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/***********************************************************
* A single header file OpenGL lightmapping library *
* https : //github.com/ands/lightmapper *
* no warranty implied | use at your own risk *
* author : Andreas Mantler ( ands ) | last change : 10.05 .2018 *
* *
* License : *
* This software is in the public domain . *
* Where that dedication is not recognized , *
* you are granted a perpetual , irrevocable license to copy *
* and modify this file however you want . *
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
# ifndef LIGHTMAPPER_H
# define LIGHTMAPPER_H
# ifdef __cplusplus
# define LM_DEFAULT_VALUE(value) = value
# else
# define LM_DEFAULT_VALUE(value)
# endif
# ifndef LM_CALLOC
# define LM_CALLOC(count, size) calloc(count, size)
# endif
# ifndef LM_FREE
# define LM_FREE(ptr) free(ptr)
# endif
typedef int lm_bool ;
# define LM_FALSE 0
# define LM_TRUE 1
typedef int lm_type ;
# define LM_NONE 0
# define LM_UNSIGNED_BYTE GL_UNSIGNED_BYTE
# define LM_UNSIGNED_SHORT GL_UNSIGNED_SHORT
# define LM_UNSIGNED_INT GL_UNSIGNED_INT
# define LM_FLOAT GL_FLOAT
typedef struct lm_context lm_context ;
// creates a lightmapper instance. it can be used to render multiple lightmaps.
lm_context * lmCreate (
int hemisphereSize , // hemisphereSize: resolution of the hemisphere renderings. must be a power of two! typical: 64.
float zNear , float zFar , // zNear/zFar: hemisphere min/max draw distances.
float clearR , float clearG , float clearB , // clear color / background color / sky color.
int interpolationPasses , float interpolationThreshold , // passes: hierarchical selective interpolation passes (0-8; initial step size = 2^passes).
// threshold: error value below which lightmap pixels are interpolated instead of rendered.
// use output image from LM_DEBUG_INTERPOLATION to determine a good value.
// values around and below 0.01 are probably ok.
// the lower the value, the more hemispheres are rendered -> slower, but possibly better quality.
float cameraToSurfaceDistanceModifier LM_DEFAULT_VALUE ( 0.0f ) ) ; // modifier for the height of the rendered hemispheres above the surface
// -1.0f => stick to surface, 0.0f => minimum height for interpolated surface normals,
// > 0.0f => improves gradients on surfaces with interpolated normals due to the flat surface horizon,
// but may introduce other artifacts.
// optional: set material characteristics by specifying cos(theta)-dependent weights for incoming light.
typedef float ( * lm_weight_func ) ( float cos_theta , void * userdata ) ;
void lmSetHemisphereWeights ( lm_context * ctx , lm_weight_func f , void * userdata ) ; // precalculates weights for incoming light depending on its angle. (default: all weights are 1.0f)
// specify an output lightmap image buffer with w * h * c * sizeof(float) bytes of memory.
void lmSetTargetLightmap ( lm_context * ctx , float * outLightmap , int w , int h , int c ) ; // output HDR lightmap (linear 32bit float channels; c: 1->Greyscale, 2->Greyscale+Alpha, 3->RGB, 4->RGBA).
// set the geometry to map to the currently set target lightmap (set the target lightmap before calling this!).
void lmSetGeometry ( lm_context * ctx ,
const float * transformationMatrix , // 4x4 object-to-world transform for the geometry or NULL (no transformation).
lm_type positionsType , const void * positionsXYZ , int positionsStride , // triangle mesh in object space.
lm_type normalsType , const void * normalsXYZ , int normalsStride , // optional normals for the mesh in object space (Use LM_NONE type in case you only need flat surfaces).
lm_type lightmapCoordsType , const void * lightmapCoordsUV , int lightmapCoordsStride , // lightmap atlas texture coordinates for the mesh [0..1]x[0..1] (integer types are normalized to 0..1 range).
int count , lm_type indicesType LM_DEFAULT_VALUE ( LM_NONE ) , const void * indices LM_DEFAULT_VALUE ( 0 ) ) ; // if mesh indices are used, count = number of indices else count = number of vertices.
// as long as lmBegin returns true, the scene has to be rendered with the
// returned camera and view parameters to the currently bound framebuffer.
// if lmBegin returns true, it must be followed by lmEnd after rendering!
lm_bool lmBegin ( lm_context * ctx ,
int * outViewport4 , // output of the current viewport: { x, y, w, h }. use these to call glViewport()!
float * outView4x4 , // output of the current camera view matrix.
float * outProjection4x4 ) ; // output of the current camera projection matrix.
float lmProgress ( lm_context * ctx ) ; // should only be called between lmBegin/lmEnd!
// provides the light mapping progress as a value increasing from 0.0 to 1.0.
void lmEnd ( lm_context * ctx ) ;
// destroys the lightmapper instance. should be called to free resources.
void lmDestroy ( lm_context * ctx ) ;
// image based post processing (c is the number of color channels in the image, m a channel mask for the operation)
# define LM_ALL_CHANNELS 0x0f
float lmImageMin ( const float * image , int w , int h , int c , int m LM_DEFAULT_VALUE ( LM_ALL_CHANNELS ) ) ; // find the minimum value (across the specified channels)
float lmImageMax ( const float * image , int w , int h , int c , int m LM_DEFAULT_VALUE ( LM_ALL_CHANNELS ) ) ; // find the maximum value (across the specified channels)
void lmImageAdd ( float * image , int w , int h , int c , float value , int m LM_DEFAULT_VALUE ( LM_ALL_CHANNELS ) ) ; // in-place add to the specified channels
void lmImageScale ( float * image , int w , int h , int c , float factor , int m LM_DEFAULT_VALUE ( LM_ALL_CHANNELS ) ) ; // in-place scaling of the specified channels
void lmImagePower ( float * image , int w , int h , int c , float exponent , int m LM_DEFAULT_VALUE ( LM_ALL_CHANNELS ) ) ; // in-place powf(v, exponent) of the specified channels (for gamma)
void lmImageDilate ( const float * image , float * outImage , int w , int h , int c ) ; // widen the populated non-zero areas by 1 pixel.
void lmImageSmooth ( const float * image , float * outImage , int w , int h , int c ) ; // simple box filter on only the non-zero values.
void lmImageDownsample ( const float * image , float * outImage , int w , int h , int c ) ; // downsamples [0..w]x[0..h] to [0..w/2]x[0..h/2] by avereging only the non-zero values
void lmImageFtoUB ( const float * image , unsigned char * outImage , int w , int h , int c , float max LM_DEFAULT_VALUE ( 0.0f ) ) ; // casts a floating point image to an 8bit/channel image
// TGA file output helpers
lm_bool lmImageSaveTGAub ( const char * filename , const unsigned char * image , int w , int h , int c ) ;
lm_bool lmImageSaveTGAf ( const char * filename , const float * image , int w , int h , int c , float max LM_DEFAULT_VALUE ( 0.0f ) ) ;
# endif
////////////////////// END OF HEADER //////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
# ifdef LIGHTMAPPER_IMPLEMENTATION
# undef LIGHTMAPPER_IMPLEMENTATION
# include <stdlib.h>
# include <stdio.h>
# include <math.h>
# include <float.h>
# include <assert.h>
# include <limits.h>
# define LM_SWAP(type, a, b) { type tmp = (a); (a) = (b); (b) = tmp; }
# if defined(_MSC_VER) && !defined(__cplusplus)
# define inline __inline
# endif
# if defined(_MSC_VER) && (_MSC_VER <= 1700)
static inline lm_bool lm_finite ( float a ) { return _finite ( a ) ; }
# else
static inline lm_bool lm_finite ( float a ) { return isfinite ( a ) ; }
# endif
static inline int lm_mini ( int a , int b ) { return a < b ? a : b ; }
static inline int lm_maxi ( int a , int b ) { return a > b ? a : b ; }
static inline int lm_absi ( int a ) { return a < 0 ? - a : a ; }
static inline float lm_minf ( float a , float b ) { return a < b ? a : b ; }
static inline float lm_maxf ( float a , float b ) { return a > b ? a : b ; }
static inline float lm_absf ( float a ) { return a < 0.0f ? - a : a ; }
static inline float lm_pmodf ( float a , float b ) { return ( a < 0.0f ? 1.0f : 0.0f ) + ( float ) fmod ( a , b ) ; } // positive mod
typedef struct lm_ivec2 { int x , y ; } lm_ivec2 ;
static inline lm_ivec2 lm_i2 ( int x , int y ) { lm_ivec2 v = { x , y } ; return v ; }
typedef struct lm_vec2 { float x , y ; } lm_vec2 ;
static inline lm_vec2 lm_v2i ( int x , int y ) { lm_vec2 v = { ( float ) x , ( float ) y } ; return v ; }
static inline lm_vec2 lm_v2 ( float x , float y ) { lm_vec2 v = { x , y } ; return v ; }
static inline lm_vec2 lm_negate2 ( lm_vec2 a ) { return lm_v2 ( - a . x , - a . y ) ; }
static inline lm_vec2 lm_add2 ( lm_vec2 a , lm_vec2 b ) { return lm_v2 ( a . x + b . x , a . y + b . y ) ; }
static inline lm_vec2 lm_sub2 ( lm_vec2 a , lm_vec2 b ) { return lm_v2 ( a . x - b . x , a . y - b . y ) ; }
static inline lm_vec2 lm_mul2 ( lm_vec2 a , lm_vec2 b ) { return lm_v2 ( a . x * b . x , a . y * b . y ) ; }
static inline lm_vec2 lm_scale2 ( lm_vec2 a , float b ) { return lm_v2 ( a . x * b , a . y * b ) ; }
static inline lm_vec2 lm_div2 ( lm_vec2 a , float b ) { return lm_scale2 ( a , 1.0f / b ) ; }
static inline lm_vec2 lm_pmod2 ( lm_vec2 a , float b ) { return lm_v2 ( lm_pmodf ( a . x , b ) , lm_pmodf ( a . y , b ) ) ; }
static inline lm_vec2 lm_min2 ( lm_vec2 a , lm_vec2 b ) { return lm_v2 ( lm_minf ( a . x , b . x ) , lm_minf ( a . y , b . y ) ) ; }
static inline lm_vec2 lm_max2 ( lm_vec2 a , lm_vec2 b ) { return lm_v2 ( lm_maxf ( a . x , b . x ) , lm_maxf ( a . y , b . y ) ) ; }
static inline lm_vec2 lm_abs2 ( lm_vec2 a ) { return lm_v2 ( lm_absf ( a . x ) , lm_absf ( a . y ) ) ; }
