From 457ee6699bfbe95a387bc53667c6b2ab39917d3b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Miro=20Hron=C4=8Dok?= <miro@hroncok.cz>
Date: Thu, 22 Feb 2018 17:23:25 +0100
Subject: [PATCH] Be explicit about signed chars

Chars being signed is apparently an implementation detail, see [1].

This was failing the build on various architectures:

    ppc64le aarch64 ppc64 s390x armv7hl

With:

    CC/src/ChamferDistanceTransform.cpp:44:1:
    error: narrowing conversion of '-1' from 'int' to 'char' inside { }
    ...

[1] https://stackoverflow.com/q/31634962/1839451
---
 CC/src/ChamferDistanceTransform.cpp | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/CC/src/ChamferDistanceTransform.cpp b/CC/src/ChamferDistanceTransform.cpp
index 5cba46c6..026b2349 100644
--- a/CC/src/ChamferDistanceTransform.cpp
+++ b/CC/src/ChamferDistanceTransform.cpp
@@ -26,7 +26,7 @@
 using namespace CCLib;
 
 //! Forward mask shifts and weights (Chamfer 3-4-5)
-const char ForwardNeighbours345[14*4] = {
+const signed char ForwardNeighbours345[14*4] = {
 	-1,-1,-1, 5,
 	 0,-1,-1, 4,
 	 1,-1,-1, 5,
@@ -44,7 +44,7 @@ const char ForwardNeighbours345[14*4] = {
 };
 
 //! Backward mask shifts and weights (Chamfer 3-4-5)
-const char BackwardNeighbours345[14*4] = {
+const signed char BackwardNeighbours345[14*4] = {
 	 0, 0, 0, 0,
 	 1, 0, 0, 3,
 	-1, 1, 0, 4,
@@ -62,7 +62,7 @@ const char BackwardNeighbours345[14*4] = {
 };
 
 //! Forward mask shifts and weights (Chamfer 1-1-1)
-const char ForwardNeighbours111[14*4] = {
+const signed char ForwardNeighbours111[14*4] = {
 	-1,-1,-1, 1,
 	 0,-1,-1, 1,
 	 1,-1,-1, 1,
@@ -80,7 +80,7 @@ const char ForwardNeighbours111[14*4] = {
 };
 
 //! Backward masks shifts and weights (Chamfer 1-1-1)
-const char BackwardNeighbours111[14*4] = {
+const signed char BackwardNeighbours111[14*4] = {
 	 0, 0, 0, 0,
 	 1, 0, 0, 1,
 	-1, 1, 0, 1,
@@ -101,7 +101,7 @@ const char BackwardNeighbours111[14*4] = {
 //																					unsigned jStart,
 //																					unsigned kStart,
 //																					bool forward,
-//																					const char neighbours[14][4],
+//																					const signed char neighbours[14][4],
 //																					NormalizedProgress* normProgress/*=0*/)
 //{
 //	assert(!m_grid.empty());
@@ -169,8 +169,8 @@ int ChamferDistanceTransform::propagateDistance(CC_CHAMFER_DISTANCE_TYPE type, G
         return -1;
 	}
 
-	const char* fwNeighbours = 0;
-	const char* bwNeighbours = 0;
+	const signed char* fwNeighbours = 0;
+	const signed char* bwNeighbours = 0;
 	switch (type)
 	{
 	case CHAMFER_111:
@@ -216,7 +216,7 @@ int ChamferDistanceTransform::propagateDistance(CC_CHAMFER_DISTANCE_TYPE type, G
 		{
 			for (unsigned char v=0; v<14; ++v)
 			{
-				const char* fwNeighbour = fwNeighbours + 4*v;
+				const signed char* fwNeighbour = fwNeighbours + 4*v;
 				neighborShift[v] =	static_cast<int>(fwNeighbour[0]) +
 									static_cast<int>(fwNeighbour[1]) * static_cast<int>(m_rowSize) +
 									static_cast<int>(fwNeighbour[2]) * static_cast<int>(m_sliceSize);
@@ -233,7 +233,7 @@ int ChamferDistanceTransform::propagateDistance(CC_CHAMFER_DISTANCE_TYPE type, G
 
 					for (unsigned char v=1; v<14; ++v)
 					{
-						const char* fwNeighbour = fwNeighbours + 4*v;
+						const signed char* fwNeighbour = fwNeighbours + 4*v;
 						GridElement neighborVal = _grid[neighborShift[v]] + static_cast<GridElement>(fwNeighbour[3]);
 						minVal = std::min(minVal, neighborVal);
 					}
@@ -260,7 +260,7 @@ int ChamferDistanceTransform::propagateDistance(CC_CHAMFER_DISTANCE_TYPE type, G
 		{
 			for (unsigned char v=0; v<14; ++v)
 			{
-				const char* bwNeighbour = bwNeighbours + 4*v;
+				const signed char* bwNeighbour = bwNeighbours + 4*v;
 				neighborShift[v] =	static_cast<int>(bwNeighbour[0]) +
 									static_cast<int>(bwNeighbour[1]) * static_cast<int>(m_rowSize) +
 									static_cast<int>(bwNeighbour[2]) * static_cast<int>(m_sliceSize);
@@ -279,7 +279,7 @@ int ChamferDistanceTransform::propagateDistance(CC_CHAMFER_DISTANCE_TYPE type, G
 
 					for (unsigned char v=1; v<14; ++v)
 					{
-						const char* bwNeighbour = bwNeighbours + 4*v;
+						const signed char* bwNeighbour = bwNeighbours + 4*v;
 						GridElement neighborVal = _grid[neighborShift[v]] + static_cast<GridElement>(bwNeighbour[3]);
 						minVal = std::min(minVal, neighborVal);
 					}