SphericalPixelSource.h

/*
	SphericalPixelSource.h
	planettool
	
	
	Copyright © 2009–2010 Jens Ayton

	Permission is hereby granted, free of charge, to any person obtaining a
	copy of this software and associated documentation files (the “Software”),
	to deal in the Software without restriction, including without limitation
	the rights to use, copy, modify, merge, publish, distribute, sublicense,
	and/or sell copies of the Software, and to permit persons to whom the
	Software is furnished to do so, subject to the following conditions:

	The above copyright notice and this permission notice shall be included in
	all copies or substantial portions of the Software.

	THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
	FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
	DEALINGS IN THE SOFTWARE.
*/

#ifndef INCLUDED_SphericalPixelSource_h
#define INCLUDED_SphericalPixelSource_h

#include "FloatPixMap.h"
#include <math.h>
#include "OOMaths.h"

FPM_BEGIN_EXTERN_C


#define kPiF			(3.14159265358979323846264338327950288f)
#define kDegToRad		(kPiF / 180.0f)
#define kRadToDeg		(180.0f / kPiF)


/*	Coordinate convention: looking at a planet with the north pole upwards
	and the geographical coordinate origin in the middle, the vector coordinate
	space forms a right-handed basis with Y pointing north, X pointing east and
	Z pointing outwards. In other words:
	(0, 0, 1) is 0° N, 0° E.
	(0, 1, 0) is 90° N, <undefined>° E. (VectorToCoords will say 0° E.)
	(1, 0, 0) is 0° N, 90 °E.
*/

Vector VectorFromCoordsRad(float latitude, float longitude) FPM_PURE;
FPM_INLINE Vector VectorFromCoordsDeg(float latitude, float longitude) FPM_PURE;
FPM_INLINE Vector VectorFromCoordsDeg(float latitude, float longitude)
{
	return VectorFromCoordsRad(latitude * kDegToRad, longitude * kDegToRad);
}

void VectorToCoordsRad(Vector v, float *latitude, float *longitude);
void VectorToCoordsDeg(Vector v, float *latitude, float *longitude);


/*	Coordinate set, which can carry either lat/long or vector coordinates.
	This way, transformations are not made until it's necessary.
	
	Always manipulate Coordinates using the functions below.
*/
typedef struct Coordinates
{
	union
	{
		Vector			v;
		struct
		{
			float		lat;
			float		lon;
		}				l;
	}					d;
	enum
	{
		kCoordsVector, kCoordsLLRad, kCoordsLLDeg
	}					type;
} Coordinates;

FPM_INLINE Coordinates MakeCoordsVector(Vector v) FPM_PURE;
FPM_INLINE Coordinates MakeCoordsVector(Vector v)
{
	Coordinates result;
	result.d.v = v;
	result.type = kCoordsVector;
	return result;
}

FPM_INLINE Coordinates MakeCoordsLatLongRad(float lat, float lon)
{
	Coordinates result;
	result.d.l.lat = lat;
	result.d.l.lon = lon;
	result.type = kCoordsLLRad;
	return result;
}

FPM_INLINE Coordinates MakeCoordsLatLongDeg(float lat, float lon)
{
	Coordinates result;
	result.d.l.lat = lat;
	result.d.l.lon = lon;
	result.type = kCoordsLLDeg;
	return result;
}

FPM_INLINE Vector CoordsGetVector(Coordinates c) FPM_PURE;
FPM_INLINE Vector CoordsGetVector(Coordinates c)
{
	switch (c.type)
	{
		case kCoordsVector:  return c.d.v;
		case kCoordsLLRad:  return VectorFromCoordsRad(c.d.l.lat, c.d.l.lon);
	//	case kCoordsLLDeg:
		default: return VectorFromCoordsDeg(c.d.l.lat, c.d.l.lon);
	}
}

