medfall

commit 10e75b1c7ff4156a9a21c3a7f2050ccaad64873d
parent 272b266fa67e3d3116ddf131f734a29f77342f69
Author: Michael Savage <mikejsavage@gmail.com>
Date:   Tue Feb  2 19:41:40 +0000

Add initial LOD code

Diffstat:
terrain_manager.cc
 | 
33
+++++++++++++++++++++++++++++++++
1 file changed, 33 insertions(+), 0 deletions(-)
diff --git a/terrain_manager.cc b/terrain_manager.cc
@@ -156,6 +156,31 @@ static u32 view_add( u32 v, u32 o ) {
 	return ( v + o ) % VIEW_SIZE;
 }
 
+static u8 terrain_tile_lod(
+	s16 player_tile_x, s16 player_tile_y,
+	s16 tx, s16 ty
+) {
+	u16 manhattan_distance = abs( player_tile_x - tx )
+		+ abs( player_tile_y - ty );
+	return min( ( u16 ) 8, manhattan_distance );
+}
+
+static void terrain_update_lods(
+	TerrainManager * tm,
+	s16 player_tile_x, s16 player_tile_y
+) {
+	u8 new_lods[ WORLD_SIZE ][ WORLD_SIZE ];
+
+	for( u16 tx = 0; tx < WORLD_SIZE; tx++ ) {
+		for( u16 ty = 0; ty < WORLD_SIZE; ty++ ) {
+			new_lods[ tx ][ ty ] = terrain_tile_lod(
+				player_tile_x, player_tile_y, tx, ty );
+		}
+	}
+
+	memcpy( tm->lods, new_lods, WORLD_SIZE * WORLD_SIZE );
+}
+
 void terrain_update( TerrainManager * tm, glm::vec3 position ) {
 	u32 player_tile_x = position.x / TILE_SIZE;
 	u32 player_tile_y = position.y / TILE_SIZE;
@@ -172,6 +197,8 @@ void terrain_update( TerrainManager * tm, glm::vec3 position ) {
 			}
 			tm->tile_x++;
 			tm->view_left = view_add( tm->view_left, 1 );
+
+			terrain_update_lods( tm, tm->tile_x, tm->tile_y );
 		}
 		else {
 			// -x boundary
@@ -184,6 +211,8 @@ void terrain_update( TerrainManager * tm, glm::vec3 position ) {
 			}
 			tm->tile_x--;
 			tm->view_left = view_sub( tm->view_left, 1 );
+
+			terrain_update_lods( tm, tm->tile_x, tm->tile_y );
 		}
 	}
 
@@ -199,6 +228,8 @@ void terrain_update( TerrainManager * tm, glm::vec3 position ) {
 			}
 			tm->tile_y++;
 			tm->view_top = view_add( tm->view_top, 1 );
+
+			terrain_update_lods( tm, tm->tile_x, tm->tile_y );
 		}
 		else {
 			// -y boundary
@@ -211,6 +242,8 @@ void terrain_update( TerrainManager * tm, glm::vec3 position ) {
 			}
 			tm->tile_y--;
 			tm->view_top = view_sub( tm->view_top, 1 );
+
+			terrain_update_lods( tm, tm->tile_x, tm->tile_y );
 		}
 	}
 }