package fcagnin.jgltut.tut02;
import fcagnin.jgltut.LWJGLWindow;
import fcagnin.jgltut.framework.Framework;
import org.lwjgl.BufferUtils;
import java.nio.FloatBuffer;
import java.util.ArrayList;
import static org.lwjgl.opengl.GL11.*;
import static org.lwjgl.opengl.GL15.*;
import static org.lwjgl.opengl.GL20.*;
import static org.lwjgl.opengl.GL30.glBindVertexArray;
import static org.lwjgl.opengl.GL30.glGenVertexArrays;
/**
* Visit https://github.com/integeruser/jgltut for info, updates and license terms.
* <p/>
* Part I. The Basics
* Chapter 2. Playing with Colors
* http://www.arcsynthesis.org/gltut/Basics/Tutorial%2002.html
*
* @author integeruser
*/
public class FragPosition extends LWJGLWindow {
public static void main(String[] args) {
Framework.CURRENT_TUTORIAL_DATAPATH = "/fcagnin/jgltut/tut02/data/";
new FragPosition().start();
}
@Override
protected void init() {
initializeProgram();
initializeVertexBuffer();
vao = glGenVertexArrays();
glBindVertexArray( vao );
}
@Override
protected void display() {
glClearColor( 0.0f, 0.0f, 0.0f, 0.0f );
glClear( GL_COLOR_BUFFER_BIT );
glUseProgram( theProgram );
glBindBuffer( GL_ARRAY_BUFFER, vertexBufferObject );
glEnableVertexAttribArray( 0 );
glVertexAttribPointer( 0, 4, GL_FLOAT, false, 0, 0 );
glDrawArrays( GL_TRIANGLES, 0, 3 );
glDisableVertexAttribArray( 0 );
glUseProgram( 0 );
}
////////////////////////////////
private int theProgram;
private void initializeProgram() {
ArrayList<Integer> shaderList = new ArrayList<>();
shaderList.add( Framework.loadShader( GL_VERTEX_SHADER, "FragPosition.vert" ) );
shaderList.add( Framework.loadShader( GL_FRAGMENT_SHADER, "FragPosition.frag" ) );
theProgram = Framework.createProgram( shaderList );
}
////////////////////////////////
private final float[] vertexData = {
0.75f, 0.75f, 0.0f, 1.0f,
0.75f, -0.75f, 0.0f, 1.0f,
-0.75f, -0.75f, 0.0f, 1.0f
};
private int vertexBufferObject;
private int vao;
private void initializeVertexBuffer() {
FloatBuffer vertexDataBuffer = BufferUtils.createFloatBuffer( vertexData.length );
vertexDataBuffer.put( vertexData );
vertexDataBuffer.flip();
vertexBufferObject = glGenBuffers();
glBindBuffer( GL_ARRAY_BUFFER, vertexBufferObject );
glBufferData( GL_ARRAY_BUFFER, vertexDataBuffer, GL_STATIC_DRAW );
glBindBuffer( GL_ARRAY_BUFFER, 0 );
}
}