XMatrix ComposeDocToWorkXMat(const DocCoord ChapterPos, // Top left coord of chapter
const XLONG ChapterDepth, // Accumulated height of previous chaps
const FIXED16 ViewScale // User viewing scale
)
{
XMatrix ScaleMat(ViewScale,ViewScale);
// Conversion of chapter position from DocCoords to WorkCoords
// WorkCoord WrkChapPos(MakeXLong(ChapterPos.x), MakeXLong(ChapterPos.y));
WorkCoord WrkChapPos(MakeXLong(ChapterPos.x), MakeXLong(ChapterPos.y)+ChapterDepth);
// DocToOS matrix is initialised as the Translate matrix: saving space and performance
// by the exclusion of an extra multiplication.
XMatrix DocToWork(-(WrkChapPos));
// The following matrix compositions MUST be performed in this order. If you are tempted
// to optimise this code MAKE SURE THAT THEY ARE STILL IN THIS ORDER WHEN YOU'VE FINISHED!
//
// Apply scale factors to convert from millipoint distances to pixel distances...
DocToWork *= ScaleMat;
return DocToWork;
}
/* Compute the inverse of the transformation
which turns an ellipse into a circle */
void InvElp2Cir(Ellipse *Elp,TMat *InvMat)
{
/* Start with identity matrix */
*InvMat = IdentMat;
/* Scale back into an ellipse. */
ScaleMat(InvMat,Elp->MaxRad,Elp->MinRad);
/* Rotate */
RotateMat(InvMat,Elp->Phi);
/* Translate from origin */
TranslateMat(InvMat,Elp->Center.X,Elp->Center.Y);
}
/* Compute the transformation which turns an ellipse into a circle */
void Elp2Cir(Ellipse *Elp,TMat *CirMat)
{
/* Start with identity matrix */
*CirMat = IdentMat;
/* Translate to origin */
TranslateMat(CirMat,-Elp->Center.X,-Elp->Center.Y);
/* Rotate into standard position */
RotateMat(CirMat,-Elp->Phi);
/* Scale into a circle. */
ScaleMat(CirMat,1.0/Elp->MaxRad,1.0/Elp->MinRad);
}
Matrix ComposeDocToOilMat( const DocCoord& ChapterPos, // Top left coord of chapter
const XLONG& ChapterDepth, // Accumulated height of previous chaps
const FIXED16& ViewScale, // User viewing scale
const WorkCoord& ScrollOffset // Scroll offsets
)
{
// Scale ChapterDepth into device units so that it can be combined with the scroll offset
// BEFORE we build the scroll translation matrix. In this way we avoid storing 64-bit
// translation values in our final matrix...
//
// If we COULD store 64-bit E and F values temporarilly during this composition then
// we would not need to perform this trick at all. This would have the knock-on advantage
// that the OSMapping matrix supplied by the OIL layer could contain the scroll offsets!
//
// NOTE: This adjustment can be removed when testing the system!
Matrix DocToOil;
//**********************************************************************
// Is it just me or is there gunna be a problem with this ?
// If ChapterDepth is big (atfer all it is an XLONG) and ViewScale
// is big too (Say we are zoomed to 1000%) won't this go VERY wrong ?
//
// - Will.
Matrix Scroll( -ScrollOffset.x,
-(ScrollOffset.y + (ChapterDepth * (ViewScale)))
);
//**********************************************************************
Matrix ScaleMat(ViewScale,ViewScale);
Matrix Translate(-((Coord)ChapterPos));
// The following matrix compositions MUST be performed in this order. If you are tempted
// to optimise this code MAKE SURE THAT THEY ARE STILL IN THIS ORDER WHEN YOU'VE FINISHED!
//
// Apply translation to get coordinates into logical column...
DocToOil *= Translate;
// Apply scale factors to convert from millipoint distances to pixel distances...
DocToOil *= ScaleMat;
// Apply scroll-offset translation to move origin to viewing position...
DocToOil *= Scroll;
return DocToOil;
}
tMatrix cMathUtil::ScaleMat(double scale)
{
return ScaleMat(tVector::Ones() * scale);
}
