From 58a39a96c3e072ee3143c7a4dc3de8b04e14f357 Mon Sep 17 00:00:00 2001 From: Project Nayuki Date: Sat, 26 Aug 2017 02:03:26 +0000 Subject: [PATCH] Added an initial, incomplete, but compilable Rust implementation of this library. --- rust/Cargo.toml | 4 + rust/src/lib.rs | 783 ++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 787 insertions(+) create mode 100644 rust/Cargo.toml create mode 100644 rust/src/lib.rs diff --git a/rust/Cargo.toml b/rust/Cargo.toml new file mode 100644 index 0000000..b81eefc --- /dev/null +++ b/rust/Cargo.toml @@ -0,0 +1,4 @@ +[package] +name = "qrcodegen" +version = "0.0.0" +authors = ["Project Nayuki"] diff --git a/rust/src/lib.rs b/rust/src/lib.rs new file mode 100644 index 0000000..21bf53b --- /dev/null +++ b/rust/src/lib.rs @@ -0,0 +1,783 @@ +/* + * QR Code generator library (Rust) + * + * Copyright (c) Project Nayuki. (MIT License) + * https://www.nayuki.io/page/qr-code-generator-library + * + * Permission is hereby granted, free of charge, to any person obtaining a copy of + * this software and associated documentation files (the "Software"), to deal in + * the Software without restriction, including without limitation the rights to + * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of + * the Software, and to permit persons to whom the Software is furnished to do so, + * subject to the following conditions: + * - The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * - The Software is provided "as is", without warranty of any kind, express or + * implied, including but not limited to the warranties of merchantability, + * fitness for a particular purpose and noninfringement. In no event shall the + * authors or copyright holders be liable for any claim, damages or other + * liability, whether in an action of contract, tort or otherwise, arising from, + * out of or in connection with the Software or the use or other dealings in the + * Software. + */ + + +/*---- QrCode functionality ----*/ + +pub struct QrCode { + + // This QR Code symbol's version number, which is always between 1 and 40 (inclusive). + version: u8, + + // The width and height of this QR Code symbol, measured in modules. + // Always equal to version × 4 + 17, in the range 21 to 177. + size: i32, + + // The error correction level used in this QR Code symbol. + errorcorrectionlevel: &'static QrCodeEcc, + + // The mask pattern used in this QR Code symbol, in the range 0 to 7 (i.e. unsigned 3-bit integer). + // Note that even if a constructor was called with automatic masking requested + // (mask = -1), the resulting object will still have a mask value between 0 and 7. + mask: u8, + + // The modules of this QR Code symbol (false = white, true = black) + modules: Vec, + + // Indicates function modules that are not subjected to masking + isfunction: Vec, + +} + + +impl QrCode { + + pub fn encode(ver: u8, ecl: &'static QrCodeEcc, datacodewords: &[u8], mask: i8) -> QrCode { + // Check arguments + if ver < 1 || ver > 40 || mask < -1 || mask > 7 { + panic!("Value out of range"); + } + + // Initialize fields + let size: usize = (ver as usize) * 4 + 17; + let mut result = QrCode { + version: ver, + size: size as i32, + mask: 0, // Dummy value + errorcorrectionlevel: ecl, + modules: vec![false; size * size], // Entirely white grid + isfunction: vec![false; size * size], + }; + + // Draw function patterns, draw all codewords, do masking + result.draw_function_patterns(); + let allcodewords: Vec = result.append_error_correction(datacodewords); + result.draw_codewords(&allcodewords); + result.handle_constructor_masking(mask); + result + } + + + pub fn remask(qr: &QrCode, mask: i8) -> QrCode { + // Check arguments + if mask < -1 || mask > 7 { + panic!