OpenGL 3.3 + GLSL 1.5 Sample

  16 Responses to “OpenGL 3.3 + GLSL 1.5 Sample”

1. 

   wolfgaung says:

   14/08/2014 at 8:12 PM

   Thanks for this great Tutorial and also thanks to @swilson for the port – its not really often that you paste a code and it works immediately. Very helpful!!! Since there isnt much on the net for jogl and OpenGL 3 upwards.

   So keep up the good work!
   Greets from Austria

   Reply
2. 

   swilson says:

   24/04/2013 at 5:11 PM

   Quick java port using Jogl2.0rc11 for anyone interested:

   import static javax.media.opengl.GL.*;

   import java.awt.*;
   import java.awt.event.*;
   import java.io.*;

   import javax.media.opengl.*;
   import javax.media.opengl.awt.*;

   import com.jogamp.common.nio.*;

   /**
   * This is a port of some sample code from:
   * http://www.lighthouse3d.com/cg-topics/code-samples/opengl-3-3-glsl-1-5-sample/
   */
   public class Gl3Sample implements GLEventListener {
   // Data for drawing Axis
   float verticesAxis[] = { -20.0f, 0.0f, 0.0f, 1.0f, 20.0f, 0.0f, 0.0f, 1.0f,

   0.0f, -20.0f, 0.0f, 1.0f, 0.0f, 20.0f, 0.0f, 1.0f,

   0.0f, 0.0f, -20.0f, 1.0f, 0.0f, 0.0f, 20.0f, 1.0f };

   float colorAxis[] = { 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f,
   0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f,
   0.0f, 0.0f, 0.0f, 0.0f };

   // Data for triangle 1
   float vertices1[] = { -3.0f, 0.0f, -5.0f, 1.0f, -1.0f, 0.0f, -5.0f, 1.0f,
   -2.0f, 2.0f, -5.0f, 1.0f };

   float colors1[] = { 0.0f, 0.0f, 1.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, 0.0f,
   0.0f, 1.0f, 1.0f };

   // Data for triangle 2
   float vertices2[] = { 1.0f, 0.0f, -5.0f, 1.0f, 3.0f, 0.0f, -5.0f, 1.0f,
   2.0f, 2.0f, -5.0f, 1.0f };

   float colors2[] = { 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f,
   0.0f, 0.0f, 1.0f };

   // Shader Names
   String vertexFileName = “color.vert”;
   String fragmentFileName = “color.frag”;

   // Program and Shader Identifiers
   int p, v, f;

   // Vertex Attribute Locations
   int vertexLoc, colorLoc;

   // Uniform variable Locations
   int projMatrixLoc, viewMatrixLoc;

   // Vertex Array Objects Identifiers
   int vao[] = new int[3];

   // storage for Matrices
   float projMatrix[] = new float[16];
   float viewMatrix[] = new float[16];

   // —————————————————-
   // VECTOR STUFF
   //

   // res = a cross b;
   void crossProduct(float a[], float b[], float res[]) {

   res[0] = a[1] * b[2] – b[1] * a[2];
   res[1] = a[2] * b[0] – b[2] * a[0];
   res[2] = a[0] * b[1] – b[0] * a[1];
   }

   // Normalize a vec3
   void normalize(float a[]) {

   float mag = (float) Math.sqrt(a[0] * a[0] + a[1] * a[1] + a[2] * a[2]);

   a[0] /= mag;
   a[1] /= mag;
   a[2] /= mag;
   }

   // —————————————————-
   // MATRIX STUFF
   //

   // sets the square matrix mat to the identity matrix,
   // size refers to the number of rows (or columns)
   void setIdentityMatrix(float[] mat, int size) {

   // fill matrix with 0s
   for (int i = 0; i < size * size; ++i)
   mat[i] = 0.0f;

   // fill diagonal with 1s
   for (int i = 0; i < size; ++i)
   mat[i + i * size] = 1.0f;
   }