static inline lm_vec2 lm_floor2 ( lm_vec2 a ) { return lm_v2 ( floorf ( a . x ) , floorf ( a . y ) ) ; }
static inline lm_vec2 lm_ceil2 ( lm_vec2 a ) { return lm_v2 ( ceilf ( a . x ) , ceilf ( a . y ) ) ; }
static inline float lm_dot2 ( lm_vec2 a , lm_vec2 b ) { return a . x * b . x + a . y * b . y ; }
static inline float lm_cross2 ( lm_vec2 a , lm_vec2 b ) { return a . x * b . y - a . y * b . x ; } // pseudo cross product
static inline float lm_length2sq ( lm_vec2 a ) { return a . x * a . x + a . y * a . y ; }
static inline float lm_length2 ( lm_vec2 a ) { return sqrtf ( lm_length2sq ( a ) ) ; }
static inline lm_vec2 lm_normalize2 ( lm_vec2 a ) { return lm_div2 ( a , lm_length2 ( a ) ) ; }
static inline lm_bool lm_finite2 ( lm_vec2 a ) { return lm_finite ( a . x ) & & lm_finite ( a . y ) ; }
typedef struct lm_vec3 { float x , y , z ; } lm_vec3 ;
static inline lm_vec3 lm_v3 ( float x , float y , float z ) { lm_vec3 v = { x , y , z } ; return v ; }
static inline lm_vec3 lm_negate3 ( lm_vec3 a ) { return lm_v3 ( - a . x , - a . y , - a . z ) ; }
static inline lm_vec3 lm_add3 ( lm_vec3 a , lm_vec3 b ) { return lm_v3 ( a . x + b . x , a . y + b . y , a . z + b . z ) ; }
static inline lm_vec3 lm_sub3 ( lm_vec3 a , lm_vec3 b ) { return lm_v3 ( a . x - b . x , a . y - b . y , a . z - b . z ) ; }
static inline lm_vec3 lm_mul3 ( lm_vec3 a , lm_vec3 b ) { return lm_v3 ( a . x * b . x , a . y * b . y , a . z * b . z ) ; }
static inline lm_vec3 lm_scale3 ( lm_vec3 a , float b ) { return lm_v3 ( a . x * b , a . y * b , a . z * b ) ; }
static inline lm_vec3 lm_div3 ( lm_vec3 a , float b ) { return lm_scale3 ( a , 1.0f / b ) ; }
static inline lm_vec3 lm_pmod3 ( lm_vec3 a , float b ) { return lm_v3 ( lm_pmodf ( a . x , b ) , lm_pmodf ( a . y , b ) , lm_pmodf ( a . z , b ) ) ; }
static inline lm_vec3 lm_min3 ( lm_vec3 a , lm_vec3 b ) { return lm_v3 ( lm_minf ( a . x , b . x ) , lm_minf ( a . y , b . y ) , lm_minf ( a . z , b . z ) ) ; }
static inline lm_vec3 lm_max3 ( lm_vec3 a , lm_vec3 b ) { return lm_v3 ( lm_maxf ( a . x , b . x ) , lm_maxf ( a . y , b . y ) , lm_maxf ( a . z , b . z ) ) ; }
static inline lm_vec3 lm_abs3 ( lm_vec3 a ) { return lm_v3 ( lm_absf ( a . x ) , lm_absf ( a . y ) , lm_absf ( a . z ) ) ; }
static inline lm_vec3 lm_floor3 ( lm_vec3 a ) { return lm_v3 ( floorf ( a . x ) , floorf ( a . y ) , floorf ( a . z ) ) ; }
static inline lm_vec3 lm_ceil3 ( lm_vec3 a ) { return lm_v3 ( ceilf ( a . x ) , ceilf ( a . y ) , ceilf ( a . z ) ) ; }
static inline float lm_dot3 ( lm_vec3 a , lm_vec3 b ) { return a . x * b . x + a . y * b . y + a . z * b . z ; }
static inline lm_vec3 lm_cross3 ( lm_vec3 a , lm_vec3 b ) { return lm_v3 ( a . y * b . z - b . y * a . z , a . z * b . x - b . z * a . x , a . x * b . y - b . x * a . y ) ; }
static inline float lm_length3sq ( lm_vec3 a ) { return a . x * a . x + a . y * a . y + a . z * a . z ; }
static inline float lm_length3 ( lm_vec3 a ) { return sqrtf ( lm_length3sq ( a ) ) ; }
static inline lm_vec3 lm_normalize3 ( lm_vec3 a ) { return lm_div3 ( a , lm_length3 ( a ) ) ; }
static inline lm_bool lm_finite3 ( lm_vec3 a ) { return lm_finite ( a . x ) & & lm_finite ( a . y ) & & lm_finite ( a . z ) ; }
static lm_vec2 lm_toBarycentric ( lm_vec2 p1 , lm_vec2 p2 , lm_vec2 p3 , lm_vec2 p )
{
// http://www.blackpawn.com/texts/pointinpoly/
// Compute vectors
lm_vec2 v0 = lm_sub2 ( p3 , p1 ) ;
lm_vec2 v1 = lm_sub2 ( p2 , p1 ) ;
lm_vec2 v2 = lm_sub2 ( p , p1 ) ;
// Compute dot products
float dot00 = lm_dot2 ( v0 , v0 ) ;
float dot01 = lm_dot2 ( v0 , v1 ) ;
float dot02 = lm_dot2 ( v0 , v2 ) ;
float dot11 = lm_dot2 ( v1 , v1 ) ;
float dot12 = lm_dot2 ( v1 , v2 ) ;
// Compute barycentric coordinates
float invDenom = 1.0f / ( dot00 * dot11 - dot01 * dot01 ) ;
float u = ( dot11 * dot02 - dot01 * dot12 ) * invDenom ;
float v = ( dot00 * dot12 - dot01 * dot02 ) * invDenom ;
return lm_v2 ( u , v ) ;
}
static inline int lm_leftOf ( lm_vec2 a , lm_vec2 b , lm_vec2 c )
{
float x = lm_cross2 ( lm_sub2 ( b , a ) , lm_sub2 ( c , b ) ) ;
return x < 0 ? - 1 : x > 0 ;
}
static lm_bool lm_lineIntersection ( lm_vec2 x0 , lm_vec2 x1 , lm_vec2 y0 , lm_vec2 y1 , lm_vec2 * res )
{
lm_vec2 dx = lm_sub2 ( x1 , x0 ) ;
lm_vec2 dy = lm_sub2 ( y1 , y0 ) ;
lm_vec2 d = lm_sub2 ( x0 , y0 ) ;
float dyx = lm_cross2 ( dy , dx ) ;
if ( dyx = = 0.0f )
return LM_FALSE ;
dyx = lm_cross2 ( d , dx ) / dyx ;
if ( dyx < = 0 | | dyx > = 1 )
return LM_FALSE ;
res - > x = y0 . x + dyx * dy . x ;
res - > y = y0 . y + dyx * dy . y ;
return LM_TRUE ;
}
// this modifies the poly array! the poly array must be big enough to hold the result!
// res must be big enough to hold the result!
static int lm_convexClip ( lm_vec2 * poly , int nPoly , const lm_vec2 * clip , int nClip , lm_vec2 * res )
{
int nRes = nPoly ;
int dir = lm_leftOf ( clip [ 0 ] , clip [ 1 ] , clip [ 2 ] ) ;
for ( int i = 0 , j = nClip - 1 ; i < nClip & & nRes ; j = i + + )
{
if ( i ! = 0 )
for ( nPoly = 0 ; nPoly < nRes ; nPoly + + )
poly [ nPoly ] = res [ nPoly ] ;
nRes = 0 ;
lm_vec2 v0 = poly [ nPoly - 1 ] ;
int side0 = lm_leftOf ( clip [ j ] , clip [ i ] , v0 ) ;
if ( side0 ! = - dir )
res [ nRes + + ] = v0 ;
for ( int k = 0 ; k < nPoly ; k + + )
{
lm_vec2 v1 = poly [ k ] , x ;
int side1 = lm_leftOf ( clip [ j ] , clip [ i ] , v1 ) ;
if ( side0 + side1 = = 0 & & side0 & & lm_lineIntersection ( clip [ j ] , clip [ i ] , v0 , v1 , & x ) )
res [ nRes + + ] = x ;
if ( k = = nPoly - 1 )
break ;
if ( side1 ! = - dir )
res [ nRes + + ] = v1 ;
v0 = v1 ;
side0 = side1 ;
}
}
return nRes ;
}
struct lm_context
{
struct
{
const float * modelMatrix ;
float normalMatrix [ 9 ] ;
const unsigned char * positions ;
lm_type positionsType ;
int positionsStride ;
const unsigned char * normals ;
lm_type normalsType ;
int normalsStride ;
const unsigned char * uvs ;
lm_type uvsType ;
int uvsStride ;
const unsigned char * indices ;
lm_type indicesType ;
unsigned int count ;
} mesh ;
struct
{
int pass ;
int passCount ;
struct
{
unsigned int baseIndex ;
lm_vec3 p [ 3 ] ;
lm_vec3 n [ 3 ] ;
lm_vec2 uv [ 3 ] ;
} triangle ;
struct
{
int minx , miny ;
int maxx , maxy ;
int x , y ;
} rasterizer ;
struct
{
lm_vec3 position ;
lm_vec3 direction ;
lm_vec3 up ;
} sample ;
struct
{
int side ;
} hemisphere ;
} meshPosition ;
struct
{
int width ;
int height ;
int channels ;
float * data ;
# ifdef LM_DEBUG_INTERPOLATION
unsigned char * debug ;
# endif
} lightmap ;
struct
{
unsigned int size ;
float zNear , zFar ;
float cameraToSurfaceDistanceModifier ;
struct { float r , g , b ; } clearColor ;
unsigned int fbHemiCountX ;
unsigned int fbHemiCountY ;
unsigned int fbHemiIndex ;
lm_ivec2 * fbHemiToLightmapLocation ;
GLuint fbTexture [ 2 ] ;
GLuint fb [ 2 ] ;
GLuint fbDepth ;
GLuint vao ;
struct
{
GLuint programID ;
GLuint hemispheresTextureID ;
GLuint weightsTextureID ;
GLuint weightsTexture ;
} firstPass ;
struct
{
GLuint programID ;
GLuint hemispheresTextureID ;
} downsamplePass ;
struct
{
GLuint texture ;
lm_ivec2 writePosition ;
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int width , height ;
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lm_ivec2 * toLightmapLocation ;
} storage ;
} hemisphere ;
float interpolationThreshold ;
} ;
// pass order of one 4x4 interpolation patch for two interpolation steps (and the next neighbors right of/below it)
// 0 4 1 4 0
// 5 6 5 6 5
// 2 4 3 4 2
// 5 6 5 6 5
// 0 4 1 4 0
static unsigned int lm_passStepSize ( lm_context * ctx )
{
unsigned int shift = ctx - > meshPosition . passCount / 3 - ( ctx - > meshPosition . pass - 1 ) / 3 ;
unsigned int step = ( 1 < < shift ) ;
assert ( step > 0 ) ;
return step ;
}
static unsigned int lm_passOffsetX ( lm_context * ctx )
{
if ( ! ctx - > meshPosition . pass )
return 0 ;
int passType = ( ctx - > meshPosition . pass - 1 ) % 3 ;
unsigned int halfStep = lm_passStepSize ( ctx ) > > 1 ;
return passType ! = 1 ? halfStep : 0 ;
}
static unsigned int lm_passOffsetY ( lm_context * ctx )
{
if ( ! ctx - > meshPosition . pass )
return 0 ;
int passType = ( ctx - > meshPosition . pass - 1 ) % 3 ;
unsigned int halfStep = lm_passStepSize ( ctx ) > > 1 ;
return passType ! = 0 ? halfStep : 0 ;
}
static lm_bool lm_hasConservativeTriangleRasterizerFinished ( lm_context * ctx )
{
return ctx - > meshPosition . rasterizer . y > = ctx - > meshPosition . rasterizer . maxy ;
}
static void lm_moveToNextPotentialConservativeTriangleRasterizerPosition ( lm_context * ctx )
{
unsigned int step = lm_passStepSize ( ctx ) ;
ctx - > meshPosition . rasterizer . x + = step ;
while ( ctx - > meshPosition . rasterizer . x > = ctx - > meshPosition . rasterizer . maxx )
{
ctx - > meshPosition . rasterizer . x = ctx - > meshPosition . rasterizer . minx + lm_passOffsetX ( ctx ) ;
ctx - > meshPosition . rasterizer . y + = step ;
if ( lm_hasConservativeTriangleRasterizerFinished ( ctx ) )
break ;
}
}
static float * lm_getLightmapPixel ( lm_context * ctx , int x , int y )
{
assert ( x > = 0 & & x < ctx - > lightmap . width & & y > = 0 & & y < ctx - > lightmap . height ) ;
return ctx - > lightmap . data + ( y * ctx - > lightmap . width + x ) * ctx - > lightmap . channels ;
}
static void lm_setLightmapPixel ( lm_context * ctx , int x , int y , float * in )
{
assert ( x > = 0 & & x < ctx - > lightmap . width & & y > = 0 & & y < ctx - > lightmap . height ) ;
float * p = ctx - > lightmap . data + ( y * ctx - > lightmap . width + x ) * ctx - > lightmap . channels ;
for ( int j = 0 ; j < ctx - > lightmap . channels ; j + + )
* p + + = * in + + ;
}
# define lm_baseAngle 0.1f
static const float lm_baseAngles [ 3 ] [ 3 ] = {
