diff options
| -rw-r--r-- | src/viewport.cpp | 178 |
1 files changed, 92 insertions, 86 deletions
diff --git a/src/viewport.cpp b/src/viewport.cpp index cb4307f0a..11a158712 100644 --- a/src/viewport.cpp +++ b/src/viewport.cpp @@ -1044,41 +1044,29 @@ draw_inner: } /** - * Returns the Y coordinate in the viewport coordinate system where a given - * tile should be painted. Can be used on virtual "black" tiles outside map. - * - * @param tile Tile coordinates of the tile. Map outside is allowed. - * @return Viewport Y coordinate where the northern corner of the tile is located (foundations not included). + * Returns the y coordinate in the viewport coordinate system where the given + * tile is painted. + * @param tile Any tile. + * @return The viewport y coordinate where the tile is painted. */ -static inline int GetTilePaintY(Point tile) +static int GetViewportY(Point tile) { - return RemapCoords(tile.x * TILE_SIZE, tile.y * TILE_SIZE, TilePixelHeightOutsideMap(tile.x, tile.y)).y; + /* Each increment in X or Y direction moves down by half a tile, i.e. TILE_PIXELS / 2. */ + return (tile.y * (int)(TILE_PIXELS / 2) + tile.x * (int)(TILE_PIXELS / 2) - TilePixelHeightOutsideMap(tile.x, tile.y)) << ZOOM_LVL_SHIFT; } /** - * Add sprites of a single tile to the viewport. - * - * @param[in,out] ti Filled-in tile information of the tile. On return, \a z coordinate will be updated and include foundations (if any). - * @param tile_type Type of the tile (#GetTileType) or #MP_VOID for virtual "black" tiles outside map. + * Add the landscape to the viewport, i.e. all ground tiles and buildings. */ -static void ViewportAddTile(TileInfo *ti, TileType tile_type) +static void ViewportAddLandscape() { - _vd.foundation_part = FOUNDATION_PART_NONE; - _vd.foundation[0] = -1; - _vd.foundation[1] = -1; - _vd.last_foundation_child[0] = NULL; - _vd.last_foundation_child[1] = NULL; + assert(_vd.dpi.top <= _vd.dpi.top + _vd.dpi.height); + assert(_vd.dpi.left <= _vd.dpi.left + _vd.dpi.width); - _cur_ti = ti; - _tile_type_procs[tile_type]->draw_tile_proc(ti); -} + Point upper_left = InverseRemapCoords(_vd.dpi.left, _vd.dpi.top); + Point upper_right = InverseRemapCoords(_vd.dpi.left + _vd.dpi.width, _vd.dpi.top); -/** - * Add the landscape to the viewport, i.e. all ground tiles, buildings and bridges. - */ -static void ViewportAddLandscape() -{ - /* Transformations between tile x/y coordinates and 45-degree rotated rows/columns: + /* Transformations between tile coordinates and viewport rows/columns: See vp_column_row * column = y - x * row = x + y * x = (row - column) / 2 @@ -1086,46 +1074,38 @@ static void ViewportAddLandscape() * Note: (row, columns) pairs are only valid, if they are both even or both odd. */ - /* Rectangle to repaint. Includes oversize for tile sprites. - * There is no oversize for the bottom side of a tile so the first tile we draw - * in a column must have its northern corner above or at the 'top' bound. */ - const int left = _vd.dpi.left - MAX_TILE_EXTENT_RIGHT; // inclusive - const int top = _vd.dpi.top; // unlike to other bounds, this one is relative to S tile corner, not N, not inclusive (for S corner) - const int right = _vd.dpi.left + _vd.dpi.width + MAX_TILE_EXTENT_LEFT; // not inclusive - const int bottom_empty = _vd.dpi.top + _vd.dpi.height; // bottom bound for void tiles and tiles outside map, includes only clear ground sprites, not inclusive - const int bottom_building = bottom_empty + MAX_TILE_EXTENT_TOP; // bottom