add warnings to javadoc about api issues

core/src/processing/opengl/PGL.java

@@ -1494,6 +1494,9 @@ public class PGL {
   }
 
 
+  /**
+   * Not an approved function, this will change or be removed in the future.
+   */
   public void drawTexture(int target, int id, int width, int height,
                           int X0, int Y0, int X1, int Y1) {
     drawTexture(target, id, width, height, width, height,
@@ -1501,6 +1504,9 @@ public class PGL {
   }
 
 
+  /**
+   * Not an approved function, this will change or be removed in the future.
+   */
   public void drawTexture(int target, int id,
                           int texW, int texH, int scrW, int scrH,
                           int texX0, int texY0, int texX1, int texY1,

core/src/processing/opengl/PGraphicsOpenGL.java

@@ -5768,6 +5768,7 @@ public class PGraphicsOpenGL extends PGraphics {
 
 
   /**
+   * Not an approved function, this will change or be removed in the future.
    * This utility method returns the texture associated to the renderer's.
    * drawing surface, making sure is updated to reflect the current contents
    * off the screen (or offscreen drawing surface).
@@ -5779,6 +5780,7 @@ public class PGraphicsOpenGL extends PGraphics {
 
 
   /**
+   * Not an approved function, this will change or be removed in the future.
    * This utility method returns the texture associated to the image.
    * creating and/or updating it if needed.
    *