initial import of GL-CL Mandelbrot Set example.

2 files changed, 338 insertions, 0 deletions

diff --git a/src/com/mbien/opencl/demos/fractal/Fractal.java b/src/com/mbien/opencl/demos/fractal/Fractal.java
new file mode 100644
index 0000000..06cde84
--- /dev/null
+++ b/src/com/mbien/opencl/demos/fractal/Fractal.java
@@ -0,0 +1,294 @@
+package com.mbien.opencl.demos.fractal;
+
+import com.mbien.opencl.CLBuffer;
+import com.mbien.opencl.CLCommandQueue;
+import com.mbien.opencl.CLException;
+import com.mbien.opencl.CLGLBuffer;
+import com.mbien.opencl.CLGLContext;
+import com.mbien.opencl.CLKernel;
+import com.mbien.opencl.CLProgram;
+import com.mbien.opencl.CLProgram.CompilerOptions;
+import java.awt.Color;
+import java.awt.Dimension;
+import java.awt.Point;
+import java.awt.event.MouseAdapter;
+import java.awt.event.MouseEvent;
+import java.awt.event.MouseWheelEvent;
+import java.io.IOException;
+import java.nio.IntBuffer;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import javax.media.opengl.DebugGL2;
+import javax.media.opengl.GL;
+import javax.media.opengl.GL2;
+import javax.media.opengl.GLAutoDrawable;
+import javax.media.opengl.GLCapabilities;
+import javax.media.opengl.GLContext;
+import javax.media.opengl.GLEventListener;
+import javax.media.opengl.GLProfile;
+import javax.media.opengl.awt.GLCanvas;
+import javax.swing.JFrame;
+import javax.swing.SwingUtilities;
+
+import static com.sun.gluegen.runtime.BufferFactory.*;
+import static javax.media.opengl.GL2.*;
+import static com.mbien.opencl.CLMemory.Mem.*;
+import static com.mbien.opencl.CLDevice.Type.*;
+
+/**
+ * Computes the Mandelbrot set with OpenCL and renders the result with OpenGL.
+ * A shared PBO is used as storage for the fractal image.
+ * http://en.wikipedia.org/wiki/Mandelbrot_set
+ * @author Michael Bien
+ */
+public class Fractal implements GLEventListener {
+
+    private GLCanvas canvas;
+
+    private CLGLContext clContext;
+    private CLCommandQueue commandQueue;
+    private CLKernel kernel;
+
+    private CLGLBuffer<IntBuffer> pboBuffer;
+
+    private int width  = 0;
+    private int height = 0;
+
+    private float minX = -2f;
+    private float minY = -1.2f;
+    private float maxX  = 0.6f;
+    private float maxY  = 1.3f;
+
+    public Fractal(int width, int height) {
+
+        this.width = width;
+        this.height = height;
+
+        canvas = new GLCanvas(new GLCapabilities(GLProfile.get(GLProfile.GL2)));
+        canvas.addGLEventListener(this);
+        initSceneInteraction();
+
+        JFrame frame = new JFrame("JOCL Mandelbrot Set");
+        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+        canvas.setPreferredSize(new Dimension(width, height));
+        frame.add(canvas);
+        frame.pack();
+
+        frame.setVisible(true);
+    }
+
+    public void init(GLAutoDrawable drawable) {
+
+        // enable GL error checking using the composable pipeline
+        drawable.setGL(new DebugGL2(drawable.getGL().getGL2()));
+
+        initCL(drawable.getContext());
+
+        GL2 gl = drawable.getGL().getGL2();
+
+        gl.setSwapInterval(0);
+        gl.glDisable(GL_DEPTH_TEST);
+        gl.glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
+
+        initView(gl, drawable.getWidth(), drawable.getHeight());
+
+        initPBO(gl);
+
+    }
+
+    private void initCL(GLContext glCtx){
+        try {
+            clContext = CLGLContext.create(glCtx);
+
+            // load and build program
+            CLProgram program = clContext.createProgram(getClass().getResourceAsStream("Mandelbrot.cl"))
+                                         .build(CompilerOptions.FAST_RELAXED_MATH);
+
+            // setup colormap and create command queue on fastest GPU