("Mask value out of range"); + } + + // Copy fields + let mut result = QrCode { + version: qr.version, + size: qr.size, + mask: 0, // Dummy value + errorcorrectionlevel: qr.errorcorrectionlevel, + modules: qr.modules.clone(), + isfunction: qr.isfunction.clone(), + }; + + // Handle masking + result.apply_mask(qr.mask); // Undo old mask + result.handle_constructor_masking(mask); + result + } + + + // Returns this QR Code's version, in the range [1, 40]. + pub fn version(&self) -> u8 { + self.version + } + + + // Returns this QR Code's size, in the range [21, 177]. + pub fn size(&self) -> i32 { + self.size + } + + + // Returns this QR Code's error correction level. + pub fn error_correction_level(&self) -> &'static QrCodeEcc { + self.errorcorrectionlevel + } + + + // Returns this QR Code's mask, in the range [0, 7]. + pub fn mask(&self) -> u8 { + self.mask + } + + + // Returns the color of the module (pixel) at the given coordinates, which is either false for white or true for black. The top + // left corner has the coordinates (x=0, y=0). If the given coordinates are out of bounds, then 0 (white) is returned. + pub fn get_module(&self, x: i32, y: i32) -> bool { + 0 <= x && x < self.size && 0 <= y && y < self.size && self.module(x, y) + } + + + fn module(&self, x: i32, y: i32) -> bool { + self.modules[(y * self.size + x) as usize] + } + + + fn module_mut(&mut self, x: i32, y: i32) -> &mut bool { + &mut self.modules[(y * self.size + x) as usize] + } + + + /*---- Private helper methods for constructor: Drawing function modules ----*/ + + fn draw_function_patterns(&mut self) { + // Draw horizontal and vertical timing patterns + let size: i32 = self.size; + for i in 0 .. size { + self.set_function_module(6, i, i % 2 == 0); + self.set_function_module(i, 6, i % 2 == 0); + } + + // Draw 3 finder patterns (all corners except bottom right; overwrites some timing modules) + self.draw_finder_pattern(3, 3); + self.draw_finder_pattern(size - 4, 3); + self.draw_finder_pattern(3, size - 4); + + // Draw numerous alignment patterns + let alignpatpos: Vec = QrCode::get_alignment_pattern_positions(self.version); + let numalign: usize = alignpatpos.len(); + for i in 0 .. numalign { + for j in 0 .. numalign { + if i == 0 && j == 0 || i == 0 && j == numalign - 1 || i == numalign - 1 && j == 0 { + continue; // Skip the three finder corners + } else { + self.draw_alignment_pattern(alignpatpos[i], alignpatpos[j]); + } + } + } + + // Draw configuration data + self.draw_format_bits(0); // Dummy mask value; overwritten later in the constructor + self.draw_version(); + } + + + // Draws two copies of the format bits (with its own error correction code) + // based on the given mask and this object's error correction level field. + fn draw_format_bits(&mut self, mask: u8) { + // Calculate error correction code and pack bits + let size: i32 = self.size; + let mut data: u32 = (self.errorcorrectionlevel.formatbits << 3 | mask) as u32; // errcorrlvl is uint2, mask is uint3 + let mut rem: u32 = data; + for _ in 0 .. 10 { + rem = (rem << 1) ^ ((rem >> 9) * 0x537); + } + data = data << 10 | rem; + data ^= 0x5412; // uint15 + if data >> 15 != 0 { + panic!("Assertion error"); + } + + // Draw first copy + for i in 0 .. 6 { + self.set_function_module(8, i, (data >> i) & 1 != 0); + } + self.set_function_module(8, 7, (data >> 6) & 1 != 0); + self.set_function_module(8, 8, (data >> 7) & 1 != 0); + self.set_function_module(7, 8, (data >> 8) & 1 != 0); + for i in 9 .. 15 { + self.set_function_module(14 - i, 8, (data >> i) & 1 != 0); + } + + // Draw second copy + for i in 0 .. 