{ lm_baseAngle , lm_baseAngle + 1.0f / 3.0f , lm_baseAngle + 2.0f / 3.0f } ,
{ lm_baseAngle + 1.0f / 3.0f , lm_baseAngle + 2.0f / 3.0f , lm_baseAngle } ,
{ lm_baseAngle + 2.0f / 3.0f , lm_baseAngle , lm_baseAngle + 1.0f / 3.0f }
} ;
static lm_bool lm_trySamplingConservativeTriangleRasterizerPosition ( lm_context * ctx )
{
if ( lm_hasConservativeTriangleRasterizerFinished ( ctx ) )
return LM_FALSE ;
// check if lightmap pixel was already set
float * pixelValue = lm_getLightmapPixel ( ctx , ctx - > meshPosition . rasterizer . x , ctx - > meshPosition . rasterizer . y ) ;
for ( int j = 0 ; j < ctx - > lightmap . channels ; j + + )
if ( pixelValue [ j ] ! = 0.0f )
return LM_FALSE ;
// try calculating centroid by clipping the pixel against the triangle
lm_vec2 pixel [ 16 ] ;
pixel [ 0 ] = lm_v2i ( ctx - > meshPosition . rasterizer . x , ctx - > meshPosition . rasterizer . y ) ;
pixel [ 1 ] = lm_v2i ( ctx - > meshPosition . rasterizer . x + 1 , ctx - > meshPosition . rasterizer . y ) ;
pixel [ 2 ] = lm_v2i ( ctx - > meshPosition . rasterizer . x + 1 , ctx - > meshPosition . rasterizer . y + 1 ) ;
pixel [ 3 ] = lm_v2i ( ctx - > meshPosition . rasterizer . x , ctx - > meshPosition . rasterizer . y + 1 ) ;
lm_vec2 res [ 16 ] ;
int nRes = lm_convexClip ( pixel , 4 , ctx - > meshPosition . triangle . uv , 3 , res ) ;
if ( nRes = = 0 )
return LM_FALSE ; // nothing left
// calculate centroid position and area
lm_vec2 centroid = res [ 0 ] ;
float area = res [ nRes - 1 ] . x * res [ 0 ] . y - res [ nRes - 1 ] . y * res [ 0 ] . x ;
for ( int i = 1 ; i < nRes ; i + + )
{
centroid = lm_add2 ( centroid , res [ i ] ) ;
area + = res [ i - 1 ] . x * res [ i ] . y - res [ i - 1 ] . y * res [ i ] . x ;
}
centroid = lm_div2 ( centroid , ( float ) nRes ) ;
area = lm_absf ( area / 2.0f ) ;
if ( area < = 0.0f )
return LM_FALSE ; // no area left
// calculate barycentric coords
lm_vec2 uv = lm_toBarycentric (
ctx - > meshPosition . triangle . uv [ 0 ] ,
ctx - > meshPosition . triangle . uv [ 1 ] ,
ctx - > meshPosition . triangle . uv [ 2 ] ,
centroid ) ;
if ( ! lm_finite2 ( uv ) )
return LM_FALSE ; // degenerate
// try to interpolate color from neighbors:
if ( ctx - > meshPosition . pass > 0 )
{
float * neighbors [ 4 ] ;
int neighborCount = 0 ;
int neighborsExpected = 0 ;
int d = ( int ) lm_passStepSize ( ctx ) / 2 ;
int dirs = ( ( ctx - > meshPosition . pass - 1 ) % 3 ) + 1 ;
if ( dirs & 1 ) // check x-neighbors with distance d
{
neighborsExpected + = 2 ;
if ( ctx - > meshPosition . rasterizer . x - d > = ctx - > meshPosition . rasterizer . minx & &
ctx - > meshPosition . rasterizer . x + d < = ctx - > meshPosition . rasterizer . maxx )
{
neighbors [ neighborCount + + ] = lm_getLightmapPixel ( ctx , ctx - > meshPosition . rasterizer . x - d , ctx - > meshPosition . rasterizer . y ) ;
neighbors [ neighborCount + + ] = lm_getLightmapPixel ( ctx , ctx - > meshPosition . rasterizer . x + d , ctx - > meshPosition . rasterizer . y ) ;
}
}
if ( dirs & 2 ) // check y-neighbors with distance d
{
neighborsExpected + = 2 ;
if ( ctx - > meshPosition . rasterizer . y - d > = ctx - > meshPosition . rasterizer . miny & &
ctx - > meshPosition . rasterizer . y + d < = ctx - > meshPosition . rasterizer . maxy )
{
neighbors [ neighborCount + + ] = lm_getLightmapPixel ( ctx , ctx - > meshPosition . rasterizer . x , ctx - > meshPosition . rasterizer . y - d ) ;
neighbors [ neighborCount + + ] = lm_getLightmapPixel ( ctx , ctx - > meshPosition . rasterizer . x , ctx - > meshPosition . rasterizer . y + d ) ;
}
}
if ( neighborCount = = neighborsExpected ) // are all interpolation neighbors available?
{
// calculate average neighbor pixel value
float avg [ 4 ] = { 0 } ;
for ( int i = 0 ; i < neighborCount ; i + + )
for ( int j = 0 ; j < ctx - > lightmap . channels ; j + + )
avg [ j ] + = neighbors [ i ] [ j ] ;
float ni = 1.0f / neighborCount ;
for ( int j = 0 ; j < ctx - > lightmap . channels ; j + + )
avg [ j ] * = ni ;
// check if error from average pixel to neighbors is above the interpolation threshold
lm_bool interpolate = LM_TRUE ;
for ( int i = 0 ; i < neighborCount ; i + + )
{
lm_bool zero = LM_TRUE ;
for ( int j = 0 ; j < ctx - > lightmap . channels ; j + + )
{
if ( neighbors [ i ] [ j ] ! = 0.0f )
zero = LM_FALSE ;
if ( fabs ( neighbors [ i ] [ j ] - avg [ j ] ) > ctx - > interpolationThreshold )
interpolate = LM_FALSE ;
}
if ( zero )
interpolate = LM_FALSE ;
if ( ! interpolate )
break ;
}
// set interpolated value and return if interpolation is acceptable
if ( interpolate )
{
lm_setLightmapPixel ( ctx , ctx - > meshPosition . rasterizer . x , ctx - > meshPosition . rasterizer . y , avg ) ;
# ifdef LM_DEBUG_INTERPOLATION
// set interpolated pixel to green in debug output
ctx - > lightmap . debug [ ( ctx - > meshPosition . rasterizer . y * ctx - > lightmap . width + ctx - > meshPosition . rasterizer . x ) * 3 + 1 ] = 255 ;
# endif
return LM_FALSE ;
}
}
}
// could not interpolate. must render a hemisphere.
// calculate 3D sample position and orientation
lm_vec3 p0 = ctx - > meshPosition . triangle . p [ 0 ] ;
lm_vec3 p1 = ctx - > meshPosition . triangle . p [ 1 ] ;
lm_vec3 p2 = ctx - > meshPosition . triangle . p [ 2 ] ;
lm_vec3 v1 = lm_sub3 ( p1 , p0 ) ;
lm_vec3 v2 = lm_sub3 ( p2 , p0 ) ;
ctx - > meshPosition . sample . position = lm_add3 ( p0 , lm_add3 ( lm_scale3 ( v2 , uv . x ) , lm_scale3 ( v1 , uv . y ) ) ) ;
lm_vec3 n0 = ctx - > meshPosition . triangle . n [ 0 ] ;
lm_vec3 n1 = ctx - > meshPosition . triangle . n [ 1 ] ;
lm_vec3 n2 = ctx - > meshPosition . triangle . n [ 2 ] ;
lm_vec3 nv1 = lm_sub3 ( n1 , n0 ) ;
lm_vec3 nv2 = lm_sub3 ( n2 , n0 ) ;
ctx - > meshPosition . sample . direction = lm_normalize3 ( lm_add3 ( n0 , lm_add3 ( lm_scale3 ( nv2 , uv . x ) , lm_scale3 ( nv1 , uv . y ) ) ) ) ;
ctx - > meshPosition . sample . direction = lm_normalize3 ( ctx - > meshPosition . sample . direction ) ;
float cameraToSurfaceDistance = ( 1.0f + ctx - > hemisphere . cameraToSurfaceDistanceModifier ) * ctx - > hemisphere . zNear * sqrtf ( 2.0f ) ;
ctx - > meshPosition . sample . position = lm_add3 ( ctx - > meshPosition . sample . position , lm_scale3 ( ctx - > meshPosition . sample . direction , cameraToSurfaceDistance ) ) ;
if ( ! lm_finite3 ( ctx - > meshPosition . sample . position ) | |
! lm_finite3 ( ctx - > meshPosition . sample . direction ) | |
lm_length3sq ( ctx - > meshPosition . sample . direction ) < 0.5f ) // don't allow 0.0f. should always be ~1.0f
return LM_FALSE ;
lm_vec3 up = lm_v3 ( 0.0f , 1.0f , 0.0f ) ;
if ( lm_absf ( lm_dot3 ( up , ctx - > meshPosition . sample . direction ) ) > 0.8f )
up = lm_v3 ( 0.0f , 0.0f , 1.0f ) ;
#if 0
// triangle-consistent up vector
ctx - > meshPosition . sample . up = lm_normalize3 ( lm_cross3 ( up , ctx - > meshPosition . sample . direction ) ) ;
return LM_TRUE ;
# else
// "randomized" rotation with pattern
lm_vec3 side = lm_normalize3 ( lm_cross3 ( up , ctx - > meshPosition . sample . direction ) ) ;
up = lm_normalize3 ( lm_cross3 ( side , ctx - > meshPosition . sample . direction ) ) ;
int rx = ctx - > meshPosition . rasterizer . x % 3 ;
int ry = ctx - > meshPosition . rasterizer . y % 3 ;
static const float lm_pi = 3.14159265358979f ;
float phi = 2.0f * lm_pi * lm_baseAngles [ ry ] [ rx ] + 0.1f * ( ( float ) rand ( ) / ( float ) RAND_MAX ) ;
ctx - > meshPosition . sample . up = lm_normalize3 ( lm_add3 ( lm_scale3 ( side , cosf ( phi ) ) , lm_scale3 ( up , sinf ( phi ) ) ) ) ;
return LM_TRUE ;
# endif
}
// returns true if a sampling position was found and
// false if we finished rasterizing the current triangle
static lm_bool lm_findFirstConservativeTriangleRasterizerPosition ( lm_context * ctx )
{
while ( ! lm_trySamplingConservativeTriangleRasterizerPosition ( ctx ) )
{
lm_moveToNextPotentialConservativeTriangleRasterizerPosition ( ctx ) ;
if ( lm_hasConservativeTriangleRasterizerFinished ( ctx ) )
return LM_FALSE ;
}
return LM_TRUE ;
}
static lm_bool lm_findNextConservativeTriangleRasterizerPosition ( lm_context * ctx )
{
lm_moveToNextPotentialConservativeTriangleRasterizerPosition ( ctx ) ;
return lm_findFirstConservativeTriangleRasterizerPosition ( ctx ) ;
}
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static void lm_writeResultsToLightmap ( lm_context * ctx )
{
// do the GPU->CPU transfer of downsampled hemispheres
float * hemi = ( float * ) LM_CALLOC ( ctx - > hemisphere . storage . width * ctx - > hemisphere . storage . height , 4 * sizeof ( float ) ) ;
glBindTexture ( GL_TEXTURE_2D , ctx - > hemisphere . storage . texture ) ;
glGetTexImage ( GL_TEXTURE_2D , 0 , GL_RGBA , GL_FLOAT , hemi ) ;
// write results to lightmap texture
for ( int y = 0 ; y < ctx - > hemisphere . storage . writePosition . y + ( int ) ctx - > hemisphere . fbHemiCountY ; y + + )
{
for ( int x = 0 ; x < ctx - > hemisphere . storage . width ; x + + )
{
int index = y * ctx - > hemisphere . storage . width + x ;
lm_ivec2 lmUV = ctx - > hemisphere . storage . toLightmapLocation [ index ] ;
if ( lmUV . x > = 0 )
{
float * c = hemi + index * 4 ;
float validity = c [ 3 ] ;
float * lm = ctx - > lightmap . data + ( lmUV . y * ctx - > lightmap . width + lmUV . x ) * ctx - > lightmap . channels ;
if ( ! lm [ 0 ] & & validity > 0.9 )
{
float scale = 1.0f / validity ;
switch ( ctx - > lightmap . channels )
{
case 1 :
lm [ 0 ] = lm_maxf ( ( c [ 0 ] + c [ 1 ] + c [ 2 ] ) * scale / 3.0f , FLT_MIN ) ;
break ;
case 2 :
lm [ 0 ] = lm_maxf ( ( c [ 0 ] + c [ 1 ] + c [ 2 ] ) * scale / 3.0f , FLT_MIN ) ;
lm [ 1 ] = 1.0f ; // do we want to support this format?