+            CLBuffer<IntBuffer> colorMap = clContext.createIntBuffer(32*2, READ_ONLY);
+            initColorMap(colorMap.getBuffer(), 32, Color.BLUE, Color.GREEN, Color.RED);
+
+            commandQueue = clContext.getMaxFlopsDevice(GPU).createCommandQueue()
+              .putWriteBuffer(colorMap, true); // blocking upload
+
+            // init kernel with constants
+            kernel = program.getCLKernel("mandelbrot")
+              .setArg(7, colorMap)
+              .setArg(8, colorMap.getBuffer().capacity())
+              .setArg(9, 200);  // maxIterations
+
+        } catch (IOException ex) {
+            Logger.getLogger(Fractal.class.getName()).log(Level.SEVERE, "can not find OpenCL program.", ex);
+        } catch (CLException ex) {
+            Logger.getLogger(Fractal.class.getName()).log(Level.SEVERE, "something went wrong, hopefully no one got hurt", ex);
+        }
+
+    }
+
+    private void initColorMap(IntBuffer colorMap, int stepSize, Color... colors) {
+        
+        for (int n = 0; n < colors.length - 1; n++) {
+
+            Color color = colors[n];
+            int r0 = color.getRed();
+            int g0 = color.getGreen();
+            int b0 = color.getBlue();
+
+            color = colors[n + 1];
+            int r1 = color.getRed();
+            int g1 = color.getGreen();
+            int b1 = color.getBlue();
+
+            int deltaR = r1 - r0;
+            int deltaG = g1 - g0;
+            int deltaB = b1 - b0;
+
+            for (int step = 0; step < stepSize; step++) {
+                float alpha = (float) step / (stepSize - 1);
+                int r = (int) (r0 + alpha * deltaR);
+                int g = (int) (g0 + alpha * deltaG);
+                int b = (int) (b0 + alpha * deltaB);
+                colorMap.put((r << 16) | (g << 8) | (b << 0));
+            }
+        }
+        colorMap.rewind();
+
+    }
+
+    private void initView(GL2 gl, int width, int height) {
+
+        gl.glViewport(0, 0, width, height);
+
+        gl.glMatrixMode(GL_MODELVIEW);
+        gl.glLoadIdentity();
+
+        gl.glMatrixMode(GL_PROJECTION);
+        gl.glLoadIdentity();
+        gl.glOrtho(0.0, 1.0, 0.0, 1.0, 0.0, 1.0);
+    }
+
+    private void initPBO(GL gl) {
+
+        int[] pbo = new int[1];
+        gl.glGenBuffers(1, pbo, 0);
+
+        // setup empty PBO
+        gl.glBindBuffer(GL_PIXEL_UNPACK_BUFFER, pbo[0]);
+        gl.glBufferData(GL_PIXEL_UNPACK_BUFFER, width * height * SIZEOF_INT, null, GL_STREAM_DRAW);
+        gl.glBindBuffer(GL_PIXEL_UNPACK_BUFFER, 0);
+
+        pboBuffer = clContext.createFromGLBuffer(null, pbo[0], WRITE_ONLY);
+
+    }
+
+    public void display(GLAutoDrawable drawable) {
+        compute();
+        render(drawable.getGL().getGL2());
+    }
+
+    private void compute() {
+
+        kernel.putArg(pboBuffer)
+              .putArg(width).putArg(height)
+              .putArg(minX).putArg(minY)
+              .putArg(maxX).putArg(maxY)
+              .rewind();
+
+        commandQueue.putAcquireGLObject(pboBuffer.ID)
+                    .put2DRangeKernel(kernel, 0, 0, width, height, 0, 0)
+                    .putReleaseGLObject(pboBuffer.ID)
+                    .putBarrier();
+    }
+
+    private void render(GL2 gl) {
+
+        gl.glClear(GL_COLOR_BUFFER_BIT);
+
+        gl.glBindBuffer(GL_PIXEL_UNPACK_BUFFER, pboBuffer.getGLObjectID());
+            gl.glRasterPos2i(0, 0);
+            gl.glDrawPixels(width, height, GL_BGRA, GL_UNSIGNED_BYTE, 0);
+        gl.glBindBuffer(GL_PIXEL_UNPACK_BUFFER, 0);
+
+    }
+
+    public void reshape(GLAutoDrawable drawable, int x, int y, int width, int height) {
+
+        if(this.width == width && this.height == height)
