1 files changed, 317 insertions, 0 deletions
diff --git a/dev/MinGfx/src/unicam.cc b/dev/MinGfx/src/unicam.cc
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+++ b/dev/MinGfx/src/unicam.cc
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+/*
+ Copyright (c) 2017,2018 Regents of the University of Minnesota.
+ All Rights Reserved.
+ See corresponding header file for details.
+ */
+
+#include "unicam.h"
+
+#include "gfxmath.h"
+
+namespace mingfx {
+
+
+UniCam::UniCam() : state_(UniCamState::START), defaultDepth_(4.0), boundingSphereRad_(1.0), 
+    dollyFactor_(1.0), dollyInitialized_(false), elapsedTime_(0.0), hitGeometry_(false), 
+    rotAngularVel_(0.0), rotInitialized_(false), rotLastTime_(0.0), showIcon_(false)
+{
+}
+
+UniCam::UniCam(const Matrix4 &initialViewMatrix) :
+    state_(UniCamState::START), defaultDepth_(4.0), V_(initialViewMatrix), boundingSphereRad_(1.0), 
+    dollyFactor_(1.0), dollyInitialized_(false), elapsedTime_(0.0), hitGeometry_(false), 
+    rotAngularVel_(0.0), rotInitialized_(false), rotLastTime_(0.0), showIcon_(false)
+{
+}
+
+UniCam::~UniCam()
+{
+}
+
+
+void UniCam::recalc_angular_vel() {
+    // update angular velocity
+    float cutoff = (float)elapsedTime_ - 0.2f; // look just at the last 0.2 secs
+    while ((rotAngularVelBuffer_.size()) && (rotAngularVelBuffer_[0].first < cutoff)) {
+        rotAngularVelBuffer_.erase(rotAngularVelBuffer_.begin());
+    }
+    rotAngularVel_ = 0.0;
+    if (rotAngularVelBuffer_.size()) {
+        for (int i=0; i<rotAngularVelBuffer_.size(); i++) {
+            rotAngularVel_ += rotAngularVelBuffer_[i].second;
+        }
+        rotAngularVel_ /= rotAngularVelBuffer_.size();
+    }
+    //std::cout << rotAngularVelBuffer_.size() << " " << rotAngularVel_ << std::endl;
+}
+
+
+void UniCam::OnButtonDown(const Point2 &mousePos, float mouseZ) {
+    if (state_ == UniCamState::START) {
+        initialClickPos_ = mousePos;
+        mouseLast_ = mousePos;
+        elapsedTime_ = 0.0;
+        rotInitialized_ = false;
+        dollyInitialized_ = false;
+        
+        hitGeometry_ = (mouseZ < 1.0);
+        if (hitGeometry_) {
+            hitPoint_ = GfxMath::ScreenToWorld(V_, Pdraw_, mousePos, mouseZ);
+        }
+        else {
+            hitPoint_ = GfxMath::ScreenToDepthPlane(V_, Pdraw_, Point2(0,0), defaultDepth_);
+        }
+        showIcon_ = true;
+        state_ = UniCamState::PAN_DOLLY_ROT_DECISION;
+    }
+    else if (state_ == UniCamState::ROT_WAIT_FOR_SECOND_CLICK) {
+        // we have the second click now, and we will start the trackball rotate interaction
+        state_ = UniCamState::ROT;
+    }
+    else if (state_ == UniCamState::SPINNING) {
+        // this click is to "catch" the model, stopping it from spinning.
+        state_ = UniCamState::START;
+    }
+    else {
+        std::cerr << "UniCam::OnButtonDown() unexpected state." << std::endl;
+    }
+}
+
+void UniCam::OnDrag(const Point2 &mousePos) {
+    if (state_ == UniCamState::PAN_DOLLY_ROT_DECISION) {
+        const double panMovementThreshold  = 0.01;
+        const double dollyMovementThreshold = 0.01;
+        if (fabs(mousePos[0] - initialClickPos_[0]) > panMovementThreshold) {
+            // already lots of horizontal movement, we can go right to pan
+            state_ = UniCamState::PAN;
+            showIcon_ = false;
+        }
+        else if (fabs(mousePos[1] - initialClickPos_[1]) > dollyMovementThreshold) {
+            // already lots of vertical movement, we can go right to dolly
+            state_ = UniCamState::DOLLY;
+            showIcon_ = false;
+        }
+        else if (elapsedTime_ > 1.0) {
+            // timeout, this was not a quick click to set a center of rotation,
+            // so there is no intent to rotate.  instead we will be doing either
+            // pan or dolly.