break ;
case 3 :
lm [ 0 ] = lm_maxf ( c [ 0 ] * scale , FLT_MIN ) ;
lm [ 1 ] = lm_maxf ( c [ 1 ] * scale , FLT_MIN ) ;
lm [ 2 ] = lm_maxf ( c [ 2 ] * scale , FLT_MIN ) ;
break ;
case 4 :
lm [ 0 ] = lm_maxf ( c [ 0 ] * scale , FLT_MIN ) ;
lm [ 1 ] = lm_maxf ( c [ 1 ] * scale , FLT_MIN ) ;
lm [ 2 ] = lm_maxf ( c [ 2 ] * scale , FLT_MIN ) ;
lm [ 3 ] = 1.0f ;
break ;
default :
assert ( LM_FALSE ) ;
break ;
}
# ifdef LM_DEBUG_INTERPOLATION
// set sampled pixel to red in debug output
ctx - > lightmap . debug [ ( lmUV . y * ctx - > lightmap . width + lmUV . x ) * 3 + 0 ] = 255 ;
# endif
}
}
ctx - > hemisphere . storage . toLightmapLocation [ index ] . x = - 1 ; // reset
}
}
LM_FREE ( hemi ) ;
ctx - > hemisphere . storage . writePosition = lm_i2 ( 0 , 0 ) ;
}
static lm_bool lm_integrateHemisphereBatch ( lm_context * ctx )
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{
if ( ! ctx - > hemisphere . fbHemiIndex )
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return LM_FALSE ; // nothing to do
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glDisable ( GL_DEPTH_TEST ) ;
glBindVertexArray ( ctx - > hemisphere . vao ) ;
int fbRead = 0 ;
int fbWrite = 1 ;
// weighted downsampling pass
int outHemiSize = ctx - > hemisphere . size / 2 ;
glBindFramebuffer ( GL_FRAMEBUFFER , ctx - > hemisphere . fb [ fbWrite ] ) ;
glFramebufferTexture2D ( GL_FRAMEBUFFER , GL_COLOR_ATTACHMENT0 , GL_TEXTURE_2D , ctx - > hemisphere . fbTexture [ fbWrite ] , 0 ) ;
glViewport ( 0 , 0 , outHemiSize * ctx - > hemisphere . fbHemiCountX , outHemiSize * ctx - > hemisphere . fbHemiCountY ) ;
glUseProgram ( ctx - > hemisphere . firstPass . programID ) ;
glUniform1i ( ctx - > hemisphere . firstPass . hemispheresTextureID , 0 ) ;
glActiveTexture ( GL_TEXTURE0 ) ;
glBindTexture ( GL_TEXTURE_2D , ctx - > hemisphere . fbTexture [ fbRead ] ) ;
glUniform1i ( ctx - > hemisphere . firstPass . weightsTextureID , 1 ) ;
glActiveTexture ( GL_TEXTURE1 ) ;
glBindTexture ( GL_TEXTURE_2D , ctx - > hemisphere . firstPass . weightsTexture ) ;
glActiveTexture ( GL_TEXTURE0 ) ;
glDrawArrays ( GL_TRIANGLE_STRIP , 0 , 4 ) ;
//glBindTexture(GL_TEXTURE_2D, 0);
#if 0
// debug output
int w = outHemiSize * ctx - > hemisphere . fbHemiCountX , h = outHemiSize * ctx - > hemisphere . fbHemiCountY ;
glBindBuffer ( GL_PIXEL_PACK_BUFFER , 0 ) ;
glBindFramebuffer ( GL_READ_FRAMEBUFFER , ctx - > hemisphere . fb [ fbWrite ] ) ;
glReadBuffer ( GL_COLOR_ATTACHMENT0 ) ;
float * image = new float [ 3 * w * h ] ;
glReadPixels ( 0 , 0 , w , h , GL_RGB , GL_FLOAT , image ) ;
lmImageSaveTGAf ( " firstpass.png " , image , w , h , 3 ) ;
delete [ ] image ;
# endif
// downsampling passes
glUseProgram ( ctx - > hemisphere . downsamplePass . programID ) ;
glUniform1i ( ctx - > hemisphere . downsamplePass . hemispheresTextureID , 0 ) ;
while ( outHemiSize > 1 )
{
LM_SWAP ( int , fbRead , fbWrite ) ;
outHemiSize / = 2 ;
glBindFramebuffer ( GL_FRAMEBUFFER , ctx - > hemisphere . fb [ fbWrite ] ) ;
glViewport ( 0 , 0 , outHemiSize * ctx - > hemisphere . fbHemiCountX , outHemiSize * ctx - > hemisphere . fbHemiCountY ) ;
glBindTexture ( GL_TEXTURE_2D , ctx - > hemisphere . fbTexture [ fbRead ] ) ;
glDrawArrays ( GL_TRIANGLE_STRIP , 0 , 4 ) ;
//glBindTexture(GL_TEXTURE_2D, 0);
}
// copy results to storage texture
glBindTexture ( GL_TEXTURE_2D , ctx - > hemisphere . storage . texture ) ;
glCopyTexSubImage2D ( GL_TEXTURE_2D , 0 ,
ctx - > hemisphere . storage . writePosition . x , ctx - > hemisphere . storage . writePosition . y ,
0 , 0 , ctx - > hemisphere . fbHemiCountX , ctx - > hemisphere . fbHemiCountY ) ;
glBindTexture ( GL_TEXTURE_2D , 0 ) ;
glBindFramebuffer ( GL_FRAMEBUFFER , 0 ) ;
glBindVertexArray ( 0 ) ;
glEnable ( GL_DEPTH_TEST ) ;
// copy position mapping to storage
for ( unsigned int y = 0 ; y < ctx - > hemisphere . fbHemiCountY ; y + + )
{
int sy = ctx - > hemisphere . storage . writePosition . y + y ;
for ( unsigned int x = 0 ; x < ctx - > hemisphere . fbHemiCountX ; x + + )
{
int sx = ctx - > hemisphere . storage . writePosition . x + x ;
unsigned int hemiIndex = y * ctx - > hemisphere . fbHemiCountX + x ;
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ctx - > hemisphere . storage . toLightmapLocation [ sy * ctx - > hemisphere . storage . width + sx ] =
( hemiIndex > = ctx - > hemisphere . fbHemiIndex ) ?
lm_i2 ( - 1 , - 1 ) :
ctx - > hemisphere . fbHemiToLightmapLocation [ hemiIndex ] ;
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}
}
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lm_bool needWrite = LM_TRUE ;
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// advance storage texture write position
ctx - > hemisphere . storage . writePosition . x + = ctx - > hemisphere . fbHemiCountX ;
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if ( ctx - > hemisphere . storage . writePosition . x + ( int ) ctx - > hemisphere . fbHemiCountX > ctx - > hemisphere . storage . width )
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{
ctx - > hemisphere . storage . writePosition . x = 0 ;
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// storage is full
if ( ctx - > hemisphere . storage . writePosition . y + ( int ) ctx - > hemisphere . fbHemiCountY > = ctx - > hemisphere . storage . height ) {
lm_writeResultsToLightmap ( ctx ) ; // read storage data from gpu memory and write it to the lightmap
needWrite = LM_FALSE ;
} else {
ctx - > hemisphere . storage . writePosition . y + = ctx - > hemisphere . fbHemiCountY ;
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}
}
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ctx - > hemisphere . fbHemiIndex = 0 ;
return needWrite ;
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}
static void lm_setView (
int * viewport , int x , int y , int w , int h ,
float * view , lm_vec3 pos , lm_vec3 dir , lm_vec3 up ,
float * proj , float l , float r , float b , float t , float n , float f )
{
// viewport
viewport [ 0 ] = x ; viewport [ 1 ] = y ; viewport [ 2 ] = w ; viewport [ 3 ] = h ;
// view matrix: lookAt(pos, pos + dir, up)
lm_vec3 side = lm_cross3 ( dir , up ) ;
//up = cross(side, dir);
dir = lm_negate3 ( dir ) ; pos = lm_negate3 ( pos ) ;
view [ 0 ] = side . x ; view [ 1 ] = up . x ; view [ 2 ] = dir . x ; view [ 3 ] = 0.0f ;
view [ 4 ] = side . y ; view [ 5 ] = up . y ; view [ 6 ] = dir . y ; view [ 7 ] = 0.0f ;
view [ 8 ] = side . z ; view [ 9 ] = up . z ; view [ 10 ] = dir . z ; view [ 11 ] = 0.0f ;
view [ 12 ] = lm_dot3 ( side , pos ) ; view [ 13 ] = lm_dot3 ( up , pos ) ; view [ 14 ] = lm_dot3 ( dir , pos ) ; view [ 15 ] = 1.0f ;
// projection matrix: frustum(l, r, b, t, n, f)
float ilr = 1.0f / ( r - l ) , ibt = 1.0f / ( t - b ) , ninf = - 1.0f / ( f - n ) , n2 = 2.0f * n ;
proj [ 0 ] = n2 * ilr ; proj [ 1 ] = 0.0f ; proj [ 2 ] = 0.0f ; proj [ 3 ] = 0.0f ;
proj [ 4 ] = 0.0f ; proj [ 5 ] = n2 * ibt ; proj [ 6 ] = 0.0f ; proj [ 7 ] = 0.0f ;
proj [ 8 ] = ( r + l ) * ilr ; proj [ 9 ] = ( t + b ) * ibt ; proj [ 10 ] = ( f + n ) * ninf ; proj [ 11 ] = - 1.0f ;
proj [ 12 ] = 0.0f ; proj [ 13 ] = 0.0f ; proj [ 14 ] = f * n2 * ninf ; proj [ 15 ] = 0.0f ;
}
// returns true if a hemisphere side was prepared for rendering and
// false if we finished the current hemisphere
static lm_bool lm_beginSampleHemisphere ( lm_context * ctx , int * viewport , float * view , float * proj )
{
if ( ctx - > meshPosition . hemisphere . side > = 5 )
return LM_FALSE ;
if ( ctx - > meshPosition . hemisphere . side = = 0 )
{
// prepare hemisphere
glBindFramebuffer ( GL_FRAMEBUFFER , ctx - > hemisphere . fb [ 0 ] ) ;
if ( ctx - > hemisphere . fbHemiIndex = = 0 )
{
// prepare hemisphere batch
glClearColor ( // clear to valid background pixels!
