How to load an external shader from disk to use it in JOGL?

[ElNormeo]

hello

I’m looking for code how to load an external shader file from disk to use it in my JOGL program.
There is a very good code i found, while searching for hours, but that one doesn’t work.
Here is the link:
http://www.davidcornette.com/glsl/
& code:

            int v = gl.glCreateShader(GL.GL_VERTEX_SHADER);
	int f = gl.glCreateShader(GL.GL_FRAGMENT_SHADER);

	BufferedReader brv = new BufferedReader(new FileReader("./shader/vertex.shader"));
	String vsrc = "";
	String line;
	while ((line=brv.readLine()) != null) {
	  vsrc += line + "\n";
	}
	gl.glShaderSource(v, 1, vsrc, (int[])null);
	gl.glCompileShader(v);

	BufferedReader brf = new BufferedReader(new FileReader("./shader/fragment.shader"));
	String fsrc = "";
	while ((line=brf.readLine()) != null) {
	  fsrc += line + "\n";
	}
	gl.glShaderSource(f, 1, fsrc, (int[])null);
	gl.glCompileShader(f);
	int shaderprogram = gl.glCreateProgram();
	gl.glAttachShader(shaderprogram, v);
	gl.glAttachShader(shaderprogram, f);
	gl.glLinkProgram(shaderprogram);
	gl.glValidateProgram(shaderprogram);
	gl.glUseProgram(shaderprogram);	

Unfortunately, this doesn’t work, coz of some string vs. string array issue. Does anyone have a clue how to do that properly??!?!?

Thanks very much,

[irreversible_kev]

Shader.java

public class Shader {

    private int id;

    public Shader(int shaderType, String path) throws IOException {
        InputStream inputStream = getClass().getResourceAsStream(path);
        InputStreamReader inputStreamReader = new InputStreamReader(inputStream);
        BufferedReader bufferedReader = new BufferedReader(inputStreamReader);

        ArrayList<String> source = new ArrayList<String>();

        while (bufferedReader.ready()) {
            source.add(bufferedReader.readLine()+"\n");
        }

        init(shaderType, source.toArray(new String[source.size()]));
    }

    public Shader(int shaderType, String[] source) {
        init(shaderType, source);
    }

    private void init(int shaderType, String[] source) {
        GL gl = GLU.getCurrentGL();

        id = gl.glCreateShader(shaderType);

        gl.glShaderSource(id, source.length, source, getLengths(source));
        gl.glCompileShader(id);

        checkCompileError(gl);
    }

    private void checkCompileError(GL gl) {
        IntBuffer status = BufferUtil.newIntBuffer(1);
        gl.glGetShaderiv(id, GL.GL_COMPILE_STATUS, status);

        if (status.get() == GL.GL_FALSE) {
            getInfoLog(gl);
        } else {
            System.out.println("Successfully compiled shader " + id);
        }
    }

    private void getInfoLog(GL gl) {
        IntBuffer infoLogLength = BufferUtil.newIntBuffer(1);
        gl.glGetShaderiv(id, GL.GL_INFO_LOG_LENGTH, infoLogLength);
        int infoLogLengthInt = infoLogLength.get();

        ByteBuffer infoLog = BufferUtil.newByteBuffer(infoLogLengthInt);
        gl.glGetShaderInfoLog(id, infoLogLengthInt, null, infoLog);

        String infoLogString =
                Charset.forName("US-ASCII").decode(infoLog).toString();
        throw new Error("Shader compile error\n" + infoLogString);
    }

    public void delete() {
        GL gl = GLU.getCurrentGL();
        gl.glDeleteShader(id);
    }

    public int getID() {
        return id;
    }

    private static IntBuffer getLengths(String[] strings) {
        IntBuffer intBuffer = BufferUtil.newIntBuffer(strings.length);
        for (int i = 0; i < strings.length; i++) {
            intBuffer.put(strings[i].length());
        }
        intBuffer.rewind();
        return intBuffer;
    }
}

Program.java

public class Program {

    private Shader[] attachedShaders = null;
    private int id;

    public Program(Shader... shaders) {
        GL gl = GLU.getCurrentGL();

        id = gl.glCreateProgram();

        attachedShaders = shaders;
        for (Shader shader : attachedShaders) {
            gl.glAttachShader(id, shader.getID());
        }
    }

    public void link() {
        GL gl = GLU.getCurrentGL();
        gl.glLinkProgram(id);
        checkLinkAndValidationErrors(gl);
    }

    private void checkLinkAndValidationErrors(GL gl) {
        IntBuffer status = BufferUtil.newIntBuffer(1);
        gl.glGetProgramiv(id, GL.GL_LINK_STATUS, status);

