@Override
public void draw() {
checkCreated();
// Bind the vao and enable all attributes
GL30.glBindVertexArray(id);
for (int i = 0; i < attributeBufferIDs.length; i++) {
GL20.glEnableVertexAttribArray(i);
}
// Bind the indices buffer
GL15.glBindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, indicesBufferID);
// Draw all indices with the provided mode
GL11.glDrawElements(
drawingMode.getGLConstant(),
indicesCount,
GL11.GL_UNSIGNED_INT,
indicesOffset * DataType.INT.getByteSize());
// Unbind the indices buffer
GL15.glBindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, 0);
// Disable all attributes and unbind the vao
for (int i = 0; i < attributeBufferIDs.length; i++) {
GL20.glDisableVertexAttribArray(i);
}
GL30.glBindVertexArray(0);
// Check for errors
LWJGLUtil.checkForGLError();
}
@Override
public void create() {
if (isCreated()) {
throw new IllegalStateException("Vertex array has already been created");
}
if (vertexData == null) {
throw new IllegalStateException("Vertex data has not been set");
}
// Generate and bind the vao
id = GL30.glGenVertexArrays();
GL30.glBindVertexArray(id);
// Generate, bind and fill the indices vbo then unbind
indicesBufferID = GL15.glGenBuffers();
GL15.glBindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, indicesBufferID);
GL15.glBufferData(
GL15.GL_ELEMENT_ARRAY_BUFFER, vertexData.getIndicesBuffer(), GL15.GL_STATIC_DRAW);
GL15.glBindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, 0);
// Save the count of indices to draw
indicesCountCache = vertexData.getIndicesCount();
resetIndicesCountAndOffset();
// Create the map for attribute index to buffer ID
attributeBufferIDs = new int[vertexData.getAttributeCount()];
// For each attribute, generate, bind and fill the vbo, then setup the attribute in the vao and
// save the buffer ID for the index
for (int i = 0; i < vertexData.getAttributeCount(); i++) {
final VertexAttribute attribute = vertexData.getAttribute(i);
final int bufferID = GL15.glGenBuffers();
GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, bufferID);
GL15.glBufferData(GL15.GL_ARRAY_BUFFER, attribute.getData(), GL15.GL_STATIC_DRAW);
attributeBufferIDs[i] = bufferID;
// Three ways to interpret integer data
if (attribute.getType().isInteger() && attribute.getUploadMode() == UploadMode.KEEP_INT) {
// Directly as an int
GL30.glVertexAttribIPointer(
i, attribute.getSize(), attribute.getType().getGLConstant(), 0, 0);
} else {
// Or as a float, normalized or not
GL20.glVertexAttribPointer(
i,
attribute.getSize(),
attribute.getType().getGLConstant(),
attribute.getUploadMode().normalize(),
0,
0);
}
}
// Unbind the vbo and vao
GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, 0);
GL30.glBindVertexArray(0);
// Update state
super.create();
// Check for errors
LWJGLUtil.checkForGLError();
}
@Override
public void destroy() {
checkCreated();
// Unbind any bound buffer
GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, 0);
// Unbind and delete the indices buffer
GL15.glBindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, 0);
GL15.glDeleteBuffers(indicesBufferID);
// Bind the vao for deletion
GL30.glBindVertexArray(id);
// Disable each attribute and delete its buffer
for (int i = 0; i < attributeBufferIDs.length; i++) {
GL20.glDisableVertexAttribArray(i);
GL15.glDeleteBuffers(attributeBufferIDs[i]);
}
// Unbind the vao and delete it
GL30.glBindVertexArray(0);
GL30.glDeleteVertexArrays(id);
super.destroy();
// Check for errors
LWJGLUtil.checkForGLError();
}