+            return;
+
+        this.width = width;
+        this.height = height;
+
+        pboBuffer.release();
+
+        initPBO(drawable.getGL());
+        initView(drawable.getGL().getGL2(), drawable.getWidth(), drawable.getHeight());
+    }
+
+    private void initSceneInteraction() {
+
+        MouseAdapter adapter = new MouseAdapter() {
+
+            Point lastpos = new Point();
+
+            @Override
+            public void mouseDragged(MouseEvent e) {
+                
+                float offsetX = (lastpos.x - e.getX()) * (maxX - minX) / width;
+                float offsetY = (lastpos.y - e.getY()) * (maxY - minY) / height;
+
+                minX += offsetX;
+                minY -= offsetY;
+
+                maxX += offsetX;
+                maxY -= offsetY;
+
+                lastpos = e.getPoint();
+
+                canvas.display();
+
+            }
+
+            @Override
+            public void mouseMoved(MouseEvent e) {
+                lastpos = e.getPoint();
+            }
+            
+            @Override
+            public void mouseWheelMoved(MouseWheelEvent e) {
+                float rotation = e.getWheelRotation() / 25.0f;
+
+                float deltaX = rotation * (maxX - minX);
+                float deltaY = rotation * (maxY - minY);
+
+                // offset for "zoom to cursor"
+                float offsetX = (e.getX() / (float)width - 0.5f) * deltaX * 2;
+                float offsetY = (e.getY() / (float)height- 0.5f) * deltaY * 2;
+
+                minX += deltaX+offsetX;
+                minY += deltaY-offsetY;
+
+                maxX    +=-deltaX+offsetX;
+                maxY    +=-deltaY-offsetY;
+
+                canvas.display();
+            }
+        };
+
+        canvas.addMouseMotionListener(adapter);
+        canvas.addMouseWheelListener(adapter);
+    }
+
+    public void dispose(GLAutoDrawable drawable) {
+    }
+
+    public static void main(String args[]) {
+        SwingUtilities.invokeLater(new Runnable() {
+
+            public void run() {
+                new Fractal(500, 500);
+            }
+        });
+    }
+
+}
diff --git a/src/com/mbien/opencl/demos/fractal/Mandelbrot.cl b/src/com/mbien/opencl/demos/fractal/Mandelbrot.cl
new file mode 100644
index 0000000..e6583f4
--- /dev/null
+++ b/src/com/mbien/opencl/demos/fractal/Mandelbrot.cl
@@ -0,0 +1,44 @@
+/**
+ * For a description of this algorithm please refer to
+ * http://en.wikipedia.org/wiki/Mandelbrot_set
+ * @author Michael Bien
+ */
+kernel void mandelbrot(
+        global uint *output,
+        const int width, const int height,
+        const float x0, const float y0,
+        const float x1, const float y1,
+        global uint *colorMap, const int colorMapSize, const int maxIterations) {
+
+    unsigned int ix = get_global_id(0);
+    unsigned int iy = get_global_id(1);
+
+    float r = x0 + ix * (x1-x0) / width;
+    float i = y0 + iy * (y1-y0) / height;
+
+    float x = 0;
+    float y = 0;
+
+    float magnitudeSquared = 0;
+    int iteration = 0;
+
+    while (magnitudeSquared < 4 && iteration < maxIterations) {
+        float x2 = x*x;
+        float y2 = y*y;
+        y = 2 * x * y + i;
+        x = x2 - y2 + r;
+        magnitudeSquared = x2+y2;
+        iteration++;
+    }
+
+    if (iteration == maxIterations)  {
+        output[iy * width + ix] = 0;
+    }else {
+        float alpha = (float)iteration / maxIterations;
+        int colorIndex = (int)(alpha * colorMapSize);
+        output[iy * width + ix] = colorMap[colorIndex];
+      // monochrom
+      //  output[iy * width + ix] = 255*iteration/maxIterations;
+    }
+
+}
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