CLAUDE: GpuQuadJna updateTasks + getWH + native tp_proc_get_tasks (pre-empt task-readback NPE)

updateTasks is called all over ImageDtt right after execSetTilesOffsets (reads gpu_ftasks back to
rebuild TpTask[] with computed centerXY/disp_dist) -> tp_proc_get_tasks (DtoH). getWH returns full
frame (base returns null gpu_clt_wh). Proactive (locating same-cause base-method derefs of null
JCuda fields).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/main/java/com/elphel/imagej/gpu/jna/GpuQuadJna.java

@@ -196,6 +196,18 @@ public class GpuQuadJna extends GpuQuad {
         lib.tp_proc_set_tasks(proc, ftasks, num_task_tiles, task_size * num_task_tiles);
     }
 
+    // Read tasks back after calculate_tiles_offsets (computed centerXY/disp_dist) -> rebuild TpTask[].
+    @Override public void updateTasks(TpTask[] tile_tasks, boolean use_aux) {
+        num_task_tiles = tile_tasks.length;
+        int task_size = getTaskSize();
+        float[] ftasks = new float[task_size * num_task_tiles];
+        lib.tp_proc_get_tasks(proc, ftasks, task_size * num_task_tiles);
+        for (int i = 0; i < num_task_tiles; i++)
+            tile_tasks[i] = new TpTask(getNumSensors(), ftasks, i, use_aux);
+    }
+    // Full-frame dims (base returns the null gpu_clt_wh).
+    @Override public int[] getWH(boolean use_ref) { return new int[]{img_width, img_height}; }
+
     // ---- geometry execution (calc_reverse_distortions + rot_derivs + calculate_tiles_offsets) ----
     @Override public void execSetTilesOffsets(boolean uniform_grid) {
         setGeometryCorrection();                                   // gc

src/main/java/com/elphel/imagej/gpu/jna/TpJna.java

@@ -74,6 +74,7 @@ public interface TpJna extends Library {
     /** use_center_image: broadcast one center image to all sensors (FPN back-prop mode). */
     int     tp_proc_set_center_image(Pointer proc, float[] d);
     int     tp_proc_set_tasks(Pointer proc, float[] ftasks, int ntiles, int totalFloats);
+    int     tp_proc_get_tasks(Pointer proc, float[] out, int totalFloats);
     int     tp_proc_exec_geometry(Pointer proc, int uniformGrid);
     /** convert_direct: ref_scene (0/1 -> clt vs clt_ref), erase_clt (-1/0/1), no_kernels (0/1). */
     int     tp_proc_exec_convert_direct(Pointer proc, int refScene, int eraseClt, int noKernels);