Padded Row Byte Count
Plan row byte alignment padding using arbitrary positive integer alignment, not only powers of two.
Description
Plan row byte alignment padding using arbitrary positive integer alignment, not only powers of two.
A row stride can be enlarged by the smallest byte padding that meets a positive alignment.
When to use this tool
Plan row byte alignment padding using arbitrary positive integer alignment, not only powers of two.
- Prepare the supplied rowBytes, alignmentBytes fields for this operation.
- Compare the complete example with the representation used by your own input before carrying the result into another step.
How to use the tool and how it works
- Enter rowBytes, alignmentBytes. Use the exact text syntax, units and index conventions explained below.
- Run the tool. If input validation fails, correct the supplied fields before interpreting any result.
- Read result.paddingBytes, result.paddedBytes. Interpret false, null and empty lists using the distinctions below; they can be valid outputs.
Require nonnegative integer rowBytes and positive alignmentBytes. paddingBytes is nonnegative modulo(-rowBytes,alignmentBytes); paddedBytes adds it to rowBytes.1
| Input field | Meaning and representation | Accepted input |
|---|---|---|
| rowBytes | row bytes. | Integer from 0 to 1e12 inclusive |
| alignmentBytes | alignment bytes. | Integer from 1 to 1e9 inclusive |
| Output field | Interpretation |
|---|---|
| result | Object containing the named outputs below. |
| result.paddingBytes | The padding bytes value under the stated formula or text convention. |
| result.paddedBytes | The padded bytes value under the stated formula or text convention. |
{
"input": {
"rowBytes": 13,
"alignmentBytes": 4
},
"output": {
"result": {
"paddingBytes": 3,
"paddedBytes": 16
}
}
}Limitations and assumptions
- Alignment need not be a power of two. No image format, allocator or actual buffer is queried.
- Coordinate pairs use [row,column] where stated. Masks are nonempty rectangular zero/one matrices of at most 128 rows, 128 columns and 16,384 cells; outside-mask values are unset for the neighborhood operations.
- Every declared top-level field is required and unexpected fields are rejected. Numeric inputs must be finite; ordinary text fields are bounded to 8,192 UTF-16 code units, with tighter operation-specific limits where stated.
- String lists have at most 128 entries of at most 128 code units; matrices have at most 128 rows and columns. Larger numeric lists and parsed JSON have separate bounded budgets. Nonfinite results and excessively large serialized outputs are rejected.
- Indexes are zero-based and spans have an exclusive end unless explicitly stated otherwise. A valid false, null or empty-list result is distinct from malformed input.
Alternative or Complementary methods
Keep row/column coordinates distinct from x/y pairs and byte offsets. Select the neighborhood metric, outside-mask rule and storage-order convention explicitly; these operations do not infer an image format.
References
Similar or alternative tools
- Grid Mask Row Run Table
Tabulate maximal set-cell runs along rows of a rectangular binary mask with half-open local bounds.
- Row Major Stride Offset
Compute a contiguous row-major byte offset with explicit element size and base address; no memory access or inferred padding.