8 { + self.set_function_module(size - 1 - i, 8, (data >> i) & 1 != 0); + } + for i in 8 .. 15 { + self.set_function_module(8, size - 15 + i, (data >> i) & 1 != 0); + } + self.set_function_module(8, size - 8, true); + } + + + // Draws two copies of the version bits (with its own error correction code), + // based on this object's version field (which only has an effect for 7 <= version <= 40). + fn draw_version(&mut self) { + if self.version < 7 { + return; + } + + // Calculate error correction code and pack bits + let mut rem: u32 = self.version as u32; // version is uint6, in the range [7, 40] + for _ in 0 .. 12 { + rem = (rem << 1) ^ ((rem >> 11) * 0x1F25); + } + let data: u32 = (self.version as u32) << 12 | rem; // uint18 + if data >> 18 != 0 { + panic!("Assertion error"); + } + + // Draw two copies + for i in 0 .. 18 { + let bit: bool = (data >> i) & 1 != 0; + let a: i32 = self.size - 11 + i % 3; + let b: i32 = i / 3; + self.set_function_module(a, b, bit); + self.set_function_module(b, a, bit); + } + } + + + // Draws a 9*9 finder pattern including the border separator, with the center module at (x, y). + fn draw_finder_pattern(&mut self, x: i32, y: i32) { + for i in -4i32 .. 5 { + for j in -4i32 .. 5 { + let dist: i32 = std::cmp::max(i.abs(), j.abs()); // Chebyshev/infinity norm + let xx: i32 = x + j; + let yy: i32 = y + i; + if 0 <= xx && xx < self.size && 0 <= yy && yy < self.size { + self.set_function_module(xx, yy, dist != 2 && dist != 4); + } + } + } + } + + + // Draws a 5*5 alignment pattern, with the center module at (x, y). + fn draw_alignment_pattern(&mut self, x: i32, y: i32) { + for i in -2i32 .. 3 { + for j in -2i32 .. 3 { + self.set_function_module(x + j, y + i, std::cmp::max(i.abs(), j.abs()) != 1); + } + } + } + + + // Sets the color of a module and marks it as a function module. + // Only used by the constructor. Coordinates must be in range. + fn set_function_module(&mut self, x: i32, y: i32, isblack: bool) { + *self.module_mut(x, y) = isblack; + self.isfunction[(y * self.size + x) as usize] = true; + } + + + /*---- Private helper methods for constructor: Codewords and masking ----*/ + + // Returns a new byte string representing the given data with the appropriate error correction + // codewords appended to it, based on this object's version and error correction level. + fn append_error_correction(&self, data: &[u8]) -> Vec { + if data.len() != QrCode::get_num_data_codewords(self.version, self.errorcorrectionlevel) { + panic!("Illegal argument"); + } + + // Calculate parameter numbers + let numblocks: usize = QrCode::table_get(&QrCode_NUM_ERROR_CORRECTION_BLOCKS, self.version, self.errorcorrectionlevel); + let blockecclen: usize = QrCode::table_get(&QrCode_ECC_CODEWORDS_PER_BLOCK, self.version, self.errorcorrectionlevel); + let rawcodewords: usize = QrCode::get_num_raw_data_modules(self.version) / 8; + let numshortblocks: usize = numblocks - rawcodewords % numblocks; + let shortblocklen: usize = rawcodewords / numblocks; + + // Split data into blocks and append ECC to each block + let mut blocks: Vec> = Vec::with_capacity(numblocks); + let rs = ReedSolomonGenerator::new(blockecclen as u8); + let mut k: usize = 0; + for i in 0 .. numblocks { + let mut dat: Vec = Vec::with_capacity(shortblocklen + 1); + dat.copy_from_slice(&data[k .. k + shortblocklen - blockecclen + ((i < numshortblocks) as usize)]); + k += dat.len(); + let ecc: Vec = rs.get_remainder(&dat); + if i < numshortblocks { + dat.push(0); + } + dat.extend_from_slice(&ecc); + blocks.push(dat); + } + + // Interleave (not concatenate) the bytes from every block into a single sequence + let mut result: Vec = Vec::with_capacity(rawcodewords); + for