+            state_ = UniCamState::PAN_DOLLY_DECISION;
+            showIcon_ = false;
+        }
+    }
+    else if (state_ == UniCamState::PAN_DOLLY_DECISION) {
+        const double panMovementThreshold  = 0.01;
+        const double dollyMovementThreshold = 0.01;
+        if (fabs(mousePos[0] - initialClickPos_[0]) > panMovementThreshold) {
+            // lots of horizontal movement, go to pan
+            state_ = UniCamState::PAN;
+        }
+        else if (fabs(mousePos[1] - initialClickPos_[1]) > dollyMovementThreshold) {
+            // lots of vertical movement, go to dolly
+            state_ = UniCamState::DOLLY;
+        }
+    }
+    else if (state_ == UniCamState::PAN) {
+        Matrix4 camMat = V_.Inverse();
+        Point3 eye = camMat.ColumnToPoint3(3);
+        Vector3 look = -camMat.ColumnToVector3(2);
+        float depth = (hitPoint_ - eye).Dot(look);
+        Point3 pWorld1 = GfxMath::ScreenToDepthPlane(V_, Pdraw_, mouseLast_, depth);
+        Point3 pWorld2 = GfxMath::ScreenToDepthPlane(V_, Pdraw_, mousePos, depth);
+        V_ = V_ * Matrix4::Translation(pWorld2 - pWorld1);
+    }
+    else if (state_ == UniCamState::DOLLY) {
+        if (!dollyInitialized_) {
+            // Setup dollyFactor so that if you move the mouse to the bottom of the screen, the point
+            // you clicked on will be right on top of the camera.
+            Matrix4 camMat = V_.Inverse();
+            Point3 eye = camMat.ColumnToPoint3(3);
+            Vector3 look = -camMat.ColumnToVector3(2);
+            float depth = (hitPoint_ - eye).Dot(look);
+            float deltaYToBottom = initialClickPos_[1] + 1;
+            dollyFactor_ = depth / deltaYToBottom;
+            dollyInitialized_ = true;
+        }
+        Vector3 d(0, 0, -dollyFactor_ * (mousePos[1] - mouseLast_[1]));
+        V_ = Matrix4::Translation(d) * V_ ;
+    }
+    else if (state_ == UniCamState::ROT) {
+        if (!rotInitialized_) {
+            float depth = 0.0;
+            if (hitGeometry_) {
+                // if we hit some geometry, then make that the center of rotation
+                boundingSphereCtr_ = hitPoint_;
+                Matrix4 camMat = V_.Inverse();
+                Point3 eye = camMat.ColumnToPoint3(3);
+                Vector3 look = -camMat.ColumnToVector3(2);
+                depth = (hitPoint_ - eye).Dot(look);
+            }
+            else {
+                // if we did not hit any geometry, then center the bounding sphere in front of
+                // the camera at a distance that can be configured by the user.
+                boundingSphereCtr_ = GfxMath::ScreenToDepthPlane(V_, Pdraw_, Point2(0,0), defaultDepth_);
+                depth = defaultDepth_;
+            }
+            
+            // determine the size of the bounding sphere by projecting a screen-space
+            // distance of 0.75 units to the depth of the sphere center
+            Point3 pWorld1 = GfxMath::ScreenToDepthPlane(V_, Pdraw_, Point2(0,0), depth);
+            Point3 pWorld2 = GfxMath::ScreenToDepthPlane(V_, Pdraw_, Point2(0.75,0), depth);
+            boundingSphereRad_ = (pWorld2-pWorld1).Length();
+            
+            rotLastTime_ = elapsedTime_;
+            rotAngularVelBuffer_.clear();
+            rotInitialized_ = true;
+        }
+        else {
+            // Do a trackball rotation based on the mouse movement and the bounding sphere
+            // setup earlier.
