gecko/xpcom/ds/nsUnitConversion.h

179 lines
6.1 KiB
C

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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*
* The Original Code is mozilla.org code.
*
* The Initial Developer of the Original Code is
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#ifndef nsUnitConversion_h__
#define nsUnitConversion_h__
#include "nscore.h"
#include "nsCoord.h"
#include "nsMathUtils.h"
#include <math.h>
#include <float.h>
/// handy constants
#define TWIPS_PER_POINT_INT 20
#define TWIPS_PER_POINT_FLOAT 20.0f
/*
* Coord Rounding Functions
*/
inline nscoord NSToCoordFloor(float aValue)
{
return nscoord(NS_floorf(aValue));
}
inline nscoord NSToCoordCeil(float aValue)
{
return nscoord(NS_ceilf(aValue));
}
inline nscoord NSToCoordRound(float aValue)
{
return nscoord(NS_floorf(aValue + 0.5f));
}
/*
* Int Rounding Functions
*/
inline PRInt32 NSToIntFloor(float aValue)
{
return PRInt32(NS_floorf(aValue));
}
inline PRInt32 NSToIntCeil(float aValue)
{
return PRInt32(NS_ceilf(aValue));
}
inline PRInt32 NSToIntRound(float aValue)
{
return NS_lroundf(aValue);
}
/*
* App Unit/Pixel conversions
*/
inline nscoord NSFloatPixelsToAppUnits(float aPixels, PRInt32 aAppUnitsPerPixel)
{
float product = aPixels * aAppUnitsPerPixel;
nscoord result;
#ifdef NS_COORD_IS_FLOAT
// No need to bounds-check if converting float to float
result = NSToCoordRound(product);
#else
// Bounds-check before converting out of float, to avoid overflow
if (product >= nscoord_MAX) {
NS_WARNING("Overflowed nscoord_MAX in conversion to nscoord");
result = nscoord_MAX;
} else if (product <= nscoord_MIN) {
NS_WARNING("Overflowed nscoord_MIN in conversion to nscoord");
result = nscoord_MIN;
} else {
result = NSToCoordRound(product);
}
#endif
VERIFY_COORD(result);
return result;
}
inline nscoord NSIntPixelsToAppUnits(PRInt32 aPixels, PRInt32 aAppUnitsPerPixel)
{
// The cast to nscoord makes sure we don't overflow if we ever change
// nscoord to float
nscoord r = aPixels * (nscoord)aAppUnitsPerPixel;
VERIFY_COORD(r);
return r;
}
inline float NSAppUnitsToFloatPixels(nscoord aAppUnits, PRInt32 aAppUnitsPerPixel)
{
return (float(aAppUnits) / aAppUnitsPerPixel);
}
inline PRInt32 NSAppUnitsToIntPixels(nscoord aAppUnits, PRInt32 aAppUnitsPerPixel)
{
return NSToIntRound(float(aAppUnits) / aAppUnitsPerPixel);
}
/*
* 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_POINTS_TO_TWIPS(x) NSUnitsToTwips((x), 1.0f)
#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_POINTS(x) NSTwipsToUnits((x), 1.0f)
#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