   //
   // a = a * b;
   //
   void multMatrix(float[] a, float[] b) {

   float[] res = new float[16];

   for (int i = 0; i < 4; ++i) {
   for (int j = 0; j < 4; ++j) {
   res[j * 4 + i] = 0.0f;
   for (int k = 0; k < 4; ++k) {
   res[j * 4 + i] += a[k * 4 + i] * b[j * 4 + k];
   }
   }
   }

   System.arraycopy(res, 0, a, 0, 16);
   }

   // Defines a transformation matrix mat with a translation
   void setTranslationMatrix(float[] mat, float x, float y, float z) {

   setIdentityMatrix(mat, 4);
   mat[12] = x;
   mat[13] = y;
   mat[14] = z;
   }

   // —————————————————-
   // Projection Matrix
   //

   void buildProjectionMatrix(float fov, float ratio, float nearP, float farP) {

   float f = 1.0f / (float) Math.tan(fov * (Math.PI / 360.0));

   setIdentityMatrix(projMatrix, 4);

   projMatrix[0] = f / ratio;
   projMatrix[1 * 4 + 1] = f;
   projMatrix[2 * 4 + 2] = (farP + nearP) / (nearP – farP);
   projMatrix[3 * 4 + 2] = (2.0f * farP * nearP) / (nearP – farP);
   projMatrix[2 * 4 + 3] = -1.0f;
   projMatrix[3 * 4 + 3] = 0.0f;
   }

   // —————————————————-
   // View Matrix
   //
   // note: it assumes the camera is not tilted,
   // i.e. a vertical up vector (remmeber gluLookAt?)
   //

   void setCamera(float posX, float posY, float posZ, float lookAtX,
   float lookAtY, float lookAtZ) {

   float[] dir = new float[3];
   float[] right = new float[3];
   float[] up = new float[3];

   up[0] = 0.0f;
   up[1] = 1.0f;
   up[2] = 0.0f;

   dir[0] = (lookAtX – posX);
   dir[1] = (lookAtY – posY);
   dir[2] = (lookAtZ – posZ);
   normalize(dir);

   crossProduct(dir, up, right);
   normalize(right);

   crossProduct(right, dir, up);
   normalize(up);

   float[] aux = new float[16];

   viewMatrix[0] = right[0];
   viewMatrix[4] = right[1];
   viewMatrix[8] = right[2];
   viewMatrix[12] = 0.0f;

   viewMatrix[1] = up[0];
   viewMatrix[5] = up[1];
   viewMatrix[9] = up[2];
   viewMatrix[13] = 0.0f;

   viewMatrix[2] = -dir[0];
   viewMatrix[6] = -dir[1];
   viewMatrix[10] = -dir[2];
   viewMatrix[14] = 0.0f;

   viewMatrix[3] = 0.0f;
   viewMatrix[7] = 0.0f;
   viewMatrix[11] = 0.0f;
   viewMatrix[15] = 1.0f;

   setTranslationMatrix(aux, -posX, -posY, -posZ);

   multMatrix(viewMatrix, aux);
   }

   // —————————————————-

   void changeSize(GL3 gl, int w, int h) {

   float ratio;
   // Prevent a divide by zero, when window is too short
   // (you cant make a window of zero width).
   if (h == 0)
   h = 1;

   // Set the viewport to be the entire window
   gl.glViewport(0, 0, w, h);

   ratio = (1.0f * w) / h;
   buildProjectionMatrix(53.13f, ratio, 1.0f, 30.0f);
   }

   void setupBuffers(GL3 gl) {

   int buffers[] = new int[2];
   gl.glGenVertexArrays(3, vao, 0);
   //
   // VAO for first triangle
   //
   gl.glBindVertexArray(vao[0]);
   // Generate two slots for the vertex and color buffers
   gl.glGenBuffers(2, buffers, 0);
   // bind buffer for vertices and copy data into buffer
   gl.glBindBuffer(GL_ARRAY_BUFFER, buffers[0]);
   gl.glBufferData(GL_ARRAY_BUFFER, vertices1.length * Float.SIZE / 8,
   Buffers.newDirectFloatBuffer(vertices1), GL_STATIC_DRAW);
   gl.glEnableVertexAttribArray(vertexLoc);
   gl.glVertexAttribPointer(vertexLoc, 4, GL_FLOAT, false, 0, 0);

