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| ID | Project | Category | View Status | Date Submitted | Last Update | ||||
|---|---|---|---|---|---|---|---|---|---|
| 0000686 | Spring engine | General | public | 2007-11-18 00:48 | 2010-07-07 09:57 | ||||
| Reporter | redstar | ||||||||
| Assigned To | jK | ||||||||
| Priority | normal | Severity | crash | Reproducibility | have not tried | ||||
| Status | resolved | Resolution | fixed | ||||||
| Product Version | |||||||||
| Target Version | Fixed in Version | ||||||||
| Summary | 0000686: Ground Tearing and a Game Crash | ||||||||
| Description | I noticed on comet catcher that soemtimes there ws a tear in the ground between 2 sections, which showed up depending on the terrain view radius and the angle of viewing. While trying to examine the error a crash occurred. An image of the glitch and a screenshot of VS2005 debugger in the crash are attatched. | ||||||||
| Tags | No tags attached. | ||||||||
| Checked infolog.txt for Errors | |||||||||
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tvo (reporter) 2007-11-19 00:40 |
Out of bounds heightData array access, no clue why. Here is the math: CC is 12 x 16, meaning 769 x 1025 = 788225 heightmap size line 372 more readable is: float h = ( heightData[(y)*heightDataX+x+lod] + heightData[(y+lod*2)*heightDataX+x+lod])*0.5f*(1-camxpart) + heightData[(y+lod)*heightDataX+x+lod]*(camxpart); so the array element that would be the first to be accessed out of range is heightData[(y+lod*2)*heightDataX+x+lod] y = 0, lod = 512, heightDataX = 769, x = 512, so the array index is: 788480 788480 > 788225 --> out of bounds array access |
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tvo (reporter) 2007-11-19 12:02 Last edited: 2007-11-19 12:09 |
For anyone picking this up, here is some code snippet that may help debugging it: struct HeightDataCheck { int size; float* heightData; HeightDataCheck(float* h) : size((gs->mapx+1)*(gs->mapy+1)), heightData(h) { } int operator[] (int i) const { if (i >= size) __asm { int 3 }; return heightData[i]; } } heightData(this->heightData); Add this to the start of CBFGroundDrawer::Draw (MSVC only) and you have a fast (and actually working) conditional breakpoint on all out of bounds heightData array access (works by shadowing the heightData member with a local HeightDataCheck variable.) Personally I still don't know why it happens, debugging 450 line functions isn't particularly easy :-) Either way, reproducing is easy: - Add the above debugging code to BFGroundDrawer.cpp & compile - Start spring with Comet Catcher Remake - Set viewRadius to 4 (/decreaseviewradius) - Move camera to lower left corner of map. - Press tab. - Conditional breakpoint triggers => good luck debugging :-) EDIT: ok, not that easy, it doesn't seem 100% deterministic, but using shift+tab instead of tab (faster zoom out) seems to work pretty often too. |
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jK (developer) 2010-07-07 09:57 |
happened cause of too low terrain detail |
| Notes |
| Issue History |
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| Date Modified | Username | Field | Change |
|---|---|---|---|
| 2007-11-18 00:48 | redstar | New Issue | |
| 2007-11-18 00:48 | redstar | File Added: ground_tears.jpg | |
| 2007-11-18 00:49 | redstar | File Added: crash.png | |
| 2007-11-19 00:40 | tvo | Note Added: 0001447 | |
| 2007-11-19 12:02 | tvo | Note Added: 0001449 | |
| 2007-11-19 12:09 | tvo | Note Edited: 0001449 | |
| 2010-07-07 09:57 | jK | Note Added: 0005072 | |
| 2010-07-07 09:57 | jK | Status | new => resolved |
| 2010-07-07 09:57 | jK | Resolution | open => fixed |
| 2010-07-07 09:57 | jK | Assigned To | => jK |
| Issue History |