Attachment 73 Details for Bug 202 – Framebuffer object implementation of the desired functionality

Framebuffer object implementation of the desired functionality

RenderToTextureFBO.java (text/plain), 18.25 KB, created by Sven Gothel on 2006-02-07 14:28:00 CET

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Creator: Sven Gothel

Created: 2006-02-07 14:28:00 CET

Size: 18.25 KB

patch

obsolete

>package demos.renderToTexture;
>
>import java.awt.event.WindowAdapter;
>import java.awt.event.WindowEvent;
>
>import javax.media.opengl.DebugGL;
>import javax.media.opengl.GL;
>import javax.media.opengl.GLAutoDrawable;
>import javax.media.opengl.GLCanvas;
>import javax.media.opengl.GLEventListener;
>import javax.media.opengl.GLException;
>import javax.swing.JFrame;
>
>import com.sun.opengl.utils.GLUT;
>
>public class RenderToTextureFBO implements GLEventListener
>{
>    private static GLUT glut = new GLUT();
>
>    public static void main(String[] args)
>    {
>        RenderToTextureFBO renderer = new RenderToTextureFBO();
>
>        GLCanvas canvas = new GLCanvas();
>
>        canvas.addGLEventListener(renderer);
>
>        JFrame frame = new JFrame("Render To Texture Demo");
>
>        frame.addWindowListener(new WindowAdapter()
>        {
>            public void windowClosing(WindowEvent evt)
>            {
>                System.exit(0);
>            }
>        });
>
>        frame.getContentPane().add(canvas);
>        canvas.setSize(300, 300);
>
>        frame.pack();
>        frame.setVisible(true);
>    }
>
>    private static float[] lightPosition = new float[]
>    {
>        1, 0, 10, 1
>    };
>
>    private FramebufferObjectRenderer framebufferRenderer;
>
>    private boolean isFramebufferRendererCreated = false;
>
>    public void init(GLAutoDrawable drawable)
>    {
>        drawable.setGL(new DebugGL(drawable.getGL()));
>
>        GL gl = drawable.getGL();
>
>        gl.glEnable(GL.GL_DEPTH_TEST);
>        gl.glEnable(GL.GL_NORMALIZE);
>        gl.glEnable(GL.GL_LIGHTING);
>
>        gl.glClearColor(0.5f, 0.5f, 0.5f, 0);
>
>        // Place the camera
>        gl.glMatrixMode(GL.GL_PROJECTION);
>        gl.glLoadIdentity();
>        gl.glFrustum(-2.0 / 10, 2.0 / 10, -2.0 / 10, 2.0 / 10, 1, 11);
>
>        gl.glMatrixMode(GL.GL_MODELVIEW);
>        gl.glLoadIdentity();
>        gl.glTranslated(0, 0, -10);
>
>        // Configure the light
>        gl.glEnable(GL.GL_LIGHT0);
>        gl.glLightfv(GL.GL_LIGHT0, GL.GL_POSITION, lightPosition, 0);
>
>        if (!isFramebufferRendererCreated)
>        {
>            framebufferRenderer = new FramebufferObjectRenderer(256);
>            framebufferRenderer.init(drawable);
>            isFramebufferRendererCreated = true;
>        }
>    }
>
>    public void display(GLAutoDrawable drawable)
>    {
>        GL gl = drawable.getGL();
>
>        gl.glClear(GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT);
>
>        framebufferRenderer.renderToFrameBuffer(drawable);
>
>        // Draw the teapot casting a shadow on a repeated picture of the
>        // offscreen colour buffer.
>        // We'll use multi-texture unit 1 for the shadowing...
>        framebufferRenderer.prepareForShadowedRendering(drawable,
>                                                        GL.GL_TEXTURE1);
>        // ... and multi-texture unit 0 for the picture
>        framebufferRenderer.prepareForColouredRendering(drawable,
>                                                        GL.GL_TEXTURE0);
>        drawSquare(drawable);
>        framebufferRenderer.stopColouredRendering(drawable);
>        drawFloatingTeapot(drawable);
>        framebufferRenderer.stopShadowedRendering(drawable, GL.GL_TEXTURE1);
>    }
>
>    private static void drawFloatingTeapot(GLAutoDrawable drawable)
>    {
>        GL gl = drawable.getGL();
>
