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2D texture font - NeHe Tutorial JOGL Port E-mail
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This example shows how to write any character or phrase you want to the screen using texture mapped quads.

This is the Java port of the one of the NeHe OpenGL tutorials.

You can get complete IntelliJ IDEA project structure (all source, resources, build script, ) by downloading the source distribution from here.

The original post of the programmer who ported the examples can be found here.


Image

package demos.nehe.lesson17;

import demos.common.GLDisplay;

/**
 @author Pepijn Van Eeckhoudt
 */
public class Lesson17 {
    public static void main(String[] args) {
        GLDisplay neheGLDisplay = GLDisplay.createGLDisplay("Lesson 17: 2D Texture Fonts");
        Renderer renderer = new Renderer();
        neheGLDisplay.addGLEventListener(renderer);
        neheGLDisplay.start();
    }
}


package demos.nehe.lesson17;

import demos.common.TextureReader;
import javax.media.opengl.GL;
import javax.media.opengl.GLAutoDrawable;
import javax.media.opengl.GLEventListener;
import javax.media.opengl.glu.GLU;

import java.io.IOException;
import java.nio.ByteBuffer;

import com.sun.opengl.util.BufferUtil;

class Renderer implements GLEventListener {
    private int base;  // Base Display List For The Font
    private int[] textures = new int[2];  // Storage For Our Font Texture

    private float cnt1;    // 1st Counter Used To Move Text & For Coloring
    private float cnt2;    // 2nd Counter Used To Move Text & For Coloring

    private GLU glu = new GLU();
    private ByteBuffer stringBuffer = BufferUtil.newByteBuffer(256);

    public Renderer() {
    }

    public void loadGLTextures(GL glthrows IOException {
        
        String tileNames [] 
            {"demos/data/images/font.png""demos/data/images/bumps.png"};


        gl.glGenTextures(2, textures, 0);

        for (int i = 0; i < 2; i++) {
            TextureReader.Texture texture;
            texture = TextureReader.readTexture(tileNames[i]);
            //Create Nearest Filtered Texture
            gl.glBindTexture(GL.GL_TEXTURE_2D, textures[i]);

            gl.glTexParameteri(GL.GL_TEXTURE_2D, GL.GL_TEXTURE_MAG_FILTER, GL.GL_LINEAR);
            gl.glTexParameteri(GL.GL_TEXTURE_2D, GL.GL_TEXTURE_MIN_FILTER, GL.GL_LINEAR);

            gl.glTexImage2D(GL.GL_TEXTURE_2D,
                    0,
                    3,
                    texture.getWidth(),
                    texture.getHeight(),
                    0,
                    GL.GL_RGB,
                    GL.GL_UNSIGNED_BYTE,
                    texture.getPixels());


        }
    }

    private void buildFont(GL gl)  // Build Our Font Display List
    {
        float cx;      // Holds Our X Character Coord
        float cy;      // Holds Our Y Character Coord

        base = gl.glGenLists(256);  // Creating 256 Display Lists
        gl.glBindTexture(GL.GL_TEXTURE_2D, textures[0]);  // Select Our Font Texture
        for (int loop = 0; loop < 256; loop++)      // Loop Through All 256 Lists
        {
            cx = (float) (loop % 1616.0f;  // X Position Of Current Character
            cy = (float) (loop / 1616.0f;  // Y Position Of Current Character

            gl.glNewList(base + loop, GL.GL_COMPILE);  // Start Building A List
            gl.glBegin(GL.GL_QUADS);      // Use A Quad For Each Character
            gl.glTexCoord2f(cx, - cy - 0.0625f);  // Texture Coord (Bottom Left)
            gl.glVertex2i(00);      // Vertex Coord (Bottom Left)
            gl.glTexCoord2f(cx + 0.0625f- cy - 0.0625f);  // Texture Coord (Bottom Right)
            gl.glVertex2i(160);      // Vertex Coord (Bottom Right)
            gl.glTexCoord2f(cx + 0.0625f- cy);  // Texture Coord (Top Right)
            gl.glVertex2i(1616);      // Vertex Coord (Top Right)
            gl.glTexCoord2f(cx, - cy);    // Texture Coord (Top Left)
            gl.glVertex2i(016);      // Vertex Coord (Top Left)
            gl.glEnd();          // Done Building Our Quad (Character)
            gl.glTranslated(1000);      // Move To The Right Of The Character
            gl.glEndList();        // Done Building The Display List
        }            // Loop Until All 256 Are Built
    }

