Add Photonlib (#231)

Merges Photonlib into Photonvision, along with the Photonlib code examples. Also creates a new PhotonTargeting library teams can depend on.
2026-06-23 01:21:40 +00:00 · 2021-01-16 20:41:47 -08:00
parent 58b39f47aa
commit 2e1b3d0f83
79 changed files with 5867 additions and 142 deletions
--- a/photon-lib/src/main/native/cpp/photonlib/SimVisionSystem.cpp
+++ b/photon-lib/src/main/native/cpp/photonlib/SimVisionSystem.cpp
@@ -0,0 +1,119 @@
+/*
+ * Copyright (C) Photon Vision.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "photonlib/SimVisionSystem.h"
+
+#include <cmath>
+
+#include <units/angle.h>
+#include <units/length.h>
+
+namespace photonlib {
+
+SimVisionSystem::SimVisionSystem(const std::string& name,
+                                 units::degree_t camDiagFOV,
+                                 units::degree_t camPitch,
+                                 frc::Transform2d cameraToRobot,
+                                 units::meter_t cameraHeightOffGround,
+                                 units::meter_t maxLEDRange, int cameraResWidth,
+                                 int cameraResHeight, double minTargetArea)
+    : camDiagFOV(camDiagFOV),
+      camPitch(camPitch),
+      cameraToRobot(cameraToRobot),
+      cameraHeightOffGround(cameraHeightOffGround),
+      maxLEDRange(maxLEDRange),
+      cameraResWidth(cameraResWidth),
+      cameraResHeight(cameraResHeight),
+      minTargetArea(minTargetArea) {
+  double hypotPixels = std::hypot(cameraResWidth, cameraResHeight);
+  camHorizFOV = camDiagFOV * cameraResWidth / hypotPixels;
+  camVertFOV = camDiagFOV * cameraResHeight / hypotPixels;
+
+  cam = SimPhotonCamera(name);
+  tgtList.clear();
+}
+
+void SimVisionSystem::AddSimVisionTarget(SimVisionTarget tgt) {
+  tgtList.push_back(tgt);
+}
+
+void SimVisionSystem::MoveCamera(frc::Transform2d newCameraToRobot,
+                                 units::meter_t newCamHeight,
+                                 units::degree_t newCamPitch) {
+  cameraToRobot = newCameraToRobot;
+  cameraHeightOffGround = newCamHeight;
+  camPitch = newCamPitch;
+}
+
+void SimVisionSystem::ProcessFrame(frc::Pose2d robotPose) {
+  frc::Pose2d cameraPos = robotPose.TransformBy(cameraToRobot.Inverse());
+  std::vector<PhotonTrackedTarget> visibleTgtList = {};
+
+  for (auto&& tgt : tgtList) {
+    frc::Transform2d camToTargetTrans =
+        frc::Transform2d(cameraPos, tgt.targetPos);
+
+    units::meter_t distAlongGround = camToTargetTrans.Translation().Norm();
+    units::meter_t distVertical =
+        tgt.targetHeightAboveGround - cameraHeightOffGround;
+    units::meter_t distHypot =
+        units::math::hypot(distAlongGround, distVertical);
+
+    double area = tgt.tgtArea.to<double>() / GetM2PerPx(distAlongGround);
+
+    // 2D yaw mode considers the target as a point, and should ignore target
+    // rotation.
+    // Photon reports it in the correct robot reference frame.
+    // IE: targets to the left of the image should report negative yaw.
+    units::degree_t yawAngle =
+        -1.0 * units::math::atan2(camToTargetTrans.Translation().Y(),
+                                  camToTargetTrans.Translation().X());
+    units::degree_t pitchAngle =
+        units::math::atan2(distVertical, distAlongGround) - camPitch;
+
+    if (CamCanSeeTarget(distHypot, yawAngle, pitchAngle, area)) {
+      PhotonTrackedTarget newTgt =
+          PhotonTrackedTarget(yawAngle.to<double>(), pitchAngle.to<double>(),
+                              area, 0.0, camToTargetTrans);
+      visibleTgtList.push_back(newTgt);
+    }
+  }
+
+  units::second_t procDelay(0.0);  // Future - tie this to something meaningful
+  cam.SubmitProcessedFrame(
+      procDelay, wpi::MutableArrayRef<PhotonTrackedTarget>(visibleTgtList));
+}
+
+double SimVisionSystem::GetM2PerPx(units::meter_t dist) {
+  double heightMPerPx = 2 * dist.to<double>() *
+                        units::math::tan(camVertFOV / 2) / cameraResHeight;
+  double widthMPerPx = 2 * dist.to<double>() *
+                       units::math::tan(camHorizFOV / 2) / cameraResWidth;
+  return widthMPerPx * heightMPerPx;
+}
+
+bool SimVisionSystem::CamCanSeeTarget(units::meter_t distHypot,
+                                      units::degree_t yaw,
+                                      units::degree_t pitch, double area) {
+  bool inRange = (distHypot < maxLEDRange);
+  bool inHorizAngle = units::math::abs(yaw) < (camHorizFOV / 2);
+  bool inVertAngle = units::math::abs(pitch) < (camVertFOV / 2);
+  bool targetBigEnough = area > minTargetArea;
+  return (inRange && inHorizAngle && inVertAngle && targetBigEnough);
+}
+
+}  // namespace photonlib