Incorrect Displayed on Quilted Screen

[fgd3]

I'm running Windows Vista, 7, and 8 on three different computers. I've installed OpenCPN 3.3.1117 on all three. With quilting on I get this odd situation. Around 27 degrees, 59.7046 minutes north, 082 degrees, 39.3028 minutes west using NOAA RNCs I don't see any soundings in the Safety Harbor-Mobbly Bay area (north of 27 degrees 58.5934 minutes north). The area is covered by 11416, Tampa Bay Northern Section and 11412, Tampa Bay and St. Joseph Sound. Only when I turn off quilting (F9) do I see the sounding and other detail for the area in question, which is shown on an inset, 11416_4.KAP. Shouldn't insets be shown on top of the base chart so that the maximum detail is visible?

Fabbian

[cagney]

11416_4 is a bit strange. It's an extension with half the scale 1:80000 compared to 1:40000 on the main part. 11412, that covers the whole of Tampa bay, is also 1:80000. An insert or plan i normally in a larger scale.
I think that O don't change to 11416_4 because it's already in 1:80000 for that area, showing 11412. I think it boils down to this: how can O know that it's supposed to switch to another chart at exactly the same scale. A bit of a headache to code that, without going into the nightmare of exceptions for individual charts.
Over to Dave ....

Thomas

[bdbcat]

Thomas has this right.

Said another way:
OCPN does not expect more detail on a chart of smaller scale. It normally goes the other way. 1/40,000 has more detail than 1/80,000.

Except near Safety Harbor....

OCPN further does not know about insets. They are considered to be separate charts, with their own coverage and scale. So, they are placed into the quilt in that context. Normally, that works fine.

So, practically, we do the best we can. In this case, disable 11416_1 (right click on chart bar button) as you pass under the CCCauseway northbound. That makes the reference scale 1/80,000 instead of 11416_1's 1/40,000. And you will see then 11416_4 (1/80,000) in its proper place.

Dave

p.s. When I was a kid about 100 years ago, we played at Philippe Park on the indian mound. Fun....


Dave

[fgd3]

Originally Posted by cagney

I think it boils down to this: how can O know that it's supposed to switch to another chart at exactly the same scale.

Thomas

I understand OpenCPN can't know to switch to another chart automatically, but shouldn't it switch to another chart when I explicitly select that chart by clicking on the button in the chart bar?

Fabbian

[wdkester]

There are similar problems when using the ICWW charts and normal NOAA charts for the same area. If you are following the ICWW you have to disable the non-ICWW charts in the area. Otherwise it gets too confusing.

[fgd3]

I can understand the problem. You make a perfectly reasonable assumption that larger scale charts contain more detail and should be on top. It makes sense that you can't automatically pick the right charts when that assumption isn't valid.

I envision the charts as layered, with the small scale charts at the back and the larger scale charts in front. So I would expect that when I click on a specific chart from the chart bar it gets moved to the front of the stack, the way objects in a CAD program can be moved to the front or pushed to the back.

Most of the time it seems to work that way. When I switch between 11415 (Tampa Bay Entrance, 1:40000) and 11416 (Tampa Bay Northern Part, 1:40000) the chosen chart pops to the front where the two overlap--leaving the non-overlapped parts unchanged. It even works with 11416_3 (St. Petersburg Inset, 1:20000), at least some of the time. When I click on 11416_3 it moves to the front. When I click on 11416_1 it moves in front of 11416_3 even though 11416_3 is drawn to a larger scale than 11416_1. So I don't understand why 11416_4 (Safety Harbor) doesn't pop to the front when I click on it.

As I experimented with the program I noticed behavior was different at different zoom levels. Starting with quilting on and no charts hidden, 11416_4 pops to the front when I'm zoomed in to a 22500 scale (shown in the bottom right on the same line with SOG, COG, latitude, and longitude). When I zoom out to a 45000 scale the 11416_4 extension is replaced with 11412 (Tampa Bay and St. Joseph Sound). I can't select 11416_4 at that zoom level although it is still shown in the chart bar. If I turn off quilting or hide 11412 then I can select 11416_4 at the 45000 scale.

11416_4 remains visible even zoomed to a 90000 scale, but 11416_1 drops out of the picture. If I select 11416_1 at that point I get zoomed in to 45000 scale and both 11416_1 and 11416_4 are visible.

If I show 11412 it hides both 11416_1 and 11416_4 zoomed to 90000 scale. As I zoom in 11416_4 replaced 11412 when zoomed to 45000 scale (if I'm zooming into its area). If I'm zooming in south of the Courtney Campbell Causeway, of course, I don't see 11416_4 at all. But I have to zoom all the way to 5600 scale before 11412 is replaced by 11416_1.

I find that inconsistent and confusing. Is there a reason it has to be that way or do you think the handling of chart selection and zoom levels could use another look?

I would like to have my chart selection override the programs selection at any zoom level. Sure, there are lots of times when I might select a chart that's zoomed out so far that it's unreadable, but that's my problem. I can always zoom in if that happens. But maybe I just want a quick look to see if a selected chart shows certain features at all--I'll look at them in detail later.

