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/******************************************************************************
*
* El'Beem - Free Surface Fluid Simulation with the Lattice Boltzmann Method
* All code distributed as part of El'Beem is covered by the version 2 of the
* GNU General Public License. See the file COPYING for details.
* Copyright 2003-2006 Nils Thuerey
*
* API header
*/
#ifndef ELBEEM_API_H
#define ELBEEM_API_H
// simulation run callback function type (elbeemSimulationSettings->runsimCallback)
// best use with FLUIDSIM_CBxxx defines below.
// >parameters
// return values: 0=continue, 1=stop, 2=abort
// data pointer: user data pointer from elbeemSimulationSettings->runsimUserData
// status integer: 1=running simulation, 2=new frame saved
// frame integer: if status is 1, contains current frame number
typedef int (*elbeemRunSimulationCallback)(void *data, int status, int frame);
#define FLUIDSIM_CBRET_CONTINUE 0
#define FLUIDSIM_CBRET_STOP 1
#define FLUIDSIM_CBRET_ABORT 2
#define FLUIDSIM_CBSTATUS_STEP 1
#define FLUIDSIM_CBSTATUS_NEWFRAME 2
// global settings for the simulation
typedef struct elbeemSimulationSettings {
/* version number */
short version;
/* id number of simulation domain, needed if more than a
* single domain should be simulated */
short domainId;
/* geometrical extent */
float geoStart[3], geoSize[3];
/* resolutions */
short resolutionxyz;
short previewresxyz;
/* size of the domain in real units (meters along largest resolution x,y,z extent) */
float realsize;
/* fluid properties */
double viscosity;
/* gravity strength */
float gravity[3];
/* anim start end time */
float animStart, aniFrameTime;
/* no. of frames to simulate & output */
short noOfFrames;
/* g star param (LBM compressibility) */
float gstar;
/* activate refinement? */
short maxRefine;
/* probability for surface particle generation (0.0=off) */
float generateParticles;
/* amount of tracer particles to generate (0=off) */
int numTracerParticles;
/* store output path, and file prefix for baked fluid surface */
char outputPath[160+80];
/* channel for frame time, visc & gravity animations */
int channelSizeFrameTime;
float *channelFrameTime;
int channelSizeViscosity;
float *channelViscosity;
int channelSizeGravity;
float *channelGravity; // vector
/* boundary types and settings for domain walls */
short domainobsType;
float domainobsPartslip;
/* generate speed vectors for vertices (e.g. for image based motion blur)*/
short generateVertexVectors;
/* strength of surface smoothing */
float surfaceSmoothing;
/* no. of surface subdivisions */
int surfaceSubdivs;
/* global transformation to apply to fluidsim mesh */
float surfaceTrafo[4*4];
/* development variables, testing for upcoming releases...*/
float farFieldSize;
/* callback function to notify calling program of performed simulation steps
* or newly available frame data, if NULL it is ignored */
elbeemRunSimulationCallback runsimCallback;
/* pointer passed to runsimCallback for user data storage */
void* runsimUserData;
} elbeemSimulationSettings;
// defines for elbeemMesh->type below
#define OB_FLUIDSIM_FLUID 4
#define OB_FLUIDSIM_OBSTACLE 8
#define OB_FLUIDSIM_INFLOW 16
#define OB_FLUIDSIM_OUTFLOW 32
// defines for elbeemMesh->obstacleType below
#define FLUIDSIM_OBSTACLE_NOSLIP 1
#define FLUIDSIM_OBSTACLE_PARTSLIP 2
#define FLUIDSIM_OBSTACLE_FREESLIP 3
#define OB_VOLUMEINIT_VOLUME 1
#define OB_VOLUMEINIT_SHELL 2
#define OB_VOLUMEINIT_BOTH (OB_VOLUMEINIT_SHELL|OB_VOLUMEINIT_VOLUME)
