geodesic.h

//
//  geodesic
//  geometry builder
//  Copyright (c) 2013 Robby Kraft
//  MIT open source license
//

#ifndef __geodesic__geometry__
#define __geodesic__geometry__

// typedef the floating point precision used in all geodesic geometry
typedef float flo_t;
// typedef double flo_t;
// typedef long double flo_t;


typedef struct geodesicSphere geodesicSphere;
typedef struct geodesicDome geodesicDome;


geodesicSphere icosahedronSphere(unsigned int v);
geodesicSphere octahedronSphere(unsigned int v);
geodesicSphere tetrahedronSphere(unsigned int v);

// geodesicDome tetrahedronDome(unsigned int v, float crop);
geodesicDome octahedronDome(unsigned int v, float crop);
geodesicDome icosahedronDome(unsigned int v, float crop);


void deleteGeodesicSphere(geodesicSphere *g);
void deleteGeodesicDome(geodesicDome *d);

// flo_t type is cast to float, double, or long double
// and defined in platonic.h
struct geodesicSphere {

	unsigned int    numPoints;
	unsigned int    numLines;
	unsigned int    numFaces;

	flo_t           *points;  // count is numPoints * 3
	unsigned short  *lines;   // count is numLines * 2    - indices in *points array
	unsigned short  *faces;   // count is numFaces * 3    - indices in *points array

	flo_t           *pointNormals;  // count is numPoints * 3
	flo_t           *lineNormals;   // count is numLines * 3
	flo_t           *faceNormals;   // count is numFaces * 3

	unsigned int frequency;

	// legacy data. get creative!
	flo_t           *pointsNotSpherized;
	flo_t           *pointsDeltaSpherized;  // difference between spherized point and original
	unsigned short  *parentFace; // of the original platonic solid faces, from which did the point originate? size of numPoints
};

struct geodesicDome {

	geodesicSphere  sphere;

	flo_t           *slicePoints;
	flo_t           numSlicePoints;
	unsigned int    *sliceSizes;  // count is number of slices. contains number of faces within each slice
	// stuff for cropping a sphere into a dome
	unsigned int    numMeridians;
	flo_t           *pointMeridians;   // count is numMeridians + 1, the different major-axis-latitudes of points
	flo_t           *faceMeridians;    // count is numMeridians, the different major-axis-latitudes of the center of faces
	unsigned short  *faceAltitudes;    // count is numFaces, each face is paired with its altitude (major-axis-axis) (index to faceMeridians)
	unsigned int    *faceAltitudeCounts; // count is numMeridians (number of unique entries in faceAltitudes), how many triangles in each tier
	// NOTE meridians differ by 1, pointMeridians also contain top and bottom, hence +1 count, faceMeridians are everything in between

	// corresponds to order in mesh array
	unsigned int    numVisibleTriangles;
};

typedef struct geodesicAnalysis geodesicAnalysis;

geodesicAnalysis classifyLines(geodesicSphere *g);

struct geodesicAnalysis {
	double          *lineLengthValues;
	unsigned int    numLineLengths;      // the above array size
	unsigned int    *lineLengthTypes;    // count is numLines, pointers to indices in lineLengthValues
	unsigned int    *lineTypesQuantities;
};

#endif