Fix OpenCV load in simuated robot projects (PhotonVision#1001)

mcm001 · Nov 5, 2023 · 524b135 · 524b135
1 parent 623b4e5
commit 524b135
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Showing 4 changed files with 14 additions and 20 deletions.
diff --git a/photon-lib/src/main/java/org/photonvision/simulation/PhotonCameraSim.java b/photon-lib/src/main/java/org/photonvision/simulation/PhotonCameraSim.java
@@ -33,13 +33,11 @@
 import edu.wpi.first.math.MathUtil;
 import edu.wpi.first.math.Pair;
 import edu.wpi.first.math.geometry.Pose3d;
-import edu.wpi.first.util.CombinedRuntimeLoader;
 import edu.wpi.first.util.WPIUtilJNI;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Optional;
 import java.util.stream.Collectors;
-import org.opencv.core.Core;
 import org.opencv.core.CvType;
 import org.opencv.core.Mat;
 import org.opencv.core.Point;
@@ -95,11 +93,7 @@ public class PhotonCameraSim implements AutoCloseable {
     private boolean videoSimProcEnabled = true;
 
     static {
-        try {
-            CombinedRuntimeLoader.loadLibraries(OpenCVHelp.class, Core.NATIVE_LIBRARY_NAME, "cscorejni");
-        } catch (Exception e) {
-            throw new RuntimeException("Failed to load native libraries!", e);
-        }
+        OpenCVHelp.forceLoadOpenCV();
     }
 
     @Override

diff --git a/photon-lib/src/main/java/org/photonvision/simulation/VideoSimUtil.java b/photon-lib/src/main/java/org/photonvision/simulation/VideoSimUtil.java
@@ -28,7 +28,6 @@
 import edu.wpi.first.math.geometry.Pose3d;
 import edu.wpi.first.math.geometry.Translation3d;
 import edu.wpi.first.math.util.Units;
-import edu.wpi.first.util.CombinedRuntimeLoader;
 import java.awt.image.BufferedImage;
 import java.io.IOException;
 import java.util.ArrayList;
@@ -67,11 +66,7 @@ public class VideoSimUtil {
     private static double fieldWidth = 8.0137;
 
     static {
-        try {
-            CombinedRuntimeLoader.loadLibraries(OpenCVHelp.class, Core.NATIVE_LIBRARY_NAME, "cscorejni");
-        } catch (Exception e) {
-            throw new RuntimeException("Failed to load native libraries!", e);
-        }
+        OpenCVHelp.forceLoadOpenCV();
 
         // create Mats of 8x8 apriltag images
         for (int i = 0; i < VideoSimUtil.kNumTags16h5; i++) {

diff --git a/photon-targeting/build.gradle b/photon-targeting/build.gradle
@@ -8,6 +8,7 @@ apply from: "${rootDir}/shared/common.gradle"
 dependencies {
     implementation wpilibTools.deps.wpilibJava("wpimath")
     implementation wpilibTools.deps.wpilibJava("apriltag")
+    implementation wpilibTools.deps.wpilibJava("cscore")
     implementation wpilibTools.deps.wpilibOpenCvJava("frc" + wpi.frcYear.get(), wpi.versions.opencvVersion.get())
 
     implementation group: "org.ejml", name: "ejml-simple", version: wpi.versions.ejmlVersion.get()

diff --git a/photon-targeting/src/main/java/org/photonvision/estimation/OpenCVHelp.java b/photon-targeting/src/main/java/org/photonvision/estimation/OpenCVHelp.java
@@ -17,6 +17,7 @@
 
 package org.photonvision.estimation;
 
+import edu.wpi.first.cscore.CvSink;
 import edu.wpi.first.math.Matrix;
 import edu.wpi.first.math.Nat;
 import edu.wpi.first.math.Num;
@@ -26,7 +27,6 @@
 import edu.wpi.first.math.geometry.Transform3d;
 import edu.wpi.first.math.geometry.Translation3d;
 import edu.wpi.first.math.numbers.*;
-import edu.wpi.first.util.CombinedRuntimeLoader;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
@@ -52,13 +52,17 @@ public final class OpenCVHelp {
     private static Rotation3d NWU_TO_EDN;
     private static Rotation3d EDN_TO_NWU;
 
-    static {
-        try {
-            CombinedRuntimeLoader.loadLibraries(OpenCVHelp.class, Core.NATIVE_LIBRARY_NAME, "cscorejni");
-        } catch (Exception e) {
-            throw new RuntimeException("Failed to load native libraries!", e);
-        }
+    // Creating a cscore object is sufficient to load opencv, per
+    // https://www.chiefdelphi.com/t/unsatisfied-link-error-when-simulating-java-robot-code-using-opencv/426731/4
+    private static CvSink dummySink = null;
 
+    public static void forceLoadOpenCV() {
+        if (dummySink != null) return;
+        dummySink = new CvSink("ignored");
+        dummySink.close();
+    }
+
+    static {
         NWU_TO_EDN = new Rotation3d(Matrix.mat(Nat.N3(), Nat.N3()).fill(0, -1, 0, 0, 0, -1, 1, 0, 0));
         EDN_TO_NWU = new Rotation3d(Matrix.mat(Nat.N3(), Nat.N3()).fill(0, 0, 1, -1, 0, 0, 0, -1, 0));
     }