>        gl.glPushAttrib(GL.GL_TRANSFORM_BIT);
>        {
>            gl.glMatrixMode(GL.GL_MODELVIEW);
>            gl.glPushMatrix();
>            {
>                gl.glTranslated(0.5, 0, 3);
>                glut.glutSolidTeapot(0.25, true);
>            }
>            gl.glPopMatrix();
>        }
>        gl.glPopAttrib();
>    }
>
>    private static void drawSquare(GLAutoDrawable drawable)
>    {
>        GL gl = drawable.getGL();
>
>        gl.glBegin(GL.GL_QUADS);
>        {
>            gl.glNormal3d(0, 0, 1);
>            gl.glMultiTexCoord2d(GL.GL_TEXTURE0, 0, 0);
>            gl.glVertex3d(-1, -1, 0);
>            gl.glMultiTexCoord2d(GL.GL_TEXTURE0, 2, 0);
>            gl.glVertex3d(1, -1, 0);
>            gl.glMultiTexCoord2d(GL.GL_TEXTURE0, 2, 2);
>            gl.glVertex3d(1, 1, 0);
>            gl.glMultiTexCoord2d(GL.GL_TEXTURE0, 0, 2);
>            gl.glVertex3d(-1, 1, 0);
>        }
>        gl.glEnd();
>    }
>
>    public void displayChanged(GLAutoDrawable drawable,
>                               boolean modeChanged,
>                               boolean deviceChanged)
>    {
>        // Nothing to do
>    }
>
>    public void reshape(GLAutoDrawable drawable,
>                        int x,
>                        int y,
>                        int width,
>                        int height)
>    {
>        // Nothing to do
>    }
>
>    private static class FramebufferObjectRenderer
>    {
>        private int textureDimension;
>
>        private int frameBufferID;
>        private int colourTextureID;
>        private int depthTextureID;
>
>        public FramebufferObjectRenderer(int textureDimension)
>        {
>            super();
>
>            this.textureDimension = textureDimension;
>        }
>
>        public void init(GLAutoDrawable drawable)
>        {
>            GL gl = drawable.getGL();
>
>            // Allocate the framebuffer object
>            int[] result = new int[1];
>            gl.glGenFramebuffersEXT(1, result, 0);
>            frameBufferID = result[0];
>            gl.glBindFramebufferEXT(GL.GL_FRAMEBUFFER_EXT, frameBufferID);
>
>            // Allocate the colour texture
>            gl.glGenTextures(1, result, 0);
>            colourTextureID = result[0];
>            gl.glBindTexture(GL.GL_TEXTURE_2D, colourTextureID);
>            gl.glTexParameteri(GL.GL_TEXTURE_2D,
>                               GL.GL_TEXTURE_MIN_FILTER,
>                               GL.GL_NEAREST);
>            gl.glTexParameteri(GL.GL_TEXTURE_2D,
>                               GL.GL_TEXTURE_MAG_FILTER,
>                               GL.GL_NEAREST);
>            gl.glTexParameteri(GL.GL_TEXTURE_2D,
>                               GL.GL_TEXTURE_WRAP_S,
>                               GL.GL_CLAMP_TO_EDGE);
>            gl.glTexParameteri(GL.GL_TEXTURE_2D,
>                               GL.GL_TEXTURE_WRAP_T,
>                               GL.GL_CLAMP_TO_EDGE);
>            gl.glTexImage2D(GL.GL_TEXTURE_2D,
>                            0,
>                            GL.GL_RGBA8,
>                            textureDimension,
>                            textureDimension,
>                            0,
>                            GL.GL_RGBA,
>                            GL.GL_UNSIGNED_BYTE,
>                            null);
>
>            // Allocate the depth texture
>            gl.glGenTextures(1, result, 0);
>            depthTextureID = result[0];
>            gl.glBindTexture(GL.GL_TEXTURE_2D, depthTextureID);
>            gl.glTexParameteri(GL.GL_TEXTURE_2D,
>                               GL.GL_TEXTURE_MIN_FILTER,
>                               GL.GL_NEAREST);
>            gl.glTexParameteri(GL.GL_TEXTURE_2D,
>                               GL.GL_TEXTURE_MAG_FILTER,
>                               GL.GL_NEAREST);
