Swapped {dy,dx} variables in commutative operations for clarity, in all languages.

c/qrcodegen.c

@@ -361,9 +361,9 @@ static void drawWhiteFunctionModules(uint8_t qrcode[], int version) {
 	// Draw 3 finder patterns (all corners except bottom right; overwrites some timing modules)
 	for (int dy = -4; dy <= 4; dy++) {
 		for (int dx = -4; dx <= 4; dx++) {
-			int dist = abs(dy);
+			int dist = abs(dx);
-			if (abs(dx) > dist)
+			if (abs(dy) > dist)
-				dist = abs(dx);
+				dist = abs(dy);
 			if (dist == 2 || dist == 4) {
 				setModuleBounded(qrcode, 3 + dx, 3 + dy, false);
 				setModuleBounded(qrcode, qrsize - 4 + dx, 3 + dy, false);
@@ -381,7 +381,7 @@ static void drawWhiteFunctionModules(uint8_t qrcode[], int version) {
 				continue;  // Don't draw on the three finder corners
 			for (int dy = -1; dy <= 1; dy++) {
 				for (int dx = -1; dx <= 1; dx++)
-					setModule(qrcode, alignPatPos[i] + dx, alignPatPos[j] + dy, dy == 0 && dx == 0);
+					setModule(qrcode, alignPatPos[i] + dx, alignPatPos[j] + dy, dx == 0 && dy == 0);
 			}
 		}
 	}

cpp/QrCode.cpp

@@ -272,7 +272,7 @@ void QrCode::drawVersion() {
 void QrCode::drawFinderPattern(int x, int y) {
 	for (int dy = -4; dy <= 4; dy++) {
 		for (int dx = -4; dx <= 4; dx++) {
-			int dist = std::max(std::abs(dy), std::abs(dx));  // Chebyshev/infinity norm
+			int dist = std::max(std::abs(dx), std::abs(dy));  // Chebyshev/infinity norm
 			int xx = x + dx, yy = y + dy;
 			if (0 <= xx && xx < size && 0 <= yy && yy < size)
 				setFunctionModule(xx, yy, dist != 2 && dist != 4);
@@ -284,7 +284,7 @@ void QrCode::drawFinderPattern(int x, int y) {
 void QrCode::drawAlignmentPattern(int x, int y) {
 	for (int dy = -2; dy <= 2; dy++) {
 		for (int dx = -2; dx <= 2; dx++)
-			setFunctionModule(x + dx, y + dy, std::max(std::abs(dy), std::abs(dx)) != 1);
+			setFunctionModule(x + dx, y + dy, std::max(std::abs(dx), std::abs(dy)) != 1);
 	}
 }
 

java/io/nayuki/qrcodegen/QrCode.java

@@ -404,7 +404,7 @@ public final class QrCode {
 	private void drawFinderPattern(int x, int y) {
 		for (int dy = -4; dy <= 4; dy++) {
 			for (int dx = -4; dx <= 4; dx++) {
-				int dist = Math.max(Math.abs(dy), Math.abs(dx));  // Chebyshev/infinity norm
+				int dist = Math.max(Math.abs(dx), Math.abs(dy));  // Chebyshev/infinity norm
 				int xx = x + dx, yy = y + dy;
 				if (0 <= xx && xx < size && 0 <= yy && yy < size)
 					setFunctionModule(xx, yy, dist != 2 && dist != 4);
@@ -418,7 +418,7 @@ public final class QrCode {
 	private void drawAlignmentPattern(int x, int y) {
 		for (int dy = -2; dy <= 2; dy++) {
 			for (int dx = -2; dx <= 2; dx++)
-				setFunctionModule(x + dx, y + dy, Math.max(Math.abs(dy), Math.abs(dx)) != 1);
+				setFunctionModule(x + dx, y + dy, Math.max(Math.abs(dx), Math.abs(dy)) != 1);
 		}
 	}
 	

