1 files changed, 356 insertions, 0 deletions
diff --git a/genqrcode/mask.c b/genqrcode/mask.c
new file mode 100644
index 0000000000..f812132033
--- /dev/null
+++ b/genqrcode/mask.c
@@ -0,0 +1,356 @@
+/*
+ * qrencode - QR Code encoder
+ *
+ * Masking.
+ * Copyright (C) 2006-2017 Kentaro Fukuchi <kentaro@fukuchi.org>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#if HAVE_CONFIG_H
+# include "config.h"
+#endif
+#include <stdlib.h>
+#include <string.h>
+#include <limits.h>
+#include <errno.h>
+
+#include "qrencode.h"
+#include "qrspec.h"
+#include "mask.h"
+
+STATIC_IN_RELEASE int Mask_writeFormatInformation(int width, unsigned char *frame, int mask, QRecLevel level)
+{
+	unsigned int format;
+	unsigned char v;
+	int i;
+	int blacks = 0;
+
+	format = QRspec_getFormatInfo(mask, level);
+
+	for(i = 0; i < 8; i++) {
+		if(format & 1) {
+			blacks += 2;
+			v = 0x85;
+		} else {
+			v = 0x84;
+		}
+		frame[width * 8 + width - 1 - i] = v;
+		if(i < 6) {
+			frame[width * i + 8] = v;
+		} else {
+			frame[width * (i + 1) + 8] = v;
+		}
+		format= format >> 1;
+	}
+	for(i = 0; i < 7; i++) {
+		if(format & 1) {
+			blacks += 2;
+			v = 0x85;
+		} else {
+			v = 0x84;
+		}
+		frame[width * (width - 7 + i) + 8] = v;
+		if(i == 0) {
+			frame[width * 8 + 7] = v;
+		} else {
+			frame[width * 8 + 6 - i] = v;
+		}
+		format= format >> 1;
+	}
+
+	return blacks;
+}
+
+/**
+ * Penalty coefficients.
+ * See Section 8.8.2, p.45, JIS X0510:2004.
+ */
+#define N1 (3)
+#define N2 (3)
+#define N3 (40)
+#define N4 (10)
+
+#define MASKMAKER(__exp__) \
+	int x, y;\
+	int b = 0;\
+\
+	for(y = 0; y < width; y++) {\
+		for(x = 0; x < width; x++) {\
+			if(*s & 0x80) {\
+				*d = *s;\
+			} else {\
+				*d = *s ^ ((__exp__) == 0);\
+			}\
+			b += (int)(*d & 1);\
+			s++; d++;\
+		}\
+	}\
+	return b;
+
+static int Mask_mask0(int width, const unsigned char *s, unsigned char *d)
+{
+	MASKMAKER((x+y)&1)
+}
+
+static int Mask_mask1(int width, const unsigned char *s, unsigned char *d)
+{
+	MASKMAKER(y&1)
+}
+
+static int Mask_mask2(int width, const unsigned char *s, unsigned char *d)
+{
+	MASKMAKER(x%3)
+}
+
+static int Mask_mask3(int width, const unsigned char *s, unsigned char *d)
+{
+	MASKMAKER((x+y)%3)
+}
+
+static int Mask_mask4(int width, const unsigned char *s, unsigned char *d)
+{
+	MASKMAKER(((y/2)+(x/3))&1)
+}
+
+static int Mask_mask5(int width, const unsigned char *s, unsigned char *d)
+{
+	MASKMAKER(((x*y)&1)+(x*y)%3)
+}
+
+static int Mask_mask6(int width, const unsigned char *s, unsigned char *d)
+{
+	MASKMAKER((((x*y)&1)+(x*y)%3)&1)
+}
+
+static int Mask_mask7(int width, const unsigned char *s, unsigned char *d)
+{
+	MASKMAKER((((x*y)%3)+((x+y)&1))&1)
+}
+
+#define maskNum (8)
+typedef int MaskMaker(int, const unsigned char *, unsigned char *);
+static MaskMaker *maskMakers[maskNum] = {
+	Mask_mask0, Mask_mask1, Mask_mask2, Mask_mask3,
+	Mask_mask4, Mask_mask5, Mask_mask6, Mask_mask7
+};
+
+#ifdef WITH_TESTS
+unsigned char *Mask_makeMaskedFrame(int width, unsigned char *frame, int mask)
+{
+	unsigned char *masked;
+
+	masked = (unsigned char *)malloc((size_t)(width * width));
+	if(masked == NULL) return NULL;
+
+	maskMakers[mask](width, frame, masked);
+
+	return masked;
+}
+#endif
+
+unsigned char *Mask_makeMask(int width, unsigned char *frame, int mask, QRecLevel level)
+{
+	unsigned char *masked;
+
+	if(mask < 0 || mask >= maskNum) {
+		errno = EINVAL;
+		return NULL;
+	}
+
+	masked = (unsigned char *)malloc((size_t)(width * width));
+	if(masked == NULL) return NULL;
+
+	maskMakers[mask](width, frame, masked);
+	Mask_writeFormatInformation(width, masked, mask, level);
+
+	return masked;
+}
+
+
+//static int n1;