    // Where The Printing Happens
    private void glPrint(GL gl, int x, int y, String string, int set)  
    {
        if (set > 1) {
            set = 1;
        }
        gl.glBindTexture(GL.GL_TEXTURE_2D, textures[0])// Select Our Font Texture
        gl.glDisable(GL.GL_DEPTH_TEST);       // Disables Depth Testing
        gl.glMatrixMode(GL.GL_PROJECTION);     // Select The Projection Matrix
        gl.glPushMatrix();         // Store The Projection Matrix
        gl.glLoadIdentity();         // Reset The Projection Matrix
        gl.glOrtho(06400480, -11);     // Set Up An Ortho Screen
        gl.glMatrixMode(GL.GL_MODELVIEW);     // Select The Modelview Matrix
        gl.glPushMatrix();         // Store The Modelview Matrix
        gl.glLoadIdentity();         // Reset The Modelview Matrix
        gl.glTranslated(x, y, 0);       // Position The Text (0,0 - Bottom Left)
        gl.glListBase(base - 32 (128 * set));     // Choose The Font Set (0 or 1)

        if (stringBuffer.capacity() < string.length()) {
            stringBuffer = BufferUtil.newByteBuffer(string.length());
        }

        stringBuffer.clear();
        stringBuffer.put(string.getBytes());
        stringBuffer.flip();
        
        // Write The Text To The Screen
        gl.glCallLists(string.length(), GL.GL_BYTE, stringBuffer);      
        gl.glMatrixMode(GL.GL_PROJECTION);  // Select The Projection Matrix
        gl.glPopMatrix();      // Restore The Old Projection Matrix
        gl.glMatrixMode(GL.GL_MODELVIEW);  // Select The Modelview Matrix
        gl.glPopMatrix();      // Restore The Old Projection Matrix
        gl.glEnable(GL.GL_DEPTH_TEST);    // Enables Depth Testing
    }

    public void init(GLAutoDrawable glDrawable) {
        GL gl = glDrawable.getGL();
        try {
            loadGLTextures(gl);
        catch (IOException e) {
            throw new RuntimeException(e);
        }

        buildFont(gl);

        gl.glShadeModel(GL.GL_SMOOTH);                 // Enables Smooth Color Shading
        
        // This Will Clear The Background Color To Black
        gl.glClearColor(0.0f0.0f0.0f0.0f);       
        
        // Enables Clearing Of The Depth Buffer
        gl.glClearDepth(1.0);                  
        
        gl.glEnable(GL.GL_DEPTH_TEST);                 // Enables Depth Testing
        gl.glBlendFunc(GL.GL_SRC_ALPHA, GL.GL_ONE);    // Select The Type Of Blending
        gl.glDepthFunc(GL.GL_LEQUAL);                  // The Type Of Depth Test To Do
        
        // Really Nice Perspective Calculations
        gl.glHint(GL.GL_PERSPECTIVE_CORRECTION_HINT, GL.GL_NICEST);  
        gl.glEnable(GL.GL_TEXTURE_2D);      // Enable 2D Texture Mapping
    }

    public void display(GLAutoDrawable glDrawable) {
        GL gl = glDrawable.getGL();
        
        // Clear The Screen And The Depth Buffer
        gl.glClear(GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT);       
        gl.glLoadIdentity();  // Reset The View

        // Select Our Second Texture
        gl.glBindTexture(GL.GL_TEXTURE_2D, textures[1]);  
        gl.glTranslatef(0.0f0.0f, -5.0f);  // Move Into The Screen 5 Units
        
        // Rotate On The Z Axis 45 Degrees (Clockwise)
        gl.glRotatef(45.0f0.0f0.0f1.0f);  
        
