matrix.java

j2me 上面flash播放器。非常值得研究。就是版本只到2.0

package org.jflashme;

/*  This library is free software; you can redistribute it and/or modify it
 *  under the terms of the GNU Lesser General Public License, version 2, as
 *  published by the Free Software Foundation.
 *
 *  This library is distributed in the hope that it will be useful, but
 *  WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Lesser General Public License (the accompanying file named LGPL.txt)
 *  for more details.
 */



class Matrix {
  int a = 0, b = 0, c = 0, d = 0, tx = 0, ty = 0;
  static final int one = 0x10000;
  static final int sqrt2 = 0x16a0a;
  private static final int lengthTable[] = {
      0x40000000, 0x4001fff8, 0x4007ff80, 0x4011fd79, 0x401ff804, 0x4031ec87,
      0x4047d7ad, 0x4061b56a, 0x407f80fe, 0x40a134f9,
      0x40c6cb42, 0x40f03d1b, 0x411d8325, 0x414e956c, 0x41836b64, 0x41bbfbfc,
      0x41f83d9b, 0x4238262d, 0x427bab2b, 0x42c2c19f,
      0x430d5e30, 0x435b7529, 0x43acfa7f, 0x4401e1db, 0x445a1ea3, 0x44b5a3fe,
      0x451464df, 0x4576540c, 0x45db6424, 0x464387a8,
      0x46aeb0fe, 0x471cd27d, 0x478dde6e, 0x4801c717, 0x48787ebb, 0x48f1f7a3,
      0x496e2425, 0x49ecf6a2, 0x4a6e6191, 0x4af25781,
      0x4b78cb1a, 0x4c01af24, 0x4c8cf689, 0x4d1a9459, 0x4daa7bca, 0x4e3ca03c,
      0x4ed0f53c, 0x4f676e85, 0x50000000, 0x509a9dc9,
      0x51373c2e, 0x51d5cfaf, 0x52764d01, 0x5318a90f, 0x53bcd8f8, 0x5462d210,
      0x550a89e3, 0x55b3f633, 0x565f0cf6, 0x570bc45b,
      0x57ba12c3, 0x5869eec9, 0x591b4f3a, 0x59ce2b18, 0x5a82799a, 0x5a82799a
  };

  Matrix() {
    a = 0x10000;
    d = 0x10000;
  }

  Matrix(Matrix matrix) {
    a = 0x10000;
    d = 0x10000;
    a = matrix.a;
    b = matrix.b;
    c = matrix.c;
    d = matrix.d;
    tx = matrix.tx;
    ty = matrix.ty;
  }

  final void transform(Point point, Point point1) {
    int k = a;
    int i1 = point.x;
    int i = (int) ( (long) k * (long) i1 + 32768L >> 16) + tx;
    if (c != 0) {
      k = c;
      i1 = point.y;
      i += (int) ( (long) k * (long) i1 + 32768L >> 16);
    }
    k = d;
    i1 = point.y;
    int j = (int) ( (long) k * (long) i1 + 32768L >> 16) + ty;
    if (b != 0) {
      int l = b;
      int j1 = point.x;
      j += (int) ( (long) l * (long) j1 + 32768L >> 16);
    }
    point1.x = i;
    point1.y = j;
  }

  final void transform(Point point) {
    int i = a;
    int j = point.x;
    i = (int) ( (long) i * (long) j + 32768L >> 16) + tx;
    if (c != 0) {
      j = c;
      int k = point.y;
      i += (int) ( (long) j * (long) k + 32768L >> 16);
    }
    j = d;
    int l = point.y;
    j = (int) ( (long) j * (long) l + 32768L >> 16) + ty;
    if (b != 0) {
      int i1 = b;
      int j1 = point.x;
      j += (int) ( (long) i1 * (long) j1 + 32768L >> 16);
    }
    point.x = i;
    point.y = j;
  }

  final void scale(int i, int j) {
    a = i;
    d = j;
    b = c = 0;
    tx = ty = 0;
  }

  final void deltaTransform(Point point) {
    int i = a;
    int j = point.x;
    i = (int) ( (long) i * (long) j + 32768L >> 16);
    if (c != 0) {
      j = c;
      int k = point.y;
      i += (int) ( (long) j * (long) k + 32768L >> 16);
    }
    j = d;
    int l = point.y;
    j = (int) ( (long) j * (long) l + 32768L >> 16);
    if (b != 0) {
      int i1 = b;
      int j1 = point.x;
      j += (int) ( (long) i1 * (long) j1 + 32768L >> 16);
    }
    point.x = i;
    point.y = j;
  }

  final Rect transform(Rect rect) {
    Rect rect1 = new Rect();
    if (rect.xmin != 0x80000000) {
      Point point = new Point(rect.xmin, rect.ymin);
      Point point1 = new Point(0, 0);
      transform(point, point1);
      rect1.union(point1);
      point.x = rect.xmax;
      transform(point, point1);
      rect1.union(point1);
      point.y = rect.ymax;
      transform(point, point1);
      rect1.union(point1);
      point.x = rect.xmin;
      transform(point, point1);
      rect1.union(point1);
    }
    return rect1;
  }