ctx - > hemisphere . clearColor . r ,
ctx - > hemisphere . clearColor . g ,
ctx - > hemisphere . clearColor . b , 1.0f ) ;
glClear ( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT ) ;
}
ctx - > hemisphere . fbHemiToLightmapLocation [ ctx - > hemisphere . fbHemiIndex ] =
lm_i2 ( ctx - > meshPosition . rasterizer . x , ctx - > meshPosition . rasterizer . y ) ;
}
// find the target position in the batch
int x = ( ctx - > hemisphere . fbHemiIndex % ctx - > hemisphere . fbHemiCountX ) * ctx - > hemisphere . size * 3 ;
int y = ( ctx - > hemisphere . fbHemiIndex / ctx - > hemisphere . fbHemiCountX ) * ctx - > hemisphere . size ;
int size = ctx - > hemisphere . size ;
float zNear = ctx - > hemisphere . zNear ;
float zFar = ctx - > hemisphere . zFar ;
lm_vec3 pos = ctx - > meshPosition . sample . position ;
lm_vec3 dir = ctx - > meshPosition . sample . direction ;
lm_vec3 up = ctx - > meshPosition . sample . up ;
lm_vec3 right = lm_cross3 ( dir , up ) ;
// find the view parameters of the hemisphere side that we will render next
// hemisphere layout in the framebuffer:
// +-------+---+---+-------+
// | | | | D |
// | C | R | L +-------+
// | | | | U |
// +-------+---+---+-------+
switch ( ctx - > meshPosition . hemisphere . side )
{
case 0 : // center
lm_setView ( viewport , x , y , size , size ,
view , pos , dir , up ,
proj , - zNear , zNear , - zNear , zNear , zNear , zFar ) ;
break ;
case 1 : // right
lm_setView ( viewport , size + x , y , size / 2 , size ,
view , pos , right , up ,
proj , - zNear , 0.0f , - zNear , zNear , zNear , zFar ) ;
break ;
case 2 : // left
lm_setView ( viewport , size + x + size / 2 , y , size / 2 , size ,
view , pos , lm_negate3 ( right ) , up ,
proj , 0.0f , zNear , - zNear , zNear , zNear , zFar ) ;
break ;
case 3 : // down
lm_setView ( viewport , 2 * size + x , y + size / 2 , size , size / 2 ,
view , pos , lm_negate3 ( up ) , dir ,
proj , - zNear , zNear , 0.0f , zNear , zNear , zFar ) ;
break ;
case 4 : // up
lm_setView ( viewport , 2 * size + x , y , size , size / 2 ,
view , pos , up , lm_negate3 ( dir ) ,
proj , - zNear , zNear , - zNear , 0.0f , zNear , zFar ) ;
break ;
default :
assert ( LM_FALSE ) ;
break ;
}
return LM_TRUE ;
}
static void lm_endSampleHemisphere ( lm_context * ctx )
{
if ( + + ctx - > meshPosition . hemisphere . side = = 5 )
{
// finish hemisphere
glBindFramebuffer ( GL_FRAMEBUFFER , 0 ) ;
if ( + + ctx - > hemisphere . fbHemiIndex = = ctx - > hemisphere . fbHemiCountX * ctx - > hemisphere . fbHemiCountY )
{
// downsample new hemisphere batch and store the results
lm_integrateHemisphereBatch ( ctx ) ;
}
}
}
static void lm_inverseTranspose ( const float * m44 , float * n33 )
{
if ( ! m44 )
{
n33 [ 0 ] = 1.0f ; n33 [ 1 ] = 0.0f ; n33 [ 2 ] = 0.0f ;
n33 [ 3 ] = 0.0f ; n33 [ 4 ] = 1.0f ; n33 [ 5 ] = 0.0f ;
n33 [ 6 ] = 0.0f ; n33 [ 7 ] = 0.0f ; n33 [ 8 ] = 1.0f ;
return ;
}
float determinant = m44 [ 0 ] * ( m44 [ 5 ] * m44 [ 10 ] - m44 [ 9 ] * m44 [ 6 ] )
- m44 [ 1 ] * ( m44 [ 4 ] * m44 [ 10 ] - m44 [ 6 ] * m44 [ 8 ] )
+ m44 [ 2 ] * ( m44 [ 4 ] * m44 [ 9 ] - m44 [ 5 ] * m44 [ 8 ] ) ;
assert ( fabs ( determinant ) > FLT_EPSILON ) ;
float rcpDeterminant = 1.0f / determinant ;
n33 [ 0 ] = ( m44 [ 5 ] * m44 [ 10 ] - m44 [ 9 ] * m44 [ 6 ] ) * rcpDeterminant ;
n33 [ 3 ] = - ( m44 [ 1 ] * m44 [ 10 ] - m44 [ 2 ] * m44 [ 9 ] ) * rcpDeterminant ;
n33 [ 6 ] = ( m44 [ 1 ] * m44 [ 6 ] - m44 [ 2 ] * m44 [ 5 ] ) * rcpDeterminant ;
n33 [ 1 ] = - ( m44 [ 4 ] * m44 [ 10 ] - m44 [ 6 ] * m44 [ 8 ] ) * rcpDeterminant ;
n33 [ 4 ] = ( m44 [ 0 ] * m44 [ 10 ] - m44 [ 2 ] * m44 [ 8 ] ) * rcpDeterminant ;
n33 [ 7 ] = - ( m44 [ 0 ] * m44 [ 6 ] - m44 [ 4 ] * m44 [ 2 ] ) * rcpDeterminant ;
n33 [ 2 ] = ( m44 [ 4 ] * m44 [ 9 ] - m44 [ 8 ] * m44 [ 5 ] ) * rcpDeterminant ;
n33 [ 5 ] = - ( m44 [ 0 ] * m44 [ 9 ] - m44 [ 8 ] * m44 [ 1 ] ) * rcpDeterminant ;
n33 [ 8 ] = ( m44 [ 0 ] * m44 [ 5 ] - m44 [ 4 ] * m44 [ 1 ] ) * rcpDeterminant ;
}
static lm_vec3 lm_transformNormal ( const float * m , lm_vec3 n )
{
lm_vec3 r ;
r . x = m [ 0 ] * n . x + m [ 3 ] * n . y + m [ 6 ] * n . z ;
r . y = m [ 1 ] * n . x + m [ 4 ] * n . y + m [ 7 ] * n . z ;
r . z = m [ 2 ] * n . x + m [ 5 ] * n . y + m [ 8 ] * n . z ;
return r ;
}
static lm_vec3 lm_transformPosition ( const float * m , lm_vec3 v )
{
if ( ! m )
return v ;
lm_vec3 r ;
r . x = m [ 0 ] * v . x + m [ 4 ] * v . y + m [ 8 ] * v . z + m [ 12 ] ;
r . y = m [ 1 ] * v . x + m [ 5 ] * v . y + m [ 9 ] * v . z + m [ 13 ] ;
r . z = m [ 2 ] * v . x + m [ 6 ] * v . y + m [ 10 ] * v . z + m [ 14 ] ;
float d = m [ 3 ] * v . x + m [ 7 ] * v . y + m [ 11 ] * v . z + m [ 15 ] ;
assert ( lm_absf ( d - 1.0f ) < 0.00001f ) ; // could divide by d, but this shouldn't be a projection transform!
return r ;
}
static void lm_setMeshPosition ( lm_context * ctx , unsigned int indicesTriangleBaseIndex )
{
// fetch triangle at the specified indicesTriangleBaseIndex
ctx - > meshPosition . triangle . baseIndex = indicesTriangleBaseIndex ;
// load and transform triangle to process next
lm_vec2 uvMin = lm_v2 ( FLT_MAX , FLT_MAX ) , uvMax = lm_v2 ( - FLT_MAX , - FLT_MAX ) ;
lm_vec2 uvScale = lm_v2i ( ctx - > lightmap . width , ctx - > lightmap . height ) ;
unsigned int vIndices [ 3 ] ;
for ( int i = 0 ; i < 3 ; i + + )
{
// decode index
unsigned int vIndex ;
switch ( ctx - > mesh . indicesType )
{
case LM_NONE :
vIndex = ctx - > meshPosition . triangle . baseIndex + i ;
break ;
case LM_UNSIGNED_BYTE :
vIndex = ( ( const unsigned char * ) ctx - > mesh . indices + ctx - > meshPosition . triangle . baseIndex ) [ i ] ;
break ;
case LM_UNSIGNED_SHORT :
vIndex = ( ( const unsigned short * ) ctx - > mesh . indices + ctx - > meshPosition . triangle . baseIndex ) [ i ] ;
break ;
case LM_UNSIGNED_INT :
vIndex = ( ( const unsigned int * ) ctx - > mesh . indices + ctx - > meshPosition . triangle . baseIndex ) [ i ] ;
break ;
default :
assert ( LM_FALSE ) ;
break ;
}
vIndices [ i ] = vIndex ;
// decode and pre-transform vertex position
const void * pPtr = ctx - > mesh . positions + vIndex * ctx - > mesh . positionsStride ;
lm_vec3 p ;
switch ( ctx - > mesh . positionsType )
{
// TODO: signed formats
case LM_UNSIGNED_BYTE : {
const unsigned char * uc = ( const unsigned char * ) pPtr ;
p = lm_v3 ( uc [ 0 ] , uc [ 1 ] , uc [ 2 ] ) ;
} break ;
case LM_UNSIGNED_SHORT : {
const unsigned short * us = ( const unsigned short * ) pPtr ;
p = lm_v3 ( us [ 0 ] , us [ 1 ] , us [ 2 ] ) ;
} break ;
case LM_UNSIGNED_INT : {
const unsigned int * ui = ( const unsigned int * ) pPtr ;
p = lm_v3 ( ( float ) ui [ 0 ] , ( float ) ui [ 1 ] , ( float ) ui [ 2 ] ) ;
} break ;
case LM_FLOAT : {
p = * ( const lm_vec3 * ) pPtr ;
} break ;
default : {
assert ( LM_FALSE ) ;
} break ;
}
ctx - > meshPosition . triangle . p [ i ] = lm_transformPosition ( ctx - > mesh . modelMatrix , p ) ;
// decode and scale (to lightmap resolution) vertex lightmap texture coords
const void * uvPtr = ctx - > mesh . uvs + vIndex * ctx - > mesh . uvsStride ;
lm_vec2 uv ;
switch ( ctx - > mesh . uvsType )
{
case LM_UNSIGNED_BYTE : {
const unsigned char * uc = ( const unsigned char * ) uvPtr ;
uv = lm_v2 ( uc [ 0 ] / ( float ) UCHAR_MAX , uc [ 1 ] / ( float ) UCHAR_MAX ) ;
} break ;
case LM_UNSIGNED_SHORT : {
const unsigned short * us = ( const unsigned short * ) uvPtr ;
uv = lm_v2 ( us [ 0 ] / ( float ) USHRT_MAX , us [ 1 ] / ( float ) USHRT_MAX ) ;
} break ;
case LM_UNSIGNED_INT : {
const unsigned int * ui = ( const unsigned int * ) uvPtr ;
uv = lm_v2 ( ui [ 0 ] / ( float ) UINT_MAX , ui [ 1 ] / ( float ) UINT_MAX ) ;
} break ;
case LM_FLOAT : {
uv = * ( const lm_vec2 * ) uvPtr ;
} break ;
default : {
assert ( LM_FALSE ) ;
} break ;
}
ctx - > meshPosition . triangle . uv [ i ] = lm_mul2 ( lm_pmod2 ( uv , 1.0f ) , uvScale ) ; // maybe clamp to 0.0-1.0 instead of pmod?