        // Rotate On The X & Y Axis By cnt1 (Left To Right)
        gl.glRotatef(cnt1 * 30.0f1.0f1.0f0.0f);  
        gl.glDisable(GL.GL_BLEND);          // Disable Blending Before We Draw In 3D
        gl.glColor3f(1.0f1.0f1.0f);     // Bright White
        gl.glBegin(GL.GL_QUADS);            // Draw Our First Texture Mapped Quad
        gl.glTexCoord2d(0.0f0.0f);        // First Texture Coord
        gl.glVertex2f(-1.0f1.0f);         // First Vertex
        gl.glTexCoord2d(1.0f0.0f);        // Second Texture Coord
        gl.glVertex2f(1.0f1.0f);          // Second Vertex
        gl.glTexCoord2d(1.0f1.0f);        // Third Texture Coord
        gl.glVertex2f(1.0f, -1.0f);         // Third Vertex
        gl.glTexCoord2d(0.0f1.0f);        // Fourth Texture Coord
        gl.glVertex2f(-1.0f, -1.0f);        // Fourth Vertex
        gl.glEnd();                         // Done Drawing The First Quad
        
        // Rotate On The X & Y Axis By 90 Degrees (Left To Right)
        gl.glRotatef(90.0f1.0f1.0f0.0f);  
        gl.glBegin(GL.GL_QUADS);            // Draw Our Second Texture Mapped Quad
        gl.glTexCoord2d(0.0f0.0f);        // First Texture Coord
        gl.glVertex2f(-1.0f1.0f);         // First Vertex
        gl.glTexCoord2d(1.0f0.0f);        // Second Texture Coord
        gl.glVertex2f(1.0f1.0f);          // Second Vertex
        gl.glTexCoord2d(1.0f1.0f);        // Third Texture Coord
        gl.glVertex2f(1.0f, -1.0f);         // Third Vertex
        gl.glTexCoord2d(0.0f1.0f);        // Fourth Texture Coord
        gl.glVertex2f(-1.0f, -1.0f);        // Fourth Vertex
        gl.glEnd();                         // Done Drawing Our Second Quad
        gl.glEnable(GL.GL_BLEND);           // Enable Blending

        gl.glLoadIdentity();                // Reset The View
        
        // Pulsing Colors Based On Text Position
        gl.glColor3f((float) (Math.cos(cnt1))(float
                (Math.sin(cnt2))1.0f 0.5f (float) (Math.cos(cnt1 + cnt2)));
        
        // Print GL Text To The Screen
        glPrint(gl, (int) ((280 250 * Math.cos(cnt1)))
                (int) (235 200 * Math.sin(cnt2))"NeHe"0);    

        gl.glColor3f((float) (Math.sin(cnt2))1.0f 0.5f 
                (float) (Math.cos(cnt1 + cnt2))(float) (Math.cos(cnt1)));
        
        // Print GL Text To The Screen
        glPrint(gl, (int) ((280 230 * Math.cos(cnt2)))
                (int) (235 200 * Math.sin(cnt1))"OpenGL"1);  

        gl.glColor3f(0.0f0.0f1.0f);
        glPrint(gl, (int) (240 200 * Math.cos((cnt2 + cnt15))
                2"Giuseppe D'Agata"0);

        gl.glColor3f(1.0f1.0f1.0f);
        glPrint(gl, (int) (242 200 * Math.cos((cnt2 + cnt15))
                2"Giuseppe D'Agata"0);

        cnt1 += 0.01f;      // Increase The First Counter
        cnt2 += 0.0081f;    // Increase The Second Counter
    }

    public void reshape(GLAutoDrawable glDrawable, int x, int y, int w, int h) {
        if (h == 0h = 1;
        GL gl = glDrawable.getGL();
        
        // Reset The Current Viewport And Perspective Transformation
        gl.glViewport(00, w, h);                       
        gl.glMatrixMode(GL.GL_PROJECTION);    // Select The Projection Matrix
        gl.glLoadIdentity();                  // Reset The Projection Matrix
        
        // Calculate The Aspect Ratio Of The Window
        glu.gluPerspective(45.0f(floatw / (floath, 0.1f100.0f);  
        gl.glMatrixMode(GL.GL_MODELVIEW);    // Select The Modelview Matrix
        gl.glLoadIdentity();                 // Reset The ModalView Matrix
    }

    public void displayChanged(GLAutoDrawable glDrawable, boolean b, boolean b1) {
    }
}

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