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//---------------------------------------------------------------------------
//
// Copyright (C) Microsoft Corporation. All rights reserved.
//
// File: TextDpi.cs
//
// Description: Helpers to handle text dpi conversions and limitations.
//
// History:
// 04/25/2003 : Microsoft - moving from Avalon branch.
//
//---------------------------------------------------------------------------
using System; // Double, ...
using System.Windows; // DependencyObject
using System.Windows.Documents; // TextElement, ...
using System.Windows.Media; // FontFamily
using MS.Internal.PtsHost.UnsafeNativeMethods; // PTS
namespace MS.Internal.Text
{
// ----------------------------------------------------------------------
// Helpers to handle text dpi conversions and limitations.
// ----------------------------------------------------------------------
internal static class TextDpi
{
// ------------------------------------------------------------------
// Minimum width for text measurement.
// ------------------------------------------------------------------
internal static double MinWidth { get { return _minSize; } }
// ------------------------------------------------------------------
// Maximum width for text measurement.
// ------------------------------------------------------------------
internal static double MaxWidth { get { return _maxSize; } }
// ------------------------------------------------------------------
// Convert from logical measurement unit to text measurement unit.
//
// d - value in logical measurement unit
//
// Returns: value in text measurement unit.
// ------------------------------------------------------------------
internal static int ToTextDpi(double d)
{
if (DoubleUtil.IsZero(d)) { return 0; }
else if (d > 0)
{
if (d > _maxSize) { d = _maxSize; }
else if (d < _minSize) { d = _minSize; }
}
else
{
if (d < -_maxSize) { d = -_maxSize; }
else if (d > -_minSize) { d = -_minSize; }
}
return (int)Math.Round(d * _scale);
}
// ------------------------------------------------------------------
// Convert from text measurement unit to logical measurement unit.
//
// i - value in text measurement unit
//
// Returns: value in logical measurement unit.
// ------------------------------------------------------------------
internal static double FromTextDpi(int i)
{
return ((double)i) / _scale;
}
// ------------------------------------------------------------------
// Convert point from logical measurement unit to text measurement unit.
// ------------------------------------------------------------------
internal static PTS.FSPOINT ToTextPoint(Point point)
{
PTS.FSPOINT fspoint = new PTS.FSPOINT();
fspoint.u = ToTextDpi(point.X);
fspoint.v = ToTextDpi(point.Y);
return fspoint;
}
// ------------------------------------------------------------------
// Convert size from logical measurement unit to text measurement unit.
// ------------------------------------------------------------------
internal static PTS.FSVECTOR ToTextSize(Size size)
{
PTS.FSVECTOR fsvector = new PTS.FSVECTOR();
fsvector.du = ToTextDpi(size.Width);
fsvector.dv = ToTextDpi(size.Height);
return fsvector;
}
// ------------------------------------------------------------------
// Convert rect from text measurement unit to logical measurement unit.
// ------------------------------------------------------------------
internal static Rect FromTextRect(PTS.FSRECT fsrect)
{
return new Rect(
FromTextDpi(fsrect.u),
FromTextDpi(fsrect.v),
FromTextDpi(fsrect.du),
FromTextDpi(fsrect.dv));
}
// ------------------------------------------------------------------
// Make sure that LS/PTS limitations are not exceeded for offset
// within a line.
// ------------------------------------------------------------------
internal static void EnsureValidLineOffset(ref double offset)
{
// Offset has to be > min allowed size && < max allowed size.
if (offset > _maxSize) { offset = _maxSize; }
else if (offset < -_maxSize) { offset = -_maxSize; }
}
// ------------------------------------------------------------------
// Snaps the value to TextDPi, makeing sure that convertion to
// TextDpi and the to double produces the same value.
// ------------------------------------------------------------------
internal static void SnapToTextDpi(ref Size size)
{
size = new Size(FromTextDpi(ToTextDpi(size.Width)), FromTextDpi(ToTextDpi(size.Height)));
}
// ------------------------------------------------------------------
// Make sure that LS/PTS limitations are not exceeded for line width.
// ------------------------------------------------------------------
internal static void EnsureValidLineWidth(ref double width)
{
// Line width has to be > 0 && < max allowed size.
if (width > _maxSize) { width = _maxSize; }
else if (width < _minSize) { width = _minSize; }
}
internal static void EnsureValidLineWidth(ref Size size)
{
// Line width has to be > 0 && < max allowed size.
if (size.Width > _maxSize) { size.Width = _maxSize; }
else if (size.Width < _minSize) { size.Width = _minSize; }
}
internal static void EnsureValidLineWidth(ref int width)
{
// Line width has to be > 0 && < max allowed size.
if (width > _maxSizeInt) { width = _maxSizeInt; }
else if (width < _minSizeInt) { width = _minSizeInt; }
}
// ------------------------------------------------------------------
// Make sure that PTS limitations are not exceeded for page size.
