Hello 
I have some problem. I tried use GLSL into JOGL. I draw simple traingle which red green blue vertices. I obtain all blue triangle. What i do wrong?
OK I SOLVED IT:
gl.glShadeModel(GL.GL_SHADER_TYPE);
against:
gl.glShadeModel(GL.GL_FLAT);
Here is my code:
frag.txt ā
void main()
{
gl_FragColor = gl_Color;
}
vert.txt ā
void main()
{
gl_FrontColor = gl_Color;
gl_Position = ftransform();
}
.java ---
package org.yourorghere;
import com.sun.opengl.util.Animator;
import javax.media.opengl.GL;
import javax.media.opengl.GLAutoDrawable;
import javax.media.opengl.GLCanvas;
import javax.media.opengl.GLEventListener;
import javax.media.opengl.glu.GLU;
import javax.swing.*;
import java.awt.*;
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.nio.ByteBuffer;
import java.nio.IntBuffer;
public class SimpleShaderExample extends GLCanvas implements GLEventListener {
private boolean updateUniformVars = true;
private int vertexShaderProgram;
private int fragmentShaderProgram;
private int shaderprogram;
private final Animator animator = new Animator(this);
private float x = -2;
private float y = -2;
private float height = 4;
private float width = 4;
private int iterations = 255;
public SimpleShaderExample() {
addGLEventListener(this);
animator.start();
}
public void init(GLAutoDrawable drawable) {
GL gl = drawable.getGL();
// generate a VBO pointer / handle
// Enable VSync
gl.setSwapInterval(1);
gl.glShadeModel(GL.GL_FLAT);
try {
attachShaders(gl);
} catch (Exception e) {
e.printStackTrace();
}
}
private String[] loadShaderSrc(String name){
StringBuilder sb = new StringBuilder();
try{
InputStream is = getClass().getResourceAsStream(name);
BufferedReader br = new BufferedReader(new InputStreamReader(is));
String line;
while ((line = br.readLine())!=null){
sb.append(line);
sb.append('\n');
}
is.close();
}
catch (Exception e){
e.printStackTrace();
}
System.out.println("Shader is "+sb.toString());
return new String[]{sb.toString()};
}
private void attachShaders(GL gl) throws Exception {
vertexShaderProgram = gl.glCreateShader(GL.GL_VERTEX_SHADER);
fragmentShaderProgram = gl.glCreateShader(GL.GL_FRAGMENT_SHADER);
String[] vsrc = loadShaderSrc( "vert.txt" );
gl.glShaderSource(vertexShaderProgram, 1, vsrc, null, 0);
gl.glCompileShader(vertexShaderProgram);
String[] fsrc = loadShaderSrc( "frag.txt");
gl.glShaderSource(fragmentShaderProgram, 1, fsrc, null, 0);
gl.glCompileShader(fragmentShaderProgram);
shaderprogram = gl.glCreateProgram();
gl.glAttachShader(shaderprogram, vertexShaderProgram);
gl.glAttachShader(shaderprogram, fragmentShaderProgram);
gl.glLinkProgram(shaderprogram);
gl.glValidateProgram(shaderprogram);
IntBuffer intBuffer = IntBuffer.allocate(1);
gl.glGetProgramiv(shaderprogram, GL.GL_LINK_STATUS,intBuffer);
if (intBuffer.get(0)!=1){
gl.glGetProgramiv(shaderprogram, GL.GL_INFO_LOG_LENGTH,intBuffer);
int size = intBuffer.get(0);
System.err.println("Program link error: ");
if (size>0){
ByteBuffer byteBuffer = ByteBuffer.allocate(size);
gl.glGetProgramInfoLog(shaderprogram, size, intBuffer, byteBuffer);
for (byte b:byteBuffer.array()){
System.err.print((char)b);
}
} else {
System.out.println("Unknown");
}
System.exit(1);
}
gl.glLinkProgram(shaderprogram);
gl.glUseProgram(shaderprogram);
}
public void reshape(GLAutoDrawable drawable, int x, int y, int width, int height) {
GL gl = drawable.getGL();
GLU glu = new GLU();
if (height <= 0) { // avoid a divide by zero error!
height = 1;
}
final float h = (float) width / (float) height;
gl.glViewport(0, 0, width, height);
gl.glMatrixMode(GL.GL_PROJECTION);
gl.glLoadIdentity();
glu.gluOrtho2D(0, 1, 0, 1);
gl.glMatrixMode(GL.GL_MODELVIEW);
gl.glLoadIdentity();
}
public void display(GLAutoDrawable drawable) {
GL gl = drawable.getGL();
//if (updateUniformVars){
// updateUniformVars(gl);m
//}
// Reset the current matrix to the "identity"
gl.glLoadIdentity();
// Draw A Quad
//int temp = gl.glGetUniformLocation(shaderprogram, "t");
//int min = gl.glGetUniformLocation(shaderprogram, "min");
//int max = gl.glGetUniformLocation(shaderprogram, "max");
//gl.glUniform1f(temp, 500.0f);
//gl.glUniform1f(min, 400.0f);
//gl.glUniform1f(max, 900.0f);
gl.glBegin(GL.GL_TRIANGLES);
gl.glColor3f(1.0f,0.0f,0.0f);
gl.glVertex3f(0.5f, 1.0f, 0.0f);
gl.glColor3f(0.0f,1.0f,0.0f);
gl.glVertex3f(0.0f, -1.0f, 0.0f);
gl.glColor3f(0.0f,0.0f,1.0f);
gl.glVertex3f(1.0f, -1.0f, 0.0f);
// Done Drawing The Quad
gl.glEnd();
// Flush all drawing operations to the graphics card
//gl.glFlush();
}
public void displayChanged(GLAutoDrawable drawable, boolean modeChanged, boolean deviceChanged) {
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
JFrame jf = new JFrame();
jf.setSize(800,600);
jf.getContentPane().setLayout(new BorderLayout());
jf.getContentPane().add(new SimpleShaderExample(), BorderLayout.CENTER);
jf.setVisible(true);
jf.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
}
});
}
}