i in 0 .. shortblocklen + 1 { + for j in 0 .. numblocks { + // Skip the padding byte in short blocks + if i != shortblocklen - blockecclen || j >= numshortblocks { + result.push(blocks[j][i]); + } + } + } + result + } + + + // Draws the given sequence of 8-bit codewords (data and error correction) onto the entire + // data area of this QR Code symbol. Function modules need to be marked off before this is called. + fn draw_codewords(&mut self, data: &[u8]) { + if data.len() != QrCode::get_num_raw_data_modules(self.version) / 8 { + panic!("Illegal argument"); + } + + let mut i: usize = 0; // Bit index into the data + // Do the funny zigzag scan + let mut right: i32 = self.size - 1; + while right >= 1 { // Index of right column in each column pair + if right == 6 { + right = 5; + } + for vert in 0 .. self.size { // Vertical counter + for j in 0 .. 2 { + let x: i32 = right - j; // Actual x coordinate + let upward: bool = (right + 1) & 2 == 0; + let y: i32 = if upward { self.size - 1 - vert } else { vert }; // Actual y coordinate + if !self.isfunction[(y * self.size + x) as usize] && i < data.len() * 8 { + *self.module_mut(x, y) = (data[i >> 3] >> (7 - (i & 7))) & 1 != 0; + i += 2; + } + // If there are any remainder bits (0 to 7), they are already + // set to 0/false/white when the grid of modules was initialized + } + } + right -= 2; + } + if i != data.len() * 8 { + panic!("Assertion error"); + } + } + + + // 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. + // 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.). + fn apply_mask(&mut self, mask: u8) { + if mask > 7 { + panic!("Mask value out of range"); + } + for y in 0 .. self.size { + for x in 0 .. self.size { + let invert: bool = match mask { + 0 => (x + y) % 2 == 0, + 1 => y % 2 == 0, + 2 => x % 3 == 0, + 3 => (x + y) % 3 == 0, + 4 => (x / 3 + y / 2) % 2 == 0, + 5 => x * y % 2 + x * y % 3 == 0, + 6 => (x * y % 2 + x * y % 3) % 2 == 0, + 7 => ((x + y) % 2 + x * y % 3) % 2 == 0, + _ => panic!("Assertion error"), + }; + *self.module_mut(x, y) ^= invert & !self.isfunction[(y * self.size + x) as usize]; + } + } + } + + + // A messy helper function for the constructors. This QR Code must be in an unmasked state when this + // method is called. The given argument is the requested mask, which is -1 for auto or 0 to 7 for fixed. + // This method applies and returns the actual mask chosen, from 0 to 7. + fn handle_constructor_masking(&mut self, mut mask: i8) { + if mask == -1 { // Automatically choose best mask + let mut minpenalty: i32 = std::i32::MAX; + for i in 0u8 .. 8 { + self.draw_format_bits(i); + self.apply_mask(i); + let penalty: i32 = self.get_penalty_score(); + if penalty < minpenalty { + mask = i as i8; + minpenalty = penalty; + } + self.apply_mask(i); // Undoes the mask due to XOR + } + } + if mask < 0 || mask > 7 { + panic!("Assertion error"); + } + self.draw_format_bits(mask as u8); // Overwrite old format bits + self.apply_mask(mask as u8); // Apply the final choice of mask + self.mask = mask as u8; + } + + + // Calculates and returns the penalty score based on state of this QR Code's current modules. + // This is used by the automatic mask choice algorithm to find the mask pattern that yields the lowest score. + fn get_penalty_score(&self) -> i32 { + let mut result: i32 = 0; + let size: i32 = self.size; + + // Adjacent modules in row having same color + for y in 0 .. size { + let mut colorx: bool = false; + let mut runx: i32 = 0; + for x in 0 .. size { + if x == 0 || self.module(x, y) != colorx { + colorx = self.module(x, y); + runx = 1; + } else { + runx += 1; + if runx == 5 { + result += QrCode_PENALTY_N1; + } else