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Codechange: Tweak ViewportAddLandscape so it no more relies on "go down as fast as possible" tile height model (Patch by adf88, #6583)

pull/7097/head
Johannes E. Krause 2019-01-13 21:00:40 +01:00 committed by Niels Martin Hansen
parent c33596fe4a
commit 479f13fc41
1 changed files with 82 additions and 88 deletions
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170
src/viewport.cpp
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@ -1044,29 +1044,41 @@ draw_inner:
} }
/** /**
* Returns the y coordinate in the viewport coordinate system where the given * Returns the Y coordinate in the viewport coordinate system where a given
* tile is painted. * tile should be painted. Can be used on virtual "black" tiles outside map.
* @param tile Any tile. *
* @return The viewport y coordinate where the tile is painted. * @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).
*/ */
static int GetViewportY(Point tile) static inline int GetTilePaintY(Point tile)
{ {
/* Each increment in X or Y direction moves down by half a tile, i.e. TILE_PIXELS / 2. */ return RemapCoords(tile.x * TILE_SIZE, tile.y * TILE_SIZE, TilePixelHeightOutsideMap(tile.x, tile.y)).y;
return (tile.y * (int)(TILE_PIXELS / 2) + tile.x * (int)(TILE_PIXELS / 2) - TilePixelHeightOutsideMap(tile.x, tile.y)) << ZOOM_LVL_SHIFT;
} }
/** /**
* Add the landscape to the viewport, i.e. all ground tiles and buildings. * 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.
*/
static void ViewportAddTile(TileInfo *ti, TileType tile_type)
{
_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;
_cur_ti = ti;
_tile_type_procs[tile_type]->draw_tile_proc(ti);
}
/**
* Add the landscape to the viewport, i.e. all ground tiles, buildings and bridges.
*/ */
static void ViewportAddLandscape() static void ViewportAddLandscape()
{ {
assert(_vd.dpi.top <= _vd.dpi.top + _vd.dpi.height); /* Transformations between tile x/y coordinates and 45-degree rotated rows/columns:
assert(_vd.dpi.left <= _vd.dpi.left + _vd.dpi.width);
Point upper_left = InverseRemapCoords(_vd.dpi.left, _vd.dpi.top);
Point upper_right = InverseRemapCoords(_vd.dpi.left + _vd.dpi.width, _vd.dpi.top);
/* Transformations between tile coordinates and viewport rows/columns: See vp_column_row
* column = y - x * column = y - x
* row = x + y * row = x + y
* x = (row - column) / 2 * x = (row - column) / 2
@ -1074,38 +1086,46 @@ static void ViewportAddLandscape()
* Note: (row, columns) pairs are only valid, if they are both even or both odd. * Note: (row, columns) pairs are only valid, if they are both even or both odd.
*/ */
/* Columns overlap with neighbouring columns by a half tile. /* Rectangle to repaint. Includes oversize for tile sprites.
* - Left column is column of upper_left (rounded down) and one column to the left. * There is no oversize for the bottom side of a tile so the first tile we draw
* - Right column is column of upper_right (rounded up) and one column to the right. * in a column must have its northern corner above or at the 'top' bound. */
* Note: Integer-division does not round down for negative numbers, so ensure rounding with another increment/decrement. 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)
int left_column = (upper_left.y - upper_left.x) / (int)TILE_SIZE - 2; const int right = _vd.dpi.left + _vd.dpi.width + MAX_TILE_EXTENT_LEFT; // not inclusive
int right_column = (upper_right.y - upper_right.x) / (int)TILE_SIZE + 2; 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);
int potential_bridge_height = ZOOM_LVL_BASE * TILE_HEIGHT * _settings_game.construction.max_bridge_height; /* 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)
/* Rows overlap with neighbouring rows by a half tile. /* Horizontal iteration bounds. */
* The first row that could possibly be visible is the row above upper_left (if it is at height 0). int first_col = left >> column_log; // inclusive, round toward -inf
* Due to integer-division not rounding down for negative numbers, we need another decrement. int last_col = -(-right >> column_log); // not inclusive, round toward +inf
*/
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; /* Use tile that intersects with the left-top corner of the repaint
tilecoord.x = (row - column) / 2; * rectangle as an approximate start row of the iteration. */
tilecoord.y = (row + column) / 2; 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
assert(column == tilecoord.y - tilecoord.x); int first_row = (start.x >> 4) + (start.y >> 4);
assert(row == tilecoord.y + tilecoord.x); /* 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 {
TileType tile_type; TileType tile_type;
TileInfo tile_info; TileInfo tile_info;
_cur_ti = &tile_info; tile_info.x = tilecoord.x * TILE_SIZE; // FIXME: tile_info should use signed integers
tile_info.x = tilecoord.x * TILE_SIZE; // FIXME tile_info should use signed integers
tile_info.y = tilecoord.y * TILE_SIZE; tile_info.y = tilecoord.y * TILE_SIZE;
if (IsInsideBS(tilecoord.x, 0, MapSizeX()) && IsInsideBS(tilecoord.y, 0, MapSizeY())) { if (IsInsideBS(tilecoord.x, 0, MapSizeX()) && IsInsideBS(tilecoord.y, 0, MapSizeY())) {
@ -1117,58 +1137,32 @@ static void ViewportAddLandscape()
tile_type = MP_VOID; tile_type = MP_VOID;
} }
if (tile_type != MP_VOID) { /* Check if tile is "visible".
/* We are inside the map => paint landscape. */ *
tile_info.tileh = GetTilePixelSlope(tile_info.tile, &tile_info.z); * Until 'bottom_empty' every tile is visible, also "black" tiles outside map.
} else { * Since 'bottom_empty' only tiles with a content might be visible. */
/* We are outside the map => paint black. */ if (y_pos >= bottom_empty) {
tile_info.tileh = GetTilePixelSlopeOutsideMap(tilecoord.x, tilecoord.y, &tile_info.z); 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.
int viewport_y = GetViewportY(tilecoord); /* Since 'bottom_building' only bridges might be visible. */
if (y_pos >= bottom_building) {
if (viewport_y + MAX_TILE_EXTENT_BOTTOM < _vd.dpi.top) { if (!IsBridgeAbove(tile_info.tile)) continue; // no bridge above, skip
/* The tile in this column is not visible yet. if (RemapCoords(tile_info.x, tile_info.y, GetBridgePixelHeight(GetNorthernBridgeEnd(tile_info.tile))).y >= bottom_building) continue; // bridge isn't high enough, skip
* Tiles in other columns may be visible, but we need more rows in any case. */
last_row = false;
continue;
}
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;
} }
/* 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) { /* Paint the tile. */
last_row = false; tile_info.tileh = (tile_info.tile != INVALID_TILE) ? GetTilePixelSlope(tile_info.tile, &tile_info.z) : GetTilePixelSlopeOutsideMap(tilecoord.x, tilecoord.y, &tile_info.z);
_vd.foundation_part = FOUNDATION_PART_NONE; ViewportAddTile(&tile_info, tile_type);
_vd.foundation[0] = -1; if (tile_info.tile != INVALID_TILE) DrawTileSelection(&tile_info);
_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); /* Next tile. */
if (tile_info.tile != INVALID_TILE) DrawTileSelection(&tile_info); } while (tilecoord.x++, tilecoord.y++, y_pos = GetTilePaintY(tilecoord), y_pos < bottom);
}
} /* 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++;
} }
} }