+//static int n2;
+//static int n3;
+//static int n4;
+
+STATIC_IN_RELEASE int Mask_calcN1N3(int length, int *runLength)
+{
+	int i;
+	int penalty = 0;
+	int fact;
+
+	for(i = 0; i < length; i++) {
+		if(runLength[i] >= 5) {
+			penalty += N1 + (runLength[i] - 5);
+			//n1 += N1 + (runLength[i] - 5);
+		}
+		if(i & 1) {
+			if(i >= 3 && i < length-2 && (runLength[i] % 3) == 0) {
+				fact = runLength[i] / 3;
+				if(runLength[i-2] == fact &&
+				   runLength[i-1] == fact &&
+				   runLength[i+1] == fact &&
+				   runLength[i+2] == fact) {
+					if(i == 3 || runLength[i-3] >= 4 * fact) {
+						penalty += N3;
+						//n3 += N3;
+					} else if(i+4 >= length || runLength[i+3] >= 4 * fact) {
+						penalty += N3;
+						//n3 += N3;
+					}
+				}
+			}
+		}
+	}
+
+	return penalty;
+}
+
+STATIC_IN_RELEASE int Mask_calcN2(int width, unsigned char *frame)
+{
+	int x, y;
+	unsigned char *p;
+	unsigned char b22, w22;
+	int penalty = 0;
+
+	p = frame;
+	for(y = 1; y < width; y++) {
+		for(x = 1; x < width; x++) {
+			b22 = (p[0] & p[1] & p[width] & p[width+1]) & 1;
+			w22 = (p[0] | p[1] | p[width] | p[width+1]) & 1;
+			if(b22 != 0 || w22 == 0) {
+				penalty += N2;
+			}
+			p++;
+		}
+		p++;
+	}
+
+	return penalty;
+}
+
+STATIC_IN_RELEASE int Mask_calcRunLengthH(int width, unsigned char *frame, int *runLength)
+{
+	int head;
+	int i;
+	unsigned char prev;
+
+	prev = frame[0];
+	head = prev & 1;
+	if(head) {
+		runLength[0] = -1;
+	}
+	runLength[head] = 1;
+
+	for(i = 1; i < width; i++) {
+		if((frame[i] ^ prev) & 1) {
+			head++;
+			runLength[head] = 1;
+			prev = frame[i];
+		} else {
+			runLength[head]++;
+		}
+	}
+
+	return head + 1;
+}
+
+STATIC_IN_RELEASE int Mask_calcRunLengthV(int width, unsigned char *frame, int *runLength)
+{
+	int head;
+	int i;
+	unsigned char prev;
+
+	prev = frame[0];
+	head = prev & 1;
+	if(head) {
+		runLength[0] = -1;
+	} else {
+	}
+	runLength[head] = 1;
+	frame += width;
+
+	for(i = 1; i < width; i++) {
+		if((*frame ^ prev) & 1) {
+			head++;
+			runLength[head] = 1;
+			prev = *frame;
+		} else {
+			runLength[head]++;
+		}
+		frame += width;
+	}
+
+	return head + 1;
+}
+
+STATIC_IN_RELEASE int Mask_evaluateSymbol(int width, unsigned char *frame)
+{
+	int x, y;
+	int penalty = 0;
+	int runLength[QRSPEC_WIDTH_MAX + 1];
+	int length;
+
+	penalty += Mask_calcN2(width, frame);
+
+	for(y = 0; y < width; y++) {
+		length = Mask_calcRunLengthH(width, frame + y * width, runLength);
+		penalty += Mask_calcN1N3(length, runLength);
+	}
+
+	for(x = 0; x < width; x++) {
+		length = Mask_calcRunLengthV(width, frame + x, runLength);
+		penalty += Mask_calcN1N3(length, runLength);
+	}
+
+	return penalty;
+}
+
+unsigned char *Mask_mask(int width, unsigned char *frame, QRecLevel level)
+{
+	int i;
+	unsigned char *mask, *bestMask;
+	int minPenalty = INT_MAX;
+	int blacks;
+	int bratio;
+	int penalty;
+	int w2 = width * width;
+
+	mask = (unsigned char *)malloc((size_t)w2);
+	if(mask == NULL) return NULL;
+	bestMask = (unsigned char *)malloc((size_t)w2);
+	if(bestMask == NULL) {
+		free(mask);
+		return NULL;
+	}
+
+	for(i = 0; i < maskNum; i++) {
+//		n1 = n2 = n3 = n4 = 0;
+		penalty = 0;
+		blacks = maskMakers[i](width, frame, mask);
+		blacks += Mask_writeFormatInformation(width, mask, i, level);
+		bratio = (200 * blacks + w2) / w2 / 2; /* (int)(100*blacks/w2+0.5) */
+		penalty = (abs(bratio - 50) / 5) * N4;
+//		n4 = penalty;
+		penalty += Mask_evaluateSymbol(width, mask);
+//		printf("(%d,%d,%d,%d)=%d\n", n1, n2, n3 ,n4, penalty);
+		if(penalty < minPenalty) {
+			minPenalty = penalty;
+			memcpy(bestMask, mask, (size_t)w2);
+		}
+	}
+	free(mask);
+	return bestMask;
+}