if runx > 5 { + result += 1; + } + } + } + } + // Adjacent modules in column having same color + for x in 0 .. size { + let mut colory: bool = false; + let mut runy: i32 = 0; + for y in 0 .. size { + if y == 0 || self.module(x, y) != colory { + colory = self.module(x, y); + runy = 1; + } else { + runy += 1; + if runy == 5 { + result += QrCode_PENALTY_N1; + } else if runy > 5 { + result += 1; + } + } + } + } + + // 2*2 blocks of modules having same color + for y in 0 .. size - 1 { + for x in 0 .. size - 1 { + let color: bool = self.module(x, y); + if color == self.module(x + 1, y) && + color == self.module(x, y + 1) && + color == self.module(x + 1, y + 1) { + result += QrCode_PENALTY_N2; + } + } + } + + // Finder-like pattern in rows + for y in 0 .. size { + let mut bits: u32 = 0; + for x in 0 .. size { + bits = ((bits << 1) & 0x7FF) | (self.module(x, y) as u32); + if x >= 10 && (bits == 0x05D || bits == 0x5D0) { // Needs 11 bits accumulated + result += QrCode_PENALTY_N3; + } + } + } + // Finder-like pattern in columns + for x in 0 .. size { + let mut bits: u32 = 0; + for y in 0 .. size { + bits = ((bits << 1) & 0x7FF) | (self.module(x, y) as u32); + if y >= 10 && (bits == 0x05D || bits == 0x5D0) { // Needs 11 bits accumulated + result += QrCode_PENALTY_N3; + } + } + } + + // Balance of black and white modules + let mut black: i32 = 0; + for color in &self.modules { + black += *color as i32; + } + let total: i32 = size * size; + // Find smallest k such that (45-5k)% <= dark/total <= (55+5k)% + let mut k: i32 = 0; + while black*20 < (9-k)*total || black*20 > (11+k)*total { + result += QrCode_PENALTY_N4; + k += 1; + } + result + } + + + /*---- Private static helper functions ----*/ + + // Returns a set of positions of the alignment patterns in ascending order. These positions are + // used on both the x and y axes. Each value in the resulting array is in the range [0, 177). + // This stateless pure function could be implemented as table of 40 variable-length lists of unsigned bytes. + fn get_alignment_pattern_positions(ver: u8) -> Vec { + if ver < 1 || ver > 40 { + panic!("Version number out of range"); + } else if ver == 1 { + vec![] + } else { + let numalign: i32 = (ver as i32) / 7 + 2; + let step: i32 = if ver != 32 { + // ceil((size - 13) / (2*numAlign - 2)) * 2 + ((ver as i32) * 4 + numalign * 2 + 1) / (2 * numalign - 2) * 2 + } else { // C-C-C-Combo breaker! + 26 + }; + let mut result: Vec = vec![6]; + let mut pos: i32 = (ver as i32) * 4 + 10; + for _ in 0 .. numalign - 1 { + result.insert(1, pos); + pos -= step; + } + result + } + } + + + // Returns the number of data bits that can be stored in a QR Code of the given version number, after + // all function modules are excluded. This includes remainder bits, so it might not be a multiple of 8. + // The result is in the range [208, 29648]. This could be implemented as a 40-entry lookup table. + fn get_num_raw_data_modules(ver: u8) -> usize { + if ver < 1 || ver > 40 { + panic!("Version number out of range"); + } + let mut result: usize = (16 * (ver as usize) + 128) * (ver as usize) + 64; + if ver >= 2 { + let numalign: usize = (ver as usize) / 7 + 2; + result -= (25 * numalign - 10) * numalign - 55; + if ver >= 7 { + result -= 18 * 2; // Subtract version information + } + } + result + } + + + // Returns the number of 8-bit data (i.e. not error correction) codewords contained in any + // QR Code of the given version number and error correction level, with remainder bits discarded. + // This stateless pure function could be implemented as a (40*4)-cell lookup table. + fn get_num_data_codewords(ver: u8, ecl: &QrCodeEcc) -> usize { + if ver < 1 || ver > 40 { + panic!