public Gradient(ref PixelYhs pxUpper, ref PixelYhs pxLower)
{
bool bGood = true;
try {
if (pxUpper == null || pxLower == null)
{
if (pxUpper == null)
{
RReporting.ShowErr("pxUpper is null", "Gradient(YHS,YHS)", "creating gradient");
}
else if (pxLower == null)
{
RReporting.ShowErr("pxUpper is null", "Gradient(YHS,YHS)", "creating gradient");
}
}
else
{
From(ref pxUpper, ref pxLower);
}
}
catch (Exception exn) {
RReporting.ShowExn(exn, "Gradient(YHS,YHS)", "initializing");
}
}
} //end From(YHSA,YHSA)
public bool From(ref PixelYhs pxUpper, ref PixelYhs pxLower)
{
bool bGood = false;
try {
STEPS = 2;
pxarrStep[0].Y = pxLower.Y;
pxarrStep[0].H = pxLower.H;
pxarrStep[0].S = pxLower.S;
pxarrStep[0].A = (REAL)1.0;
pxarrStep[1].Y = pxUpper.Y;
pxarrStep[1].H = pxUpper.H;
pxarrStep[1].S = pxUpper.S;
pxarrStep[1].A = (REAL)1.0;
rarrStep[0] = (REAL)0.0;
rarrStep[1] = (REAL)1.0;
bGood = true;
}
catch (Exception exn) {
RReporting.ShowExn(exn, "Gradient.From(YHS,YHS)");
bGood = false;
}
return(bGood);
} //end From(YHS,YHS)
public bool Shade(ref PixelYhs pxDest, REAL rSrcZeroTo1)
{
//TODO:? return top or bottom if out of range
bool bFound = false;
bool bWasNull = false;
try {
if (pxDest == null)
{
bWasNull = true;
pxDest = new PixelYhs();
}
if (STEPS > 0)
{
if (rSrcZeroTo1 <= (REAL)0.0)
{
pxDest.From(pxarrStep[0]);
}
//else if (rSrcZeroTo1==(REAL)1.0) pxDest.From(pxarrStep[STEPS-1]);//unnecessary since !bFound is checked below
else
{
int iLower = 0; //this is actually found in the iUpper "for" statement below!
//for (int iNow=iTop; iTop>=0; iTop--) {
// if (rSrcZeroTo1>=rarrStep[iNow]) {
// iLower=iNow;
// break;
// }
//}
REAL ratio;
for (int iUpper = 1; iUpper < STEPS; iUpper++, iLower++)
{
//start at 1 since the first "Top" is 1
if (rSrcZeroTo1 <= rarrStep[iUpper])
{
//the ratio formula: (abs-min)/(max-min)
ratio = (rSrcZeroTo1 - rarrStep[iLower]) / (rarrStep[iUpper] - rarrStep[iLower]);
if (ratio <= RMath.r0)
{
pxDest.From(pxarrStep[iLower]);
}
else if (ratio >= RMath.r1)
{
pxDest.From(pxarrStep[iUpper]);
}
else
{
//use the alpha formula even though non-alpha: (src-dest)*fAlphaRatio+dest
//-(overlays the "top" over the "bottom" based on the "topness" ("ratio")
pxDest.Y = (pxarrStep[iUpper].Y - pxarrStep[iLower].Y) * ratio + pxarrStep[iLower].Y;
pxDest.H = (pxarrStep[iUpper].H - pxarrStep[iLower].H) * ratio + pxarrStep[iLower].H;
pxDest.S = (pxarrStep[iUpper].S - pxarrStep[iLower].S) * ratio + pxarrStep[iLower].S;
}
bFound = true;
break;
}
}
if (!bFound)
{
pxDest.From(pxarrStep[STEPS - 1]);
}
}
} //end if steps are initialized
else
{
pxDest.Set(0, 0, 0);
}
}
catch (Exception exn) {
RReporting.ShowExn(exn, "Gradient Shade(YHS)");
}
if (bWasNull)
{
RReporting.ShowErr("Null dest pixel", "Gradient Shade(YHS)");
}
return(bFound); //TODO: is this right?
} //end Shade(YHS,REAL)
} //end Shade(YHSA,REAL)
public bool Shade(ref PixelYhs pxDest, PixelYhs pxAssumeGrayAndUseY)
{
return(Shade(ref pxDest, pxAssumeGrayAndUseY.Y));
}