   // bind buffer for colors and copy data into buffer
   gl.glBindBuffer(GL_ARRAY_BUFFER, buffers[1]);
   gl.glBufferData(GL_ARRAY_BUFFER, colors1.length * Float.SIZE / 8,
   Buffers.newDirectFloatBuffer(colors1), GL_STATIC_DRAW);
   gl.glEnableVertexAttribArray(colorLoc);
   gl.glVertexAttribPointer(colorLoc, 4, GL_FLOAT, false, 0, 0);

   //
   // VAO for second triangle
   //
   gl.glBindVertexArray(vao[1]);
   // Generate two slots for the vertex and color buffers
   gl.glGenBuffers(2, buffers, 0);

   // bind buffer for vertices and copy data into buffer
   gl.glBindBuffer(GL_ARRAY_BUFFER, buffers[0]);
   gl.glBufferData(GL_ARRAY_BUFFER, vertices2.length * Float.SIZE / 8,
   Buffers.newDirectFloatBuffer(vertices2), GL_STATIC_DRAW);
   gl.glEnableVertexAttribArray(vertexLoc);
   gl.glVertexAttribPointer(vertexLoc, 4, GL_FLOAT, false, 0, 0);

   // bind buffer for colors and copy data into buffer
   gl.glBindBuffer(GL_ARRAY_BUFFER, buffers[1]);
   gl.glBufferData(GL_ARRAY_BUFFER, colors2.length * Float.SIZE / 8,
   Buffers.newDirectFloatBuffer(colors2), GL_STATIC_DRAW);
   gl.glEnableVertexAttribArray(colorLoc);
   gl.glVertexAttribPointer(colorLoc, 4, GL_FLOAT, false, 0, 0);

   //
   // This VAO is for the Axis
   //
   gl.glBindVertexArray(vao[2]);
   // Generate two slots for the vertex and color buffers
   gl.glGenBuffers(2, buffers, 0);
   // bind buffer for vertices and copy data into buffer
   gl.glBindBuffer(GL_ARRAY_BUFFER, buffers[0]);
   gl.glBufferData(GL_ARRAY_BUFFER, verticesAxis.length * Float.SIZE / 8,
   Buffers.newDirectFloatBuffer(verticesAxis), GL_STATIC_DRAW);
   gl.glEnableVertexAttribArray(vertexLoc);
   gl.glVertexAttribPointer(vertexLoc, 4, GL_FLOAT, false, 0, 0);

   // bind buffer for colors and copy data into buffer
   gl.glBindBuffer(GL_ARRAY_BUFFER, buffers[1]);
   gl.glBufferData(GL_ARRAY_BUFFER, colorAxis.length * Float.SIZE / 8,
   Buffers.newDirectFloatBuffer(colorAxis), GL_STATIC_DRAW);
   gl.glEnableVertexAttribArray(colorLoc);
   gl.glVertexAttribPointer(colorLoc, 4, GL_FLOAT, false, 0, 0);

   }

   void setUniforms(GL3 gl) {

   // must be called after glUseProgram
   gl.glUniformMatrix4fv(projMatrixLoc, 1, false, projMatrix, 0);
   gl.glUniformMatrix4fv(viewMatrixLoc, 1, false, viewMatrix, 0);
   }

   void renderScene(GL3 gl) {

   gl.glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

   setCamera(10, 2, 10, 0, 2, -5);

   gl.glUseProgram(p);
   setUniforms(gl);

   gl.glBindVertexArray(vao[0]);
   gl.glDrawArrays(GL_TRIANGLES, 0, 3);

   gl.glBindVertexArray(vao[1]);
   gl.glDrawArrays(GL_TRIANGLES, 0, 3);

   gl.glBindVertexArray(vao[2]);
   gl.glDrawArrays(GL_LINES, 0, 6);
   }

   /** Retrieves the info log for the shader */
   public String printShaderInfoLog(GL3 gl, int obj) {
   // Otherwise, we'll get the GL info log
   final int logLen = getShaderParameter(gl, obj, GL3.GL_INFO_LOG_LENGTH);
   if (logLen <= 0)
   return "";

