X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;ds=sidebyside;f=src%2Forg%2Fibex%2Fgraphics%2FAffine.java;h=df9208bf1d6347d907b36efa728b09f5b519d12a;hb=f034e224e9cd306b6114a989b52d11393ce5c479;hp=1b47071259d934414d301b914a0b5fe4ef97e1b1;hpb=c8598d51fe71ce77d466c02b6fa264617be9335b;p=org.ibex.core.git

diff --git a/src/org/ibex/graphics/Affine.java b/src/org/ibex/graphics/Affine.java
index 1b47071..df9208b 100644
--- a/src/org/ibex/graphics/Affine.java
+++ b/src/org/ibex/graphics/Affine.java
@@ -1,19 +1,23 @@
+// Copyright 2000-2005 the Contributors, as shown in the revision logs.
+// Licensed under the GNU General Public License version 2 ("the License").
+// You may not use this file except in compliance with the License.
+
 // FIXME
-// Copyright 2004 Adam Megacz, see the COPYING file for licensing [GPL]
 package org.ibex.graphics;
 import java.util.*;
 
 /** an affine transform; all operations are destructive */
 public final class Affine {
 
-    //  [ a b e ]
-    //  [ c d f ]
+    //  [ a c e ]
+    //  [ b d f ]
     //  [ 0 0 1 ]
     public float a, b, c, d, e, f;
 
     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; }
     public String toString() { return "[ " + a + ", " + b + ", " + c + ", " + d + ", " + e + ", " + f + " ]"; }
     public Affine copy() { return new Affine(a, b, c, d, e, f); }
+    public boolean doesNotRotate() { return a==0 && b==0 && c==0 && d==0; }
     public static Affine identity() { return new Affine(1, 0, 0, 1, 0, 0); }
     public static Affine scale(float sx, float sy) { return new Affine(sx, 0, 0, sy, 0, 0); }
     public static Affine shear(float degrees) {
@@ -22,7 +26,19 @@ public final class Affine {
     public static Affine flip(boolean horiz, boolean vert) { return new Affine(horiz ? -1 : 1, 0, 0, vert ? -1 : 1, 0, 0); }
     public float multiply_px(float x, float y) { return x * a + y * c + e; }
     public float multiply_py(float x, float y) { return x * b + y * d + f; }
+    public float sign(float x) { return x >= 0 ? 1 : -1; }
+    public float divide_boundingbox_x(float bx, float by, float aspect) {
+        return (float)Math.min(Math.abs(bx * (sign(a) * sign(c)) / (aspect * a + c)),
+                               Math.abs(by * (sign(b) * sign(d)) / (aspect * b + d)));
+    }
+    public float multiply_boundingbox_x(float x, float y) {
+        return (float)Math.max((int)Math.abs(multiply_px(x, y) - multiply_px(0, 0)),
+                               (int)Math.abs(multiply_px(x, 0) - multiply_px(0, y))); }
+    public float multiply_boundingbox_y(float x, float y) {
+        return (float)Math.max((int)Math.abs(multiply_py(x, y) - multiply_py(0, 0)),
+                               (int)Math.abs(multiply_py(x, 0) - multiply_py(0, y))); }
     public boolean equalsIgnoringTranslation(Affine x) { return a == x.a && b == x.b && c == x.c && d == x.d; }
+    public Affine clearTranslation() { e = (float)0.0; f = (float)0.0; return this; }
 
     public boolean equals(Object o) {
         if (!(o instanceof Affine)) return false;
@@ -36,8 +52,8 @@ public final class Affine {
         return new Affine(c, s, -s, c, 0, 0);
     }
 
-    /** this = this * a */
-    public Affine multiply(Affine A) {
+    /** this = a * this */
+    public Affine premultiply(Affine A) {
         float _a = this.a * A.a + this.b * A.c;
         float _b = this.a * A.b + this.b * A.d;
         float _c = this.c * A.a + this.d * A.c;
@@ -48,8 +64,8 @@ public final class Affine {
         return this;
     }
 
-    /** this = a * this */
-    public Affine premultiply(Affine A) {
+    /** this = this * a */
+    public Affine multiply(Affine A) {
         float _a = A.a * this.a + A.b * this.c;
         float _b = A.a * this.b + A.b * this.d;
         float _c = A.c * this.a + A.d * this.c;
@@ -60,15 +76,16 @@ public final class Affine {
         return this;
     }
 
-    public void invert() {
-        float det = 1 / (a * d - b * c);
-        float _a = d * det;
-        float _b = -1 * b * det;
-        float _c = -1 * c * det;
-        float _d = a * det;
-        float _e = -1 * e * a - f * c;
-        float _f = -1 * e * b - f * d;
+    public Affine invert() {
+        float det = (a * d - b * c);
+        float _a = d / det;
+        float _b = -1 * b / det;
+        float _c = -1 * c / det;
+        float _d = a / det;
+        float _e = (f*c-e*d)/det;
+        float _f = (b*e-a*f)/det;
         a = _a; b = _b; c = _c; d = _d; e = _e; f = _f;
+        return this;
     }
 
     public static Affine parse(String t) {