1 files changed, 136 insertions, 0 deletions
diff --git a/indra/newview/llflycam.cpp b/indra/newview/llflycam.cpp
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+++ b/indra/newview/llflycam.cpp
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+/**
+ * @file llflycam.cpp
+ * @brief LLFlycam class implementation
+ *
+ * $LicenseInfo:firstyear=2024&license=viewerlgpl$
+ * Second Life Viewer Source Code
+ * Copyright (C) 2024, Linden Research, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License only.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
+ * $/LicenseInfo$
+ */
+
+#include "llflycam.h"
+
+#include <algorithm>
+#include "llcamera.h"
+#include "llcoordframe.h"
+
+LLFlycam::LLFlycam()
+{
+}
+
+
+void LLFlycam::setTransform(const LLVector3& position, const LLQuaternion& rotation)
+{
+    mPosition = position;
+    mRotation = rotation;
+    mRotation.normalize();
+}
+
+void LLFlycam::getTransform(LLVector3& position_out, LLQuaternion& rotation_out)
+{
+    position_out = mPosition;
+    rotation_out = mRotation;
+}
+
+// 'view' is expected to be in radians
+void LLFlycam::setView(F32 view)
+{
+    mView = std::clamp(view, MIN_FIELD_OF_VIEW, MAX_FIELD_OF_VIEW);
+}
+
+
+void LLFlycam::setLinearVelocity(const LLVector3& velocity)
+{
+    // Note: this math expects velocity components to be in range [-1.0, 1.0]
+    mLinearVelocity = velocity;
+}
+
+
+void LLFlycam::setPitchRate(F32 pitch_rate)
+{
+    // Note: this math expects pitch_rate to be in range [-1.0, 1.0]
+    constexpr F32 PITCH_RATE_FACTOR = 0.75f;
+    mPitchRate = pitch_rate * PITCH_RATE_FACTOR;
+}
+
+
+void LLFlycam::setYawRate(F32 yaw_rate)
+{
+    // Note: this math expects yaw_rate to be in range [-1.0, 1.0]
+    constexpr F32 YAW_RATE_FACTOR = 0.90f;
+    mYawRate = yaw_rate * YAW_RATE_FACTOR;
+}
+
+
+void LLFlycam::setZoomRate(F32 zoom_rate)
+{
+    // Note: this math expects zoom_rate to be in range [-1.0, 1.0]
+    constexpr F32 FULL_ZOOM_PERIOD = 5.0f; // seconds
+    constexpr F32 ZOOM_RATE_FACTOR = (MAX_FIELD_OF_VIEW - MIN_FIELD_OF_VIEW) / FULL_ZOOM_PERIOD;
+    mZoomRate = zoom_rate * ZOOM_RATE_FACTOR;
+}
+
+
+void LLFlycam::integrate(F32 delta_time)
+{
+    // cap delta_time to slow camera motion when framerates are low
+    constexpr F32 MAX_DELTA_TIME = 0.2f;
+    if (delta_time > MAX_DELTA_TIME)
+    {
+        delta_time = MAX_DELTA_TIME;
+    }
+
+    // Note: we modulate pitch and yaw rates by view ratio
+    // to make pitch and yaw work better when zoomed in close
+    F32 angle = delta_time * mPitchRate * (mView / DEFAULT_FIELD_OF_VIEW);
+    bool needs_renormalization = false;
+    if (fabsf(angle) > 0.0f)
+    {
+        LLQuaternion dQ;
+        dQ.setAngleAxis(angle, 0.0f, 1.0f, 0.0f);
+        mRotation = dQ * mRotation;
+        needs_renormalization = true;
+    }
+
+    angle = delta_time * mYawRate * (mView / DEFAULT_FIELD_OF_VIEW);
+    if (fabsf(angle) > 0.0f)
+    {
+        LLQuaternion dQ;
+        dQ.setAngleAxis(angle, 0.0f, 0.0f, 1.0f);
+        mRotation = mRotation * dQ;
+        needs_renormalization = true;
+    }
+
+    if (mLinearVelocity.lengthSquared() > 0.0f)
+    {
+        mPosition += (delta_time * mLinearVelocity) * mRotation;
+    }
+
+    if (mZoomRate != 0.0f)
+    {
+        // Note: we subtract the delta because "positive" zoom (e.g. "zoom in")
+        // produces smaller view angle
+        mView = std::clamp(mView - delta_time * mZoomRate, MIN_FIELD_OF_VIEW, MAX_FIELD_OF_VIEW);
+    }
+
+    if (needs_renormalization)
+    {
+        mRotation.normalize();
+    }
+}