2 files changed, 174 insertions, 20 deletions

diff --git a/src/com/mbien/opencl/CLProgram.java b/src/com/mbien/opencl/CLProgram.java
index 829809de..562df69b 100644
--- a/src/com/mbien/opencl/CLProgram.java
+++ b/src/com/mbien/opencl/CLProgram.java
@@ -206,6 +206,10 @@ public class CLProgram extends CLObject implements CLResource {
      */
     public CLProgram build(String options, CLDevice... devices) {
 
+        if(released) {
+            throw new CLException("can not build a released program");
+        }
+
         if(!kernels.isEmpty()) {
             //No changes to the program executable are allowed while there are
             //kernel objects associated with a program object.
@@ -214,7 +218,7 @@ public class CLProgram extends CLObject implements CLResource {
 
         PointerBuffer deviceIDs = null;
         int count = 0;
-        if(devices != null) {
+        if(devices != null && devices.length != 0) {
             deviceIDs = PointerBuffer.allocateDirect(devices.length);
             for (int i = 0; i < devices.length; i++) {
                 deviceIDs.put(i, devices[i].ID);
@@ -223,6 +227,11 @@ public class CLProgram extends CLObject implements CLResource {
             count = devices.length;
         }
 
+        // nvidia driver doesn't like empty strings
+        if(options != null && options.trim().isEmpty()) {
+            options = null;
+        }
+
         // invalidate build status
         buildStatusMap = null;
         executable = false;
@@ -238,6 +247,13 @@ public class CLProgram extends CLObject implements CLResource {
     }
 
     /**
+     * Prepares the build for this program by returning a {@link CLProgramBuilder}.
+     */
+    public CLProgramBuilder prepare() {
+        return new CLProgramBuilder(this);
+    }
+
+    /**
      * Creates a kernel with the specified kernel name.
      */
     public CLKernel createCLKernel(String kernelName) {
@@ -256,24 +272,6 @@ public class CLProgram extends CLObject implements CLResource {
     }
 
