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done! 

perlin next I guess
This commit is contained in:
John Cupitt 2016-07-19 11:53:56 +01:00
parent dac671439c
commit e14c97359a
1 changed files with 30 additions and 30 deletions
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60
libvips/create/worley.c
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@ -1,6 +1,6 @@
/* Worley noise generator
/* Worley noise generator.
*
* 13/6/13
* 19/7/16
*/
/*
@ -120,7 +120,7 @@ vips_worley_random( int previous )
return( ((guint64) 1103515245 * previous + 12345) & 0xffffff );
}
/* Generate a 3 x 3 grid of cells around a point.
/* Generate a 3 x 3 grid of cells around a point.
*/
static void
vips_worley_create_cells( VipsWorley *worley,
@ -135,24 +135,29 @@ vips_worley_create_cells( VipsWorley *worley,
int seed;
int j;
/* We wrap cells around, so that out output will
* tesselate.
/* Can go <0 and >width for edges.
*/
cell->cell_x = cell_x + x - 1;
if( cell->cell_x >= worley->cells_across )
cell->cell_x = 0;
if( cell->cell_x < 0 )
cell->cell_x = worley->cells_across - 1;
cell->cell_y = cell_y + y - 1;
if( cell->cell_y >= worley->cells_down )
cell->cell_y = 0;
if( cell->cell_y < 0 )
cell->cell_y = worley->cells_down - 1;
/* Seed our rng.
seed = worley->seed;
/* When we calculate the seed for this cell, we wrap
* around so that our output will tesselate.
*/
seed = worley->seed +
(cell->cell_x << 16) + cell->cell_y;
if( cell->cell_x >= worley->cells_across )
seed ^= 0;
else if( cell->cell_x < 0 )
seed ^= worley->cells_across - 1;
else
seed ^= cell->cell_x;
if( cell->cell_y >= worley->cells_down )
seed ^= 0;
else if( cell->cell_y < 0 )
seed ^= worley->cells_down - 1;
else
seed ^= cell->cell_y;
/* [1, MAX_FEATURES)
*/
@ -162,8 +167,9 @@ vips_worley_create_cells( VipsWorley *worley,
for( j = 0; j < cell->n_features; j++ ) {
seed = vips_worley_random( seed );
cell->feature_x[j] =
cell->cell_y * worley->cell_size +
cell->cell_x * worley->cell_size +
seed % worley->cell_size;
seed = vips_worley_random( seed );
cell->feature_y[j] =
cell->cell_y * worley->cell_size +
@ -202,15 +208,9 @@ vips_worley_start( VipsImage *out, void *a, void *b )
static int
vips_hypot( int x, int y )
{
int result;
#ifdef HAVE_HYPOT
result = hypot( x, y );
#else
result = sqrt( x * x + y * y );
#endif
return( result );
/* Faster than hypot() for int args.
*/
return( sqrt( x * x + y * y ) );
}
static int
@ -230,7 +230,7 @@ vips_worley_distance( VipsWorley *worley, Cell cells[9], int x, int y )
x - cell->feature_x[j],
y - cell->feature_y[j] );
distance = VIPS_MIN( d, distance );
distance = VIPS_MIN( distance, d );
}
}
@ -251,8 +251,8 @@ vips_worley_gen( VipsRegion *or, void *vseq, void *a, void *b,
int *q = (int *) VIPS_REGION_ADDR( or, r->left, r->top + y );
for( x = 0; x < r->width; x++ ) {
int cell_x = (r->left + x) % worley->cell_size;
int cell_y = (r->top + y) % worley->cell_size;
int cell_x = (r->left + x) / worley->cell_size;
int cell_y = (r->top + y) / worley->cell_size;
if( cell_x != seq->cell_x ||
cell_y != seq->cell_y ) {
@ -362,7 +362,7 @@ vips_worley_init( VipsWorley *worley )
* Use @cell_size to set the size of the cells from which the image is
* constructed. The default is 256 x 256.
*
* If @width and @height are mutiples of @cell_size, the image will tessellate.
* If @width and @height are multiples of @cell_size, the image will tessellate.
*
* See also: vips_gaussnoise().
*