VertexData.java

/*******************************************************************************
 * Copyright 2011 See AUTHORS file.
 * 
 * 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.
 ******************************************************************************/

package com.badlogic.gdx.graphics.glutils;

import java.nio.FloatBuffer;

import com.badlogic.gdx.graphics.VertexAttributes;
import com.badlogic.gdx.utils.Disposable;

/**
 * A VertexData instance holds vertices for rendering with OpenGL. It is implemented as either a {@link VertexArray} or
 * a {@link VertexBufferObject}. Only the later supports OpenGL ES 2.0.
 * 
 * @author mzechner
 */
public interface VertexData extends Disposable {
	/** @return the number of vertices this VertexData stores */
	public int getNumVertices();

	/** @return the number of vertices this VertedData can store */
	public int getNumMaxVertices();

	/** @return the {@link VertexAttributes} as specified during construction. */
	public VertexAttributes getAttributes();

	/**
	 * <p>
	 * Sets the vertices of this VertexData, discarding the old vertex data. The count must equal the number of floats
	 * per vertex times the number of vertices to be copied to this VertexData. The order of the vertex attributes must
	 * be the same as specified at construction time via {@link VertexAttributes}.
	 * </p>
	 * 
	 * <p>
	 * This can be called in between calls to {@link #bind()} and {@link #unbind()}. The vertex data will be updated
	 * instantly.
	 * </p>
	 * 
	 * @param vertices
	 *            the vertex data
	 * @param offset
	 *            the offset to start copying the data from
	 * @param count
	 *            the number of floats to copy
	 */
	public void setVertices(float[] vertices, int offset, int count);

	/**
	 * <p>
	 * Returns the underlying FloatBuffer. If you modify the buffer contents they will be uploaded on the next call to
	 * {@link #bind()}. If you need immediate uploading use {@link #setVertices(float[], int, int)};
	 * </p>
	 * 
	 * @return the underlying FloatBuffer holding the vertex data.
	 */
	public FloatBuffer getBuffer();

	/** Binds this VertexData for rendering via glDrawArrays or glDrawElements. */
	public void bind();

	/** Unbinds this VertexData. */
	public void unbind();

	/** Binds this VertexData for rendering via glDrawArrays or glDrawElements. */
	public void bind(ShaderProgram shader);

	/** Unbinds this VertexData. */
	public void unbind(ShaderProgram shader);

	/** Disposes this VertexData and all its associated OpenGL resources. */
	public void dispose();
}