>            gl.glTexParameteri(GL.GL_TEXTURE_2D,
>                               GL.GL_TEXTURE_WRAP_S,
>                               GL.GL_CLAMP_TO_EDGE);
>            gl.glTexParameteri(GL.GL_TEXTURE_2D,
>                               GL.GL_TEXTURE_WRAP_T,
>                               GL.GL_CLAMP_TO_EDGE);
>            gl.glGetIntegerv(GL.GL_DEPTH_BITS, result, 0);
>            int depthFormat;
>            switch (result[0])
>            {
>                case 16:
>                    depthFormat = GL.GL_DEPTH_COMPONENT16;
>                    break;
>                case 24:
>                    depthFormat = GL.GL_DEPTH_COMPONENT24;
>                    break;
>                case 32:
>                    depthFormat = GL.GL_DEPTH_COMPONENT32;
>                    break;
>                default:
>                    throw new GLException("Unexpected number of depth bits: "
>                                          + result[0]);
>            }
>            gl.glTexImage2D(GL.GL_TEXTURE_2D,
>                            0,
>                            depthFormat,
>                            textureDimension,
>                            textureDimension,
>                            0,
>                            GL.GL_DEPTH_COMPONENT,
>                            GL.GL_UNSIGNED_INT,
>                            null);
>
>            // Attach the textures to the framebuffer
>            gl.glFramebufferTexture2DEXT(GL.GL_FRAMEBUFFER_EXT,
>                                         GL.GL_COLOR_ATTACHMENT0_EXT,
>                                         GL.GL_TEXTURE_2D,
>                                         colourTextureID,
>                                         0);
>            gl.glFramebufferTexture2DEXT(GL.GL_FRAMEBUFFER_EXT,
>                                         GL.GL_DEPTH_ATTACHMENT_EXT,
>                                         GL.GL_TEXTURE_2D,
>                                         depthTextureID,
>                                         0);
>            
>            gl.glBindFramebufferEXT(GL.GL_FRAMEBUFFER_EXT, 0);
>        }
>
>        private int counter = 0;
>
>        public void renderToFrameBuffer(GLAutoDrawable drawable)
>        {
>            GL gl = drawable.getGL();
>
>            gl.glPushAttrib(GL.GL_TRANSFORM_BIT | GL.GL_ENABLE_BIT
>                            | GL.GL_COLOR_BUFFER_BIT);
>
>            gl.glBindFramebufferEXT(GL.GL_FRAMEBUFFER_EXT, frameBufferID);
>
>            gl.glEnable(GL.GL_DEPTH_TEST);
>            gl.glEnable(GL.GL_NORMALIZE);
>            gl.glDisable(GL.GL_LIGHTING);
>
>            gl.glClearColor(0, 0, 1, 0);
>
>            // Place the offscreen camera at the light position
>            gl.glMatrixMode(GL.GL_PROJECTION);
>            gl.glPushMatrix();
>            gl.glLoadIdentity();
>            applyLightFrustum(gl);
>
>            gl.glMatrixMode(GL.GL_MODELVIEW);
>            gl.glPushMatrix();
>            gl.glLoadIdentity();
>            applyLightTransformation(gl);
>
>            gl.glClear(GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT);
>
>            // Draw the teapot as a red silhouette
>            if (counter++ % 2 == 0)
>            {
>                gl.glColor3d(1, 0, 0);
>            }
>            else
>            {
>                gl.glColor3d(0, 1, 0);
>            }
>            drawFloatingTeapot(drawable);
>            // Don't draw the square (because we don't want it to cast a shadow)
>
>            // Unbind the framebuffer
>            gl.glBindFramebufferEXT(GL.GL_FRAMEBUFFER_EXT, 0);
>
>            gl.glMatrixMode(GL.GL_PROJECTION);
>            gl.glPopMatrix();
>            gl.glMatrixMode(GL.GL_MODELVIEW);
>            gl.glPopMatrix();
>            gl.glPopAttrib();
>        }
>
>        private void applyLightFrustum(GL gl)
>        {