+
+            Matrix4 camMat = V_.Inverse();
+            Point3 eye = camMat.ColumnToPoint3(3);
+            
+            // last mouse pos
+            bool hit1 = false;
+            Point3 mouse3D1 = GfxMath::ScreenToNearPlane(V_, Pdraw_, mouseLast_);
+            Ray ray1(eye, mouse3D1 - eye);
+            float t1;
+            Point3 iPoint1;
+            if (ray1.IntersectSphere(boundingSphereCtr_, boundingSphereRad_, &t1, &iPoint1)) {
+                hit1 = true;
+            }
+            
+            // current mouse pos
+            bool hit2 = false;
+            Point3 mouse3D2 = GfxMath::ScreenToNearPlane(V_, Pdraw_, mousePos);
+            Ray ray2(eye, mouse3D2 - eye);
+            float t2;
+            Point3 iPoint2;
+            if (ray2.IntersectSphere(boundingSphereCtr_, boundingSphereRad_, &t2, &iPoint2)) {
+                hit2 = true;
+            }
+            rotLastIPoint_ = iPoint2;
+            
+            if (hit1 && hit2) {
+                Vector3 v1 = (iPoint1 - boundingSphereCtr_).ToUnit();
+                Vector3 v2 = (iPoint2 - boundingSphereCtr_).ToUnit();
+                
+                rotAxis_ = v1.Cross(v2).ToUnit();
+                float angle = std::acos(v1.Dot(v2));
+
+                if (std::isfinite(angle)) {
+                    Matrix4 R = Matrix4::Rotation(boundingSphereCtr_, rotAxis_, angle);
+                    R = R.Orthonormal();
+                    V_ = V_ * R;
+                    //V_ = V_.orthonormal();
+                
+                    // add a sample to the angular vel vector
+                    double dt = elapsedTime_ - rotLastTime_;
+                    double avel = angle / dt;
+                    if (std::isfinite(avel)) {
+                        rotAngularVelBuffer_.push_back(std::make_pair(elapsedTime_, avel));
+                    }
+                    rotLastTime_ = elapsedTime_;
+                }
+            }
+            
+            recalc_angular_vel();
+        }
+    }
+    else if (state_ == UniCamState::START) {
+        // picked up a little mouse movement after "catching" a spinning model
+        // nothing to do, just wait for the button up.
+    }
+    else {
+        std::cerr << "UniCam::OnDrag() unexpected state." << std::endl;
+    }
+    mouseLast_ = mousePos;
+}
+
+void UniCam::OnButtonUp(const Point2 &mousePos) {
+    if (state_ == UniCamState::PAN_DOLLY_ROT_DECISION) {
+        // here, we got a quick click of the mouse to indicate a center of rotation
+        // so we now go into a mode of waiting for a second click to start rotating
+        // around that point.
+        state_ = UniCamState::ROT_WAIT_FOR_SECOND_CLICK;
+    }
+    else if (state_ == UniCamState::ROT) {
+        showIcon_ = false;
+        // if we are leaving the rotation state and the angular velocity is
+        // greater than some thresold, then the user has "thrown" the model
+        // keep rotating the same way by entering the spinning state.
+
+        recalc_angular_vel();
+        //std::cout << "check for spin: " << n-start << " " << rotAngularVel_ << " " << avel2 << std::endl;
+
+        const float threshold = 0.2f;
+        if (std::fabs(rotAngularVel_) > threshold) {
+            state_ = UniCamState::SPINNING;
+        }
+        else {
+            state_ = UniCamState::START;
+        }
+    }
+    else {
+        showIcon_ = false;
+        // all other cases go back to the start state
+        state_ = UniCamState::START;
+    }
+}
+
+void UniCam::AdvanceAnimation(double dt) {
+    elapsedTime_ += dt;
+    
+    if (state_ == UniCamState::SPINNING) {
+        double deltaT = elapsedTime_ - rotLastTime_;
+        rotLastTime_ = elapsedTime_;
+        double angle = (double)rotAngularVel_ * deltaT;
+        Matrix4 R = Matrix4::Rotation(boundingSphereCtr_, rotAxis_, (float)angle);
+        //R = R.orthonormal();
+        V_ = V_ * R;
+    }
+}
+
+
+void UniCam::Draw(const Matrix4 &projectionMatrix) {
+    Pdraw_ = projectionMatrix;
+    
+    if (showIcon_) {
+        Matrix4 camMat = V_.Inverse();
+        Point3 eye = camMat.ColumnToPoint3(3);
+        Vector3 look = -camMat.ColumnToVector3(2);
+        float depth = (hitPoint_ - eye).Dot(look);
+        Point3 pWorld1 = GfxMath::ScreenToDepthPlane(V_, Pdraw_, Point2(0.f,0.f), depth);
+        Point3 pWorld2 = GfxMath::ScreenToDepthPlane(V_, Pdraw_, Point2(0.015f,0.f), depth);
+        float rad = (pWorld2 - pWorld1).Length();
+        Matrix4 M = Matrix4::Translation(hitPoint_ - Point3::Origin()) * Matrix4::Scale(Vector3(rad, rad, rad));
+        quickShapes_.DrawSphere(M, V_, Pdraw_, Color(0,0,0));
+    }
+}
+
+
+Matrix4 UniCam::view_matrix() {
+    return V_;
+}
+
+void UniCam::set_view_matrix(Matrix4 viewMatrix) {
+    V_ = viewMatrix;
+}
+
+void UniCam::set_default_depth(float d) {
+    defaultDepth_ = d;
+}
+
+Point3 UniCam::eye() {
+    Matrix4 camMat = V_.Inverse();
+    return camMat.ColumnToPoint3(3);
+}
+
+Vector3 UniCam::look() {
+    Matrix4 camMat = V_.Inverse();
+    return -camMat.ColumnToVector3(2);
+}
+
+
+
+
+} // end namespace