// update bounds on lightmap
uvMin = lm_min2 ( uvMin , ctx - > meshPosition . triangle . uv [ i ] ) ;
uvMax = lm_max2 ( uvMax , ctx - > meshPosition . triangle . uv [ i ] ) ;
}
lm_vec3 flatNormal = lm_cross3 (
lm_sub3 ( ctx - > meshPosition . triangle . p [ 1 ] , ctx - > meshPosition . triangle . p [ 0 ] ) ,
lm_sub3 ( ctx - > meshPosition . triangle . p [ 2 ] , ctx - > meshPosition . triangle . p [ 0 ] ) ) ;
for ( int i = 0 ; i < 3 ; i + + )
{
// decode and pre-transform vertex normal
const void * nPtr = ctx - > mesh . normals + vIndices [ i ] * ctx - > mesh . normalsStride ;
lm_vec3 n ;
switch ( ctx - > mesh . normalsType )
{
// TODO: signed formats
case LM_FLOAT : {
n = * ( const lm_vec3 * ) nPtr ;
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n = lm_normalize3 ( lm_transformNormal ( ctx - > mesh . normalMatrix , n ) ) ;
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} break ;
case LM_NONE : {
n = flatNormal ;
} break ;
default : {
assert ( LM_FALSE ) ;
} break ;
}
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ctx - > meshPosition . triangle . n [ i ] = n ;
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}
// calculate area of interest (on lightmap) for conservative rasterization
lm_vec2 bbMin = lm_floor2 ( uvMin ) ;
lm_vec2 bbMax = lm_ceil2 ( uvMax ) ;
ctx - > meshPosition . rasterizer . minx = lm_maxi ( ( int ) bbMin . x - 1 , 0 ) ;
ctx - > meshPosition . rasterizer . miny = lm_maxi ( ( int ) bbMin . y - 1 , 0 ) ;
ctx - > meshPosition . rasterizer . maxx = lm_mini ( ( int ) bbMax . x + 1 , ctx - > lightmap . width - 1 ) ;
ctx - > meshPosition . rasterizer . maxy = lm_mini ( ( int ) bbMax . y + 1 , ctx - > lightmap . height - 1 ) ;
assert ( ctx - > meshPosition . rasterizer . minx < = ctx - > meshPosition . rasterizer . maxx & &
ctx - > meshPosition . rasterizer . miny < = ctx - > meshPosition . rasterizer . maxy ) ;
ctx - > meshPosition . rasterizer . x = ctx - > meshPosition . rasterizer . minx + lm_passOffsetX ( ctx ) ;
ctx - > meshPosition . rasterizer . y = ctx - > meshPosition . rasterizer . miny + lm_passOffsetY ( ctx ) ;
// try moving to first valid sample position
if ( ctx - > meshPosition . rasterizer . x < = ctx - > meshPosition . rasterizer . maxx & &
ctx - > meshPosition . rasterizer . y < = ctx - > meshPosition . rasterizer . maxy & &
lm_findFirstConservativeTriangleRasterizerPosition ( ctx ) )
ctx - > meshPosition . hemisphere . side = 0 ; // we can start sampling the hemisphere
else
ctx - > meshPosition . hemisphere . side = 5 ; // no samples on this triangle! put hemisphere sampler into finished state
}
static GLuint lm_LoadShader ( GLenum type , const char * source )
{
GLuint shader = glCreateShader ( type ) ;
if ( shader = = 0 )
{
fprintf ( stderr , " Could not create shader! \n " ) ;
return 0 ;
}
glShaderSource ( shader , 1 , & source , NULL ) ;
glCompileShader ( shader ) ;
GLint compiled ;
glGetShaderiv ( shader , GL_COMPILE_STATUS , & compiled ) ;
if ( ! compiled )
{
fprintf ( stderr , " Could not compile shader! \n " ) ;
GLint infoLen = 0 ;
glGetShaderiv ( shader , GL_INFO_LOG_LENGTH , & infoLen ) ;
if ( infoLen )
{
char * infoLog = ( char * ) malloc ( infoLen ) ;
glGetShaderInfoLog ( shader , infoLen , NULL , infoLog ) ;
fprintf ( stderr , " %s \n " , infoLog ) ;
free ( infoLog ) ;
}
glDeleteShader ( shader ) ;
return 0 ;
}
return shader ;
}
static GLuint lm_LoadProgram ( const char * vp , const char * fp )
{
GLuint program = glCreateProgram ( ) ;
if ( program = = 0 )
{
fprintf ( stderr , " Could not create program! \n " ) ;
return 0 ;
}
GLuint vertexShader = lm_LoadShader ( GL_VERTEX_SHADER , vp ) ;
GLuint fragmentShader = lm_LoadShader ( GL_FRAGMENT_SHADER , fp ) ;
glAttachShader ( program , vertexShader ) ;
glAttachShader ( program , fragmentShader ) ;
glLinkProgram ( program ) ;
glDeleteShader ( vertexShader ) ;
glDeleteShader ( fragmentShader ) ;
GLint linked ;
glGetProgramiv ( program , GL_LINK_STATUS , & linked ) ;
if ( ! linked )
{
fprintf ( stderr , " Could not link program! \n " ) ;
GLint infoLen = 0 ;
glGetProgramiv ( program , GL_INFO_LOG_LENGTH , & infoLen ) ;
if ( infoLen )
{
char * infoLog = ( char * ) malloc ( sizeof ( char ) * infoLen ) ;
glGetProgramInfoLog ( program , infoLen , NULL , infoLog ) ;
fprintf ( stderr , " %s \n " , infoLog ) ;
free ( infoLog ) ;
}
glDeleteProgram ( program ) ;
return 0 ;
}
return program ;
}
static float lm_defaultWeights ( float cos_theta , void * userdata )
{
return 1.0f ;
}
lm_context * lmCreate ( int hemisphereSize , float zNear , float zFar ,
float clearR , float clearG , float clearB ,
int interpolationPasses , float interpolationThreshold ,
float cameraToSurfaceDistanceModifier )
{
assert ( hemisphereSize = = 512 | | hemisphereSize = = 256 | | hemisphereSize = = 128 | |
hemisphereSize = = 64 | | hemisphereSize = = 32 | | hemisphereSize = = 16 ) ;
assert ( zNear < zFar & & zNear > 0.0f ) ;
assert ( cameraToSurfaceDistanceModifier > = - 1.0f ) ;
assert ( interpolationPasses > = 0 & & interpolationPasses < = 8 ) ;
assert ( interpolationThreshold > = 0.0f ) ;
lm_context * ctx = ( lm_context * ) LM_CALLOC ( 1 , sizeof ( lm_context ) ) ;
ctx - > meshPosition . passCount = 1 + 3 * interpolationPasses ;
ctx - > interpolationThreshold = interpolationThreshold ;
ctx - > hemisphere . size = hemisphereSize ;
ctx - > hemisphere . zNear = zNear ;
ctx - > hemisphere . zFar = zFar ;
ctx - > hemisphere . cameraToSurfaceDistanceModifier = cameraToSurfaceDistanceModifier ;
ctx - > hemisphere . clearColor . r = clearR ;
ctx - > hemisphere . clearColor . g = clearG ;
ctx - > hemisphere . clearColor . b = clearB ;
// calculate hemisphere batch size
ctx - > hemisphere . fbHemiCountX = 1536 / ( 3 * ctx - > hemisphere . size ) ;
ctx - > hemisphere . fbHemiCountY = 512 / ctx - > hemisphere . size ;
// hemisphere batch framebuffers
unsigned int w [ ] = {
ctx - > hemisphere . fbHemiCountX * ctx - > hemisphere . size * 3 ,
ctx - > hemisphere . fbHemiCountX * ctx - > hemisphere . size / 2 } ;
unsigned int h [ ] = {
ctx - > hemisphere . fbHemiCountY * ctx - > hemisphere . size ,
ctx - > hemisphere . fbHemiCountY * ctx - > hemisphere . size / 2 } ;
glGenTextures ( 2 , ctx - > hemisphere . fbTexture ) ;
glGenFramebuffers ( 2 , ctx - > hemisphere . fb ) ;
glGenRenderbuffers ( 1 , & ctx - > hemisphere . fbDepth ) ;
glBindRenderbuffer ( GL_RENDERBUFFER , ctx - > hemisphere . fbDepth ) ;
glRenderbufferStorage ( GL_RENDERBUFFER , GL_DEPTH_COMPONENT24 , w [ 0 ] , h [ 0 ] ) ;
glBindFramebuffer ( GL_FRAMEBUFFER , ctx - > hemisphere . fb [ 0 ] ) ;
glFramebufferRenderbuffer ( GL_FRAMEBUFFER , GL_DEPTH_ATTACHMENT , GL_RENDERBUFFER , ctx - > hemisphere . fbDepth ) ;
for ( int i = 0 ; i < 2 ; i + + )
{
glBindTexture ( GL_TEXTURE_2D , ctx - > hemisphere . fbTexture [ i ] ) ;
glTexParameteri ( GL_TEXTURE_2D , GL_TEXTURE_WRAP_S , GL_CLAMP_TO_EDGE ) ;
glTexParameteri ( GL_TEXTURE_2D , GL_TEXTURE_WRAP_T , GL_CLAMP_TO_EDGE ) ;
glTexParameteri ( GL_TEXTURE_2D , GL_TEXTURE_MIN_FILTER , GL_NEAREST ) ;
glTexParameteri ( GL_TEXTURE_2D , GL_TEXTURE_MAG_FILTER , GL_NEAREST ) ;
glTexImage2D ( GL_TEXTURE_2D , 0 , GL_RGBA32F , w [ i ] , h [ i ] , 0 , GL_RGBA , GL_FLOAT , 0 ) ;
glBindFramebuffer ( GL_FRAMEBUFFER , ctx - > hemisphere . fb [ i ] ) ;
glFramebufferTexture2D ( GL_FRAMEBUFFER , GL_COLOR_ATTACHMENT0 , GL_TEXTURE_2D , ctx - > hemisphere . fbTexture [ i ] , 0 ) ;
GLenum status = glCheckFramebufferStatus ( GL_FRAMEBUFFER ) ;
if ( status ! = GL_FRAMEBUFFER_COMPLETE )
{
fprintf ( stderr , " Could not create framebuffer! \n " ) ;
glDeleteRenderbuffers ( 1 , & ctx - > hemisphere . fbDepth ) ;
glDeleteFramebuffers ( 2 , ctx - > hemisphere . fb ) ;
glDeleteTextures ( 2 , ctx - > hemisphere . fbTexture ) ;
LM_FREE ( ctx ) ;
return NULL ;
}
}
glBindFramebuffer ( GL_FRAMEBUFFER , 0 ) ;
// dummy vao for fullscreen quad rendering
glGenVertexArrays ( 1 , & ctx - > hemisphere . vao ) ;
// hemisphere shader (weighted downsampling of the 3x1 hemisphere layout to a 0.5x0.5 square)
{
const char * vs =
" #version 150 core \n "
" const vec2 ps[4] = vec2[](vec2(1, -1), vec2(1, 1), vec2(-1, -1), vec2(-1, 1)); \n "
" void main() \n "
" { \n "
" gl_Position = vec4(ps[gl_VertexID], 0, 1); \n "
" } \n " ;
const char * fs =
" #version 150 core \n "
" uniform sampler2D hemispheres; \n "
" uniform sampler2D weights; \n "
" layout(pixel_center_integer) in vec4 gl_FragCoord; \n " // whole integer values represent pixel centers, GL_ARB_fragment_coord_conventions
" out vec4 outColor; \n "
" vec4 weightedSample(ivec2 h_uv, ivec2 w_uv, ivec2 quadrant) \n "
" { \n "
" vec4 sample = texelFetch(hemispheres, h_uv + quadrant, 0); \n "
" vec2 weight = texelFetch(weights, w_uv + quadrant, 0).rg; \n "
" return vec4(sample.rgb * weight.r, sample.a * weight.g); \n "
" } \n "
" vec4 threeWeightedSamples(ivec2 h_uv, ivec2 w_uv, ivec2 offset) \n "
" { \n " // horizontal triple sum
" vec4 sum = weightedSample(h_uv, w_uv, offset); \n "
" sum += weightedSample(h_uv, w_uv, offset + ivec2(2, 0)); \n "
" sum += weightedSample(h_uv, w_uv, offset + ivec2(4, 0)); \n "
" return sum; \n "
" } \n "
" void main() \n "
" { \n " // this is a weighted sum downsampling pass (alpha component contains the weighted valid sample count)
" vec2 in_uv = gl_FragCoord.xy * vec2(6.0, 2.0) + vec2(0.5); \n "
" ivec2 h_uv = ivec2(in_uv); \n "
" ivec2 w_uv = ivec2(mod(in_uv, vec2(textureSize(weights, 0)))); \n " // there's no integer modulo :(
" vec4 lb = threeWeightedSamples(h_uv, w_uv, ivec2(0, 0)); \n "
" vec4 rb = threeWeightedSamples(h_uv, w_uv, ivec2(1, 0)); \n "
" vec4 lt = threeWeightedSamples(h_uv, w_uv, ivec2(0, 1)); \n "
" vec4 rt = threeWeightedSamples(h_uv, w_uv, ivec2(1, 1)); \n "
" outColor = lb + rb + lt + rt; \n "
" } \n " ;
ctx - > hemisphere . firstPass . programID = lm_LoadProgram ( vs , fs ) ;
if ( ! ctx - > hemisphere . firstPass . programID )
