int CountJumpTally(DmtxRegion reg, int xStart, int yStart, DmtxDirection dir)
{
int x, xInc = 0;
int y, yInc = 0;
int state = DmtxConstants.DmtxModuleOn;
int jumpCount = 0;
int jumpThreshold;
int tModule, tPrev;
bool darkOnLight;
int color;
if (xStart != 0 && yStart != 0)
{
throw new Exception("CountJumpTally failed, xStart or yStart must be zero!");
}
if (dir == DmtxDirection.DmtxDirRight)
{
xInc = 1;
}
else
{
yInc = 1;
}
if (xStart == -1 || xStart == reg.SymbolCols ||
yStart == -1 || yStart == reg.SymbolRows)
{
state = DmtxConstants.DmtxModuleOff;
}
darkOnLight = (reg.OffColor > reg.OnColor);
jumpThreshold = Math.Abs((int)(0.4 * (reg.OnColor - reg.OffColor) + 0.5));
color = ReadModuleColor(reg, yStart, xStart, reg.SizeIdx, reg.FlowBegin.Plane);
tModule = (darkOnLight) ? reg.OffColor - color : color - reg.OffColor;
for (x = xStart + xInc, y = yStart + yInc;
(dir == DmtxDirection.DmtxDirRight && x < reg.SymbolCols) ||
(dir == DmtxDirection.DmtxDirUp && y < reg.SymbolRows);
x += xInc, y += yInc)
{
tPrev = tModule;
color = ReadModuleColor(reg, y, x, reg.SizeIdx, reg.FlowBegin.Plane);
tModule = (darkOnLight) ? reg.OffColor - color : color - reg.OffColor;
if (state == DmtxConstants.DmtxModuleOff)
{
if (tModule > tPrev + jumpThreshold)
{
jumpCount++;
state = DmtxConstants.DmtxModuleOn;
}
}
else
{
if (tModule < tPrev - jumpThreshold)
{
jumpCount++;
state = DmtxConstants.DmtxModuleOff;
}
}
}
return jumpCount;
}
private void TallyModuleJumps(DmtxRegion reg, int[,] tally, int xOrigin, int yOrigin, int mapWidth, int mapHeight, DmtxDirection dir)
{
int extent, weight;
int mapRow, mapCol;
int lineStart, lineStop;
int travelStart, travelStop;
int line;
int travel;
int jumpThreshold;
int color;
int statusPrev, statusModule;
int tPrev, tModule;
if (!(dir == DmtxDirection.DmtxDirUp || dir == DmtxDirection.DmtxDirLeft || dir == DmtxDirection.DmtxDirDown || dir == DmtxDirection.DmtxDirRight))
{
throw new ArgumentException("Only orthogonal directions are allowed in tally module jumps!");
}
int travelStep = (dir == DmtxDirection.DmtxDirUp || dir == DmtxDirection.DmtxDirRight) ? 1 : -1;
/* Abstract row and column progress using pointers to allow grid
traversal in all 4 directions using same logic */
bool horizontal = false;
if ((dir & DmtxDirection.DmtxDirHorizontal) != 0x00)
{
horizontal = true;
line = 0;
travel = 0;
extent = mapWidth;
lineStart = yOrigin;
lineStop = yOrigin + mapHeight;
travelStart = (travelStep == 1) ? xOrigin - 1 : xOrigin + mapWidth;
travelStop = (travelStep == 1) ? xOrigin + mapWidth : xOrigin - 1;
}
else
{
line = 0;
travel = 0;
extent = mapHeight;
lineStart = xOrigin;
lineStop = xOrigin + mapWidth;
travelStart = (travelStep == 1) ? yOrigin - 1 : yOrigin + mapHeight;
travelStop = (travelStep == 1) ? yOrigin + mapHeight : yOrigin - 1;
}
bool darkOnLight = (reg.OffColor > reg.OnColor);
jumpThreshold = Math.Abs((int)(0.4 * (reg.OffColor - reg.OnColor) + 0.5));
if (jumpThreshold < 0)
{
throw new Exception("Negative jump threshold is not allowed in tally module jumps");
}
for (line = lineStart; line < lineStop; line++)
{
/* Capture tModule for each leading border module as normal but
decide status based on predictable barcode border pattern */
travel = travelStart;
if (horizontal)
{
color = ReadModuleColor(reg, line, travel, reg.SizeIdx, reg.FlowBegin.Plane);
}
else
{
color = ReadModuleColor(reg, travel, line, reg.SizeIdx, reg.FlowBegin.Plane);
}
tModule = (darkOnLight) ? reg.OffColor - color : color - reg.OffColor;
statusModule = (travelStep == 1 || (line & 0x01) == 0) ? DmtxConstants.DmtxModuleOnRGB : DmtxConstants.DmtxModuleOff;
weight = extent;
while ((travel += travelStep) != travelStop)
{
tPrev = tModule;
statusPrev = statusModule;
/* For normal data-bearing modules capture color and decide
module status based on comparison to previous "known" module */
if (horizontal)
{
color = ReadModuleColor(reg, line, travel, reg.SizeIdx, reg.FlowBegin.Plane);
}
else
{
color = ReadModuleColor(reg, travel, line, reg.SizeIdx, reg.FlowBegin.Plane);
}
tModule = (darkOnLight) ? reg.OffColor - color : color - reg.OffColor;
if (statusPrev == DmtxConstants.DmtxModuleOnRGB)
{
if (tModule < tPrev - jumpThreshold)
{
statusModule = DmtxConstants.DmtxModuleOff;
}
else
{
statusModule = DmtxConstants.DmtxModuleOnRGB;
}
}
else if (statusPrev == DmtxConstants.DmtxModuleOff)
{
if (tModule > tPrev + jumpThreshold)
{
statusModule = DmtxConstants.DmtxModuleOnRGB;
}
else
{
statusModule = DmtxConstants.DmtxModuleOff;
}
}
if (horizontal)
{
mapRow = line - yOrigin;
mapCol = travel - xOrigin;
}
else
{
mapRow = travel - yOrigin;
mapCol = line - xOrigin;
}
if (!(mapRow < 24 && mapCol < 24))
{
throw new Exception("Tally module mump failed, index out of range!");
}
if (statusModule == DmtxConstants.DmtxModuleOnRGB)
{
tally[mapRow, mapCol] += (2 * weight);
}
weight--;
}
if (weight != 0)
{
throw new Exception("Tally module jump failed, weight <> 0!");
}
}
}