>            // Set up the viewing frustum so that the light only sees the
>            // volume between itself and the unit X-Y square at the origin
>            // (because that is the only volume in which we will be casting
>            // shadows).
>            gl.glFrustum(-2.0 / 10, 0, -1.0 / 10, 1.0 / 10, 1, 10);
>        }
>
>        private void applyLightTransformation(GL gl)
>        {
>            gl.glTranslated(-lightPosition[0],
>                            -lightPosition[1],
>                            -lightPosition[2]);
>        }
>
>        public void prepareForShadowedRendering(GLAutoDrawable targetDrawable,
>                                                int textureUnitID)
>        {
>            GL gl = targetDrawable.getGL();
>
>            // The state modified by this preparation will be restored by a call
>            // to finishShadowedRendering()
>            gl.glPushAttrib(GL.GL_TEXTURE_BIT);
>
>            gl.glActiveTexture(textureUnitID);
>            gl.glBindTexture(GL.GL_TEXTURE_2D, depthTextureID);
>            gl.glPushAttrib(GL.GL_TEXTURE_BIT);
>            // Generate texture coordinates - an object-linear texture
>            // generation that sets the texture coordinates to be the
>            // object-space vertex coordinates (we will use the texture matrix
>            // to transform from object-space to light-space)
>            gl.glEnable(GL.GL_TEXTURE_GEN_S);
>            gl.glEnable(GL.GL_TEXTURE_GEN_T);
>            gl.glEnable(GL.GL_TEXTURE_GEN_R);
>            gl.glEnable(GL.GL_TEXTURE_GEN_Q);
>            gl.glTexGeni(GL.GL_S, GL.GL_TEXTURE_GEN_MODE, GL.GL_OBJECT_LINEAR);
>            gl.glTexGeni(GL.GL_T, GL.GL_TEXTURE_GEN_MODE, GL.GL_OBJECT_LINEAR);
>            gl.glTexGeni(GL.GL_R, GL.GL_TEXTURE_GEN_MODE, GL.GL_OBJECT_LINEAR);
>            gl.glTexGeni(GL.GL_Q, GL.GL_TEXTURE_GEN_MODE, GL.GL_OBJECT_LINEAR);
>            gl.glPushAttrib(GL.GL_TRANSFORM_BIT);
>            {
>                gl.glMatrixMode(GL.GL_MODELVIEW);
>                gl.glPushMatrix();
>                {
>                    gl.glLoadIdentity();
>                    float[] objectPlane = new float[]
>                    {
>                        1, 0, 0, 0
>                    };
>                    gl.glTexGenfv(GL.GL_S, GL.GL_OBJECT_PLANE, objectPlane, 0);
>                    objectPlane[0] = 0;
>                    objectPlane[1] = 1;
>                    gl.glTexGenfv(GL.GL_T, GL.GL_OBJECT_PLANE, objectPlane, 0);
>                    objectPlane[1] = 0;
>                    objectPlane[2] = 1;
>                    gl.glTexGenfv(GL.GL_R, GL.GL_OBJECT_PLANE, objectPlane, 0);
>                    objectPlane[2] = 0;
>                    objectPlane[3] = 1;
>                    gl.glTexGenfv(GL.GL_Q, GL.GL_OBJECT_PLANE, objectPlane, 0);
>                }
>                gl.glPopMatrix();
>
>                // Modify texture matrix - the texture matrix will transform
>                // from object-space coordinates to light-space (i.e. the same
>                // transformation that was applied when rendering the shadow
>                // texture)
>                gl.glMatrixMode(GL.GL_TEXTURE);
>                // The texture matrix will be restored by
>                // stopShadowedRendering()
>                gl.glPushMatrix();
>                gl.glLoadIdentity();
>                // Go from the unit square to the upper quadrant (because
>                // texture coords run from 0 to 1)
>                gl.glScalef(0.5f, 0.5f, 0.5f);
>                gl.glTranslatef(1, 1, 1);
>                // Apply the transformation to light-space
>                applyLightFrustum(gl);
>                applyLightTransformation(gl);
>            }
>            gl.glPopAttrib();
>
>            // Set the texture up to be used as a depth comparison
