medfall

commit 7651cd98b8d8a2f3cfd86e1854914b5d994d0526
parent 4845c6f755e600053866a59aa265a89e6f82fcd7
Author: Michael Savage <mikejsavage@gmail.com>
Date:   Fri, 10 Nov 2017 21:34:39 +0200

Forgot to copy the tree planting code

Diffstat:
pp.cc
 | 
76
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

1 file changed, 76 insertions(+), 0 deletions(-)
diff --git a/pp.cc b/pp.cc
@@ -9,6 +9,8 @@
 #include "decompress_bc.h"
 #include "autogdb.h"
 
+#include "rng/well512.h"
+
 #include "libs/lz4/lz4.h"
 #include "libs/lz4/lz4hc.h"
 
@@ -195,6 +197,66 @@ static u8 * write_compressed_texture( MemoryArena * arena, const DynamicString &
 	return dxt;
 }
 
+const size_t MAX_TREES = 262144 / 4;
+
+static bool ok_tree_position( RNGWell512 * rng, const array2d< u16 > heightmap, const array2d< v3 > normalmap, v2 pos, v3 * tree ) {
+	u16 height = bilerp01( heightmap, pos.x, pos.y );
+	double p = 1;
+	if( height <= 5 * 256 ) return false;
+	if( height > 235 * 256 ) return false;
+	if( height >= 200 * 256 ) {
+		p *= double( 235 * 256 - height ) / double( 235 * 256 - 200 * 256 );
+	}
+
+	v3 normal = normalize( bilerp01( normalmap, pos.x, pos.y ) );
+	if( normal.z < 0.3 ) return false;
+
+	p *= ( normal.z - 0.3 ) / 0.7;
+
+	if( !rng_p( rng, p ) ) return false;
+
+	*tree = v3( pos.x * heightmap.w, pos.y * heightmap.h, height / 256 );
+	return true;
+}
+
+static void hammersley( size_t n, array< v2 > points ) {
+	for( size_t i = 0; i < n; i++ ) {
+		float u = 0;
+		float v = ( i + 0.5f ) / n;
+		float p = 0.5;
+
+		size_t x = i;
+		while( x > 0 ) {
+			if( x % 2 == 1 ) u += p;
+			p /= 2;
+			x /= 2;
+		}
+
+		points[ i ] = v2( u, v );
+	}
+}
+
+static size_t place_trees( MemoryArena * arena, const array2d< u16 > heightmap, const array2d< v3 > normalmap, array< v3 > trees ) {
+	MEMARENA_SCOPED_CHECKPOINT( arena );
+
+	array< v2 > points = memarena_push_array( arena, v2, trees.n );
+	hammersley( MAX_TREES, points );
+
+	RNGWell512 rng;
+	rng_well512_init( &rng );
+
+	size_t placed = 0;
+	for( v2 point : points ) {
+		v3 pos;
+		if( ok_tree_position( &rng, heightmap, normalmap, point, &pos ) ) {
+			trees[ placed ] = pos;
+			placed++;
+		}
+	}
+
+	return placed;
+}
+
 int main( int argc, char ** argv ) {
 	install_debug_signal_handlers( true );
 
@@ -213,6 +275,9 @@ int main( int argc, char ** argv ) {
 	array2d< u16 > heightmap( png, w, h );
 	u8 * bc5_heightmap;
 
+	mkdir( "terrains", 0755 );
+	mkdir( output_path.c_str(), 0755 );
+
 	{
 		printf( "computing heightmaps\n" );
 
@@ -252,6 +317,17 @@ int main( int argc, char ** argv ) {
 		printf( "compressing\n" );
 		DynamicString normalmap_path( "{}/normalmap.bc5.lz4", output_path );
 		write_compressed_texture( &arena, normalmap_path, normalmap, squish::kBc5 );
+
+		{
+			printf( "planting trees\n" );
+
+			array< v3 > trees = alloc_array< v3 >( &arena, MAX_TREES );
+			size_t num_trees = place_trees( &arena, heightmap, normalmap_v3, trees );
+
+			printf( "compressing\n" );
+			DynamicString trees_path( "{}/trees.lz4", output_path );
+			write_compressed_file( &arena, trees_path, trees.ptr(), num_trees * sizeof( v3 ) );
+		}
 	}
 
 	{