{
fprintf ( stderr , " Error loading the hemisphere first pass shader program... leaving! \n " ) ;
glDeleteVertexArrays ( 1 , & ctx - > hemisphere . vao ) ;
glDeleteRenderbuffers ( 1 , & ctx - > hemisphere . fbDepth ) ;
glDeleteFramebuffers ( 2 , ctx - > hemisphere . fb ) ;
glDeleteTextures ( 2 , ctx - > hemisphere . fbTexture ) ;
LM_FREE ( ctx ) ;
return NULL ;
}
ctx - > hemisphere . firstPass . hemispheresTextureID = glGetUniformLocation ( ctx - > hemisphere . firstPass . programID , " hemispheres " ) ;
ctx - > hemisphere . firstPass . weightsTextureID = glGetUniformLocation ( ctx - > hemisphere . firstPass . programID , " weights " ) ;
}
// downsample shader
{
const char * vs =
" #version 150 core \n "
" const vec2 ps[4] = vec2[](vec2(1, -1), vec2(1, 1), vec2(-1, -1), vec2(-1, 1)); \n "
" void main() \n "
" { \n "
" gl_Position = vec4(ps[gl_VertexID], 0, 1); \n "
" } \n " ;
const char * fs =
" #version 150 core \n "
" uniform sampler2D hemispheres; \n "
" layout(pixel_center_integer) in vec4 gl_FragCoord; \n " // whole integer values represent pixel centers, GL_ARB_fragment_coord_conventions
" out vec4 outColor; \n "
" void main() \n "
" { \n " // this is a sum downsampling pass (alpha component contains the weighted valid sample count)
" ivec2 h_uv = ivec2(gl_FragCoord.xy) * 2; \n "
" vec4 lb = texelFetch(hemispheres, h_uv + ivec2(0, 0), 0); \n "
" vec4 rb = texelFetch(hemispheres, h_uv + ivec2(1, 0), 0); \n "
" vec4 lt = texelFetch(hemispheres, h_uv + ivec2(0, 1), 0); \n "
" vec4 rt = texelFetch(hemispheres, h_uv + ivec2(1, 1), 0); \n "
" outColor = lb + rb + lt + rt; \n "
" } \n " ;
ctx - > hemisphere . downsamplePass . programID = lm_LoadProgram ( vs , fs ) ;
if ( ! ctx - > hemisphere . downsamplePass . programID )
{
fprintf ( stderr , " Error loading the hemisphere downsample pass shader program... leaving! \n " ) ;
glDeleteProgram ( ctx - > hemisphere . firstPass . programID ) ;
glDeleteVertexArrays ( 1 , & ctx - > hemisphere . vao ) ;
glDeleteRenderbuffers ( 1 , & ctx - > hemisphere . fbDepth ) ;
glDeleteFramebuffers ( 2 , ctx - > hemisphere . fb ) ;
glDeleteTextures ( 2 , ctx - > hemisphere . fbTexture ) ;
LM_FREE ( ctx ) ;
return NULL ;
}
ctx - > hemisphere . downsamplePass . hemispheresTextureID = glGetUniformLocation ( ctx - > hemisphere . downsamplePass . programID , " hemispheres " ) ;
}
// hemisphere weights texture
glGenTextures ( 1 , & ctx - > hemisphere . firstPass . weightsTexture ) ;
lmSetHemisphereWeights ( ctx , lm_defaultWeights , 0 ) ;
glTexParameteri ( GL_TEXTURE_2D , GL_TEXTURE_MAG_FILTER , GL_NEAREST ) ;
glTexParameteri ( GL_TEXTURE_2D , GL_TEXTURE_MIN_FILTER , GL_NEAREST ) ;
glTexParameteri ( GL_TEXTURE_2D , GL_TEXTURE_WRAP_S , GL_REPEAT ) ;
glTexParameteri ( GL_TEXTURE_2D , GL_TEXTURE_WRAP_T , GL_REPEAT ) ;
// allocate batchPosition-to-lightmapPosition map
ctx - > hemisphere . fbHemiToLightmapLocation = ( lm_ivec2 * ) LM_CALLOC ( ctx - > hemisphere . fbHemiCountX * ctx - > hemisphere . fbHemiCountY , sizeof ( lm_ivec2 ) ) ;
return ctx ;
}
void lmDestroy ( lm_context * ctx )
{
// reset state
glUseProgram ( 0 ) ;
glBindTexture ( GL_TEXTURE_2D , 0 ) ;
glBindBuffer ( GL_PIXEL_PACK_BUFFER , 0 ) ;
glBindVertexArray ( 0 ) ;
glBindFramebuffer ( GL_FRAMEBUFFER , 0 ) ;
glBindFramebuffer ( GL_READ_FRAMEBUFFER , 0 ) ;
glBindFramebuffer ( GL_DRAW_FRAMEBUFFER , 0 ) ;
// delete gl objects
glDeleteTextures ( 1 , & ctx - > hemisphere . firstPass . weightsTexture ) ;
glDeleteTextures ( 1 , & ctx - > hemisphere . storage . texture ) ;
glDeleteProgram ( ctx - > hemisphere . downsamplePass . programID ) ;
glDeleteProgram ( ctx - > hemisphere . firstPass . programID ) ;
glDeleteVertexArrays ( 1 , & ctx - > hemisphere . vao ) ;
glDeleteRenderbuffers ( 1 , & ctx - > hemisphere . fbDepth ) ;
glDeleteFramebuffers ( 2 , ctx - > hemisphere . fb ) ;
glDeleteTextures ( 2 , ctx - > hemisphere . fbTexture ) ;
glDeleteTextures ( 1 , & ctx - > hemisphere . storage . texture ) ;
// free memory
LM_FREE ( ctx - > hemisphere . storage . toLightmapLocation ) ;
LM_FREE ( ctx - > hemisphere . fbHemiToLightmapLocation ) ;
# ifdef LM_DEBUG_INTERPOLATION
LM_FREE ( ctx - > lightmap . debug ) ;
# endif
LM_FREE ( ctx ) ;
}
void lmSetHemisphereWeights ( lm_context * ctx , lm_weight_func f , void * userdata )
{
// hemisphere weights texture. bakes in material dependent attenuation behaviour.
float * weights = ( float * ) LM_CALLOC ( 2 * 3 * ctx - > hemisphere . size * ctx - > hemisphere . size , sizeof ( float ) ) ;
float center = ( ctx - > hemisphere . size - 1 ) * 0.5f ;
double sum = 0.0 ;
for ( unsigned int y = 0 ; y < ctx - > hemisphere . size ; y + + )
{
float dy = 2.0f * ( y - center ) / ( float ) ctx - > hemisphere . size ;
for ( unsigned int x = 0 ; x < ctx - > hemisphere . size ; x + + )
{
float dx = 2.0f * ( x - center ) / ( float ) ctx - > hemisphere . size ;
lm_vec3 v = lm_normalize3 ( lm_v3 ( dx , dy , 1.0f ) ) ;
float solidAngle = v . z * v . z * v . z ;
float * w0 = weights + 2 * ( y * ( 3 * ctx - > hemisphere . size ) + x ) ;
float * w1 = w0 + 2 * ctx - > hemisphere . size ;
float * w2 = w1 + 2 * ctx - > hemisphere . size ;
// center weights
w0 [ 0 ] = solidAngle * f ( v . z , userdata ) ;
w0 [ 1 ] = solidAngle ;
// left/right side weights
w1 [ 0 ] = solidAngle * f ( lm_absf ( v . x ) , userdata ) ;
w1 [ 1 ] = solidAngle ;
// up/down side weights
w2 [ 0 ] = solidAngle * f ( lm_absf ( v . y ) , userdata ) ;
w2 [ 1 ] = solidAngle ;
sum + = 3.0 * ( double ) solidAngle ;
}
}
// normalize weights
float weightScale = ( float ) ( 1.0 / sum ) ;
for ( unsigned int i = 0 ; i < 2 * 3 * ctx - > hemisphere . size * ctx - > hemisphere . size ; i + + )
weights [ i ] * = weightScale ;
// upload weight texture
glBindTexture ( GL_TEXTURE_2D , ctx - > hemisphere . firstPass . weightsTexture ) ;
glTexImage2D ( GL_TEXTURE_2D , 0 , GL_RG32F , 3 * ctx - > hemisphere . size , ctx - > hemisphere . size , 0 , GL_RG , GL_FLOAT , weights ) ;
LM_FREE ( weights ) ;
}
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static void lm_initStorage ( lm_context * ctx , int w , int h )
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{
// allocate storage texture
if ( ! ctx - > hemisphere . storage . texture )
glGenTextures ( 1 , & ctx - > hemisphere . storage . texture ) ;
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ctx - > hemisphere . storage . width = w ;
ctx - > hemisphere . storage . height = h ;
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glBindTexture ( GL_TEXTURE_2D , ctx - > hemisphere . storage . texture ) ;
glTexParameteri ( GL_TEXTURE_2D , GL_TEXTURE_WRAP_S , GL_CLAMP_TO_EDGE ) ;
glTexParameteri ( GL_TEXTURE_2D , GL_TEXTURE_WRAP_T , GL_CLAMP_TO_EDGE ) ;
glTexParameteri ( GL_TEXTURE_2D , GL_TEXTURE_MIN_FILTER , GL_NEAREST ) ;
glTexParameteri ( GL_TEXTURE_2D , GL_TEXTURE_MAG_FILTER , GL_NEAREST ) ;
glTexImage2D ( GL_TEXTURE_2D , 0 , GL_RGBA32F , w , h , 0 , GL_RGBA , GL_FLOAT , 0 ) ;
// allocate storage position to lightmap position map
if ( ctx - > hemisphere . storage . toLightmapLocation )
LM_FREE ( ctx - > hemisphere . storage . toLightmapLocation ) ;
ctx - > hemisphere . storage . toLightmapLocation = ( lm_ivec2 * ) LM_CALLOC ( w * h , sizeof ( lm_ivec2 ) ) ;
// invalidate all positions
for ( int i = 0 ; i < w * h ; i + + )
ctx - > hemisphere . storage . toLightmapLocation [ i ] . x = - 1 ;
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}
void lmSetTargetLightmap ( lm_context * ctx , float * outLightmap , int w , int h , int c )
{
ctx - > lightmap . data = outLightmap ;
ctx - > lightmap . width = w ;
ctx - > lightmap . height = h ;
ctx - > lightmap . channels = c ;
unsigned int sw = w > ctx - > hemisphere . fbHemiCountX ? w : ctx - > hemisphere . fbHemiCountX ;
unsigned int sh = h > ctx - > hemisphere . fbHemiCountY ? h : ctx - > hemisphere . fbHemiCountY ;
lm_initStorage ( ctx , sw , sh ) ;
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# ifdef LM_DEBUG_INTERPOLATION
if ( ctx - > lightmap . debug )
LM_FREE ( ctx - > lightmap . debug ) ;
ctx - > lightmap . debug = ( unsigned char * ) LM_CALLOC ( ctx - > lightmap . width * ctx - > lightmap . height , 3 ) ;
# endif
}
void lmSetGeometry ( lm_context * ctx ,
const float * transformationMatrix ,
lm_type positionsType , const void * positionsXYZ , int positionsStride ,
lm_type normalsType , const void * normalsXYZ , int normalsStride ,
lm_type lightmapCoordsType , const void * lightmapCoordsUV , int lightmapCoordsStride ,
int count , lm_type indicesType , const void * indices )
{
ctx - > mesh . modelMatrix = transformationMatrix ;
ctx - > mesh . positions = ( const unsigned char * ) positionsXYZ ;
ctx - > mesh . positionsType = positionsType ;
ctx - > mesh . positionsStride = positionsStride = = 0 ? sizeof ( lm_vec3 ) : positionsStride ;
ctx - > mesh . normals = ( const unsigned char * ) normalsXYZ ;
ctx - > mesh . normalsType = normalsType ;
ctx - > mesh . normalsStride = normalsStride = = 0 ? sizeof ( lm_vec3 ) : normalsStride ;
ctx - > mesh . uvs = ( const unsigned char * ) lightmapCoordsUV ;
ctx - > mesh . uvsType = lightmapCoordsType ;
ctx - > mesh . uvsStride = lightmapCoordsStride = = 0 ? sizeof ( lm_vec2 ) : lightmapCoordsStride ;
ctx - > mesh . indicesType = indicesType ;
ctx - > mesh . indices = ( const unsigned char * ) indices ;
ctx - > mesh . count = count ;
lm_inverseTranspose ( transformationMatrix , ctx - > mesh . normalMatrix ) ;
ctx - > meshPosition . pass = 0 ;
lm_setMeshPosition ( ctx , 0 ) ;
}
lm_bool lmBegin ( lm_context * ctx , int * outViewport4 , float * outView4x4 , float * outProjection4x4 )
{
assert ( ctx - > meshPosition . triangle . baseIndex < ctx - > mesh . count ) ;
while ( ! lm_beginSampleHemisphere ( ctx , outViewport4 , outView4x4 , outProjection4x4 ) )
{ // as long as there are no hemisphere sides to render...