bound that accounts for buildings but does not include oversize for bridges, not inclusive - const int bottom = bottom_building + ZOOM_LVL_BASE * TILE_HEIGHT * _settings_game.construction.max_bridge_height; // bottom bound that includes entire oversize, also for bridges, not inclusive - assert(left < right && top < bottom); - - /* Base 2 logarithm of the distance between tile columns in a viewport. - * It will be used to achieve proper rounding easily. */ - assert_compile(TILE_SIZE == 1 << 4); - static const uint column_log = ZOOM_LVL_SHIFT + 4 + 1; // +1 comes from the factor 2 that is used when remapping to horizontal 'x' screen coordinate (see RemapCoords) - - /* Horizontal iteration bounds. */ - int first_col = left >> column_log; // inclusive, round toward -inf - int last_col = -(-right >> column_log); // not inclusive, round toward +inf - - /* Use tile that intersects with the left-top corner of the repaint - * rectangle as an approximate start row of the iteration. */ - Point start = InverseRemapCoords2(left, top, false); // warning, it will take foundations into account, might return a tile that is further to S, but that's OK because coordinates will be moved toward N later if needed - int first_row = (start.x >> 4) + (start.y >> 4); - /* Combine with the first column, round toward S. */ - start.x = (first_row - first_col + 1) >> 1; - start.y = (first_row + first_col + 1) >> 1; - - /* Iterate over columns of tiles. */ - while (first_col++ < last_col) { - /* Fix column start tile - move it toward N until it reaches the 'top' bound. */ - int y_pos; - while (top < (y_pos = GetTilePaintY(start))) start.x--, start.y--; - - /* Iterate over tiles in a column. */ - Point tilecoord = start; - do { + /* Columns overlap with neighbouring columns by a half tile. + * - Left column is column of upper_left (rounded down) and one column to the left. + * - Right column is column of upper_right (rounded up) and one column to the right. + * Note: Integer-division does not round down for negative numbers, so ensure rounding with another increment/decrement. + */ + int left_column = (upper_left.y - upper_left.x) / (int)TILE_SIZE - 2; + int right_column = (upper_right.y - upper_right.x) / (int)TILE_SIZE + 2; + + int potential_bridge_height = ZOOM_LVL_BASE * TILE_HEIGHT * _settings_game.construction.max_bridge_height; + + /* Rows overlap with neighbouring rows by a half tile. + * The first row that could possibly be visible is the row above upper_left (if it is at height 0). + * Due to integer-division not rounding down for negative numbers, we need another decrement. + */ + int row = (upper_left.x + upper_left.y) / (int)TILE_SIZE - 2; + bool last_row = false; + for (; !last_row; row++) { + last_row = true; + for (int column = left_column; column <= right_column; column++) { + /* Valid row/column? */ + if ((row + column) % 2 != 0) continue; + + Point tilecoord; + tilecoord.x = (row - column) / 2; + tilecoord.y = (row + column) / 2; + assert(column == tilecoord.y - tilecoord.x); + assert(row == tilecoord.y + tilecoord.x); + TileType tile_type; TileInfo tile_info; - tile_info.x = tilecoord.x * TILE_SIZE; // FIXME: tile_info should use signed integers + _cur_ti = &tile_info; + tile_info.x = tilecoord.x * TILE_SIZE; // FIXME tile_info should use signed integers tile_info.y = tilecoord.y * TILE_SIZE; if (IsInsideBS(tilecoord.x, 0, MapSizeX()) && IsInsideBS(tilecoord.y, 0, MapSizeY())) { @@ -1137,32 +1117,58 @@ static void