javascript/qrcodegen.js

@@ -278,7 +278,7 @@ var qrcodegen = new function() {
 		function drawFinderPattern(x, y) {
 			for (var dy = -4; dy <= 4; dy++) {
 				for (var dx = -4; dx <= 4; dx++) {
-					var dist = Math.max(Math.abs(dy), Math.abs(dx));  // Chebyshev/infinity norm
+					var dist = Math.max(Math.abs(dx), Math.abs(dy));  // Chebyshev/infinity norm
 					var xx = x + dx, yy = y + dy;
 					if (0 <= xx && xx < size && 0 <= yy && yy < size)
 						setFunctionModule(xx, yy, dist != 2 && dist != 4);
@@ -292,7 +292,7 @@ var qrcodegen = new function() {
 		function drawAlignmentPattern(x, y) {
 			for (var dy = -2; dy <= 2; dy++) {
 				for (var dx = -2; dx <= 2; dx++)
-					setFunctionModule(x + dx, y + dy, Math.max(Math.abs(dy), Math.abs(dx)) != 1);
+					setFunctionModule(x + dx, y + dy, Math.max(Math.abs(dx), Math.abs(dy)) != 1);
 			}
 		}
 		

python/qrcodegen.py

@@ -327,7 +327,7 @@ class QrCode(object):
 				xx, yy = x + dx, y + dy
 				if (0 <= xx < self._size) and (0 <= yy < self._size):
 					# Chebyshev/infinity norm
-					self._set_function_module(xx, yy, max(abs(dy), abs(dx)) not in (2, 4))
+					self._set_function_module(xx, yy, max(abs(dx), abs(dy)) not in (2, 4))
 	
 	
 	def _draw_alignment_pattern(self, x, y):
@@ -335,7 +335,7 @@ class QrCode(object):
 		at (x, y). All modules must be in bounds."""
 		for dy in range(-2, 3):
 			for dx in range(-2, 3):
-				self._set_function_module(x + dx, y + dy, max(abs(dy), abs(dx)) != 1)
+				self._set_function_module(x + dx, y + dy, max(abs(dx), abs(dy)) != 1)
 	
 	
 	def _set_function_module(self, x, y, isblack):

rust/src/lib.rs

@@ -372,7 +372,7 @@ impl QrCode {
 				let xx: i32 = x + dx;
 				let yy: i32 = y + dy;
 				if 0 <= xx && xx < self.size && 0 <= yy && yy < self.size {
-					let dist: i32 = std::cmp::max(dy.abs(), dx.abs());  // Chebyshev/infinity norm
+					let dist: i32 = std::cmp::max(dx.abs(), dy.abs());  // Chebyshev/infinity norm
 					self.set_function_module(xx, yy, dist != 2 && dist != 4);
 				}
 			}
@@ -385,7 +385,7 @@ impl QrCode {
 	fn draw_alignment_pattern(&mut self, x: i32, y: i32) {
 		for dy in -2 .. 3 {
 			for dx in -2 .. 3 {
-				self.set_function_module(x + dx, y + dy, std::cmp::max(dy.abs(), dx.abs()) != 1);
+				self.set_function_module(x + dx, y + dy, std::cmp::max(dx.abs(), dy.abs()) != 1);
 			}
 		}
 	}

typescript/qrcodegen.ts

@@ -347,7 +347,7 @@ namespace qrcodegen {
 		private drawFinderPattern(x: int, y: int): void {
 			for (let dy = -4; dy <= 4; dy++) {
 				for (let dx = -4; dx <= 4; dx++) {
-					let dist: int = Math.max(Math.abs(dy), Math.abs(dx));  // Chebyshev/infinity norm
+					let dist: int = Math.max(Math.abs(dx), Math.abs(dy));  // Chebyshev/infinity norm
 					let xx: int = x + dx;
 					let yy: int = y + dy;
 					if (0 <= xx && xx < this.size && 0 <= yy && yy < this.size)
@@ -362,7 +362,7 @@ namespace qrcodegen {
 		private drawAlignmentPattern(x: int, y: int): void {
 			for (let dy = -2; dy <= 2; dy++) {
 				for (let dx = -2; dx <= 2; dx++)
-					this.setFunctionModule(x + dx, y + dy, Math.max(Math.abs(dy), Math.abs(dx)) != 1);
+					this.setFunctionModule(x + dx, y + dy, Math.max(Math.abs(dx), Math.abs(dy)) != 1);
 			}
 		}