From 4e0224f32f6a9db613f73706f102c49150c0a631 Mon Sep 17 00:00:00 2001
From: Stefan Huber <shuber2@gmx.at>
Date: Sat, 24 Dec 2011 11:59:40 +0100
Subject: [PATCH] restructuring, guarantee permutation property

---
 src/main.c | 212 ++++++++++++++++++++++++++++++++++++-----------------
 1 file changed, 145 insertions(+), 67 deletions(-)

diff --git a/src/main.c b/src/main.c
index 93362df..aa79461 100644
--- a/src/main.c
+++ b/src/main.c
@@ -15,7 +15,8 @@
 #include "config.h"
 
 
-#define MAXFN 1024
+#define BTN_CNT (KEY_MAX - BTN_MISC + 1)
+
 #define EXIT_INVARG 1
 #define EXIT_OPEN 2
 #define EXIT_IOCTL 3
@@ -48,21 +49,37 @@ void printHelp(FILE* out, int argc, char** argv)
 }
 
 
-void listAxismap(int fd)
+__u8 getNumberOfAxes(int fd)
 {
 	__u8 cnt=0;
-	__u8 map[ABS_CNT] = {-1};
-
-
 	if (ioctl(fd, JSIOCGAXES, &cnt) )
 	{
 		perror(PACKAGE_STRING ": error getting number of axes");
 		exit(EXIT_IOCTL);
 	}
+	return cnt;
+}
+
+
+__u8 getNumberOfButtons(int fd)
+{
+	__u8 cnt=0;
+	if (ioctl(fd, JSIOCGBUTTONS, &cnt) )
+	{
+		perror(PACKAGE_STRING ": error getting number of buttons");
+		exit(EXIT_IOCTL);
+	}
+	return cnt;
+}
+
+
+void listAxismap(int fd)
+{
+	__u8 map[ABS_CNT] = {-1};
+	const __u8 cnt = getNumberOfAxes(fd);
 	printf("Got %d axes:\n", cnt);
 	assert( cnt <= ABS_CNT);
 
-
 	if( ioctl(fd, JSIOCGAXMAP, &map) < 0 )
 	{
 		perror(PACKAGE_STRING ": error getting axis map");
@@ -87,17 +104,10 @@ void listAxismap(int fd)
 
 void listButtonmap(int fd)
 {
-	__u8 cnt=0;
-	__u16 map[KEY_MAX - BTN_MISC + 1] = {-1};
-
-	if (ioctl(fd, JSIOCGBUTTONS, &cnt) )
-	{
-		perror(PACKAGE_STRING ": error getting number of buttons");
-		exit(EXIT_IOCTL);
-	}
+	__u16 map[BTN_CNT] = {-1};
+	const __u8 cnt = getNumberOfButtons(fd);
 	printf("Got %d buttons:\n", cnt);
 
-
 	if( ioctl(fd, JSIOCGBTNMAP, &map) < 0 )
 	{
 		perror(PACKAGE_STRING ": error getting button map");
@@ -120,47 +130,116 @@ void listButtonmap(int fd)
 }
 
 
-void setAxismap(int fd, char* mapstr)
+/** Fill an integer array of given size by comma-separated values in str.
+ * Return the number of values contained in str. */
+unsigned parseIntArray(int* array, unsigned size, char* str)
 {
-	__u8 cnt=0;
-	__u8 map[ABS_CNT] = {-1};
+	unsigned i;
+	for(i=0; i<size; ++i)
+	{
+		sscanf(str, "%d", &array[i]);
 
+		// Move up to next comma, and one step further
+		str = strstr(str, ",");
+		if( !str )
+			break;
+		str++;
+	}
 
-	if (ioctl(fd, JSIOCGAXES, &cnt) )
+	// Skip further commas
+	while( str )
 	{
-		perror(PACKAGE_STRING ": error getting number of axes");
-		exit(EXIT_IOCTL);
+		i++;
+		str = strstr(str, ",");
+		if( !str )
+			break;
+		str++;
 	}
-	printf("Setting %d axes.\n", cnt);
-	assert( cnt <= ABS_CNT);
 
+	return i+1;
+}
+
+
+/** Take an array of size that contains cnt values and fill the rest of array
+ * such that a permutation on {0, ..., size-1} results.
+ * Returns 1 if resulting array is a permutation */
+int fillPermutation(int* array, unsigned cnt, unsigned size)
+{
+	assert( cnt <= size );
+
+	int* contains = malloc(sizeof(int)*size );
+	memset(contains, 0, sizeof(int)*size );
 
-	char* s = mapstr;
+
+	// Check which value is already there
 	for(unsigned i=0; i<cnt; ++i)
 	{
-		if( !s )
+		const unsigned v = array[i];
+		if( v>=size || contains[v] )
+			return 0;
+		contains[v] = 1;
+	}
+
+	// Do it the hard way on array[cnt, max]
+	unsigned min=0;
+	for(unsigned i=cnt; i<size; ++i)
+	{
+		// Get minimum free value
+		while( contains[min] )
 		{
-			fprintf(stderr, "Missing value for axis %d.\n", i);
-			exit(EXIT_VALUE);
+			min++;
+			assert( min<size );
 		}
 
