implementing new gl resource disposal method based on WeakReferences

core/src/processing/opengl/VertexBuffer.java

@@ -0,0 +1,63 @@
+package processing.opengl;
+
+import processing.opengl.PGraphicsOpenGL.GLResourceVertexBuffer;
+
+public class VertexBuffer {
+  static protected final int INIT_VERTEX_BUFFER_SIZE  = 256;
+  static protected final int INIT_INDEX_BUFFER_SIZE   = 512;
+
+  public int glId;
+  int target;
+  int elementSize;
+  int ncoords;
+  boolean index;
+
+  protected PGL pgl;                // The interface between Processing and OpenGL.
+  protected int context;            // The context that created this texture.
+  private GLResourceVertexBuffer glres;
+
+  VertexBuffer(PGraphicsOpenGL pg, int target, int ncoords, int esize) {
+    this(pg, target, ncoords, esize, false);
+  }
+
+  VertexBuffer(PGraphicsOpenGL pg, int target, int ncoords, int esize, boolean index) {
+    pgl = pg.pgl;
+    context = pgl.createEmptyContext();
+
+    this.target = target;
+    this.ncoords = ncoords;
+    this.elementSize = esize;
+    this.index = index;
+    create();
+    init();
+  }
+
+  protected void create() {
+    context = pgl.getCurrentContext();
+    glres = new GLResourceVertexBuffer(this);
+  }
+
+  protected void init() {
+    int size = index ? ncoords * INIT_INDEX_BUFFER_SIZE * elementSize :
+                       ncoords * INIT_VERTEX_BUFFER_SIZE * elementSize;
+    pgl.bindBuffer(target, glId);
+    pgl.bufferData(target, size, null, PGL.STATIC_DRAW);
+  }
+
+  protected void dispose() {
+    if (glres != null) {
+      glres.dispose();
+      glId = 0;
+      glres = null;
+    }
+  }
+
+  protected boolean contextIsOutdated() {
+    boolean outdated = !pgl.contextIsCurrent(context);
+    if (outdated) {
+      dispose();
+    }
+    return outdated;
+  }
+
+}