RetroZilla/xpcom/ds/nsUnitConversion.h
2015-10-20 23:03:22 -04:00

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6.8 KiB
C

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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#ifndef nsUnitConversion_h__
#define nsUnitConversion_h__
#include "nscore.h"
#include "nsCoord.h"
#include <math.h>
#include <float.h>
#ifndef FLT_EPSILON
// Not an ANSI compiler... oh, well. Use an IEEE value.
#define FLT_EPSILON 1.19209290e-7f
#endif
/// handy constants
#define TWIPS_PER_POINT_INT 20
#define TWIPS_PER_POINT_FLOAT 20.0f
#define ROUND_CONST_FLOAT 0.5f
#define CEIL_CONST_FLOAT (1.0f - 0.5f*FLT_EPSILON)
/*
* Coord Rounding Functions
*/
inline nscoord NSToCoordFloor(float aValue)
{
#ifdef NS_COORD_IS_FLOAT
return floorf(aValue);
#else
return ((0.0f <= aValue) ? nscoord(aValue) : nscoord(aValue - CEIL_CONST_FLOAT));
#endif
}
inline nscoord NSToCoordCeil(float aValue)
{
#ifdef NS_COORD_IS_FLOAT
return ceilf(aValue);
#else
return ((0.0f <= aValue) ? nscoord(aValue + CEIL_CONST_FLOAT) : nscoord(aValue));
#endif
}
inline nscoord NSToCoordRound(float aValue)
{
#ifdef NS_COORD_IS_FLOAT
return floorf(aValue + ROUND_CONST_FLOAT);
#else
return ((0.0f <= aValue) ? nscoord(aValue + ROUND_CONST_FLOAT) : nscoord(aValue - ROUND_CONST_FLOAT));
#endif
}
/*
* Int Rounding Functions
*/
inline PRInt32 NSToIntFloor(float aValue)
{
return ((0.0f <= aValue) ? PRInt32(aValue) : PRInt32(aValue - CEIL_CONST_FLOAT));
}
inline PRInt32 NSToIntCeil(float aValue)
{
return ((0.0f <= aValue) ? PRInt32(aValue + CEIL_CONST_FLOAT) : PRInt32(aValue));
}
inline PRInt32 NSToIntRound(float aValue)
{
return ((0.0f <= aValue) ? PRInt32(aValue + ROUND_CONST_FLOAT) : PRInt32(aValue - ROUND_CONST_FLOAT));
}
/*
* Twips/Points conversions
*/
inline nscoord NSFloatPointsToTwips(float aPoints)
{
return NSToCoordRound(aPoints * TWIPS_PER_POINT_FLOAT);
}
inline nscoord NSIntPointsToTwips(PRInt32 aPoints)
{
// If nscoord is a float, do the multiplication as float to avoid
// overflow
return nscoord(aPoints) * TWIPS_PER_POINT_INT;
}
inline PRInt32 NSTwipsToIntPoints(nscoord aTwips)
{
return NSToIntRound(aTwips / TWIPS_PER_POINT_FLOAT);
}
inline PRInt32 NSTwipsToFloorIntPoints(nscoord aTwips)
{
return NSToIntFloor(aTwips / TWIPS_PER_POINT_FLOAT);
}
inline PRInt32 NSTwipsToCeilIntPoints(nscoord aTwips)
{
return NSToIntCeil(aTwips / TWIPS_PER_POINT_FLOAT);
}
inline float NSTwipsToFloatPoints(nscoord aTwips)
{
return (float(aTwips) / TWIPS_PER_POINT_FLOAT);
}
/*
* Twips/Pixel conversions
*/