        if (status.get() == GL.GL_FALSE) {
            getInfoLog(gl);
        } else {
            status.rewind();
            gl.glValidateProgram(id);
            gl.glGetProgramiv(id, GL.GL_VALIDATE_STATUS, status);
            if (status.get() == GL.GL_FALSE) {
                getInfoLog(gl);
            } else {
                System.out.println("Successfully linked program " + id);
            }
        }
    }

    private void getInfoLog(GL gl) {
        IntBuffer infoLogLength = BufferUtil.newIntBuffer(1);
        gl.glGetProgramiv(id, GL.GL_INFO_LOG_LENGTH, infoLogLength);
        int infoLogLengthInt = infoLogLength.get();

        ByteBuffer infoLog = BufferUtil.newByteBuffer(infoLogLengthInt);
        gl.glGetProgramInfoLog(id, infoLogLengthInt, null, infoLog);

        String infoLogString =
                Charset.forName("US-ASCII").decode(infoLog).toString();
        throw new Error("Program compile error\n" + infoLogString);
    }

    public void delete() {
        GL gl = GLU.getCurrentGL();

        for (Shader shader : attachedShaders) {
            shader.delete();
        }

        gl.glDeleteProgram(id);
    }

    public int getID() {
        return id;
    }
}

Then you can do

            Shader vertexShader = new Shader(GL.GL_VERTEX_SHADER, "/shaders/normalizer.vert");
            Shader fragmentShader = new Shader(GL.GL_FRAGMENT_SHADER, "/shaders/normalizer.frag");

            Program normalizerProgram = new Program(vertexShader, fragmentShader);

(You must ensure you create instances of Shader and Program on the GL Thread)

[ElNormeo]

Thanks very much!
Allthough by creating instances of Program & Shader in my GL Thread, i suppose you mean the init method or just below the class declaration by typing:

Program prg = new program();
Shader shady = new Shader();

??
Unfortunately, he don’t like it to create an instance of Shader. It says ‘cannot find symbol…’
I use Netbeans 6.5 with OpenGL Pack. I just creates two subclasses and put your code into it. Subclass ‘Program’ looks good but not ‘Shader’. Do you got any Idea?
Thanks anyway;-)!!

[irreversible_kev]

@ElNormeo

Program prg = new program();
Shader shady = new Shader();

Obviously you can’t type that since both Program and Shader do not have constructors that take no arguments.

Yes I mean in either your init or display method.

        try {
            Shader vertexShader = new Shader(GL.GL_VERTEX_SHADER, "/shaders/normalizer.vert");
            Shader fragmentShader = new Shader(GL.GL_FRAGMENT_SHADER, "/shaders/normalizer.frag");

            normalizerProgram = new Program(vertexShader, fragmentShader);
            normalizerProgram.link();
        } catch (IOException ex) {
            System.out.println("Error creating normalizer program : " + ex);
        }

gl.glUseProgram(normalizerProgram.getID());

@ElNormeo

It says ‘cannot find symbol…’

What is the exact error?

[ElNormeo]

heyho!
The error is gone;-) I got an error message when i tried to create an instance of Shader by typing: "Shader shady = new Shader();
Therefore you said, thats not possible, coz i got the error message:
cannot find symbol
symbol: constructor Shader ();
location: bla.blu.bla.Shader

So right now without this, my program, including your subclasses at least show no errors at all. I can run them with of course no effect at all;-)
I just test this by let the prg loading some shaders which comes with the Shader Designer.
What i’m trying to do is:

I wrote an little scene with a texture mapping planet, over it an rotating, blended cloud sphere, including an third little texture moon, which rotate around the planet.
My FINAL Goal is: Rayleigh Scattering! So i want to setup an basic prg, where i’m able to experiment with the shaders to get that effect. There are tons of papers & stuff which explain how to program that fancy atmospheric look. Thats why i need to setup and load the functionality of shaders. Due to the Orange Book, it looked soo easy to setup the shaders;-) lol

Right now, when i move the code where the prg loads the shaderfiles into the Init method, nothing happens.
When i put that snippet into my Display Method, the program hangs instantly and throws a ‘NullPointerException’.
Thanks anyway, i think, that Shader Issue is just to high for me right now.

[memecs]

you just need to catch IO exception…

try {
	BufferedReader reader = new BufferedReader(new FileReader(new File( fileName)));
	String shader = "";
	String text = reader.readLine();
		
             while (text != null) {
		shader += text + "\n";
	        text = reader.readLine();
	}
	return shader;

	} catch (FileNotFoundException e) {
		e.printStackTrace();
	} catch (IOException e) {
		e.printStackTrace();
	}