>            int textureTarget = GL.GL_TEXTURE_2D;
>            gl.glEnable(textureTarget);
>            gl.glTexEnvi(GL.GL_TEXTURE_ENV,
>                         GL.GL_TEXTURE_ENV_MODE,
>                         GL.GL_MODULATE);
>            gl.glTexParameteri(textureTarget,
>                               GL.GL_TEXTURE_MIN_FILTER,
>                               GL.GL_LINEAR);
>            gl.glTexParameteri(textureTarget,
>                               GL.GL_TEXTURE_MAG_FILTER,
>                               GL.GL_LINEAR);
>            gl.glTexParameteri(textureTarget,
>                               GL.GL_TEXTURE_WRAP_S,
>                               GL.GL_CLAMP_TO_EDGE);
>            gl.glTexParameteri(textureTarget,
>                               GL.GL_TEXTURE_WRAP_T,
>                               GL.GL_CLAMP_TO_EDGE);
>            gl.glTexParameteri(textureTarget,
>                               GL.GL_TEXTURE_COMPARE_MODE,
>                               GL.GL_COMPARE_R_TO_TEXTURE);
>            gl.glTexParameteri(textureTarget,
>                               GL.GL_TEXTURE_COMPARE_FUNC,
>                               GL.GL_LEQUAL);
>            gl.glTexParameteri(textureTarget,
>                               GL.GL_DEPTH_TEXTURE_MODE,
>                               GL.GL_LUMINANCE);
>        }
>
>        public void stopShadowedRendering(GLAutoDrawable targetDrawable,
>                                          int textureUnitID)
>        {
>            GL gl = targetDrawable.getGL();
>            gl.glActiveTexture(textureUnitID);
>            gl.glPushAttrib(GL.GL_TRANSFORM_BIT);
>            {
>                gl.glMatrixMode(GL.GL_TEXTURE);
>                gl.glPopMatrix();
>            }
>            gl.glPopAttrib();
>
>            // Restore the texture attributes for the textureUnith texture
>            gl.glPopAttrib();
>
>            // Unbind the depth texture
>            gl.glBindTexture(GL.GL_TEXTURE_2D, 0);
>
>            // Restore the active texture
>            gl.glPopAttrib();
>        }
>
>        public void prepareForColouredRendering(GLAutoDrawable targetDrawable,
>                                                int textureUnitID)
>        {
>            GL gl = targetDrawable.getGL();
>
>            // The state modified by this preparation will be restored by a call
>            // to finishShadowedRendering()
>            gl.glPushAttrib(GL.GL_TEXTURE_BIT);
>
>            gl.glActiveTexture(textureUnitID);
>            gl.glBindTexture(GL.GL_TEXTURE_2D, colourTextureID);
>
>            // Set the texture up to be used for painting a surface
>            int textureTarget = GL.GL_TEXTURE_2D;
>            gl.glEnable(textureTarget);
>            gl.glTexEnvi(GL.GL_TEXTURE_ENV,
>                         GL.GL_TEXTURE_ENV_MODE,
>                         GL.GL_MODULATE);
>            gl.glTexParameteri(textureTarget,
>                               GL.GL_TEXTURE_MIN_FILTER,
>                               GL.GL_LINEAR);
>            gl.glTexParameteri(textureTarget,
>                               GL.GL_TEXTURE_MAG_FILTER,
>                               GL.GL_LINEAR);
>            gl.glTexParameteri(textureTarget,
>                               GL.GL_TEXTURE_WRAP_S,
>                               GL.GL_REPEAT);
>            gl.glTexParameteri(textureTarget,
>                               GL.GL_TEXTURE_WRAP_T,
>                               GL.GL_REPEAT);
>        }
>
>        public void stopColouredRendering(GLAutoDrawable targetDrawable)
>        {
>            GL gl = targetDrawable.getGL();
>
>            gl.glBindTexture(GL.GL_TEXTURE_2D, 0);
>
>            // Restore the active texture
>            gl.glPopAttrib();
>        }
>
>    }
>
>}

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