From 0cfed8c5de6db5b74f258f387ffe99106bf5cdd5 Mon Sep 17 00:00:00 2001 From: Project Nayuki Date: Wed, 19 Apr 2017 21:40:14 +0000 Subject: [PATCH] Updated function-level comments in C code. --- c/qrcodegen.c | 2 +- c/qrcodegen.h | 10 ++++++---- 2 files changed, 7 insertions(+), 5 deletions(-) diff --git a/c/qrcodegen.c b/c/qrcodegen.c index 261dcb3..5c7f57f 100644 --- a/c/qrcodegen.c +++ b/c/qrcodegen.c @@ -704,7 +704,7 @@ static void drawCodewords(const uint8_t data[], int dataLen, uint8_t qrcode[], i /*---- Reed-Solomon ECC generator functions ----*/ // XORs the data modules in this QR Code with the given mask pattern. Due to XOR's mathematical -// properties, calling applyMask(m) twice with the same value is equivalent to no change at all. +// properties, calling applyMask(..., m) twice with the same value is equivalent to no change at all. // This means it is possible to apply a mask, undo it, and try another mask. Note that a final // well-formed QR Code symbol needs exactly one mask applied (not zero, not two, etc.). static void applyMask(const uint8_t functionModules[], uint8_t qrcode[], int size, int mask) { diff --git a/c/qrcodegen.h b/c/qrcodegen.h index 069f836..99cf8f5 100644 --- a/c/qrcodegen.h +++ b/c/qrcodegen.h @@ -65,7 +65,8 @@ enum qrcodegen_Mask { // can store any single QR Code from version 1 to 25, inclusive. #define qrcodegen_BUFFER_LEN_FOR_VERSION(n) ((((n) * 4 + 17) * ((n) * 4 + 17) + 7) / 8) -// The worst-case number of bytes needed to store one QR Code, up to and including version 40. +// The worst-case number of bytes needed to store one QR Code, up to and including +// version 40. This value equals 3917, which is just under 4 kilobytes. #define qrcodegen_BUFFER_LEN_MAX qrcodegen_BUFFER_LEN_FOR_VERSION(40) @@ -83,7 +84,7 @@ int qrcodegen_encodeText(const char *text, uint8_t tempBuffer[], uint8_t qrcode[ /* - * Encodes the given binary data to a QR Code symbol, return the actual version number used. + * Encodes the given binary data to a QR Code symbol, returning the actual version number used. * If the data is too long to fit in any version in the given range at the given ECC level, * then 0 is returned. dataAndTemp[0 : dataLen] represents the input data, and the function * may overwrite the array's contents as a temporary work area. Both dataAndTemp and qrcode @@ -97,9 +98,10 @@ int qrcodegen_encodeBinary(uint8_t dataAndTemp[], size_t dataLen, uint8_t qrcode /*---- Low-level QR Code functions ----*/ /* - * Returns the side length of any QR Code of the given version. + * Returns the side length of any QR Code of the given version number. * The version must be in the range [1, 40]. The result is in the range [21, 177]. - * Note that the length of any QR Code byte buffer must be at least ceil(size^2 / 8). + * Note that every 'uint8_t qrcode[]' buffer must have a length of at least + * ceil(size^2 / 8), which also equals qrcodegen_BUFFER_LEN_FOR_VERSION(version). */ int qrcodegen_getSize(int version);