// a single mesh object
typedef struct elbeemMesh {
/* obstacle,fluid or inflow... */
short type;
/* id of simulation domain it belongs to */
short parentDomainId;
/* vertices */
int numVertices;
float *vertices; // = float[n][3];
/* animated vertices */
int channelSizeVertices;
float *channelVertices; // = float[channelSizeVertices* (n*3+1) ];
/* triangles */
int numTriangles;
int *triangles; // = int[][3];
/* animation channels */
int channelSizeTranslation;
float *channelTranslation;
int channelSizeRotation;
float *channelRotation;
int channelSizeScale;
float *channelScale;
/* active channel */
int channelSizeActive;
float *channelActive;
/* initial velocity channel (e.g. for inflow) */
int channelSizeInitialVel;
float *channelInitialVel; // vector
/* use initial velocity in object coordinates? (e.g. for rotation) */
short localInivelCoords;
/* boundary types and settings */
short obstacleType;
float obstaclePartslip;
/* amount of force transfer from fluid to obj, 0=off, 1=normal */
float obstacleImpactFactor;
/* init volume, shell or both? use OB_VOLUMEINIT_xxx defines above */
short volumeInitType;
/* name of the mesh, mostly for debugging */
char *name;
} elbeemMesh;
// API functions
#ifdef __cplusplus
extern "C" {
#endif // __cplusplus
// reset elbeemSimulationSettings struct with defaults
void elbeemResetSettings(struct elbeemSimulationSettings*);
// start fluidsim init (returns !=0 upon failure)
int elbeemInit(void);
// start fluidsim init (returns !=0 upon failure)
int elbeemAddDomain(struct elbeemSimulationSettings*);
// get failure message during simulation or init
// if an error occured (the string is copied into buffer,
// max. length = 256 chars )
void elbeemGetErrorString(char *buffer);
// reset elbeemMesh struct with zeroes
void elbeemResetMesh(struct elbeemMesh*);
// add mesh as fluidsim object
int elbeemAddMesh(struct elbeemMesh*);
// do the actual simulation
int elbeemSimulate(void);
// continue a previously stopped simulation
int elbeemContinueSimulation(void);
// helper functions
// simplify animation channels
// returns if the channel and its size changed
int elbeemSimplifyChannelFloat(float *channel, int *size);
int elbeemSimplifyChannelVec3(float *channel, int *size);
// helper functions implemented in utilities.cpp
/* set elbeem debug output level (0=off to 10=full on) */
void elbeemSetDebugLevel(int level);
/* elbeem debug output function, prints if debug level >0 */
void elbeemDebugOut(char *msg);
/* estimate how much memory a given setup will require */
double elbeemEstimateMemreq(int res,
float sx, float sy, float sz,
int refine, char *retstr);
#ifdef __cplusplus
}
#endif // __cplusplus
/******************************************************************************/
// internal defines, do not use for initializing elbeemMesh
// structs, for these use OB_xxx defines above
/*! fluid geometry init types */
#define FGI_FLAGSTART 16
#define FGI_FLUID (1<<(FGI_FLAGSTART+ 0))
#define FGI_NO_FLUID (1<<(FGI_FLAGSTART+ 1))
#define FGI_BNDNO (1<<(FGI_FLAGSTART+ 2))
#define FGI_BNDFREE (1<<(FGI_FLAGSTART+ 3))
#define FGI_BNDPART (1<<(FGI_FLAGSTART+ 4))
#define FGI_NO_BND (1<<(FGI_FLAGSTART+ 5))
#define FGI_MBNDINFLOW (1<<(FGI_FLAGSTART+ 6))
#define FGI_MBNDOUTFLOW (1<<(FGI_FLAGSTART+ 7))
// all boundary types at once
#define FGI_ALLBOUNDS ( FGI_BNDNO | FGI_BNDFREE | FGI_BNDPART | FGI_MBNDINFLOW | FGI_MBNDOUTFLOW )
#endif // ELBEEM_API_H
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