package com.badlogic.gdx.graphics.glutils;
import java.nio.ByteBuffer;
import java.nio.FloatBuffer;
import java.nio.IntBuffer;
import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.graphics.GL20;
import com.badlogic.gdx.graphics.GL30;
import com.badlogic.gdx.graphics.VertexAttribute;
import com.badlogic.gdx.graphics.VertexAttributes;
import com.badlogic.gdx.utils.BufferUtils;
import com.badlogic.gdx.utils.IntArray;
/**
* <p>
* A {@link VertexData} implementation that uses vertex buffer objects and vertex array objects.
* (This is required for OpenGL 3.0+ core profiles. In particular, the default VAO has been
* deprecated, as has the use of client memory for passing vertex attributes.) Use of VAOs should
* give a slight performance benefit since you don't have to bind the attributes on every draw
* anymore.
* </p>
*
* <p>
* If the OpenGL ES context was lost you can call {@link #invalidate()} to recreate a new OpenGL vertex buffer object.
* </p>
*
* <p>
* VertexBufferObjectWithVAO objects must be disposed via the {@link #dispose()} method when no longer needed
* </p>
*
* Code adapted from {@link VertexBufferObject}.
* @author mzechner, Dave Clayton <contact@redskyforge.com>, Nate Austin <nate.austin gmail>
*/
public class VertexBufferObjectWithVAO implements VertexData {
final static IntBuffer tmpHandle = BufferUtils.newIntBuffer(1);
final VertexAttributes attributes;
final FloatBuffer buffer;
int bufferHandle;
final boolean isStatic;
final int usage;
boolean isDirty = false;
boolean isBound = false;
int vaoHandle = -1;
IntArray cachedLocations = new IntArray();
/**
* Constructs a new interleaved VertexBufferObjectWithVAO.
*
* @param isStatic whether the vertex data is static.
* @param numVertices the maximum number of vertices
* @param attributes the {@link com.badlogic.gdx.graphics.VertexAttribute}s.
*/
public VertexBufferObjectWithVAO (boolean isStatic, int numVertices, VertexAttribute... attributes) {
this(isStatic, numVertices, new VertexAttributes(attributes));
}
/**
* Constructs a new interleaved VertexBufferObjectWithVAO.
*
* @param isStatic whether the vertex data is static.
* @param numVertices the maximum number of vertices
* @param attributes the {@link VertexAttributes}.
*/
public VertexBufferObjectWithVAO (boolean isStatic, int numVertices, VertexAttributes attributes) {
this.isStatic = isStatic;
this.attributes = attributes;
buffer = BufferUtils.newFloatBuffer(this.attributes.vertexSize / 4 * numVertices);
buffer.flip();
bufferHandle = Gdx.gl20.glGenBuffer();
usage = isStatic ? GL20.GL_STATIC_DRAW : GL20.GL_DYNAMIC_DRAW;
createVAO();
}
@Override
public VertexAttributes getAttributes () {
return attributes;
}
@Override
public int getNumVertices () {
return buffer.limit() * 4 / attributes.vertexSize;
}
@Override
public int getNumMaxVertices () {
return buffer.capacity() * 4 / attributes.vertexSize;
}
@Override
public FloatBuffer getBuffer () {
isDirty = true;
return buffer;
}
private void bufferChanged () {
if (isBound) {
Gdx.gl20.glBufferData(GL20.GL_ARRAY_BUFFER, buffer.limit(), buffer, usage);
isDirty = false;
}
}
@Override
public void setVertices (float[] vertices, int offset, int count) {
isDirty = true;
BufferUtils.copy(vertices, buffer, count, offset);
buffer.position(0);
buffer.limit(count);
bufferChanged();
}
@Override
public void updateVertices (int targetOffset, float[] vertices, int sourceOffset, int count) {
isDirty = true;