   // Get the log
   final int[] retLength = new int[1];
   final byte[] bytes = new byte[logLen + 1];
   gl.glGetShaderInfoLog(obj, logLen, retLength, 0, bytes, 0);
   final String logMessage = new String(bytes);

   return String.format("ShaderLog: %s", logMessage);
   }

   /** Get a shader parameter value. See 'glGetShaderiv' */
   private int getShaderParameter(GL3 gl, int obj, int paramName) {
   final int params[] = new int[1];
   gl.glGetShaderiv(obj, paramName, params, 0);
   return params[0];
   }

   /** Retrieves the info log for the program */
   public String printProgramInfoLog(GL3 gl, int obj) {
   // get the GL info log
   final int logLen = getProgramParameter(gl, obj, GL3.GL_INFO_LOG_LENGTH);
   if (logLen <= 0)
   return "";

   // Get the log
   final int[] retLength = new int[1];
   final byte[] bytes = new byte[logLen + 1];
   gl.glGetProgramInfoLog(obj, logLen, retLength, 0, bytes, 0);
   final String logMessage = new String(bytes);

   return logMessage;
   }

   /** Gets a program parameter value */
   public int getProgramParameter(GL3 gl, int obj, int paramName) {
   final int params[] = new int[1];
   gl.glGetProgramiv(obj, paramName, params, 0);
   return params[0];
   }

   public String textFileRead(String filePath) {
   // Read the data in
   BufferedReader reader = null;
   try {
   // Read in the source
   reader = new BufferedReader(new FileReader(filePath));
   final StringBuilder sb = new StringBuilder();
   String line;
   while ((line = reader.readLine()) != null)
   sb.append(line).append("\n");
   final String text = sb.toString();

   return text;

   } catch (final Exception ex) {
   ex.printStackTrace();

   } finally {
   try {
   reader.close();
   } catch (final Exception ex) {
   }
   }

   return "";
   }

   int setupShaders(GL3 gl) {

   String vs = null;
   String fs = null;
   String fs2 = null;

   int p, v, f;

   v = gl.glCreateShader(GL3.GL_VERTEX_SHADER);
   f = gl.glCreateShader(GL3.GL_FRAGMENT_SHADER);

   vs = textFileRead(vertexFileName);
   fs = textFileRead(fragmentFileName);

   String vv = vs;
   String ff = fs;

   gl.glShaderSource(v, 1, new String[] { vv }, null);
   gl.glShaderSource(f, 1, new String[] { ff }, null);

   gl.glCompileShader(v);
   gl.glCompileShader(f);

   printShaderInfoLog(gl, v);
   printShaderInfoLog(gl, f);

   p = gl.glCreateProgram();
   gl.glAttachShader(p, v);
   gl.glAttachShader(p, f);

   gl.glBindFragDataLocation(p, 0, "outputF");
   gl.glLinkProgram(p);
   printProgramInfoLog(gl, p);

   vertexLoc = gl.glGetAttribLocation(p, "position");
   colorLoc = gl.glGetAttribLocation(p, "color");

   projMatrixLoc = gl.glGetUniformLocation(p, "projMatrix");
   viewMatrixLoc = gl.glGetUniformLocation(p, "viewMatrix");

   return (p);
   }

   /** GL Init */
   @Override
   public void init(GLAutoDrawable drawable) {
   GL3 gl = drawable.getGL().getGL3();
   gl.glEnable(GL_DEPTH_TEST);
   gl.glClearColor(1.0f, 1.0f, 1.0f, 1.0f);

   p = setupShaders(gl);
   setupBuffers(gl);
   }

   /** GL Window Reshape */
   @Override
   public void reshape(GLAutoDrawable drawable, int x, int y, int width,
   int height) {
   GL3 gl = drawable.getGL().getGL3();
   changeSize(gl, width, height);
   }

