README
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mybits
This is a collection of functions for bit-manipulative stuff.
The most important thing in here is the encoder and decoder for our event tile bitmaps. This is documented at the top of onoff.c
In addition, we compile the onoff decoder into a WASM module.
Test/debug the native C code
See debug/test-bits.c and debug/test-onoff.c
Test the Go interface
go test .
Build and test the WASM code
./build-wasm && node test-wasm.mjs
Documentation
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Index ¶
- Variables
- func AndBitmapsCount(a, b []byte) int
- func AndBitmapsNonZero(a, b []byte) bool
- func BitmapFillRect(bits []byte, width, x, y, w, h int)
- func DecodeOnoff(enc []byte, out []byte) (int, error)
- func DecodeOnoff3(enc []byte, out []byte) (int, error)
- func EncodeOnoff(bits []byte, out []byte) (int, error)
- func EncodeOnoff3(bits []byte, out []byte) (int, error)
- func MaxEncodedBytes(inputBitCount int) int
Constants ¶
This section is empty.
Variables ¶
var ErrOutOfSpace = errors.New("out of buffer space")
Functions ¶
func AndBitmapsCount ¶
Compute the binary AND of the bitmaps 'a' and 'b', and return the number of 'on' bits.
func AndBitmapsNonZero ¶
Compute the binary AND of the bitmaps 'a' and 'b', and return true if any bits are set
func BitmapFillRect ¶
Fill a bitmap with a rectangle of 'on' bits. The bitmap's width must be a multiple of 8
func DecodeOnoff ¶
Returns the number of BITS decoded. Returns ErrOutOfSpace if the decoded bit stream is larger than 'out'
func DecodeOnoff3 ¶
Returns the number of BITS decoded. Returns ErrOutOfSpace if the decoded bit stream is larger than 'out'. Note that DecodeOnoff is a wrapper around this function.
func EncodeOnoff ¶
Encode the given bit stream using our on/off encoding. Returns the number of bytes written into 'out'. If the resulting bit stream ends up being larger than 'out', then abort and return ErrOutOfSpace.
func EncodeOnoff3 ¶
Final version Note that EncodeOnoff is a wrapper around this function.
func MaxEncodedBytes ¶
Return the maximum number of bytes required to encode an input of the given bit length
Types ¶
This section is empty.
Source Files