inline nscoord NSFloatPixelsToTwips(float aPixels, float aTwipsPerPixel)
{
nscoord r = NSToCoordRound(aPixels * aTwipsPerPixel);
VERIFY_COORD(r);
return r;
}
inline nscoord NSIntPixelsToTwips(PRInt32 aPixels, float aTwipsPerPixel)
{
#ifdef NS_COORD_IS_FLOAT
nscoord r = aPixels * aTwipsPerPixel;
#else
nscoord r = NSToCoordRound(float(aPixels) * aTwipsPerPixel);
#endif
VERIFY_COORD(r);
return r;
}
inline float NSTwipsToFloatPixels(nscoord aTwips, float aPixelsPerTwip)
{
return (float(aTwips) * aPixelsPerTwip);
}
inline PRInt32 NSTwipsToIntPixels(nscoord aTwips, float aPixelsPerTwip)
{
return NSToIntRound(float(aTwips) * aPixelsPerTwip);
}
/*
* Twips/unit conversions
*/
inline nscoord NSUnitsToTwips(float aValue, float aPointsPerUnit)
{
return NSToCoordRound(aValue * aPointsPerUnit * TWIPS_PER_POINT_FLOAT);
}
inline float NSTwipsToUnits(nscoord aTwips, float aUnitsPerPoint)
{
return (aTwips * (aUnitsPerPoint / TWIPS_PER_POINT_FLOAT));
}
/// Unit conversion macros
//@{
#define NS_INCHES_TO_TWIPS(x) NSUnitsToTwips((x), 72.0f) // 72 points per inch
#define NS_FEET_TO_TWIPS(x) NSUnitsToTwips((x), (72.0f * 12.0f)) // 12 inches per foot
#define NS_MILES_TO_TWIPS(x) NSUnitsToTwips((x), (72.0f * 12.0f * 5280.0f)) // 5280 feet per mile
#define NS_MILLIMETERS_TO_TWIPS(x) NSUnitsToTwips((x), (72.0f * 0.03937f))
#define NS_CENTIMETERS_TO_TWIPS(x) NSUnitsToTwips((x), (72.0f * 0.3937f))
#define NS_METERS_TO_TWIPS(x) NSUnitsToTwips((x), (72.0f * 39.37f))
#define NS_KILOMETERS_TO_TWIPS(x) NSUnitsToTwips((x), (72.0f * 39370.0f))
#define NS_PICAS_TO_TWIPS(x) NSUnitsToTwips((x), 12.0f) // 12 points per pica
#define NS_DIDOTS_TO_TWIPS(x) NSUnitsToTwips((x), (16.0f / 15.0f)) // 15 didots per 16 points
#define NS_CICEROS_TO_TWIPS(x) NSUnitsToTwips((x), (12.0f * (16.0f / 15.0f))) // 12 didots per cicero
#define NS_TWIPS_TO_INCHES(x) NSTwipsToUnits((x), 1.0f / 72.0f)
#define NS_TWIPS_TO_FEET(x) NSTwipsToUnits((x), 1.0f / (72.0f * 12.0f))
#define NS_TWIPS_TO_MILES(x) NSTwipsToUnits((x), 1.0f / (72.0f * 12.0f * 5280.0f))
#define NS_TWIPS_TO_MILLIMETERS(x) NSTwipsToUnits((x), 1.0f / (72.0f * 0.03937f))
#define NS_TWIPS_TO_CENTIMETERS(x) NSTwipsToUnits((x), 1.0f / (72.0f * 0.3937f))
#define NS_TWIPS_TO_METERS(x) NSTwipsToUnits((x), 1.0f / (72.0f * 39.37f))
#define NS_TWIPS_TO_KILOMETERS(x) NSTwipsToUnits((x), 1.0f / (72.0f * 39370.0f))
#define NS_TWIPS_TO_PICAS(x) NSTwipsToUnits((x), 1.0f / 12.0f)
#define NS_TWIPS_TO_DIDOTS(x) NSTwipsToUnits((x), 1.0f / (16.0f / 15.0f))
#define NS_TWIPS_TO_CICEROS(x) NSTwipsToUnits((x), 1.0f / (12.0f * (16.0f / 15.0f)))
//@}
#endif