medfall

commit 3889c3d127d96d0330913e86c961324fb985dab9
parent bea04b83bd1a69fce0480d69df68fa07663a40b5
Author: Michael Savage <mikejsavage@gmail.com>
Date:   Fri Sep 18 13:00:38 +0100

Fix terrain_height

Diffstat:
hm.cc
 | 
2
+-
terrain_manager.cc
 | 
29
++++++++++++++++++++++-------
terrain_manager.h
 | 
2
+-
3 files changed, 24 insertions(+), 9 deletions(-)
diff --git a/hm.cc b/hm.cc
@@ -228,7 +228,7 @@ extern "C" GAME_FRAME( game_frame ) {
 	state->pos += angles_to_vector_xy( state->angles ) * speed * dt * ( float ) fb;
 	const glm::vec3 sideways = glm::vec3( -cosf( state->angles.y ), sinf( state->angles.y ), 0 );
 	state->pos += sideways * speed * dt * ( float ) lr;
-	// state->pos.z = terrain_height( &state->tm, state->pos.x, state->pos.y ) + 2;
+	// state->pos.z = terrain_height( &state->tm, state->pos ) + 2;
 	state->pos.z += dz * 50.0f * dt;
 
 	terrain_update( &state->tm, state->pos );
diff --git a/terrain_manager.cc b/terrain_manager.cc
@@ -226,13 +226,28 @@ void terrain_render( const TerrainManager * const tm, const glm::mat4 VP, const 
 	glUseProgram( 0 );
 }
 
-float terrain_height( const TerrainManager * const tm, const float x, const float y ) {
-	const u32 tx = x / TILE_SIZE;
-	const u32 ty = y / TILE_SIZE;
+// TODO: this is horrible
+// it's probably worth using view_x/y instead of view_left/top
+// and using signed arithmetic to make this less annoying
+// also implement the bounded arithmetic class
+float terrain_height( const TerrainManager * const tm, const glm::vec3 position ) {
+	// see doodles/tile_coords_to_view_coords.png for docs
+	const u32 player_tile_x = position.x / TILE_SIZE;
+	const u32 player_tile_y = position.y / TILE_SIZE;
+
+	if( player_tile_x < tm->tile_x ) assert( tm->tile_x - player_tile_x <= VIEW_HALF );
+	else assert( player_tile_x - tm->tile_x <= VIEW_HALF );
+	if( player_tile_y < tm->tile_y ) assert( tm->tile_y - player_tile_y <= VIEW_HALF );
+	else assert( player_tile_y - tm->tile_y <= VIEW_HALF );
+
+	const u32 dx = player_tile_x - tm->tile_x;
+	const u32 dy = player_tile_y - tm->tile_y;
+
+	const u32 vx = view_add( tm->view_left, VIEW_HALF + dx );
+	const u32 vy = view_add( tm->view_top, VIEW_HALF + dy );
 
-	// TODO: totally wrong
-	// convert into tile space
-	const Heightmap * const hm = &tm->tiles[ tx ][ ty ];
+	const Heightmap * const hm = &tm->tiles[ vx ][ vy ];
 
-	return hm->bilerp_height( x - tx * TILE_SIZE, y - ty * TILE_SIZE );
+	return hm->bilerp_height( position.x - player_tile_x * TILE_SIZE,
+		position.y - player_tile_y * TILE_SIZE );
 }
diff --git a/terrain_manager.h b/terrain_manager.h
@@ -43,6 +43,6 @@ void terrain_init( TerrainManager * const tm, const char * const tiles_dir,
 void terrain_teleport( TerrainManager * const tm, const glm::vec3 position );
 void terrain_update( TerrainManager * const tm, const glm::vec3 position );
 void terrain_render( const TerrainManager * const tm, const glm::mat4 VP, const float sun_slope );
-float terrain_height( const TerrainManager * const tm, const float x, const float y );
+float terrain_height( const TerrainManager * const tm, const glm::vec3 position );
 
 #endif // _TERRAIN_MANAGER_H_