@ -24,23 +24,28 @@
package io.nayuki.fastqrcodegen ; package io.nayuki.fastqrcodegen ;
// Stores the parts of a QR Code that depend only on the version number,
// and does not depend on the data or error correction level or mask.
final class QrTemplate { final class QrTemplate {
// Use this memoizer to get instances of this class.
public static final Memoizer < Integer , QrTemplate > MEMOIZER
public static final Memoizer < Integer , QrTemplate > MEMOIZER
= new Memoizer < > ( QrTemplate : : new ) ;
= new Memoizer < > ( QrTemplate : : new ) ;
private final int version ;
private final int version ; // In the range [1, 40].
private final int size ;
private final int size ; // Derived from version.
final int [ ] template ;
final int [ ] template ; // Length and values depend on version.
final int [ ] [ ] masks ;
final int [ ] [ ] masks ; // masks.length == 8, and masks[i].length == template.length.
final int [ ] dataOutputBitIndexes ;
final int [ ] dataOutputBitIndexes ; // Length and values depend on version.
// Indicates function modules that are not subjected to masking. Discarded when constructor finishes.
// Indicates function modules that are not subjected to masking. Discarded when constructor finishes.
// Otherwise when the constructor is running, isFunction.length == template.length.
private int [ ] isFunction ;
private int [ ] isFunction ;
// Creates a QR Code template for the given version number.
private QrTemplate ( int ver ) {
private QrTemplate ( int ver ) {
if ( ver < QrCode . MIN_VERSION | | ver > QrCode . MAX_VERSION )
if ( ver < QrCode . MIN_VERSION | | ver > QrCode . MAX_VERSION )
throw new IllegalArgumentException ( "Version out of range" ) ;
throw new IllegalArgumentException ( "Version out of range" ) ;
@ -56,6 +61,7 @@ final class QrTemplate {
}
}
// Reads this object's version field, and draws and marks all function modules.
private void drawFunctionPatterns ( ) {
private void drawFunctionPatterns ( ) {
// Draw horizontal and vertical timing patterns
// Draw horizontal and vertical timing patterns
for ( int i = 0 ; i < size ; i + + ) {
for ( int i = 0 ; i < size ; i + + ) {
@ -101,7 +107,7 @@ final class QrTemplate {
darkenFunctionModule ( size - 1 - i , 8 , 0 ) ;
darkenFunctionModule ( size - 1 - i , 8 , 0 ) ;
for ( int i = 8 ; i < 15 ; i + + )
for ( int i = 8 ; i < 15 ; i + + )
darkenFunctionModule ( 8 , size - 15 + i , 0 ) ;
darkenFunctionModule ( 8 , size - 15 + i , 0 ) ;
darkenFunctionModule ( 8 , size - 8 , 1 ) ;
darkenFunctionModule ( 8 , size - 8 , 1 ) ; // Always black
}
}
@ -153,6 +159,7 @@ final class QrTemplate {
}
}
// Computes and returns a new array of masks, based on this object's various fields.
private int [ ] [ ] generateMasks ( ) {
private int [ ] [ ] generateMasks ( ) {
int [ ] [ ] result = new int [ 8 ] [ template . length ] ;
int [ ] [ ] result = new int [ 8 ] [ template . length ] ;
for ( int mask = 0 ; mask < result . length ; mask + + ) {
for ( int mask = 0 ; mask < result . length ; mask + + ) {
@ -180,6 +187,7 @@ final class QrTemplate {
}
}
// Computes and returns an array of bit indexes, based on this object's various fields.
private int [ ] generateZigzagScan ( ) {
private int [ ] generateZigzagScan ( ) {
int [ ] result = new int [ getNumRawDataModules ( version ) / 8 * 8 ] ;
int [ ] result = new int [ getNumRawDataModules ( version ) / 8 * 8 ] ;
int i = 0 ; // Bit index into the data
int i = 0 ; // Bit index into the data
@ -203,6 +211,7 @@ final class QrTemplate {
}
}
// Returns the value of the bit at the given coordinates in the given grid.
private int getModule ( int [ ] grid , int x , int y ) {
private int getModule ( int [ ] grid , int x , int y ) {
assert 0 < = x & & x < size ;
assert 0 < = x & & x < size ;
assert 0 < = y & & y < size ;
assert 0 < = y & & y < size ;
Project Nayuki
5 years ago