Android Open Source - gles2_sample_android Vec3f

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License

The source code is released under:

Apache License

Java Source Code

package nz.gen.geek_central.GLUseful;
/*/*w  w w.  j  av a2 s .  c  om*/
    functional 3D vector operations

    Copyright 2011, 2013 by Lawrence D'Oliveiro <ldo@geek-central.gen.nz>.

    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.
*/

public class Vec3f
  /* 3D vectors */
  {
    public final float x, y, z, w;

    public Vec3f
      (
        float x,
        float y,
        float z
      )
      {
        this.x = x;
        this.y = y;
        this.z = z;
        this.w = 1.0f;
      } /*Vec3f*/

    public Vec3f
      (
        float x,
        float y,
        float z,
        float w
      )
      {
        this.x = x;
        this.y = y;
        this.z = z;
        this.w = w;
      } /*Vec3f*/

    public Vec3f
      (
        float[] v
      )
      {
        if (v.length != 3 && v.length != 4)
          {
            throw new RuntimeException("need 3 or 4 floats to make a vector");
          } /*if*/
        x = v[0];
        y = v[1];
        z = v[2];
        w = v.length == 4 ? v[3] : 1.0f;
      } /*Vec3f*/

    public float[] to_floats
      (
        int nrelts /* 3 or 4 */
      )
      {
        float[] v;
        switch (nrelts)
          {
        case 3:
            v = new float[] {x, y, z};
        break;
        case 4:
            v = new float[] {x, y, z, w};
        break;
        default:
            throw new RuntimeException("vector can only convert to 3 or 4 floats");
      /* break; */
          } /*switch*/
        return
            v;
      } /*to_floats*/

    public static float to_radians
      (
        float angle,
        boolean from_degrees /* angle is in degrees */
      )
      /* returns angle in radians. */
      {
        return
            from_degrees ?
                (float)Math.toRadians(angle)
            :
                angle;
      } /*to_radians*/

    public static float from_radians
      (
        float angle, /* always radians */
        boolean want_degrees /* result is in degrees */
      )
      /* returns angle in radians or degrees, depending on want_degrees. */
      {
        return
            want_degrees ?
                (float)Math.toDegrees(angle)
            :
                angle;
      } /*from_radians*/

    public static Vec3f zero()
      {
        return
            new Vec3f(0.0f, 0.0f, 0.0f);
      } /*zero*/

    public Vec3f neg()
      /* returns the same-magnitude vector in the opposite direction. */
      {
        return
            new Vec3f(-x, -y, -z, w);
      } /*neg*/

    public Vec3f add
      (
        Vec3f v
      )
      {
        return
            new Vec3f(x + v.x, y + v.y, z + v.z);
      } /*add*/

    public Vec3f sub
      (
        Vec3f v
      )
      {
        return
            new Vec3f(x - v.x, y - v.y, z - v.z);
      } /*sub*/

    public Vec3f mul
      (
        float s
      )
      {
        return
            new Vec3f(x * s, y * s, z * s, w);
      } /*mul*/

    public Vec3f mul
      (
        Vec3f v
      )
      /* multiplication of corresponding components. */
      {
        return
            new Vec3f(x * v.x, y * v.y, z * v.z);
      } /*mul*/

    public Vec3f div
      (
        float s
      )
      {
        return
            new Vec3f(x / s, y / s, z / s, w);
      } /*div*/

    public Vec3f div
      (
        Vec3f v
      )
      /* division of corresponding components. */
      {
        return
            new Vec3f(x / v.x, y / v.y, z / v.z);
      } /*div*/

    public Vec3f recip()
      {
        return
            new Vec3f(1.0f / x, 1.0f / y, 1.0f / z);
      } /*recip*/

    public float dot
      (
        Vec3f v
      )
      /* dot product. */
      {
        return
            v.x * this.x + v.y * this.y + v.z * this.z;
      } /*dot*/

    public Vec3f cross
      (
        Vec3f v
      )
      /* cross product. */
      {
        return
            new Vec3f
              (
                this.y * v.z - v.y * this.z,
                this.z * v.x - v.z * this.x,
                this.x * v.y - v.x * this.y
              );
      } /*cross*/

    public float azimuth
      (
        boolean want_degrees
      )
        /* returns the angle between the x-axis and the line from the origin to the point. */
      {
        return
            from_radians((float)Math.atan2(y, x), want_degrees);
      } /*azimuth*/

    public float elevation
      (
        boolean want_degrees
      )
        /* returns the angle between the x-y plane and the line from the origin to the point. */
      {
        return
            from_radians((float)Math.atan2(z, Math.hypot(x, y)), want_degrees);
      } /*elevation*/

    public float abs()
        /* returns the distance between the point and the origin. */
      {
        return
            (float)Math.sqrt((x * x + y * y + z * z) / (w * w));
      } /*abs*/

    public Vec3f unit()
      /* returns the unit vector in the same direction. */
      {
        final float abs = this.abs();
        return
            new Vec3f(x / abs, y / abs, z / abs);
      } /*unit*/

    public Vec3f norm()
      /* rescales so w = 1. */
      {
        return
            new Vec3f(x / w, y / w, z / w);
      } /*norm*/

    @Override
    public String toString()
      {
        return
            String.format("Vec3f(%.3f, %.3f, %.3f, %.3f)", x, y, z, w); /* should I worry about locale? */
      } /*toString*/

  } /*Vec3f*/

Java Source Code List

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