   /** GL Render loop */
   @Override
   public void display(GLAutoDrawable drawable) {
   GL3 gl = drawable.getGL().getGL3();
   renderScene(gl);
   }

   /** GL Complete */
   @Override
   public void dispose(GLAutoDrawable drawable) {
   }

   /** Main entry point for the application */
   public static void main(String[] args) {
   Gl3Sample sample = new Gl3Sample();

   GLProfile glp = GLProfile.get(GLProfile.GL3);
   GLCapabilities glCapabilities = new GLCapabilities(glp);
   final GLCanvas glCanvas = new GLCanvas(glCapabilities);
   final Frame frame = new Frame("GL3 Test");
   glCanvas.addGLEventListener(sample);

   frame.add(glCanvas);
   frame.addWindowListener(new WindowAdapter() {
   @Override
   public void windowClosing(WindowEvent windowevent) {
   frame.remove(glCanvas);
   frame.dispose();
   System.exit(0);
   }
   });

   frame.setSize(320, 320);
   frame.setVisible(true);
   }
   }

   Reply
   • 

     ARF says:

     08/09/2014 at 11:06 PM

     Thanks. Great work.

     Reply
3. 

   test says:

   20/11/2012 at 12:47 AM

   Now runs, but crash everytime in this line: memcpy(&faceArray[faceIndex], face->mIndices,3 * sizeof(float));

   Do you have a solution maybe?

   Reply
   • 

     ARF says:

     20/11/2012 at 7:22 PM

     Hi, Where is that line?

     Reply
     • 

       test says:

       20/11/2012 at 7:24 PM

       Somewhere in project. Anyway thanks for your help, but I already use another tutorial.

       Reply
4. 

   Executor says:

   10/08/2012 at 7:53 PM

   textfile.h not found, ERROR!

   Reply
   • 

     ARF says:

     04/10/2012 at 3:18 PM

     Hi,

     There is a link on the top of the page to download both textfile header and source.

     Reply
5. 

   bananu7 says:

   08/06/2012 at 7:58 PM

   near and far are reserved keywords, at least in VS2010

   Reply
   • 

     ARF says:

     04/10/2012 at 3:17 PM

     Thanks. Fixed it.

     Reply
6. 

   Christopher says:

   27/05/2012 at 12:15 AM

   Hi!
   This is super interesting suff I’m mosly new to all of this so I’m not sure how this works. When compiling and running your program I get a blank white screen, even tho it semes to succesfully load the object. Have his something to do with the output being a reserved word error (fragment sahder compilation error #133) or is it the cameras default possition or somehing? I have not edited the code in any way. Tnx

   Reply
7. 

   hmm says:

   05/04/2012 at 10:45 AM

   ” gl_Position = projMatrix * viewMatrix * position ; ”

   ^^ the projection matrix and modelview matrices are probably in the wrong order

   Reply
   • 

     ARF says:

     25/04/2012 at 4:08 PM

     The projection matrix is the last matrix to be applied. The point (position) must be first transformed by the view matrix.

     Reply
8. 

   Aditya says:

   17/03/2012 at 12:30 AM

   I am new to open gl and trying to implement a code where i load obj ussing assimp and perform transformation on it, i am getting struck since my basic r not very clear is this the right forum to get help

   My code compile in debug it displays the model take the key input but never performs any transformation

   Reply
9. 

   Gele says:

   27/01/2012 at 4:15 PM

   Just tried the shaders in Shader Maker and got:
   Fragment shader failed to compile with the following errors:
   ERROR: 0:5: error(#133) Reserved word: output
   ERROR: 0:5: error(#132) Syntax error: ‘output’ parse error
   ERROR: error(#273) 2 compilation errors. No code generated
   The GL info shows
   ….
   Renderer: ATI Radeon HD 4550
   Version: 3.3.11079 Compatibility Profile Context

   Reply
   • 

     ARF says:

     28/01/2012 at 9:19 PM

     Yes, you’re right. It works fine with NVIDIA, but not with ATI. Actually ATI is right, since “output” is a reserved word.

     Thanks for the comment.

     Reply

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