View.draw2d and AA - precision
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While experimenting with view.draw2d I noticed a couple of things:
When drawing lines of odd width one must offset the X and Y coords by 0.5 in order to maintain a sharp line. The coords must be on the centre of the line, even if the pixel coords contains half a pixel.For even width one must use whole values.
Notice that the corner never is sharp when drawing with
GL_LINE_LOOP.
Then you have the drawing of points:
When AA is on - the points become drawn fuzzy. Even if you offset. There does not appear to be a way by using the SU Ruby API to draw sharp 1px points. (UsingGL_POINTS)
When AA is off, then the 1px points appear sharp and in exactly the colour one specify.
I really wish there was a way I could draw 1px points - sharp - without the AA fuzzing it up. I'd appreciate if anyone has any ideas. Or even some insight to how OpenGL treats screen coordinates.
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See how the pixel is blurred no matter what?
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I just noticed that ATI cars, while they don't draw points where the X and Y is whole numbers, they do draw the pixel sharply.
The first set of icons are drawn with
GL_POINTS- same method the turned blurred on nVidia.The second set is pixels drawn with
GL_LINES- which is slower, but draws sharply on both nVidia and ATI.If only I could detect the make and AA settings of SU from Ruby...
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I can confirm that the ATI machine I am on draws sharp edges always. On some stuff I've been working on, my nVidia card draws fuzzy edges, but this ATI mcahine is drawing those same edges as sharp.
Chris
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All edges?
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It is the edges around my gradient boxes that are coming out as sharp on this machine. I am not drawing any single pixels anymore at this point. So yeah, just edges. But they definietly come out different than they do on my nvidia card at home.
Chris
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@chris fullmer said:
It is the edges around my gradient boxes that are coming out as sharp on this machine. I am not drawing any single pixels anymore at this point. So yeah, just edges. But they definietly come out different than they do on my nvidia card at home.
Chris
Even if they are not offset 0.5?
See my last screenshot - the top rectangle is 1px with whole number values. It's fuzzy. (not as fuzzy as on nVidia - but the colour is fainter.) The next one, is offset 0.5.
What cards have you tried? And what OS?
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it is an 128mb ATI Radeon X600 SE on Win XP.
It appears to be drawing a solid single pixel line. But I have no screen capture utility or anything like photoshop to magnify and inspect the line work. After work tonight I'll install jing and get a good screen capture shoing what it looks like, then you can decide what it really is doing.
Chris
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And I see that there is no AA turned on in SU (or when I got to the Preference > OPEN_GL tab is says aa=0x)
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Ah! No AA. Does it not have any AA option?
@chris fullmer said:
After work tonight I'll install jing and get a good screen capture shoing what it looks like, then you can decide what it really is doing.
video? is it not easier to just PrntScrn? -
Jimg makes great .png screen captures and saves them to the desktop. Lets you specify a window size, etc. Add comments, arrows and lines on it afterwards.
For prntscrn, I don't have any app I can paste it into and edit it on this computer. Its like the stone age of computers in this house I'm staying at
No, there was no option avaiable to turn on aa. Maybe I can do it through the video card first? And then it might be available in SU? This is an area I never get into because I have never really cared about how smooth the detail is on my games
But maybe I should figure it out since it also pertains to SketchUp.Chris
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hmm... I can use the SU preferences to detect the AA settings of SU. On Windows it's under GLConfig > Display. Then I need to locate that on OSX.
Only thing is that reading registry requires more files and makes for more complicated dependabilities.
And I don't get the make of the card from SU's prefs...
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