// ------------------------------------------------------------------
internal static void EnsureValidPageSize(ref Size size)
{
// Page size has to be > 0 && < max allowed size.
if (size.Width > _maxSize) { size.Width = _maxSize; }
else if (size.Width < _minSize) { size.Width = _minSize; }
if (size.Height > _maxSize) { size.Height = _maxSize; }
else if (size.Height < _minSize) { size.Height = _minSize; }
}
internal static void EnsureValidPageWidth(ref double width)
{
// Page size has to be > 0 && < max allowed size.
if (width > _maxSize) { width = _maxSize; }
else if (width < _minSize) { width = _minSize; }
}
internal static void EnsureValidPageMargin(ref Thickness pageMargin, Size pageSize)
{
if (pageMargin.Left >= pageSize.Width) { pageMargin.Right = 0.0; }
if (pageMargin.Left + pageMargin.Right >= pageSize.Width)
{
pageMargin.Right = Math.Max(0.0, pageSize.Width - pageMargin.Left - _minSize);
if (pageMargin.Left + pageMargin.Right >= pageSize.Width)
{
pageMargin.Left = pageSize.Width - _minSize;
}
}
if (pageMargin.Top >= pageSize.Height) { pageMargin.Bottom = 0.0; }
if (pageMargin.Top + pageMargin.Bottom >= pageSize.Height)
{
pageMargin.Bottom = Math.Max(0.0, pageSize.Height - pageMargin.Top - _minSize);;
if (pageMargin.Top + pageMargin.Bottom >= pageSize.Height)
{
pageMargin.Top = pageSize.Height - _minSize;
}
}
}
// ------------------------------------------------------------------
// Make sure that LS/PTS limitations are not exceeded for object's size.
// ------------------------------------------------------------------
internal static void EnsureValidObjSize(ref Size size)
{
// Embedded object can have size == 0, but its width and height
// have to be less than max allowed size.
if (size.Width > _maxObjSize) { size.Width = _maxObjSize; }
if (size.Height > _maxObjSize) { size.Height = _maxObjSize; }
}
// ------------------------------------------------------------------
// Measuring unit for PTS presenters is int, but logical measuring
// for the rest of the system is is double.
// Logical measuring dpi = 96
// PTS presenters measuring dpi = 28800
// ------------------------------------------------------------------
private const double _scale = 28800.0 / 96; // 300
// ------------------------------------------------------------------
// PTS/LS limitation for max size.
// ------------------------------------------------------------------
private const int _maxSizeInt = 0x3FFFFFFE;
private const double _maxSize = ((double)_maxSizeInt) / _scale; // = 3,579,139.40 pixels
// ------------------------------------------------------------------
// PTS/LS limitation for min size.
// ------------------------------------------------------------------
private const int _minSizeInt = 1;
private const double _minSize = ((double)_minSizeInt) / _scale; // > 0
// ------------------------------------------------------------------
// Embedded object size is limited to 1/3 of max size accepted by LS/PTS.
// ------------------------------------------------------------------
private const double _maxObjSize = _maxSize / 3; // = 1,193,046.46 pixels
}
#if TEXTLAYOUTDEBUG
// ----------------------------------------------------------------------
// Pefrormance debugging helpers.
// ----------------------------------------------------------------------
internal static class TextDebug
{
// ------------------------------------------------------------------
// Enter the scope and log the message.
// ------------------------------------------------------------------
internal static void BeginScope(string name)
{
Log(name);
++_indent;
}
// ------------------------------------------------------------------
// Exit the current scope.
// ------------------------------------------------------------------
internal static void EndScope()
{
--_indent;
}
// ------------------------------------------------------------------
// Log message.
// ------------------------------------------------------------------
internal static void Log(string msg)
{
Console.WriteLine("> " + CurrentIndent + msg);
}
// ------------------------------------------------------------------
// String representing current indent.
// ------------------------------------------------------------------
private static string CurrentIndent { get { return new string(' ', _indent * 2); } }
// ------------------------------------------------------------------
// Current indent.
// ------------------------------------------------------------------
private static int _indent;
}
#endif // TEXTLAYOUTDEBUG
}
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