final int pos = buffer.position();
buffer.position(targetOffset);
BufferUtils.copy(vertices, sourceOffset, count, buffer);
buffer.position(pos);
bufferChanged();
}
/**
* Binds this VertexBufferObject for rendering via glDrawArrays or glDrawElements
*
* @param shader the shader
*/
@Override
public void bind (ShaderProgram shader) {
bind(shader, null);
}
@Override
public void bind (ShaderProgram shader, int[] locations) {
GL30 gl = Gdx.gl30;
gl.glBindVertexArray(vaoHandle);
bindAttributes(shader, locations);
//if our data has changed upload it:
bindData(gl);
isBound = true;
}
private void bindAttributes (ShaderProgram shader, int[] locations) {
boolean stillValid = this.cachedLocations.size != 0;
final int numAttributes = attributes.size();
if (stillValid) {
if (locations == null) {
for (int i = 0; stillValid && i < numAttributes; i++) {
VertexAttribute attribute = attributes.get(i);
int location = shader.getAttributeLocation(attribute.alias);
stillValid = location == this.cachedLocations.get(i);
}
} else {
stillValid = locations.length == this.cachedLocations.size;
for (int i = 0; stillValid && i < numAttributes; i++) {
stillValid = locations[i] == this.cachedLocations.get(i);
}
}
}
if (!stillValid) {
Gdx.gl.glBindBuffer(GL20.GL_ARRAY_BUFFER, bufferHandle);
unbindAttributes(shader);
this.cachedLocations.clear();
for (int i = 0; i < numAttributes; i++) {
VertexAttribute attribute = attributes.get(i);
if (locations == null) {
this.cachedLocations.add(shader.getAttributeLocation(attribute.alias));
} else {
this.cachedLocations.add(locations[i]);
}
int location = this.cachedLocations.get(i);
if (location < 0) {
continue;
}
shader.enableVertexAttribute(location);
shader.setVertexAttribute(location, attribute.numComponents, attribute.type, attribute.normalized, attributes.vertexSize, attribute.offset);
}
}
}
private void unbindAttributes (ShaderProgram shaderProgram) {
if (cachedLocations == null) {
return;
}
int numAttributes = attributes.size();
for (int i = 0; i < numAttributes; i++) {
int location = cachedLocations.get(i);
if (location < 0) {
continue;
}
shaderProgram.disableVertexAttribute(location);
}
}
private void bindData (GL20 gl) {
if (isDirty) {
gl.glBindBuffer(GL20.GL_ARRAY_BUFFER, bufferHandle);
buffer.limit(buffer.limit());
gl.glBufferData(GL20.GL_ARRAY_BUFFER, buffer.limit(), buffer, usage);
isDirty = false;
}
}
/**
* Unbinds this VertexBufferObject.
*
* @param shader the shader
*/
@Override
public void unbind (final ShaderProgram shader) {
unbind(shader, null);
}
@Override
public void unbind (final ShaderProgram shader, final int[] locations) {
GL30 gl = Gdx.gl30;
gl.glBindVertexArray(0);
isBound = false;
}
/**
* Invalidates the VertexBufferObject so a new OpenGL buffer handle is created. Use this in case of a context loss.
*/
@Override
public void invalidate () {
bufferHandle = Gdx.gl20.glGenBuffer();
createVAO();
isDirty = true;
}
/**
* Disposes of all resources this VertexBufferObject uses.
*/
@Override
public void dispose () {
GL30 gl = Gdx.gl30;
gl.glBindBuffer(GL20.GL_ARRAY_BUFFER, 0);
gl.glDeleteBuffer(bufferHandle);
bufferHandle = 0;
deleteVAO();
}
private void createVAO () {
tmpHandle.clear();
Gdx.gl30.glGenVertexArrays(1, tmpHandle);
vaoHandle = tmpHandle.get();
}
private void deleteVAO () {
if (vaoHandle != -1) {
tmpHandle.clear();
tmpHandle.put(vaoHandle);
tmpHandle.flip();
Gdx.gl30.glDeleteVertexArrays(1, tmpHandle);
vaoHandle = -1;
}
}
}