Tracking the mapped buffer size for retracing #495
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
jrfonseca
reviewed
Apr 11, 2017
| @@ -419,6 +419,14 @@ dumpUniformBlock(StateWriter &writer, | |||
| if (raw_data) { | |||
| std::string qualifiedName = resolveUniformName(name, size); | |||
|
|
|||
| GLuint actual_count = mapping.getSize() / array_stride; | |||
There was a problem hiding this comment.
Thanks for looking into this. I agree extra checking is a good thing.
But I fear this check might be a tad too strict, as I'm not sure that the array elements are guaranteed to be contiguous in memory.
Imagine a buffer with 12 bytes, with elements of 4 bytes, and a stride of 8 bytes. There's space for two elements (with 4 bytes of padding.) But merely diving buffer size by stride would say only one element can fit...
Perhaps this can never happen -- it's hard to say if that's legal or not --, but the safest thing to do would be to pass the buffer size down dumpAttribArray and dumpAttrib, and do the checking there.
Another alternative would be to try to compensate for this when computing actual_count.
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Fixes #494
Reason it crashes is because the user provided a buffer object smaller than the UBO structure declared in the shader. This is valid for as long as the shader doesn't access the data outside of the provided region.