// try moving to the next rasterizer position
if ( lm_findNextConservativeTriangleRasterizerPosition ( ctx ) )
{ // if we successfully moved to the next sample position on the current triangle...
ctx - > meshPosition . hemisphere . side = 0 ; // start sampling a hemisphere there
}
else
{ // if there are no valid sample positions on the current triangle...
if ( ctx - > meshPosition . triangle . baseIndex + 3 < ctx - > mesh . count )
{ // ...and there are triangles left: move to the next triangle and continue sampling.
lm_setMeshPosition ( ctx , ctx - > meshPosition . triangle . baseIndex + 3 ) ;
}
else
{ // ...and there are no triangles left: finish
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if ( lm_integrateHemisphereBatch ( ctx ) ) // integrate and store last batch
lm_writeResultsToLightmap ( ctx ) ; // read storage data from gpu memory and write it to the lightmap
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if ( + + ctx - > meshPosition . pass = = ctx - > meshPosition . passCount )
{
ctx - > meshPosition . pass = 0 ;
ctx - > meshPosition . triangle . baseIndex = ctx - > mesh . count ; // set end condition (in case someone accidentally calls lmBegin again)
# ifdef LM_DEBUG_INTERPOLATION
lmImageSaveTGAub ( " debug_interpolation.tga " , ctx - > lightmap . debug , ctx - > lightmap . width , ctx - > lightmap . height , 3 ) ;
// lightmap texel statistics
int rendered = 0 , interpolated = 0 , wasted = 0 ;
for ( int y = 0 ; y < ctx - > lightmap . height ; y + + )
{
for ( int x = 0 ; x < ctx - > lightmap . width ; x + + )
{
if ( ctx - > lightmap . debug [ ( y * ctx - > lightmap . width + x ) * 3 + 0 ] )
rendered + + ;
else if ( ctx - > lightmap . debug [ ( y * ctx - > lightmap . width + x ) * 3 + 1 ] )
interpolated + + ;
else
wasted + + ;
}
}
int used = rendered + interpolated ;
int total = used + wasted ;
printf ( " \n ####################################################################### \n " ) ;
printf ( " %10d %6.2f%% rendered hemicubes integrated to lightmap texels. \n " , rendered , 100.0f * ( float ) rendered / ( float ) total ) ;
printf ( " %10d %6.2f%% interpolated lightmap texels. \n " , interpolated , 100.0f * ( float ) interpolated / ( float ) total ) ;
printf ( " %10d %6.2f%% wasted lightmap texels. \n " , wasted , 100.0f * ( float ) wasted / ( float ) total ) ;
printf ( " \n %17.2f%% of used texels were rendered. \n " , 100.0f * ( float ) rendered / ( float ) used ) ;
printf ( " ####################################################################### \n " ) ;
# endif
return LM_FALSE ;
}
lm_setMeshPosition ( ctx , 0 ) ; // start over with the next pass
}
}
}
return LM_TRUE ;
}
float lmProgress ( lm_context * ctx )
{
float passProgress = ( float ) ctx - > meshPosition . triangle . baseIndex / ( float ) ctx - > mesh . count ;
return ( ( float ) ctx - > meshPosition . pass + passProgress ) / ( float ) ctx - > meshPosition . passCount ;
}
void lmEnd ( lm_context * ctx )
{
lm_endSampleHemisphere ( ctx ) ;
}
// these are not performance tuned since their impact on the whole lightmapping duration is insignificant
float lmImageMin ( const float * image , int w , int h , int c , int m )
{
assert ( c > 0 & & m ) ;
float minValue = FLT_MAX ;
for ( int i = 0 ; i < w * h ; i + + )
for ( int j = 0 ; j < c ; j + + )
if ( m & ( 1 < < j ) )
minValue = lm_minf ( minValue , image [ i * c + j ] ) ;
return minValue ;
}
float lmImageMax ( const float * image , int w , int h , int c , int m )
{
assert ( c > 0 & & m ) ;
float maxValue = 0.0f ;
for ( int i = 0 ; i < w * h ; i + + )
for ( int j = 0 ; j < c ; j + + )
if ( m & ( 1 < < j ) )
maxValue = lm_maxf ( maxValue , image [ i * c + j ] ) ;
return maxValue ;
}
void lmImageAdd ( float * image , int w , int h , int c , float value , int m )
{
assert ( c > 0 & & m ) ;
for ( int i = 0 ; i < w * h ; i + + )
for ( int j = 0 ; j < c ; j + + )
if ( m & ( 1 < < j ) )
image [ i * c + j ] + = value ;
}
void lmImageScale ( float * image , int w , int h , int c , float factor , int m )
{
assert ( c > 0 & & m ) ;
for ( int i = 0 ; i < w * h ; i + + )
for ( int j = 0 ; j < c ; j + + )
if ( m & ( 1 < < j ) )
image [ i * c + j ] * = factor ;
}
void lmImagePower ( float * image , int w , int h , int c , float exponent , int m )
{
assert ( c > 0 & & m ) ;
for ( int i = 0 ; i < w * h ; i + + )
for ( int j = 0 ; j < c ; j + + )
if ( m & ( 1 < < j ) )
image [ i * c + j ] = powf ( image [ i * c + j ] , exponent ) ;
}
void lmImageDilate ( const float * image , float * outImage , int w , int h , int c )
{
assert ( c > 0 & & c < = 4 ) ;
for ( int y = 0 ; y < h ; y + + )
{
for ( int x = 0 ; x < w ; x + + )
{
float color [ 4 ] ;
lm_bool valid = LM_FALSE ;
for ( int i = 0 ; i < c ; i + + )
{
color [ i ] = image [ ( y * w + x ) * c + i ] ;
valid | = color [ i ] > 0.0f ;
}
if ( ! valid )
{
int n = 0 ;
const int dx [ ] = { - 1 , 0 , 1 , 0 } ;
const int dy [ ] = { 0 , 1 , 0 , - 1 } ;
for ( int d = 0 ; d < 4 ; d + + )
{
int cx = x + dx [ d ] ;
int cy = y + dy [ d ] ;
if ( cx > = 0 & & cx < w & & cy > = 0 & & cy < h )
{
float dcolor [ 4 ] ;
lm_bool dvalid = LM_FALSE ;
for ( int i = 0 ; i < c ; i + + )
{
dcolor [ i ] = image [ ( cy * w + cx ) * c + i ] ;
dvalid | = dcolor [ i ] > 0.0f ;
}
if ( dvalid )
{
for ( int i = 0 ; i < c ; i + + )
color [ i ] + = dcolor [ i ] ;
n + + ;
}
}
}
if ( n )
{
float in = 1.0f / n ;
for ( int i = 0 ; i < c ; i + + )
color [ i ] * = in ;
}
}
for ( int i = 0 ; i < c ; i + + )
outImage [ ( y * w + x ) * c + i ] = color [ i ] ;
}
}
}
void lmImageSmooth ( const float * image , float * outImage , int w , int h , int c )
{
assert ( c > 0 & & c < = 4 ) ;
for ( int y = 0 ; y < h ; y + + )
{
for ( int x = 0 ; x < w ; x + + )
{
float color [ 4 ] = { 0 } ;
int n = 0 ;
for ( int dy = - 1 ; dy < = 1 ; dy + + )
{
int cy = y + dy ;
for ( int dx = - 1 ; dx < = 1 ; dx + + )
{
int cx = x + dx ;
if ( cx > = 0 & & cx < w & & cy > = 0 & & cy < h )
{
lm_bool valid = LM_FALSE ;
for ( int i = 0 ; i < c ; i + + )
valid | = image [ ( cy * w + cx ) * c + i ] > 0.0f ;
if ( valid )
{
for ( int i = 0 ; i < c ; i + + )
color [ i ] + = image [ ( cy * w + cx ) * c + i ] ;
n + + ;
}
}
}
}
for ( int i = 0 ; i < c ; i + + )
outImage [ ( y * w + x ) * c + i ] = n ? color [ i ] / n : 0.0f ;
}
}
}
void lmImageDownsample ( const float * image , float * outImage , int w , int h , int c )
{
assert ( c > 0 & & c < = 4 ) ;
for ( int y = 0 ; y < h / 2 ; y + + )
{
for ( int x = 0 ; x < w / 2 ; x + + )
{
int p0 = 2 * ( y * w + x ) * c ;
int p1 = p0 + w * c ;
int valid [ 2 ] [ 2 ] = { 0 } ;
float sums [ 4 ] = { 0 } ;
for ( int i = 0 ; i < c ; i + + )
{
valid [ 0 ] [ 0 ] | = image [ p0 + i ] ! = 0.0f ? 1 : 0 ;
valid [ 0 ] [ 1 ] | = image [ p0 + c + i ] ! = 0.0f ? 1 : 0 ;
valid [ 1 ] [ 0 ] | = image [ p1 + i ] ! = 0.0f ? 1 : 0 ;
valid [ 1 ] [ 1 ] | = image [ p1 + c + i ] ! = 0.0f ? 1 : 0 ;
sums [ i ] + = image [ p0 + i ] + image [ p0 + c + i ] + image [ p1 + i ] + image [ p1 + c + i ] ;
}
int n = valid [ 0 ] [ 0 ] + valid [ 0 ] [ 1 ] + valid [ 1 ] [ 0 ] + valid [ 1 ] [ 1 ] ;
int p = ( y * w / 2 + x ) * c ;
for ( int i = 0 ; i < c ; i + + )
outImage [ p + i ] = n ? sums [ i ] / n : 0.0f ;
}
}
}
void lmImageFtoUB ( const float * image , unsigned char * outImage , int w , int h , int c , float max )
{
assert ( c > 0 ) ;
float scale = 255.0f / ( max ! = 0.0f ? max : lmImageMax ( image , w , h , c , LM_ALL_CHANNELS ) ) ;
for ( int i = 0 ; i < w * h * c ; i + + )
outImage [ i ] = ( unsigned char ) lm_minf ( lm_maxf ( image [ i ] * scale , 0.0f ) , 255.0f ) ;
}
// TGA output helpers
static void lm_swapRandBub ( unsigned char * image , int w , int h , int c )
{
assert ( c > = 3 ) ;
for ( int i = 0 ; i < w * h * c ; i + = c )
LM_SWAP ( unsigned char , image [ i ] , image [ i + 2 ] ) ;
}
lm_bool lmImageSaveTGAub ( const char * filename , const unsigned char * image , int w , int h , int c )
{
assert ( c = = 1 | | c = = 3 | | c = = 4 ) ;
lm_bool isGreyscale = c = = 1 ;
lm_bool hasAlpha = c = = 4 ;
unsigned char header [ 18 ] = {
0 , 0 , ( unsigned char ) ( isGreyscale ? 3 : 2 ) , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 ,
( unsigned char ) ( w & 0xff ) , ( unsigned char ) ( ( w > > 8 ) & 0xff ) , ( unsigned char ) ( h & 0xff ) , ( unsigned char ) ( ( h > > 8 ) & 0xff ) ,
( unsigned char ) ( 8 * c ) , ( unsigned char ) ( hasAlpha ? 8 : 0 )
} ;
# if defined(_MSC_VER) && _MSC_VER >= 1400
FILE * file ;
if ( fopen_s ( & file , filename , " wb " ) ! = 0 ) return LM_FALSE ;
# else
FILE * file = fopen ( filename , " wb " ) ;
if ( ! file ) return LM_FALSE ;
# endif
fwrite ( header , 1 , sizeof ( header ) , file ) ;
// we make sure to swap it back! trust me. :)
if ( ! isGreyscale )
lm_swapRandBub ( ( unsigned char * ) image , w , h , c ) ;
fwrite ( image , 1 , w * h * c , file ) ;
if ( ! isGreyscale )
lm_swapRandBub ( ( unsigned char * ) image , w , h , c ) ;
fclose ( file ) ;
return LM_TRUE ;
}
lm_bool lmImageSaveTGAf ( const char * filename , const float * image , int w , int h , int c , float max )
{
unsigned char * temp = ( unsigned char * ) LM_CALLOC ( w * h * c , sizeof ( unsigned char ) ) ;
lmImageFtoUB ( image , temp , w , h , c , max ) ;
lm_bool success = lmImageSaveTGAub ( filename , temp , w , h , c ) ;
LM_FREE ( temp ) ;
return success ;
}
2023-12-01 21:27:44 +00:00
# endif // LIGHTMAPPER_IMPLEMENTATION