-		int val=-1;
-		sscanf(s, "%d", &val);
-		if( val<0 || val>=(1<<8) )
+		array[i] = min;
+		contains[min] = 1;
+	}
+
+	return 1;
+}
+
+
+void setAxismap(int fd, char* mapstr)
+{
+	__u8 map[ABS_CNT] = {-1};
+	int imap[ABS_CNT] = {-1};
+
+
+	const __u8 cnt = getNumberOfAxes(fd);
+	printf("Setting %d axes.\n", cnt);
+	assert( cnt <= ABS_CNT);
+
+
+	const unsigned readcnt = parseIntArray(imap, cnt, mapstr);
+	if( readcnt != cnt )
+	{
+		fprintf(stderr, "Invalid number of values given: %d\n", readcnt);
+		exit(EXIT_VALUE);
+	}
+
+	// Nothing to do
+	if( cnt<=0 )
+		return;
+
+	// Fill the remaining array such that we obtain a permutation
+	if( !fillPermutation(imap, cnt, ABS_CNT) )
+	{
+		fprintf(stderr, "Mapping needs to be a permutation.\n");
+		exit(EXIT_VALUE);
+	}
+
+	// Copy array and check bounds
+	for(unsigned i=0; i<ABS_CNT; ++i)
+	{
+		if( imap[i]<0 || imap[i]>=ABS_CNT )
 		{
-			fprintf(stderr, "Value out of bounds: %d\n", val);
+			fprintf(stderr, "Value out of bounds: %d\n", imap[i]);
 			exit(EXIT_VALUE);
 		}
-		map[i] = val;
 
-		s = strstr(s, ",");
-		if(s)
-			s++;
+		map[i] = imap[i];
 	}
 
-	if( s )
-		fprintf(stderr, "Too many values given for the axismap. Ignoring the rest.\n");
-
 
 	printf("Setting the following map:\n");	
 	for(int i=0; i<cnt; i++)
@@ -177,45 +256,44 @@ void setAxismap(int fd, char* mapstr)
 
 void setButtonmap(int fd, char* mapstr)
 {
-	__u8 cnt=0;
-	__u16 map[KEY_MAX - BTN_MISC + 1] = {-1};
+	__u16 map[BTN_CNT] = {-1};
+	int imap[BTN_CNT] = {-1};
 
-	printf("foo: %d\n", 1<<8);
+	const __u8 cnt = getNumberOfButtons(fd);
+	printf("Setting %d buttons.\n", cnt);
+	assert( cnt <= ABS_CNT);
 
-	if (ioctl(fd, JSIOCGBUTTONS, &cnt) )
+
+	const unsigned readcnt = parseIntArray(imap, cnt, mapstr);
+	if( readcnt != cnt )
 	{
-		perror(PACKAGE_STRING ": error getting number of buttons");
-		exit(EXIT_IOCTL);
+		fprintf(stderr, "Invalid number of values given: %d\n", readcnt);
+		exit(EXIT_VALUE);
 	}
-	printf("Setting %d buttons.\n", cnt);
 
+	// Nothing to do
+	if( cnt<=0 )
+		return;
 
-	char* s = mapstr;
-	for(unsigned i=0; i<cnt; ++i)
+	// Fill the remaining array such that we obtain a permutation
+	if( !fillPermutation(imap, cnt, BTN_CNT) )
 	{
-		if( !s )
-		{
-			fprintf(stderr, "Missing value for axis %d.\n", i);
-			exit(EXIT_VALUE);
-		}
+		fprintf(stderr, "Mapping needs to be a permutation.\n");
+		exit(EXIT_VALUE);
+	}
 
-		int val=-1;
-		sscanf(s, "%d", &val);
-		if( val<0 || val>=(1<<16) )
+	// Copy array and check bounds
+	for(unsigned i=0; i<ABS_CNT; ++i)
+	{
+		if( imap[i]<0 || imap[i]>=BTN_CNT )
 		{
-			fprintf(stderr, "Value out of bounds: %d\n", val);
+			fprintf(stderr, "Value out of bounds: %d\n", imap[i]);
 			exit(EXIT_VALUE);
 		}
-		map[i] = val;
 
-		s = strstr(s, ",");
-		if(s)
-			s++;
+		map[i] = imap[i];
 	}
 
-	if( s )
-		fprintf(stderr, "Too many values given for the axismap. Ignoring the rest.\n");
-
 
 	printf("Setting the following map:\n");	
 	for(int i=0; i<cnt; i++)
@@ -224,7 +302,7 @@ void setButtonmap(int fd, char* mapstr)
 
 	if( ioctl(fd, JSIOCSBTNMAP, &map) )
 	{
-		perror( PACKAGE_STRING ": error setting button map");
+		perror( PACKAGE_STRING ": error setting axis map");
 		exit(EXIT_IOCTL);
 	}
 }
@@ -236,7 +314,7 @@ int main(int argc, char** argv)
 	int argListButtonmap=0;
 	char* argSetAxismap=0;
 	char* argSetButtonmap=0;
-	char dev[MAXFN+1] = "";
+	char* dev;
 
 
 
@@ -254,7 +332,7 @@ int main(int argc, char** argv)
 			i++;
 			if( i >= argc )			
 				reportMissingArgument(opt);
-			strncpy(dev, argv[i], MAXFN);
+			dev = argv[i];
 		}
 		else if( !strcmp(opt, "--list-axismap") )
 		{
@@ -286,7 +364,7 @@ int main(int argc, char** argv)
 	}
 
 
-	if( strcmp("", dev)==0 )
+	if( !dev )
 	{
 		fprintf(stderr, "You need to specify a device.\n");
 		return EXIT_INVARG;
-- 
2.39.5