  int transform(int i) {
    Point point = new Point(i, i);
    deltaTransform(point);
    int j = length(point.x, point.y);
    j = (int) (46341L * j + 32768L >> 16);
    if (i > 0)
      j = Math.max(1, j);
    return j;
  }

  final Matrix invert() {
    Matrix matrix = new Matrix();
    if (b == 0 && c == 0) {
      int i;
      matrix.a = (int) (0x100000000L / (i = a));
      matrix.d = (int) (0x100000000L / (i = d));
      i = matrix.a;
      matrix.tx = - (int) ( (long) i * tx + 32768L >> 16);
      i = matrix.d;
      matrix.ty = - (int) ( (long) i * ty + 32768L >> 16);
    }
    else {
      long l1 = a << 16;
      long l2 = b << 16;
      long l3 = c << 16;
      long l4 = d << 16;
      long l5 = l1 * l4 - l2 * l3;

      if (l5 != 0) {
        l5 = 1 / l5; // todo: replace this statement
        matrix.a = ( (int) (l4 * l5 * 65536) >> 16);
        matrix.b = - ( (int) (l2 * l5 * 65536) >> 16);
        matrix.c = - ( (int) (l3 * l5 * 65536) >> 16);
        matrix.d = ( (int) (l1 * l5 * 65536) >> 16);
        Point point = new Point(tx, ty);
        matrix.deltaTransform(point);
        matrix.tx = -point.x;
        matrix.ty = -point.y;
      }
    }
    return matrix;
  }

  static final Matrix concat(Matrix matrix, Matrix matrix1) {
    Matrix matrix2 = new Matrix();
    int i = matrix.a;
    matrix2.a = (int) ( (long) i * matrix1.a + 32768L >> 16);
    i = matrix.d;
    matrix2.d = (int) ( (long) i * matrix1.d + 32768L >> 16);
    i = matrix.tx;
    matrix2.tx = (int) (i * matrix1.a + 32768L >> 16) + matrix1.tx;
    i = matrix.ty;
    matrix2.ty = (int) (i * matrix1.d + 32768L >> 16) + matrix1.ty;
    if (matrix.b != 0 || matrix.c != 0 || matrix1.b != 0 || matrix1.c != 0) {
      int j = matrix.b;
      int l = matrix1.c;
      matrix2.a += (int) ( (long) j * (long) l + 32768L >> 16);
      j = matrix.c;
      l = matrix1.b;
      matrix2.d += (int) ( (long) j * (long) l + 32768L >> 16);
      j = matrix.a;
      l = matrix1.b;
      matrix2.b += (int) ( (long) j * (long) l + 32768L >> 16) +
          (int) ( (long) (j = matrix.b) * (long) (l = matrix1.d) + 32768L >> 16);
      j = matrix.c;
      l = matrix1.a;
      matrix2.c += (int) ( (long) j * (long) l + 32768L >> 16) +
          (int) ( (long) (j = matrix.d) * (long) (l = matrix1.c) + 32768L >> 16);
      j = matrix.ty;
      l = matrix1.c;
      matrix2.tx += (int) ( (long) j * (long) l + 32768L >> 16);
      j = matrix.tx;
      l = matrix1.b;
      matrix2.ty += (int) ( (long) j * (long) l + 32768L >> 16);
    }
    return matrix2;
  }

  static final int mul(int i, int j) {
    return (int) ( (long) i * (long) j + 32768L >> 16);
  }

  static final int div(int i, int j) {
    return (int) ( ( (long) i << 16) / j);
  }

  static final int abs(int i) {
    if (i > 0)
      return i;
    else
      return -i;
  }

  static final int fastLength(int i, int j) {
    int k = i <= 0 ? -i : i;
    int l = j <= 0 ? -j : j;
    return (k + l) - (Math.min(k, l) >> 1);
  }

  static final int length(int i, int j) {
    int k = i <= 0 ? -i : i;
    int l = j <= 0 ? -j : j;
    if (k > l) {
      int i1 = k;
      k = l;
      l = i1;
    }
    if (l == 0) {
      return 0;
    }
    else {
      int j1 = (int) ( ( (long) k << 16) / l);
      int k1 = j1 >> 10;
      int l1 = (j1 & 0x3ff) << 6;
      int i2 = 0x10000 - l1;
      int j2 = lengthTable[k1];
      i2 = (int) ( (long) i2 * (long) j2 + 32768L >> 16) +
          (int) ( (long) l1 * (long) (i2 = lengthTable[k1 + 1]) + 32768L >> 16);
      i2 >>= 14;
      return (int) ( (long) l * (long) i2 + 32768L >> 16);
    }
  }

}