 | | Type 5 lines, BFC relevance, and OpenGL
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| I wanted to bounce something that has been percolating in my brain for a few days off somebody that might be able to offer me some feedback on it. I don't know if I'm the first person to think of this (I'm probably not), but as I haven't seen (...) (20 years ago, 28-Mar-05, to lugnet.cad.dev)
| | | | | Re: Type 5 lines, BFC relevance, and OpenGL
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| Hmmm, draw the edge twice and flip the stencil bit eh? It sounds like it could work. I'll have to read up on edge flags. I haven't used them for anything yet. By the way, you should be able to get all the info you need from the type 5 line itself, (...) (20 years ago, 29-Mar-05, to lugnet.cad.dev)
| | | | | Re: Type 5 lines, BFC relevance, and OpenGL
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| (...) You know, this got me thinking last night. I knew it sounded vaguely familiar, so I searched lugnet for "stencil buffer" and found this. (URL) I was so close, but somehow got distracted before I could work it out. Damn that attention deficit (...) (20 years ago, 30-Mar-05, to lugnet.cad.dev)
| | | | | Re: Type 5 lines, BFC relevance, and OpenGL
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| (...) Interesting... so this article is suggesting that type5 lines not be used at all, which may be possible for a model that is certain to be BFC compliant. Wheras the mechanism I was suggesting would work for any model, BFC compliant or not. The (...) (20 years ago, 31-Mar-05, to lugnet.cad.dev)
| | | | | Re: Type 5 lines, BFC relevance, and OpenGL
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| (...) I think, that in this particular application it is better to deal with line type 5 syntax. Otherwise renderer has to calculate angle between adjanced polygons and select some threshold to decide whether this line is "conditional" or not. (...) (20 years ago, 1-Apr-05, to lugnet.cad.dev)
| | | | | Re: Type 5 lines, BFC relevance, and OpenGL
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| (...) Well, I tried this in LDView, and it seems to work fine. I haven't yet put the new stuff in a display list, so it's drawing all the type 5 line geometry in immediate mode. Consequently, I'm not yet sure how fast it will be (it's very similar (...) (20 years ago, 1-Apr-05, to lugnet.cad.dev, FTX)
| | | | | Re: Type 5 lines, BFC relevance, and OpenGL
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| So, I got the code updated so the conditional drawing happens in a display list, and then built LDView with full optimizations turned on in the compiler, and the new method actually runs slightly slower than the old method. (This is on an ATI Radeon (...) (20 years ago, 3-Apr-05, to lugnet.cad.dev, FTX)
| | | | | Re: Type 5 lines, BFC relevance, and OpenGL
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| Slower, you say? Are you executing the functions in immediate mode? Or using a display list? Because if you're not using a display list, it's no suprise that it's slower. If you are using a display list, however, then I'm at a loss. I guess it may (...) (20 years ago, 4-Apr-05, to lugnet.cad.dev)
| | | | | Re: Type 5 lines, BFC relevance, and OpenGL
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| (...) I'm using a display list. The triangles are drawn inside the display list using "classic" OpenGL calls (glBegin(GL_TRIANGLE....glEnd()). The lines are being drawn inside the display list using vertex arrays. Using vertex arrays to draw the (...) (20 years ago, 4-Apr-05, to lugnet.cad.dev)
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