If you let the user override automatic chart selection, how do you know he's done and wants the program to resume selection based on zoom level? I don't know. Maybe a button on the chart bar to "Select best chart" or "Resume automatic selection" based on zoom level.

Fabbian

[bdbcat]

Fabbian...

It should.

I'm confused, I guess. This para confounds me:

"As I experimented with the program I noticed behavior was different at different zoom levels. Starting with quilting on and no charts hidden, 11416_4 pops to the front when I'm zoomed in to a 22500 scale (shown in the bottom right on the same line with SOG, COG, latitude, and longitude). When I zoom out to a 45000 scale the 11416_4 extension is replaced with 11412 (Tampa Bay and St. Joseph Sound). I can't select 11416_4 at that zoom level although it is still shown in the chart bar. If I turn off quilting or hide 11412 then I can select 11416_4 at the 45000 scale."

Specifically:
"I can't select 11416_4 at that zoom level although it is still shown in the chart bar."

???

I cannot reproduce this....

Dave

[fgd3]

Originally Posted by bdbcat

Fabbian...

It should.

I'm confused, I guess. This para confounds me:

"As I experimented with the program I noticed behavior was different at different zoom levels. Starting with quilting on and no charts hidden, 11416_4 pops to the front when I'm zoomed in to a 22500 scale (shown in the bottom right on the same line with SOG, COG, latitude, and longitude). When I zoom out to a 45000 scale the 11416_4 extension is replaced with 11412 (Tampa Bay and St. Joseph Sound). I can't select 11416_4 at that zoom level although it is still shown in the chart bar. If I turn off quilting or hide 11412 then I can select 11416_4 at the 45000 scale."

Specifically:
"I can't select 11416_4 at that zoom level although it is still shown in the chart bar."

???

I cannot reproduce this....

Dave

What I understand you are saying is that with quilting on and the scale at 45000 you are able to select 11416_4. Is that right? Have you found any zoom level that prevents you from selecting 11416_4?

The computer I am using runs Windows Vista. "Use Accelerate Graphics (OpenGL)" is not selected. I get the same behavior on a Windows 7 computer and a Windows 8 computer, so I think we can rule out an operating system version problem.

I'll try to describe what happens a little better. Starting anywhere in Tampa Bay I zoom out until the scale is 45000. Now I scroll up until the Courtney Campbell Causeway runs just below the middle of the screen. I see soundings in the area covered by 11416_1 but none outside that area. The chart bar contains buttons for (from left to right) 11416_1, 11412_1, 11416_4, US4FL10M.000, US4FL12M.000, 1114A_1, 11400_1, US3GC06M.000, US2G15M.000, 11006_1, 11013_1, 411_1, and US1GC09M.000.

The first two are solid gray (maybe it's light blue). The rest are outlined in gray (for RNCs) or solid green (for ENCs). If I click on 11412_1 (the second from the left) the first button (11416_1) turns blue. Soundings vanish from Tampa Bay since 11412 doesn't have any detail in the bay. If I scroll west (without changing the zoom) I do see soundings in the Gulf of Mexico.

So far that's the behavior I would expect. But if I click on the third button from the left, 11416_4, absolutely nothing happens. The button for 11416_1 remains blue. The button for 11412_1 remains gray. The button for 11416_4 remains a gray outline. Nothing changes on the chart display. That's what I meant when I said I couldn't select 11416_4.

I hope that helps you understand what I'm seeing. If you need to see screen shots or a log file let me know.

Fabbian

[bdbcat]

Fabbian...

Following your procedure, as I pan north in Tampa Bay at about 1/45000 true scale, I see 11416_4 pop up in the chart bar. And 11416_4 automatically opens, showing detail north of the bridge. This all works as expected.

If, at this point, I manually select 11416_4, I get a slight auto-zoom out to about 1/60,000. It still displays and shows soundings just fine.

So, I guess I will need some screen shots, or a video, to see the effect you describe.

Also, for reference, please check you settings Options->Display->DisableFullScreenQuilting.

Anyone else like to try this test?

Thanks
Dave

[fgd3]

Dave,

I am mystified, since you seem to have followed the same procedure I did but get different results. I hope the log file and screen shots will be of some use to you. The red circles show where the mouse pointer was at the time I took the screen shots.

I ran the test with Options->Display->DisableFullScreenQuilting unchecked. I repeated it with Options->Display->DisableFullScreenQuilting checked. It made no difference except that the buttons in the chart bar were a little different. The buttons for the charts in question were still there, though.

Opencpn.doc is the log file from my test session, renamed so the forum would let me upload it.

I zoomed out to 45000 and scrolled up to Safety Harbor. I hovered the mouse pointer over the button for 11416_1 so the chart selection would be apparent. The screen shot is shown in 001.jpg.

Next I clicked on the button for 11416_4. The soundings disappeared. (What seems to be happening is 11412_1, which shows no detail in Tampa Bay, is displayed at that zoom level.) I moved the mouse pointer away from the button, then back to it before taking 002.jpg.

Finally, I pressed the "+" key to zoom in. The soundings for 11416_4 appeared and I hovered the mouse pointer over the button to take 003.jpg.

I hope this information helps. Let me know if you think of any other settings that might be important.

Fabbian

[fgd3]

Were the screenshots and log file I uploaded of any help?

Fabbian