psi2love
psi2love.cpp is a small C++ program which takes a HGE psi file and outputs Lua source code to create an equivalent particle system in LÖVE.
#include <stdio.h>
#include <stdint.h>
#include <errno.h>
#include <string.h>
#include <math.h>
struct hgeColor
{
float r,g,b,a;
};
struct hgeParticleSystemInfo
{
uint32_t sprite; // hgeSprite* sprite; // texture + blend mode
int32_t nEmission; // int nEmission; // particles per sec
float fLifetime;
float fParticleLifeMin;
float fParticleLifeMax;
float fDirection;
float fSpread;
int32_t bRelative; // bool bRelative;
float fSpeedMin;
float fSpeedMax;
float fGravityMin;
float fGravityMax;
float fRadialAccelMin;
float fRadialAccelMax;
float fTangentialAccelMin;
float fTangentialAccelMax;
float fSizeStart;
float fSizeEnd;
float fSizeVar;
float fSpinStart;
float fSpinEnd;
float fSpinVar;
hgeColor colColorStart; // + alpha
hgeColor colColorEnd;
float fColorVar;
float fAlphaVar;
};
int main( int argc, const char* argv[] )
{
if ( argc != 5 )
{
fprintf( stderr, "USAGE: psi2love filename.psi func_name image_name max_particles\n" );
return 1;
}
FILE* psi = fopen( argv[ 1 ], "rb" );
if ( psi == NULL )
{
fprintf( stderr, "Error: %s\n", strerror( errno ) );
return 1;
}
hgeParticleSystemInfo info;
if ( fread( &info, 1, sizeof( info ), psi ) != sizeof( info ) )
{
fprintf( stderr, "Error: %s\n", strerror( errno ) );
fclose( psi );
return 1;
}
fclose( psi );
printf( "local function %s()\n", argv[ 2 ] );
printf( " -- created from %s\n", argv[ 1 ] );
printf( "\n" );
printf( " local ps = love.graphics.newParticleSystem( %s, %s )\n", argv[ 3 ], argv[ 4 ] );
printf( "\n" );
// nEmission
printf( " ps:setEmissionRate( %d )\n", info.nEmission );
// fLifetime
printf( " ps:setLifetime( %g )%s\n", info.fLifetime, info.fLifetime == -1.0 ? " -- forever" : "" );
// fParticleLifeMin, fParticleLifeMax
printf( " ps:setParticleLife( %g, %g )\n", info.fParticleLifeMin, info.fParticleLifeMax );
// fDirection
printf( " ps:setDirection( %g )\n", info.fDirection - M_PI / 2 );
// fSpread
printf( " ps:setSpread( %g )\n", info.fSpread );
// bRelative
printf( " -- ps:setRelative( %s )\n", info.bRelative ? "true" : "false" );
// fSpeedMin, fSpeedMax
printf( " ps:setSpeed( %g, %g )\n", info.fSpeedMin, info.fSpeedMax );
// fGravityMin, fGravityMax
printf( " ps:setGravity( %g, %g )\n", info.fGravityMin, info.fGravityMax );
// fRadialAccelMin, fRadialAccelMax
printf( " ps:setRadialAcceleration( %g, %g )\n", info.fRadialAccelMin, info.fRadialAccelMax );
// fTangentialAccelMin, fTangentialAccelMax
printf( " ps:setTangentialAcceleration( %g, %g )\n", info.fTangentialAccelMin, info.fTangentialAccelMax );
// fSizeStart, fSizeEnd, fSizeVar
printf( " ps:setSize( %g, %g ) -- there's a bug in 0.7.1 that forces us to set the size variation using its own function\n", info.fSizeStart, info.fSizeEnd );
printf( " ps:setSizeVariation( %g )\n", info.fSizeVar );
// fSpinStart, fSpinEnd, fSpinVar
printf( " ps:setSpin( %g, %g, %g )\n", info.fSpinStart, info.fSpinEnd, info.fSpinVar );
// colColorStart, colColorEnd
printf(
" ps:setColor( %d, %d, %d, %d, %d, %d, %d, %d )\n",
(int)(info.colColorStart.r * 255), (int)(info.colColorStart.g * 255), (int)(info.colColorStart.b * 255), (int)(info.colColorStart.a * 255),
(int)(info.colColorEnd.r * 255), (int)(info.colColorEnd.g * 255), (int)(info.colColorEnd.b * 255), (int)(info.colColorEnd.a * 255)
);
// fColorVar
printf( " -- ps:setColorVariation( %g )\n", info.fColorVar );
// fAlphaVar
printf( " -- ps:setAlphaVariation( %g )\n", info.fAlphaVar );
printf( "\n" );
printf( " return ps\n" );
printf( "end\n" );
return 0;
}
To compile with MinGW, just type "g++ -o psi2love psi2love.cpp" on the prompt.
The bRelative, fColorVar and fAlphaVar members of HGE's particle system structure don't have counterparts in LÖVE so I generate them in comments.
Just make sure to change the parameters to love.graphics.newParticleSystem in the generated function. I've tested with a couple of emitters created with HGE's particle editor and the results were satisfactory.
Have fun!