renderer.java

NeHe用java与OpenGL结合教程源码

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 gl) throws 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 % 16) / 16.0f;						// X Position Of Current Character
            cy = (float) (loop / 16) / 16.0f;						// 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, 1 - cy - 0.0625f);			// Texture Coord (Bottom Left)
            gl.glVertex2i(0, 0);						// Vertex Coord (Bottom Left)
            gl.glTexCoord2f(cx + 0.0625f, 1 - cy - 0.0625f);	// Texture Coord (Bottom Right)
            gl.glVertex2i(16, 0);						// Vertex Coord (Bottom Right)
            gl.glTexCoord2f(cx + 0.0625f, 1 - cy);			// Texture Coord (Top Right)
            gl.glVertex2i(16, 16);						// Vertex Coord (Top Right)
            gl.glTexCoord2f(cx, 1 - cy);					// Texture Coord (Top Left)
            gl.glVertex2i(0, 16);						// Vertex Coord (Top Left)
            gl.glEnd();									// Done Building Our Quad (Character)
            gl.glTranslated(10, 0, 0);						// Move To The Right Of The Character
            gl.glEndList();									// Done Building The Display List
        }													// Loop Until All 256 Are Built
    }

    private void glPrint(GL gl, int x, int y, String string, int set)	// Where The Printing Happens
    {
        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(0, 640, 0, 480, -1, 1);							// 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();
        gl.glCallLists(string.length(), GL.GL_BYTE, stringBuffer);			// Write The Text To The Screen
        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
        gl.glClearColor(0.0f, 0.0f, 0.0f, 0.0f);               //This Will Clear The Background Color To Black
        gl.glClearDepth(1.0);                                  //Enables Clearing Of The Depth Buffer
        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
        gl.glHint(GL.GL_PERSPECTIVE_CORRECTION_HINT, GL.GL_NICEST);  // Really Nice Perspective Calculations
        gl.glEnable(GL.GL_TEXTURE_2D);							// Enable 2D Texture Mapping
    }

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

        gl.glBindTexture(GL.GL_TEXTURE_2D, textures[1]);			// Select Our Second Texture
        gl.glTranslatef(0.0f, 0.0f, -5.0f);						// Move Into The Screen 5 Units
        gl.glRotatef(45.0f, 0.0f, 0.0f, 1.0f);					// Rotate On The Z Axis 45 Degrees (Clockwise)
        gl.glRotatef(cnt1 * 30.0f, 1.0f, 1.0f, 0.0f);				// Rotate On The X & Y Axis By cnt1 (Left To Right)
        gl.glDisable(GL.GL_BLEND);								// Disable Blending Before We Draw In 3D
        gl.glColor3f(1.0f, 1.0f, 1.0f);							// Bright White
        gl.glBegin(GL.GL_QUADS);									// Draw Our First Texture Mapped Quad
        gl.glTexCoord2d(0.0f, 0.0f);						// First Texture Coord
        gl.glVertex2f(-1.0f, 1.0f);						// First Vertex
        gl.glTexCoord2d(1.0f, 0.0f);						// Second Texture Coord
        gl.glVertex2f(1.0f, 1.0f);						// Second Vertex
        gl.glTexCoord2d(1.0f, 1.0f);						// Third Texture Coord
        gl.glVertex2f(1.0f, -1.0f);						// Third Vertex
        gl.glTexCoord2d(0.0f, 1.0f);						// Fourth Texture Coord
        gl.glVertex2f(-1.0f, -1.0f);						// Fourth Vertex
        gl.glEnd();											// Done Drawing The First Quad
        gl.glRotatef(90.0f, 1.0f, 1.0f, 0.0f);					// Rotate On The X & Y Axis By 90 Degrees (Left To Right)
        gl.glBegin(GL.GL_QUADS);									// Draw Our Second Texture Mapped Quad
        gl.glTexCoord2d(0.0f, 0.0f);						// First Texture Coord
        gl.glVertex2f(-1.0f, 1.0f);						// First Vertex
        gl.glTexCoord2d(1.0f, 0.0f);						// Second Texture Coord
        gl.glVertex2f(1.0f, 1.0f);						// Second Vertex
        gl.glTexCoord2d(1.0f, 1.0f);						// Third Texture Coord
        gl.glVertex2f(1.0f, -1.0f);						// Third Vertex
        gl.glTexCoord2d(0.0f, 1.0f);						// 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)));
        glPrint(gl, (int) ((280 + 250 * Math.cos(cnt1))), (int) (235 + 200 * Math.sin(cnt2)), "NeHe", 0);		// Print GL Text To The Screen

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

        gl.glColor3f(0.0f, 0.0f, 1.0f);
        glPrint(gl, (int) (240 + 200 * Math.cos((cnt2 + cnt1) / 5)), 2, "Giuseppe D'Agata", 0);

        gl.glColor3f(1.0f, 1.0f, 1.0f);
        glPrint(gl, (int) (242 + 200 * Math.cos((cnt2 + cnt1) / 5)), 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 == 0) h = 1;
        GL gl = glDrawable.getGL();
        gl.glViewport(0, 0, w, h);                       // Reset The Current Viewport And Perspective Transformation
        gl.glMatrixMode(GL.GL_PROJECTION);                           // Select The Projection Matrix
        gl.glLoadIdentity();                                      // Reset The Projection Matrix
        glu.gluPerspective(45.0f, (float) w / (float) h, 0.1f, 100.0f);  // Calculate The Aspect Ratio Of The Window
        gl.glMatrixMode(GL.GL_MODELVIEW);                            // Select The Modelview Matrix
        gl.glLoadIdentity();                                      // Reset The ModalView Matrix
    }

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