1.02.15 (11-15-2006) Improved spline traversal code: more accurate representation of normal force small bugfixes & parameter edits Bugfix: There is an error with friction on the ground, and falling through the ground. Bugfix: Deleting a control point during spline traversal crashes the application. Bugfix: Gravity value doesn't change sometimes after a record/playback. Bugfix: Identified a problem that caused skater to get stuck on the high part of his spline traversal, or in low gravity. 1.02.14 (11-10-2006) Bugfix: History buttons are displaying total energy without thermal, and calling it total. -Added a thermal energy readout, and fix the total energy value to reflect all energy (not just mechanical energy). Reduced maximum allowed friction. Removed keypress focus from friction control (so it won't change while using thrust). Bugfix: Skater rotates back and forth quickly when at the bottom of a potential well (with friction). Skater can traverse the track while underground. Relabeled "Slow Motion" to "Playback Slow" Bugfix: After some combination of recording and playback, the track graphic becomes dissociated from the skater. -The skater will continue to traverse the path where the track used to be, even after it has been dragged. -This solution is a bit of a hack, not elegant, passes tests, but not guaranteed accurate. 1.02.13 (11-10-2006) Set the bounciness to correspond to the bounciness slider. Set the minimum mass of the skater to 1.0 kg. Fixed a bug that caused save/load to fail sometimes. 1.02.12 (11-8-2006) Bugfix: When you move from space to earth the "use arrow keys to thrust" stays up. Bugfix: When I pulled up energy vs time graph, and messed around with pausing, using cursor, and trying to go again ... it got confused. (Right now I can't get the guy to start moving again ... even when I hit Reset.) Added friction for bounces, when friction is enabled. Added coefficient of restitution as a nonlinear function of friction coefficient. Added insurance that the skater won't pass through a spline while in free-fall. Removed some bogus collision code (for handling ends of spline). Added code that prevents the skater from bouncing back and forth centered on a track. Added save/load for splines & skaters. Added roller-coaster mode (sticky tracks). Deleted some spline traversal code that caused the skater to get stuck. 1.02.11 (11-3-2006) Made the "Return The Skater" button pop up when the skater is partially offscreen (rather than when he is completely offscreen). Bugfix: The man jiggles around when on a nearly horizontal piece of track. 1.02.10 (11-3-2006) Added a "Step" button to playback, live, and record modes. Added another mechanism to reduce energy errors in spline traversal mode. This prevents the problem where the skater gets stuck at a high point at slow velocity. 1.02.09 (11-2-2006) Improvements in spline traversal. Consolidate top/bottom splines. Rewrote Track Toolbox to work at different scales. Track Toolbox code is more elegant. Fixed: Dragging a control point of the skater's track can cause him to freeze. Fixed: Track graphic is stopping one segment before the end of the track. 1.02.08 (10-25-2006) Removed track graphic at ground-level. Added friction to ground. Added preliminary collision code to avoid getting stuck in a track (needs more testing). 1.02.07 (10-18-2006) Bugfixes in old references to FreeSplineMode (1st version) 1.02.06 (10-18-2006) Added improved frame sizes for deployment Added tests Bugfix in spline traversal (if error is too high, rollback change, don't use global energy) 1.02.05 (10-18-2006) Rewrote spline traversal physics. Added tests. 1.02.03 (10-11-2006) Added smoothing for spline traversal (to smooth out jerkiness e.g. at bottom of parabola) Added code so the skater can fall off of spline when his velocity dotted with the unit normal of the segment is positive. Found an instance of unconserved energy and remedied it. Bugfix: pressing go after playing back a sequence inverts the angle. Bugfix: Jet pack isn't visible after reset. Bugfix: When I go to space or set gravity to zero, if I don't use the arrows before I hit RESET, the arrow keys don't work. For example, if you go to space and then hit Reset, the arrows work the far right slider. Bugfix: If you use the space simulation, and change to gravity and back, sometimes (can't be sure how exactly) the thruster/jets don't show on the skater in space mode, though he does move as if they are firing. Seems like the simulation of his jet pack is not quite getting reset. 1.02.02 (10-11-2006) Bugfix: When he's stationary and the track is moved he doesn't fall. Bugfix: When he's oscillating on the track and I lift the track up the skater can end up oscillating back and forth, as if a track was there, but it's not really there. Fixed a memory leak. Bugfix: 'Reset Skater' turns him upside down sometimes. Bugfix: Reset doesn't work any more ... the skater is just frozen (and the red dot doesn't go with him). Bugfix: After a long time, the man is stopped and when I tried to grab him, all I could move around was the little red dot, not the actual skater. 