     /**
-     * Creates n instances of a kernel with the specified kernel name.
-     */
-    /*
-    public CLKernel[] createCLKernels(String kernelName, int instanceCount) {
-
-        if(released) {
-            return new CLKernel[0];
-        }
-
-        CLKernel[] newKernels = new CLKernel[instanceCount];
-        for (int i = 0; i < newKernels.length; i++) {
-            newKernels[i] = createCLKernel(kernelName);
-        }
-        return newKernels;
-    }
-    */
-
-    /**
      * Creates all kernels of this program and stores them a Map with the kernel name as key.
      */
     public Map<String, CLKernel> createCLKernels() {
@@ -596,7 +594,7 @@ public class CLProgram extends CLObject implements CLResource {
          * This option is ignored for single precision numbers if the device does not support single precision denormalized
          * numbers i.e. {@link CLDevice.FPConfig#DENORM} is not present in the set returned by {@link CLDevice#getSingleFPConfig()}<br>
          * This option is ignored for double precision numbers if the device does not support double precision or if it does support
-         * double precison but {@link CLDevice.FPConfig#DENORM} is not present in the set returned by {@link CLDevice#getDoubleFPConfig()}.<br>
+         * double precision but {@link CLDevice.FPConfig#DENORM} is not present in the set returned by {@link CLDevice#getDoubleFPConfig()}.<br>
          * This flag only applies for scalar and vector single precision floating-point variables and computations on
          * these floating-point variables inside a program. It does not apply to reading from or writing to image objects.
          */
diff --git a/src/com/mbien/opencl/CLProgramBuilder.java b/src/com/mbien/opencl/CLProgramBuilder.java
new file mode 100644
index 00000000..3f7ab07b
--- /dev/null
+++ b/src/com/mbien/opencl/CLProgramBuilder.java
@@ -0,0 +1,156 @@
+package com.mbien.opencl;
+
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+
+/**
+ * CLProgramBuilder is a helper for building programs with more complex configurations or
+ * building multiple programs with the same configuration.
+ * @see CLProgram#prepare()
+ * @author Michael Bien
+ */
+public final class CLProgramBuilder {
+
+    private transient CLProgram program;
+    private final Set<String> optionList = new HashSet<String>();
+    private final Set<String> defineList = new HashSet<String>();
+    private final Set<CLDevice> deviceList = new HashSet<CLDevice>();
+
+    public CLProgramBuilder() {  }
+
+    public CLProgramBuilder(CLProgram program) {
+        this.program = program;
+    }
+
+    public CLProgramBuilder withOption(String option) {
+        this.optionList.add(option);
+        return this;
+    }
+
+    public CLProgramBuilder withOptions(String... options) {
+        for (String option : options) {
+            this.optionList.add(option);
+        }
+        return this;
+    }
+
+    public CLProgramBuilder withDefine(String name) {
+        this.defineList.add(CLProgram.define(name));
+        return this;
+    }
+
+    public CLProgramBuilder withDefines(String... names) {
+        for (String name : names) {
+            this.defineList.add(CLProgram.define(name));
+        }
+        return this;
+    }
+
+    public CLProgramBuilder withDefine(String name, Object value) {
+        this.defineList.add(CLProgram.define(name, value.toString()));
+        return this;
+    }
+
+    public CLProgramBuilder withDefines(Map<String, String> defines) {
+        for (String name : defines.keySet()) {
+            defineList.add(CLProgram.define(name, defines.get(name)));
+        }
+        return this;
+    }
+
+    public CLProgramBuilder forDevice(CLDevice device) {
+        CLDevice[] devices = new CLDevice[]{device};
+        for (CLDevice device1 : devices) {
+            this.deviceList.add(device1);
+        }
+        return this;
+    }
+
+    public CLProgramBuilder forDevices(CLDevice... devices) {
+        for (CLDevice device : devices) {
+            this.deviceList.add(device);
+        }
+        return this;
+    }
+
+    /**
+     * Builds or rebuilds a program.
+     */
+    public CLProgram build() {
+        return build(program);
+    }
+
+    /**
+     * Builds or rebuilds a program.
+     */
+    public CLProgram build(CLProgram program) {
+        if(program == null) {
+            throw new NullPointerException("no program has been set");
+        }
+        List<String> setup = new ArrayList<String>();
+        setup.addAll(optionList);
+        setup.addAll(defineList);
+        String options = CLProgram.optionsOf(setup.toArray(new String[setup.size()]));
+        CLDevice[] devices = deviceList.toArray(new CLDevice[deviceList.size()]);
+        return program.build(options, devices);
+    }
+
+    /**
+     * Resets this builder's configuration like options, devices and defines.
+     */
+    public CLProgramBuilder reset() {
+        optionList.clear();
+        defineList.clear();
+        deviceList.clear();
+        return this;
+    }
+
+    public CLProgram getProgram() {
+        return program;
+    }
+
+    /**
+     * Sets the program which should be build.
+     */
+    public CLProgramBuilder setProgram(CLProgram program) {
+        this.program = program;
+        return this;
+    }
+
+    @Override
+    public String toString() {
+        final StringBuilder sb = new StringBuilder();
+        sb.append("CLProgramBuilder");
+        sb.append("{optionList=").append(optionList);
+        sb.append(", defineList=").append(defineList);
+        sb.append(", deviceList=").append(deviceList);
+        sb.append('}');
+        return sb.toString();
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+
+        CLProgramBuilder that = (CLProgramBuilder) o;
+
+        if (defineList != null ? !defineList.equals(that.defineList) : that.defineList != null) return false;
+        if (deviceList != null ? !deviceList.equals(that.deviceList) : that.deviceList != null) return false;
+        if (optionList != null ? !optionList.equals(that.optionList) : that.optionList != null) return false;
+
+        return true;
+    }
+
+    @Override
+    public int hashCode() {
+        int result = optionList != null ? optionList.hashCode() : 0;
+        result = 31 * result + (defineList != null ? defineList.hashCode() : 0);
+        result = 31 * result + (deviceList != null ? deviceList.hashCode() : 0);
+        return result;
+    }
+}