
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	338 Point point() const { return _point; }
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	339 Vector gradient() const { return _gradient; }
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	340
62 6c3993f4c3eb Checkpoint daveb parents: 51 diff changeset	341 string toString() {
34 c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	342 return std.string.format("{%s %s}", _point, _gradient);
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	343 }
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	344
33 157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	345 private {
51 0eaf39fda206 First cut at palette class daveb parents: 48 diff changeset	346 Point _point; // Arbitrary point along line
33 157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	347 Vector _gradient;
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	348 }
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	349 }
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	350
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	351 // Calculate the point "p" where lines "a" and "b" intersect.
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	352 // Returns false if lines are parallel or too close for numerical stability
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	353 bool intersection(in Line a, in Line b, out Point p) {
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	354 Point pa = a.point;
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	355 Vector va = a.gradient;
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	356 double ua;
34 c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	357
33 157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	358 Point pb = b.point;
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	359 Vector vb = b.gradient;
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	360 double ub;
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	361
48 1b4c9ba58673 Stylistic overhaul. daveb parents: 41 diff changeset	362 if (computeIntersection(pa, pa + va, ua, pb, pb + vb, ub)) {
33 157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	363 // We could just have easily evaluated for line b...
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	364 p = pa + ua * va;
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	365 // p = pb + ub * vb;
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	366 return true;
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	367 }
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	368 else {
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	369 return false;
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	370 }
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	371 }
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	372
34 c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	373 //
33 157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	374 // A line segment (has a beginning and an end) in 2D space.
34 c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	375 //
33 157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	376
25 8f58a8f88735 Checkpoint "David Bryant <bagnose@gmail.com>" parents: 19 diff changeset	377 struct Segment {
33 157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	378 this(in Point a, in Point b) {
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	379 _begin = a;
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	380 _end = b;
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	381 }
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	382
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	383 Point begin() const { return _begin; }
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	384 Point end() const { return _end; }
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	385
62 6c3993f4c3eb Checkpoint daveb parents: 51 diff changeset	386 string toString() {
34 c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	387 return std.string.format("{%s %s}", _begin, _end);
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	388 }
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	389
25 8f58a8f88735 Checkpoint "David Bryant <bagnose@gmail.com>" parents: 19 diff changeset	390 private {
8f58a8f88735 Checkpoint "David Bryant <bagnose@gmail.com>" parents: 19 diff changeset	391 Point _begin, _end;
8f58a8f88735 Checkpoint "David Bryant <bagnose@gmail.com>" parents: 19 diff changeset	392 }
8f58a8f88735 Checkpoint "David Bryant <bagnose@gmail.com>" parents: 19 diff changeset	393 }
8f58a8f88735 Checkpoint "David Bryant <bagnose@gmail.com>" parents: 19 diff changeset	394
79 535bae7a7305 Checkpoint "David Bryant <bagnose@gmail.com>" parents: 78 diff changeset	395 /*
34 c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	396 Segment reverse(in Segment s) {
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	397 return Segment(s.end, s.begin);
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	398 }
79 535bae7a7305 Checkpoint "David Bryant <bagnose@gmail.com>" parents: 78 diff changeset	399 */
34 c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	400
33 157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	401 bool intersection(in Segment a, in Segment b, out Point p) {
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	402 Point pa1 = a.begin;
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	403 Point pa2 = a.end;
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	404 double ua;
34 c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	405
33 157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	406 Point pb1 = b.begin;
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	407 Point pb2 = b.end;
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	408 double ub;
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	409
48 1b4c9ba58673 Stylistic overhaul. daveb parents: 41 diff changeset	410 if (computeIntersection(pa1, pa2, ua, pb1, pb2, ub)) {
33 157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	411 if (ua >= 0.0 && ua <= 1.0 && // inside of segment a
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	412 ub >= 0.0 && ub <= 1.0) { // inside of segment b
67 31d10176415d Checkpoint daveb parents: 66 diff changeset	413 // We could just as easily evaluated for line b...
33 157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	414 p = pa1 + ua * (pa2 - pa1);
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	415 // p = pa2 + ub * (pb2 - pb1);
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	416 return true;
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	417 }
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	418 else {
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	419 return false;
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	420 }
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	421 }
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	422 else {
157b4ad5615d Added intersection code for lines and segments. David Bryant <bagnose@gmail.com> parents: 28 diff changeset	423 return false;
25 8f58a8f88735 Checkpoint "David Bryant <bagnose@gmail.com>" parents: 19 diff changeset	424 }
8f58a8f88735 Checkpoint "David Bryant <bagnose@gmail.com>" parents: 19 diff changeset	425 }
34 c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	426
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	427 bool intersection(in Segment a, in Line b, out Point p) {
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	428 Point pa1 = a.begin;
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	429 Point pa2 = a.end;
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	430 double ua;
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	431
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	432 Point pb = b.point;
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	433 Vector vb = b.gradient;
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	434 double ub;
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	435
48 1b4c9ba58673 Stylistic overhaul. daveb parents: 41 diff changeset	436 if (computeIntersection(pa1, pa2, ua, pb, pb + vb, ub)) {
34 c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	437 if (ua >= 0.0 && ua <= 1.0) { // inside of segment
67 31d10176415d Checkpoint daveb parents: 66 diff changeset	438 // We could just as easily evaluated for line b...
34 c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	439 p = pa1 + ua * (pa2 - pa1);
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	440 // p = pb + ub * vb;
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	441 return true;
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	442 }
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	443 else {
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	444 return false;
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	445 }
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	446 }
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	447 else {
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	448 return false;
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	449 }
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	450 }
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	451
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	452 bool intersection(in Line a, in Segment b, out Point p) {
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	453 // Equivalent to intersection of segment and line. Just reverse the args.
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	454 return intersection(b, a, p);
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	455 }
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	456
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	457 /+
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	458 bool intersection(in Line l, in Rectangle r, out Point p1, out Point p2) {
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	459 // TODO
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	460 return false;
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	461 }
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	462
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	463 bool intersection(in Segment s, in Rectangle r, out Point p1, out Point p2) {
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	464 // TODO
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	465 return false;
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	466 }
c2f11e1d7470 Geometry cleanup and checkpoint. David Bryant <bagnose@gmail.com> parents: 33 diff changeset	467 +/

Mercurial > projects > doodle

annotate doodle/tk/geometry.d @ 100:a274d16ab6ce