("Version number out of range"); + } + QrCode::get_num_raw_data_modules(ver) / 8 + - QrCode::table_get(&QrCode_ECC_CODEWORDS_PER_BLOCK, ver, ecl) + * QrCode::table_get(&QrCode_NUM_ERROR_CORRECTION_BLOCKS, ver, ecl) + } + + + fn table_get(table: &'static [[i8; 41]; 4], ver: u8, ecl: &QrCodeEcc) -> usize { + table[ecl.ordinal as usize][ver as usize] as usize + } + +} + + +/*---- Private tables of constants ----*/ + +// For use in get_penalty_score(), when evaluating which mask is best. +const QrCode_PENALTY_N1: i32 = 3; +const QrCode_PENALTY_N2: i32 = 3; +const QrCode_PENALTY_N3: i32 = 40; +const QrCode_PENALTY_N4: i32 = 10; + + +static QrCode_ECC_CODEWORDS_PER_BLOCK: [[i8; 41]; 4] = [ + // Version: (note that index 0 is for padding, and is set to an illegal value) + //0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40 Error correction level + [-1, 7, 10, 15, 20, 26, 18, 20, 24, 30, 18, 20, 24, 26, 30, 22, 24, 28, 30, 28, 28, 28, 28, 30, 30, 26, 28, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30], // Low + [-1, 10, 16, 26, 18, 24, 16, 18, 22, 22, 26, 30, 22, 22, 24, 24, 28, 28, 26, 26, 26, 26, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28], // Medium + [-1, 13, 22, 18, 26, 18, 24, 18, 22, 20, 24, 28, 26, 24, 20, 30, 24, 28, 28, 26, 30, 28, 30, 30, 30, 30, 28, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30], // Quartile + [-1, 17, 28, 22, 16, 22, 28, 26, 26, 24, 28, 24, 28, 22, 24, 24, 30, 28, 28, 26, 28, 30, 24, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30], // High +]; + +static QrCode_NUM_ERROR_CORRECTION_BLOCKS: [[i8; 41]; 4] = [ + // Version: (note that index 0 is for padding, and is set to an illegal value) + //0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40 Error correction level + [-1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 4, 4, 4, 4, 4, 6, 6, 6, 6, 7, 8, 8, 9, 9, 10, 12, 12, 12, 13, 14, 15, 16, 17, 18, 19, 19, 20, 21, 22, 24, 25], // Low + [-1, 1, 1, 1, 2, 2, 4, 4, 4, 5, 5, 5, 8, 9, 9, 10, 10, 11, 13, 14, 16, 17, 17, 18, 20, 21, 23, 25, 26, 28, 29, 31, 33, 35, 37, 38, 40, 43, 45, 47, 49], // Medium + [-1, 1, 1, 2, 2, 4, 4, 6, 6, 8, 8, 8, 10, 12, 16, 12, 17, 16, 18, 21, 20, 23, 23, 25, 27, 29, 34, 34, 35, 38, 40, 43, 45, 48, 51, 53, 56, 59, 62, 65, 68], // Quartile + [-1, 1, 1, 2, 4, 4, 4, 5, 6, 8, 8, 11, 11, 16, 16, 18, 16, 19, 21, 25, 25, 25, 34, 30, 32, 35, 37, 40, 42, 45, 48, 51, 54, 57, 60, 63, 66, 70, 74, 77, 81], // High +]; + + + +/*---- QrCodeEcc functionality ----*/ + +pub struct QrCodeEcc { + + // In the range 0 to 3 (unsigned 2-bit integer). + pub ordinal: u8, + + // In the range 0 to 3 (unsigned 2-bit integer). + formatbits: u8, + +} + + +pub static QrCodeEcc_LOW : QrCodeEcc = QrCodeEcc { ordinal: 0, formatbits: 1 }; +pub static QrCodeEcc_MEDIUM : QrCodeEcc = QrCodeEcc { ordinal: 1, formatbits: 0 }; +pub static QrCodeEcc_QUARTILE: QrCodeEcc = QrCodeEcc { ordinal: 2, formatbits: 3 }; +pub static QrCodeEcc_HIGH : QrCodeEcc = QrCodeEcc { ordinal: 3, formatbits: 2 }; + + + +/*---- ReedSolomonGenerator functionality ----*/ + +struct ReedSolomonGenerator { + + // Coefficients of the divisor polynomial, stored from highest to lowest power, excluding the leading term which + // is always 1. For example the polynomial x^3 + 255x^2 + 8x + 93 is stored as the uint8 array {255, 8, 93}. + coefficients: Vec, + +} + + +impl ReedSolomonGenerator { + + fn new(degree: u8) -> ReedSolomonGenerator { + if degree < 1 { + panic!