FPM_INLINE void CoordsGetLatLongRad(Coordinates c, float *lat, float *lon) FPM_NON_NULL_ALL;
FPM_INLINE void CoordsGetLatLongRad(Coordinates c, float *lat, float *lon)
{
	switch (c.type)
	{
		case kCoordsLLRad:  *lat = c.d.l.lat; *lon = c.d.l.lon; break;
		case kCoordsLLDeg:  *lat = c.d.l.lat * kDegToRad; *lon = c.d.l.lon * kDegToRad; break;
		case kCoordsVector:  VectorToCoordsRad(c.d.v, lat, lon); break;
	}
}

FPM_INLINE void CoordsGetLatLongDeg(Coordinates c, float *lat, float *lon) FPM_NON_NULL_ALL;
FPM_INLINE void CoordsGetLatLongDeg(Coordinates c, float *lat, float *lon)
{
	switch (c.type)
	{
		case kCoordsLLDeg:  *lat = c.d.l.lat; *lon = c.d.l.lon; break;
		case kCoordsLLRad:  *lat = c.d.l.lat * kRadToDeg; *lon = c.d.l.lon * kRadToDeg; break;
		case kCoordsVector:  VectorToCoordsDeg(c.d.v, lat, lon); break;
	}
}


enum
{
	kRenderFast		= 0x00000001,
	kRenderJitter	= 0x00000002
};
typedef uint32_t RenderFlags;


/*	Progress callback: called at unspecified intervals during rendering; if
	it returns false, rendering is stopped.
*/
typedef bool (*ProgressCallbackFunction)(size_t numerator, size_t denominator, void *cbContext);

/*	Error callback: called to describe errors during rendering, before
	returning false to indicate failure. Not called when returning false
	becuase the progress callback returned false.
*/
typedef void (*ErrorCallbackFunction)(const char *message, void *cbContext);

/*	Function which takes a (unit) vector and returns a colour, used to sample
	any generator or input format.
*/
typedef FPMColor (*SphericalPixelSourceFunction)(Coordinates where, RenderFlags flags, void *context);

typedef bool (*SphericalPixelSourceConstructorFunction)(FloatPixMapRef sourceImage, RenderFlags flags, SphericalPixelSourceFunction *source, void **context);
typedef void (*SphericalPixelSourceDestructorFunction)(void *context);

typedef FloatPixMapRef (*SphericalPixelSinkFunction)(uintmax_t size, RenderFlags flags, SphericalPixelSourceFunction source, void *sourceContext, ProgressCallbackFunction progress, ErrorCallbackFunction error, void *cbContext);


//	Build a lookup table of Gauss distribution numbers.
void BuildGaussTable(unsigned size, float *table);

//	Look up a value in a pregenerated Gauss table.
float GaussTableLookup(float value, float mid, float halfWidth, unsigned tblSize, float *table);
float GaussTableLookup2D(float x, float xmid, float y, float ymid, float halfWidth, unsigned tblSize, float *table);


bool DummyProgressCallback(size_t numerator, size_t denominator, void *context);
void PrintToStdErrErrorCallback(char *message, void *cbContext);	// Prints message to stderr.


// Shared set-up and error checking function for all sinks.
FloatPixMapRef ValidateAndCreatePixMap(uintmax_t nominalSize, uintmax_t width, uintmax_t height, ErrorCallbackFunction errorCB, void *cbContext);


// Printf()-style call for ErrroCallbackFunctions.
void CallErrorCallbackWithFormat(ErrorCallbackFunction callback, void *cbContext, const char *format, ...)
#if __GNUC__
__attribute__((format (printf, 3, 4)))
#endif
;


// [0..1]
FPM_INLINE float RandF(void)
{
	return (float)rand() / (float)RAND_MAX;
}


// [-1..1]
FPM_INLINE float RandF2(void)
{
	return RandF() * 2.0f - 1.0f;
}

FPM_END_EXTERN_C
#endif	/* INCLUDED_SphericalPixelSource_h */