medfall

commit 236e4df4c19f2205c579f05696a4f31e6be03305
parent ffa0a0b157b2c1c377c2cc2d5c63911fc259ba27
Author: Michael Savage <mikejsavage@gmail.com>
Date:   Sun Jul  2 21:50:51 +0300

Only save normal borders. Fill in the middle at runtime

Reduces normal maps from 50MB to < 1MB

Diffstat:
pp.cc
 | 
38
++++++++++++++++++++++++++++++++++++--
terrain_manager.cc
 | 
41
+++++++++++++++++++++++++++++++++++++++--
2 files changed, 75 insertions(+), 4 deletions(-)
diff --git a/pp.cc b/pp.cc
@@ -221,6 +221,41 @@ static void write_tile(
 		"{}/{}_{}{}", dir.c_str(), tx, ty, extension.c_str() );
 }
 
+static void write_normal_border(
+	MemoryArena * arena, const std::string & dir,
+	const array2d< v3 > normals, int tx, int ty
+) {
+	MEMARENA_SCOPED_CHECKPOINT( arena );
+
+	size_t border_size = OUT_SIZE * 4 - 4;
+	array< v3 > border = memarena_push_array( arena, v3, border_size );
+
+	const u32 left = tx * TILE_SIZE;
+	const u32 top = ty * TILE_SIZE;
+
+	v3 up = v3( 0, 0, 1 );
+
+	size_t n = 0;
+	for( size_t x = 0; x < OUT_SIZE; x++ ) {
+		border[ n++ ] = normals.try_get( left + x, top, up );
+	}
+	for( size_t x = 0; x < OUT_SIZE; x++ ) {
+		border[ n++ ] = normals.try_get( left + x, top + OUT_SIZE - 1, up );
+	}
+	for( size_t y = 1; y < OUT_SIZE - 1; y++ ) {
+		border[ n++ ] = normals.try_get( left, top + y, up );
+	}
+	for( size_t y = 1; y < OUT_SIZE - 1; y++ ) {
+		border[ n++ ] = normals.try_get( left + OUT_SIZE - 1, top + y, up );
+	}
+
+	ASSERT( n == border.n );
+
+	ggprint( "writing {}_{}_normals.lz4... ", tx, ty );
+	write_compressed_file( arena, border.ptr(), border.num_bytes(),
+		"{}/{}_{}_normals.lz4", dir.c_str(), tx, ty );
+}
+
 static void write_quadtree(
 	MemoryArena * arena, const std::string & dir,
 	const array2d< u16 > heightmap, int tx, int ty
@@ -327,12 +362,11 @@ int main( int argc, char ** argv ) {
 		MEMARENA_SCOPED_CHECKPOINT( &arena );
 		array2d< v3 > normals = memarena_push_array2d( &arena, v3, w, h );
 
-		// TODO: normals can be v2 since z >= 0 on a heightmap
 		compute_normals( heightmap, normals );
 
 		for( int ty = 0; ty < ytiles; ty++ ) {
 			for( int tx = 0; tx < xtiles; tx++ ) {
-				write_tile( &arena, dir, "_normals.lz4", normals, v3( 0.0f, 0.0f, 1.0f ), tx, ty );
+				write_normal_border( &arena, dir, normals, tx, ty );
 			}
 		}
 
diff --git a/terrain_manager.cc b/terrain_manager.cc
@@ -51,12 +51,49 @@ static WORK_QUEUE_CALLBACK( async_load_tile ) {
 	size_t decompressed_normalmap_size = num_points * sizeof( v3 );
 	v3 * decompressed_normalmap = ( v3 * ) malloc( decompressed_normalmap_size );
 	ASSERT( decompressed_normalmap != NULL );
+
+	array2d< v3 > normals( decompressed_normalmap, dt.heightmap.width, dt.heightmap.height );
+
+	// compute centre region
+	for( size_t y = 1; y < normals.h - 1; y++ ) {
+		for( size_t x = 1; x < normals.w - 1; x++ ) {
+			v3 tangent(
+				2.0f,
+				0,
+				heightmap_height( &dt.heightmap, x + 1, y ) - heightmap_height( &dt.heightmap, x - 1, y ) );
+			v3 bitangent(
+				0,
+				2.0f,
+				heightmap_height( &dt.heightmap, x, y + 1 ) - heightmap_height( &dt.heightmap, x, y - 1 ) );
+
+			normals( x, y ) = normalize( cross( tangent, bitangent ) );
+		}
+	}
+
+	// load border
+	array< v3 > normals_border = memarena_push_array( arena, v3, ( TILE_SIZE + 1 ) * 4 - 4 );
 	int ok_normalmap = LZ4_decompress_safe(
 		ct.normalmap.ptr(),
-		( char * ) decompressed_normalmap,
-		ct.normalmap.num_bytes(), decompressed_normalmap_size );
+		( char * ) normals_border.ptr(),
+		ct.normalmap.num_bytes(), normals_border.num_bytes() );
 	ASSERT( ok_normalmap > 0 );
 
+	{
+		size_t n = 0;
+		for( size_t x = 0; x < normals.w; x++ ) {
+			normals( x, 0 ) = normals_border[ n++ ];
+		}
+		for( size_t x = 0; x < normals.w; x++ ) {
+			normals( x, normals.h - 1 ) = normals_border[ n++ ];
+		}
+		for( size_t y = 1; y < normals.h - 1; y++ ) {
+			normals( 0, y ) = normals_border[ n++ ];
+		}
+		for( size_t y = 1; y < normals.h - 1; y++ ) {
+			normals( normals.w - 1, y ) = normals_border[ n++ ];
+		}
+	}
+
 	dt.normalmap = decompressed_normalmap;
 
 	// horizonmap