2 // Copyright 2004 Adam Megacz, see the COPYING file for licensing [GPL]
3 package org.ibex.graphics;
6 /** an affine transform; all operations are destructive */
7 public final class Affine {
12 public float a, b, c, d, e, f;
14 Affine(float _a, float _b, float _c, float _d, float _e, float _f) { a = _a; b = _b; c = _c; d = _d; e = _e; f = _f; }
15 public String toString() { return "[ " + a + ", " + b + ", " + c + ", " + d + ", " + e + ", " + f + " ]"; }
16 public Affine copy() { return new Affine(a, b, c, d, e, f); }
17 public static Affine identity() { return new Affine(1, 0, 0, 1, 0, 0); }
18 public static Affine scale(float sx, float sy) { return new Affine(sx, 0, 0, sy, 0, 0); }
19 public static Affine shear(float degrees) {
20 return new Affine(1, 0, (float)Math.tan(degrees * (float)(Math.PI / 180.0)), 1, 0, 0); }
21 public static Affine translate(float tx, float ty) { return new Affine(1, 0, 0, 1, tx, ty); }
22 public static Affine flip(boolean horiz, boolean vert) { return new Affine(horiz ? -1 : 1, 0, 0, vert ? -1 : 1, 0, 0); }
23 public float multiply_px(float x, float y) { return x * a + y * c + e; }
24 public float multiply_py(float x, float y) { return x * b + y * d + f; }
25 public boolean equalsIgnoringTranslation(Affine x) { return a == x.a && b == x.b && c == x.c && d == x.d; }
27 public boolean equals(Object o) {
28 if (!(o instanceof Affine)) return false;
30 return a == x.a && b == x.b && c == x.c && d == x.d && e == x.e && f == x.f;
33 public static Affine rotate(float degrees) {
34 float s = (float)Math.sin(degrees * (float)(Math.PI / 180.0));
35 float c = (float)Math.cos(degrees * (float)(Math.PI / 180.0));
36 return new Affine(c, s, -s, c, 0, 0);
39 /** this = this * a */
40 public Affine multiply(Affine A) {
41 float _a = this.a * A.a + this.b * A.c;
42 float _b = this.a * A.b + this.b * A.d;
43 float _c = this.c * A.a + this.d * A.c;
44 float _d = this.c * A.b + this.d * A.d;
45 float _e = this.e * A.a + this.f * A.c + A.e;
46 float _f = this.e * A.b + this.f * A.d + A.f;
47 a = _a; b = _b; c = _c; d = _d; e = _e; f = _f;
51 /** this = a * this */
52 public Affine premultiply(Affine A) {
53 float _a = A.a * this.a + A.b * this.c;
54 float _b = A.a * this.b + A.b * this.d;
55 float _c = A.c * this.a + A.d * this.c;
56 float _d = A.c * this.b + A.d * this.d;
57 float _e = A.e * this.a + A.f * this.c + this.e;
58 float _f = A.e * this.b + A.f * this.d + this.f;
59 a = _a; b = _b; c = _c; d = _d; e = _e; f = _f;
63 public void invert() {
64 float det = 1 / (a * d - b * c);
66 float _b = -1 * b * det;
67 float _c = -1 * c * det;
69 float _e = -1 * e * a - f * c;
70 float _f = -1 * e * b - f * d;
71 a = _a; b = _b; c = _c; d = _d; e = _e; f = _f;
74 public static Affine parse(String t) {
75 if (t == null) return null;
77 Affine ret = Affine.identity();
78 while (t.length() > 0) {
79 if (t.startsWith("skewX(")) {
82 } else if (t.startsWith("shear(")) {
83 // FIXME: nonstandard; remove this
84 ret.multiply(Affine.shear(Float.parseFloat(t.substring(t.indexOf('(') + 1, t.indexOf(')')))));
86 } else if (t.startsWith("skewY(")) {
89 } else if (t.startsWith("rotate(")) {
90 String sub = t.substring(t.indexOf('(') + 1, t.indexOf(')'));
91 if (sub.indexOf(',') != -1) {
92 float angle = Float.parseFloat(sub.substring(0, sub.indexOf(',')));
93 sub = sub.substring(sub.indexOf(',') + 1);
94 float cx = Float.parseFloat(sub.substring(0, sub.indexOf(',')));
95 sub = sub.substring(sub.indexOf(',') + 1);
96 float cy = Float.parseFloat(sub);
97 ret.multiply(Affine.translate(cx, cy));
98 ret.multiply(Affine.rotate(angle));
99 ret.multiply(Affine.translate(-1 * cx, -1 * cy));
101 ret.multiply(Affine.rotate(Float.parseFloat(t.substring(t.indexOf('(') + 1, t.indexOf(')')))));
104 } else if (t.startsWith("translate(")) {
105 String sub = t.substring(t.indexOf('(') + 1, t.indexOf(')'));
106 if (sub.indexOf(',') > -1) {
107 ret.multiply(Affine.translate(Float.parseFloat(t.substring(t.indexOf('(') + 1, t.indexOf(','))),
108 Float.parseFloat(t.substring(t.indexOf(',') + 1, t.indexOf(')')))));
110 ret.multiply(Affine.translate(Float.parseFloat(t.substring(t.indexOf('(') + 1, t.indexOf(','))), 0));
113 } else if (t.startsWith("flip(")) {
114 String which = t.substring(t.indexOf('(') + 1, t.indexOf(')'));
115 ret.multiply(Affine.flip(which.equals("horizontal"), which.equals("vertical")));
117 } else if (t.startsWith("scale(")) {
118 String sub = t.substring(t.indexOf('(') + 1, t.indexOf(')'));
119 if (sub.indexOf(',') > -1) {
120 ret.multiply(Affine.scale(Float.parseFloat(t.substring(t.indexOf('(') + 1, t.indexOf(','))),
121 Float.parseFloat(t.substring(t.indexOf(',') + 1, t.indexOf(')')))));
123 ret.multiply(Affine.scale(Float.parseFloat(t.substring(t.indexOf('(') + 1, t.indexOf(','))),
124 Float.parseFloat(t.substring(t.indexOf('(') + 1, t.indexOf(',')))));
127 } else if (t.startsWith("matrix(")) {
128 // FIXME: is this mapped right?
129 float d[] = new float[6];
130 StringTokenizer st = new StringTokenizer(t, ",", false);
131 for(int i=0; i<6; i++)
132 d[i] = Float.parseFloat(st.nextToken());
133 ret.multiply(new Affine(d[0], d[1], d[2], d[3], d[4], d[5]));
135 t = t.substring(t.indexOf(')') + 1).trim();