("Degree out of range"); + } + // Start with the monomial x^0 + let mut coefs = vec![0; degree as usize]; + *coefs.last_mut().unwrap() = 1; + + // Compute the product polynomial (x - r^0) * (x - r^1) * (x - r^2) * ... * (x - r^{degree-1}), + // drop the highest term, and store the rest of the coefficients in order of descending powers. + // Note that r = 0x02, which is a generator element of this field GF(2^8/0x11D). + let mut root: u8 = 1; + for _ in 0 .. degree { + // Multiply the current product by (x - r^i) + for j in 0usize .. degree as usize { + coefs[j] = ReedSolomonGenerator::multiply(coefs[j], root); + if j + 1 < coefs.len() { + coefs[j] ^= coefs[j + 1]; + } + } + root = ReedSolomonGenerator::multiply(root, 0x02); + } + ReedSolomonGenerator { + coefficients: coefs + } + } + + + fn get_remainder(&self, data: &[u8]) -> Vec { + // Compute the remainder by performing polynomial division + let mut result: Vec = vec![0; self.coefficients.len()]; + for b in data { + let factor: u8 = b ^ result[0]; + result.remove(0); + result.push(0); + for i in 0 .. result.len() { + result[i] ^= ReedSolomonGenerator::multiply(self.coefficients[i], factor); + } + } + result + } + + + // Returns the product of the two given field elements modulo GF(2^8/0x11D). The arguments and result + // are unsigned 8-bit integers. This could be implemented as a lookup table of 256*256 entries of uint8. + fn multiply(x: u8, y: u8) -> u8 { + // Russian peasant multiplication + let mut z: u8 = 0; + for i in (0 .. 8).rev() { + z = (z << 1) ^ ((z >> 7) * 0x1D); + z ^= ((y >> i) & 1) * x; + } + z + } + +} + + + +/*---- QrSegment functionality ----*/ + +pub struct QrSegment { + + // The mode indicator for this segment. + mode: &'static QrSegmentMode, + + // The length of this segment's unencoded data, measured in characters. + numchars: usize, + + // The bits of this segment. + data: Vec, + +} + + +impl QrSegment { + + pub fn make_bytes(data: &Vec) -> QrSegment { + let mut bb: Vec = Vec::new(); + for b in data { + for i in (0 .. 8).rev() { + bb.push((b >> i) & 1u8 != 0u8); + } + } + QrSegment { + mode: &QrSegmentMode_BYTE, + numchars: data.len(), + data: bb, + } + } + +} + + + +/*---- QrSegmentMode functionality ----*/ + +pub struct QrSegmentMode { + + // An unsigned 4-bit integer value (range 0 to 15) + // representing the mode indicator bits for this mode object. + modebits: u8, + + numbitscharcount: [u8; 3], + +} + + +impl QrSegmentMode { + + pub fn num_char_count_bits(&self, ver: u8) -> u8 { + if 1 <= ver && ver <= 9 { + self.numbitscharcount[0] + } else if 10 <= ver && ver <= 26 { + self.numbitscharcount[1] + } else if 27 <= ver && ver <= 40 { + self.numbitscharcount[2] + } else { + panic!("Version number out of range"); + } + } + +} + + +pub static QrSegmentMode_NUMERIC : QrSegmentMode = QrSegmentMode { modebits: 0x1, numbitscharcount: [10, 12, 14] }; +pub static QrSegmentMode_ALPHANUMERIC: QrSegmentMode = QrSegmentMode { modebits: 0x2, numbitscharcount: [ 9, 11, 13] }; +pub static QrSegmentMode_BYTE : QrSegmentMode = QrSegmentMode { modebits: 0x4, numbitscharcount: [ 8, 16, 16] }; +pub static QrSegmentMode_KANJI : QrSegmentMode = QrSegmentMode { modebits: 0x8, numbitscharcount: [ 8, 10, 12] }; +pub static QrSegmentMode_ECI : QrSegmentMode = QrSegmentMode { modebits: 0x7, numbitscharcount: [ 0, 0, 0] }; + + + +/*---- Bit buffer functionality ----*/ + +// Appends the given number of bits of the given value to this sequence. +fn append_bits(bb: &mut Vec, val: u32, len: u8) { + if len < 32 && (val >> len) != 0 || len > 32 { + panic!("Value out of range"); + } + for i in (0 .. len).rev() { // Append bit by bit + bb.push((val >> i) & 1 != 0); + } +} + + +// Appends the data of the given segment to this bit buffer. +fn append_data(bb: &mut Vec, seg: &QrSegment) { + bb.extend_from_slice(&seg.data); +}