Android Open Source - android-plotter Graph

• Back to Graphics/graph  ↑

From Project

Back to project page android-plotter.

License

The source code is released under:

Apache License

Java Source Code

package org.solovyev.android.plotter.meshes;
//from  www .j  a  v  a2  s  .com
import javax.annotation.Nonnull;

class Graph {

  float accuracy = 1f;

  int start = 0;
  int end = 0;

  int capacity = 4 * 3;

  @Nonnull
  float[] vertices = new float[capacity];

  @Nonnull
  private short[] indices = new short[capacity / 3];

  private Graph() {
  }

  @Nonnull
  static Graph create() {
    return new Graph();
  }

  void prepend(float x, float y) {
    ensureCanPrepend();

    vertices[--start] = 0;
    vertices[--start] = y;
    vertices[--start] = x;
  }

  private void ensureCanPrepend() {
    if (start < 3) {
      makeSpaceAtTheStart();
    }
  }

  void append(float x, float y) {
    ensureCanAppend();

    vertices[end++] = x;
    vertices[end++] = y;
    vertices[end++] = 0;
  }

  private void ensureCanAppend() {
    if (end + 3 > capacity) {
      makeSpaceAtTheEnd();
    }
  }

  void makeSpaceAtTheEnd() {
    if (start > capacity / 2) {
      final int length = length();
      System.arraycopy(vertices, start, vertices, 0, length);
      start = 0;
      end = length;
      return;
    }

    final int newCapacity = 5 * capacity / 4;
    final float[] newVertices = new float[newCapacity];
    System.arraycopy(vertices, start, newVertices, start, length());
    vertices = newVertices;
    capacity = newCapacity;
  }

  private void makeSpaceAtTheStart() {
    if (end != 0 && end < capacity / 2) {
      final int newStart = start + capacity - end;
      final int length = length();
      System.arraycopy(vertices, start, vertices, newStart, length);
      start = newStart;
      end = newStart + length;
      return;
    }

    final int newCapacity = 5 * capacity / 4;
    final float[] newVertices = new float[newCapacity];
    final int offset = newCapacity - capacity;
    System.arraycopy(vertices, start, newVertices, start + offset, length());
    start += offset;
    end += offset;
    vertices = newVertices;
    capacity = newCapacity;
  }


  int length() {
    return end - start;
  }

  boolean isEmpty() {
    return start == end;
  }

  void clear() {
    start = 0;
    end = 0;
  }

  public float x(int position) {
    return vertices[position];
  }

  public void moveStartTo(float x) {
    while (start < end && vertices[start] < x) {
      start += 3;
    }

    if (start > end) {
      start = end;
    }
  }

  public void moveEndTo(float x) {
    while (start < end && vertices[end - 3] > x) {
      end -= 3;
    }

    if (start > end) {
      end = start;
    }
  }

  public float xMin() {
    return vertices[start];
  }

  public float xMax() {
    return vertices[end - 3];
  }

  short[] getIndices() {
    final int indicesCount = getIndicesCount();
    if (indices.length < indicesCount) {
      indices = new short[indicesCount];
    }
    for (short i = 0; i < indicesCount; i++) {
      indices[i] = i;
    }
    return indices;
  }

  int getIndicesCount() {
    return length() / 3;
  }
}

Java Source Code List

• Back to Graphics/graph  ↑