ViewportAddLandscape() tile_type = MP_VOID; } - /* Check if tile is "visible". - * - * Until 'bottom_empty' every tile is visible, also "black" tiles outside map. - * Since 'bottom_empty' only tiles with a content might be visible. */ - if (y_pos >= bottom_empty) { - if (tilecoord.x >= (int)MapSizeX() || tilecoord.y >= (int)MapSizeY()) break; // No more non-void tiles in this column? Then stop. - if (tile_type == MP_VOID) continue; // No content on the tile? Then skip. - - /* Since 'bottom_building' only bridges might be visible. */ - if (y_pos >= bottom_building) { - if (!IsBridgeAbove(tile_info.tile)) continue; // no bridge above, skip - if (RemapCoords(tile_info.x, tile_info.y, GetBridgePixelHeight(GetNorthernBridgeEnd(tile_info.tile))).y >= bottom_building) continue; // bridge isn't high enough, skip - } + if (tile_type != MP_VOID) { + /* We are inside the map => paint landscape. */ + tile_info.tileh = GetTilePixelSlope(tile_info.tile, &tile_info.z); + } else { + /* We are outside the map => paint black. */ + tile_info.tileh = GetTilePixelSlopeOutsideMap(tilecoord.x, tilecoord.y, &tile_info.z); } - /* Paint the tile. */ - tile_info.tileh = (tile_info.tile != INVALID_TILE) ? GetTilePixelSlope(tile_info.tile, &tile_info.z) : GetTilePixelSlopeOutsideMap(tilecoord.x, tilecoord.y, &tile_info.z); - ViewportAddTile(&tile_info, tile_type); - if (tile_info.tile != INVALID_TILE) DrawTileSelection(&tile_info); + int viewport_y = GetViewportY(tilecoord); + + if (viewport_y + MAX_TILE_EXTENT_BOTTOM < _vd.dpi.top) { + /* The tile in this column is not visible yet. + * Tiles in other columns may be visible, but we need more rows in any case. */ + last_row = false; + continue; + } - /* Next tile. */ - } while (tilecoord.x++, tilecoord.y++, y_pos = GetTilePaintY(tilecoord), y_pos < bottom); + int min_visible_height = viewport_y - (_vd.dpi.top + _vd.dpi.height); + bool tile_visible = min_visible_height <= 0; + + if (tile_type != MP_VOID) { + /* Is tile with buildings visible? */ + if (min_visible_height < MAX_TILE_EXTENT_TOP) tile_visible = true; + + if (IsBridgeAbove(tile_info.tile)) { + /* Is the bridge visible? */ + TileIndex bridge_tile = GetNorthernBridgeEnd(tile_info.tile); + int bridge_height = ZOOM_LVL_BASE * (GetBridgePixelHeight(bridge_tile) - TilePixelHeight(tile_info.tile)); + if (min_visible_height < bridge_height + MAX_TILE_EXTENT_TOP) tile_visible = true; + } - /* Go one tile toward SE. This will advance us to next column. Bias toward S will - * take care of slopes too. Coordinates will be moved toward N later if needed. */ - start.y++; + /* Would a higher bridge on a more southern tile be visible? + * If yes, we need to loop over more rows to possibly find one. */ + if (min_visible_height < potential_bridge_height + MAX_TILE_EXTENT_TOP) last_row = false; + } else { + /* Outside of map. If we are on the north border of the map, there may still be a bridge visible, + * so we need to loop over more rows to possibly find one. */ + if ((tilecoord.x <= 0 || tilecoord.y <= 0) && min_visible_height < potential_bridge_height + MAX_TILE_EXTENT_TOP) last_row = false; + } + + if (tile_visible) { + last_row = false; + _vd.foundation_part = FOUNDATION_PART_NONE; + _vd.foundation[0] = -1; + _vd.foundation[1] = -1; + _vd.last_foundation_child[0] = NULL; + _vd.last_foundation_child[1] = NULL; + + _tile_type_procs[tile_type]->draw_tile_proc(&tile_info); + if (tile_info.tile != INVALID_TILE) DrawTileSelection(&tile_info); + } + } } } |