package fcagnin.jgltut.tut03;
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 II. Positioning
* Chapter 3. OpenGL's Moving Triangle
* http://www.arcsynthesis.org/gltut/Positioning/Tutorial%2003.html
*
* @author integeruser
*/
public class VertCalcOffset extends LWJGLWindow {
public static void main(String[] args) {
Framework.CURRENT_TUTORIAL_DATAPATH = "/fcagnin/jgltut/tut03/data/";
new VertCalcOffset().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 );
glUniform1f( elapsedTimeUniform, getElapsedTime() / 1000.0f );
glBindBuffer( GL_ARRAY_BUFFER, positionBufferObject );
glEnableVertexAttribArray( 0 );
glVertexAttribPointer( 0, 4, GL_FLOAT, false, 0, 0 );
glDrawArrays( GL_TRIANGLES, 0, 3 );
glDisableVertexAttribArray( 0 );
glUseProgram( 0 );
}
////////////////////////////////
private int theProgram;
private int elapsedTimeUniform;
private void initializeProgram() {
ArrayList<Integer> shaderList = new ArrayList<>();
shaderList.add( Framework.loadShader( GL_VERTEX_SHADER, "CalcOffset.vert" ) );
shaderList.add( Framework.loadShader( GL_FRAGMENT_SHADER, "Standard.frag" ) );
theProgram = Framework.createProgram( shaderList );
elapsedTimeUniform = glGetUniformLocation( theProgram, "time" );
int loopDurationUnf = glGetUniformLocation( theProgram, "loopDuration" );
glUseProgram( theProgram );
glUniform1f( loopDurationUnf, 5.0f );
glUseProgram( 0 );
}
////////////////////////////////
private final float[] vertexPositions = {
0.25f, 0.25f, 0.0f, 1.0f,
0.25f, -0.25f, 0.0f, 1.0f,
-0.25f, -0.25f, 0.0f, 1.0f
};
private int positionBufferObject;
private int vao;
private void initializeVertexBuffer() {
FloatBuffer vertexPositionsBuffer = BufferUtils.createFloatBuffer( vertexPositions.length );
vertexPositionsBuffer.put( vertexPositions );
vertexPositionsBuffer.flip();
positionBufferObject = glGenBuffers();
glBindBuffer( GL_ARRAY_BUFFER, positionBufferObject );
glBufferData( GL_ARRAY_BUFFER, vertexPositionsBuffer, GL_STATIC_DRAW );
glBindBuffer( GL_ARRAY_BUFFER, 0 );
}
}