text disappear in png with bg=False

[doutriaux1]

import vcs, EzTemplate, cdms2

canvas = vcs.init(geometry={"width":1200, "height":800}, bg=True)
canvas.open()
canvas.enableLogo = False  # Remove the UVCDAT logo
iso = canvas.createisofill()

template = canvas.gettemplate('ASD')
template.blank(["title","mean","min","max","dataname","crdate","crtime","units"])
# Now fore indvidual element to appear as needed.
template.data.priority = 1
template.box1.priority = 1
template.xtic1.priority = 1
template.xlabel1.priority = 1
template.xlabel1.y = .22 # xlabels vertical offset
template.xname.priority = 1
template.yname.priority = 1
template.ylabel1.priority = 1
# Dont want xtop and yright axis
template.xtic2.priority = 0
template.ytic2.priority = 0

# Multiple plots
M = EzTemplate.Multi(rows=2,columns=2,template=template)
M.template = template.name
M.legend.direction = 'horizontal'
M.margins.left = .07
M.margins.right = .02
M.margins.bottom = .25
M.margins.top = .10
M.legend.thickness = .1
M.legend.stretch = 0.5
M.spacing.vertical = .05
M.spacing.horizontal = .05
canvas.setcolormap("bl_to_darkred")
iso.ext_1 = True
iso.ext_2 = True

ssig = cdms2.open(vcs.sample_data+"/clt.nc")("clt")

# The actual plotting portion
for i in range(4):
    tm = ssig[i]
    tm = tm*1e9
    t = M.get(legend='none')
    t.xtic2.priority = 0
    t.ytic2.priority = 0
    t.xlabel2.priority = 0
    t.ylabel2.priority = 0
    t.xlabel1.y = .23 # xlabels vertical offset
    t.xname.y = 0.19
    t.yname.x = 0.03
    canvas.plot(tm, iso,t, yrev=True, continents=4, bg=True)
    if (i == 3):
        # Add legend label
        title = canvas.createtext()
        title.To.height = 12
        title.To.halign = "center"
        title.To.valign = "top"
        title.x = .5
        title.y = .9
        title.string = ['Mole fraction Trend (ppmb)']
        canvas.plot(title)
canvas.png("notext")

[doutriaux1]

might be related to #309

[scottwittenburg]

Hi @charlesdoutriaux, I wonder if there's some difference between our environments? I'm running with the latest vcs master, and when I copy/pasted your script, it generated the attached image.

Then I change to bg=False and get what appears to be an identical saved screenshot. Is there some text missing from that image? It does seem that the string "Mole fraction Trend (ppmb)" is not positioned where I would like to see it as someone looking at the chart. Maybe that is what you're referring to?

[sudipto00]

Folks
I had reported this issue initially. Maybe this issue is related to the template chosen. I saw this issue with the template 'ASD' but it went away when I switched to 'default' template. I am not sure if its some sort of setting in the 'ASD' template that is causing these texts to not appear in PNG files.

[scottwittenburg]

The reproduction script above uses the 'ASD' template you mentioned:

template = canvas.gettemplate('ASD')

When I ran that, it generated the image in the comment above, which does seem to have the texts in the png. I wonder if there is possibly something in your environment that is not in mine?

[sudipto00]

I am not sure. All I can say is that I am running through conda stack, v 2.12 on Mac OS Sierra.
I have a feeling that there is something unstable about that issue. In another instance also I saw the same issue happen where I was using the template 'quick'. Even there with the same configuration the text was not appearing but then after trying repeatedly it suddenly started appearing.
This is strange but that is what I have seen. If you have the canvas open what I have seen is that, the image is drawn on the canvas the first time but then when "canvas.png" is called the canvas object is refreshed and that is when the text disappears and that is what shows up in the final png file.

[doutriaux1]

@danlipsa any idea?

[aashish24]

@danlipsa @scottwittenburg what you guys think. Could it be that text rendering is slow and it is a async issue? Although the write() should have forced GL to flush?

[scottwittenburg]

I could investigate this issue if I could reproduce it. But I'm not sure what to do otherwise.

[danlipsa]

@doutriaux1 @aashish24 This seems to be a template issue. According to the original reported the issue does not appear with the default template.