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| // Vertices, the order is not important.
float[] vertices = {
150, 150, // Left top ID: 0
200, 150, // Left bottom ID: 1
200, 200, // Right bottom ID: 2
150, 201 // Right left ID: 3
};
// Sending data to OpenGL requires the usage of (flipped) byte buffers
FloatBuffer verticesBuffer = BufferUtils.createFloatBuffer(vertices.length);
verticesBuffer.put(vertices);
verticesBuffer.flip();
// OpenGL expects to draw vertices in counter clockwise order by default
byte[] indices = {
// Left bottom triangle
0, 1, 2,
// Right top triangle
2, 3, 0
};
indicesCount = indices.length;
ByteBuffer indicesBuffer = BufferUtils.createByteBuffer(indicesCount);
indicesBuffer.put(indices);
indicesBuffer.flip();
// Create a new Vertex Array Object in memory and select it (bind)
// A VAO can have up to 16 attributes (VBO's) assigned to it by default
vaio = GL30.glGenVertexArrays();
GL30.glBindVertexArray(vaio);
// Create a new Vertex Buffer Object in memory and select it (bind)
// A VBO is a collection of Vectors which in this case resemble the location of each vertex.
vbo = GL15.glGenBuffers();
GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, vbo);
GL15.glBufferData(GL15.GL_ARRAY_BUFFER, verticesBuffer, GL15.GL_STATIC_DRAW);
// Put the VBO in the attributes list at index 0
GL20.glVertexAttribPointer(0, 2, GL11.GL_FLOAT, false, 0, 0);
// Deselect (bind to 0) the VBO
GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, 0);
// Deselect (bind to 0) the VAO
GL30.glBindVertexArray(0);
// Create a new VBO for the indices and select it (bind)
vbo = GL15.glGenBuffers();
GL15.glBindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, vbo);
GL15.glBufferData(GL15.GL_ELEMENT_ARRAY_BUFFER, indicesBuffer, GL15.GL_STATIC_DRAW);
// Deselect (bind to 0) the VBO
GL15.glBindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, 0); |