1.02.01 (10-11-2006) Revision of dynamics to address problem at the bottom of a potential well. 1.02 (7-10-2006) Made the grid overlay x-axis match the Energy-Position plot's x-axis. 1.01 (7-10-2006) Posted on main site. 0.00.28 (6-8-2006) Updated gravity controls. Bugfix: Performance degrades when showing history points. Bugfix: Grid intercepted mouse clicks. 0.00.26 (6-8-2006) Fixed gravity controls. Bugfix: readout of history points is incorrect. 0.00.25 (6-7-2006) Added an optional overlay grid. Fixed a bug in the wiggle me. 0.00.24 (6-6-2006) Bugfix in the build process (wouldn't run under 1.4) 0.00.23 (6-6-2006) Renamed JNLP Launch title from Energy Sk8r to Energy Skate Park Brightened the skater image. Performance bugfix. -Version 0.00.22 (6-2-2006) Decreased the sensitivity of the 'return the skater' button; skater has to be completely offscreen (not partially offscreen) Moved the pie chart legend to the bottom of the page. Added a jet pack graphic which points the correct direction. Bugfix: Background color doesn't match image color for different screen sizes. Reduced download size by 120kb (removal of unused images). Added a wiggle me hint for using the arrow keys to apply thrust; the hint appears when choosing zero-gravity first time. Added zoom in/out for energy-position plot. Bugfix: Setting record, then live, then record resets to last record state. -Changes for 0.00.21 (5-29-2006) Added a button to return the skater when he has flown out of view. Moved friction & clear heat controls to an expandable advanced panel. Removed the text field and numerical tick labels from friction slider; labeled extrema "none" and "lots" Bugfix: Clear button erroneously shows 'this simulation is paused' when it is not. Bugfix: The measuring tape's initial readout is incorrect. Added tool icons. Increased the initial and "return" height of the skater; increased the initial track to ensure a smooth first ride. -Changes for 0.00.20 Changed the look and feel to platform specific. Bugfix: The scale for the readings on the path data is unreadably huge. Made the view of history point data toggle-based, so 2 can be visible at once. Added a warning box to the reset button that says, Are you sure you want to reset? Bugfix: Removed the ability to drag (pan/zoom) the bar graph graphics. Removed the minimize button from the bar chart. Removed the "Total Energy" entry from the pie chart legend. Added a "Clear Heat" button to the bar graph window. Bugfix: When minimizing and restoring the window, the chart & graph windows don't restore their state. Bugfix: The charts all flash up on the screen for a second during startup. Added a helmet graphic. -Changes for 0.00.19 (5-14-2006) The simulation is now titled 'Energy Skate Park' The skater's potential energy is now zero when he's on the ground (by default). The skater cannot be dragged outside the window, or below ground. -Changes for 1-2-2006, 0.17 “Play” has been changed to “Go” for clarity. Add a movable “zero-point potential energy” graphic Add a clear button to e vs t graph in skater. Remove "minimize" button from e vs t in skater. Background is on by default Improved backgrounds a bit (tone down, position properly) -Changes for 12-23-2005, 0.15 Paused shows up in the play area when skater is paused. Renamed “Live” to “Play” Radio buttons match slider values. (all off when no exact location). Energy vs. Time chart comes up recording. Added color code legend for pie chart. Energy vs Position graph has a color-coded legend. Energy vs Position graph doesn't fade during pause. Renamed “Coefficient of Restitution” to “bounciness” Reset starts module running (not paused) Reset button changes the values in “edit skater” Save graphs (e.g. to compare friction on to friction off). -Changes for 11-17-2005, 0.13 Fix playback panel button sizes for 1024x768. Move Energy vs position button near other plot buttons. Rename 'show plot' to Plot Energy vs Time Rename 'reset skater' to 'return skater' Energy Vs. Position plot: fix horizontal range rename 'title' to 'energy vs. position' horizontal axis label Earth background is kPhet Make object mass switchable. Add a control for coeff of restitution. Fix horizontal range on Energy vs Position graphs. Turned model and view upside down. Paint like Jupiter/Earth/Moon/Space. Change Locale (background & gravity). The ground can be driven on and only bounced off. -Changes for 11-14-2005, 0.10 Added performance enhancements for energy-position graph Added a vertical location indicator in energy-position graph Bugfix: A bounce entails a loss of energy (which I didn't intend). Add coefficient of restitution. -Changes for 11-8-2005, 0.09 Improved performance on energy vs. position plot. Data points fade on the energy vs. position plot. Gravity is user-settable. Better center of mass for the skater. -Changes for 11-7-2005, 0.08 1. Fixed a bug in the friction update 2. Switched to Runge-Kutta 4th order differential equation solver. 3. Max selectable coeff of kinetic friction is 0.04 4. Added plot of energy vs position (experimental, not optimized). 5. Move labels below bar chart. 6. Colorize bar chart labels. 7. Added thermal energy to plot 8. Fixed a bug that prevented the splash screen on startup. 9. Minimized download size. -Changes for 0.07 and earlier Record history dots Measuring tape Man can be re-centered without restarting application. pie chart Area is proportional to energy (not Diameter)