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authorrubidium <rubidium@openttd.org>2014-09-21 17:27:37 +0000
committerrubidium <rubidium@openttd.org>2014-09-21 17:27:37 +0000
commit4d619ad10e8a8b35b96b9772543c8fa46d5beb10 (patch)
tree00c9be1f2a1c49161d0c2655170b202da85e3127
parent8415a159991acd2263607b7d1ed4bfeed802a316 (diff)
downloadopenttd-4d619ad10e8a8b35b96b9772543c8fa46d5beb10.tar.xz
(svn r26899) -Codechange: reduce the amount of tiles that needs to be drawn by taking the height of tiles into account instead of drawing way too many (ic111)
-rw-r--r--src/viewport.cpp549
-rw-r--r--src/viewport_func.h2
2 files changed, 495 insertions, 56 deletions
diff --git a/src/viewport.cpp b/src/viewport.cpp
index bb03355d8..81c630a3a 100644
--- a/src/viewport.cpp
+++ b/src/viewport.cpp
@@ -26,6 +26,48 @@
* \endverbatim
*/
+/**
+ * @defgroup vp_column_row Rows and columns in the viewport
+ *
+ * Columns are vertical sections of the viewport that are half a tile wide.
+ * The origin, i.e. column 0, is through the northern and southern most tile.
+ * This means that the column of e.g. Tile(0, 0) and Tile(100, 100) are in
+ * column number 0. The negative columns are towards the left of the screen,
+ * or towards the west, whereas the positive ones are towards respectively
+ * the right and east.
+ * With half a tile wide is meant that the next column of tiles directly west
+ * or east of the centre line are respectively column -1 and 1. Their tile
+ * centers are only half a tile from the center of their adjoining tile when
+ * looking only at the X-coordinate.
+ *
+ * \verbatim
+ * ╳ *
+ * ╱ ╲ *
+ * ╳ 0 ╳ *
+ * ╱ ╲ ╱ ╲ *
+ * ╳-1 ╳ 1 ╳ *
+ * ╱ ╲ ╱ ╲ ╱ ╲ *
+ * ╳-2 ╳ 0 ╳ 2 ╳ *
+ * ╲ ╱ ╲ ╱ ╲ ╱ *
+ * ╳-1 ╳ 1 ╳ *
+ * ╲ ╱ ╲ ╱ *
+ * ╳ 0 ╳ *
+ * ╲ ╱ *
+ * ╳ *
+ * \endverbatim
+ *
+ *
+ * Rows are horizontal sections of the viewport, also half a tile wide.
+ * This time the nothern most tile on the map at height level 0 defines 0 and
+ * everything south of that has a positive number. In theory this works the
+ * same as for columns with the massive difference that due to the isometric
+ * projection the actual row where the tile is visible differs from the row
+ * where the tile would be if it were at height level 0. Strictly speaking,
+ * if you know the row of the tile at height level 0, then the row number
+ * where it is actually drawn is tile height / 2 lower than the row number
+ * of the same tile at height level 0.
+ */
+
#include "stdafx.h"
#include "landscape.h"
#include "viewport_func.h"
@@ -47,6 +89,9 @@
#include "window_gui.h"
#include "linkgraph/linkgraph_gui.h"
#include "viewport_sprite_sorter.h"
+#include "bridge_map.h"
+
+#include <map>
#include "table/strings.h"
#include "table/palettes.h"
@@ -1022,81 +1067,473 @@ draw_inner:
}
}
-static void ViewportAddLandscape()
+/**
+ * Given a screen coordinate (x,y) as e.g. stored in _vd.dpi, this function
+ * returns the tile coordinate of the tile which would be painted at (x,y)
+ * if one assumes height zero at that position.
+ * @param x Some x screen coordinate
+ * @param y Some y screen coordinate
+ * @return Tile coordinate assuming height zero as described
+ */
+static inline Point GetTileCoordFromScreenCoord(int x, int y)
{
- int x, y, width, height;
- TileInfo ti;
- bool direction;
+ /* First convert from the screen coordinate system (where the width of tiles
+ * is twice their height) to the tile coordinate system. That means, turn
+ * around by 45 degrees and make the tiles quadratic. */
+ Point tile_coord = InverseRemapCoords(x, y);
- _cur_ti = &ti;
+ /* Scale from a 16x16-grid to a 1x1-grid as returned by TileX/TileY. */
+ tile_coord.x /= (int)TILE_SIZE;
+ tile_coord.y /= (int)TILE_SIZE;
- /* Transform into tile coordinates and round to closest full tile */
- x = ((_vd.dpi.top >> (1 + ZOOM_LVL_SHIFT)) - (_vd.dpi.left >> (2 + ZOOM_LVL_SHIFT))) & ~TILE_UNIT_MASK;
- y = ((_vd.dpi.top >> (1 + ZOOM_LVL_SHIFT)) + (_vd.dpi.left >> (2 + ZOOM_LVL_SHIFT)) - TILE_SIZE) & ~TILE_UNIT_MASK;
+ return tile_coord;
+}
- /* determine size of area */
- {
- Point pt = RemapCoords(x, y, 241);
- width = (_vd.dpi.left + _vd.dpi.width - pt.x + 96 * ZOOM_LVL_BASE - 1) >> (6 + ZOOM_LVL_SHIFT);
- height = (_vd.dpi.top + _vd.dpi.height - pt.y) >> (5 + ZOOM_LVL_SHIFT) << 1;
+/**
+ * Assume a region, given by screen coordinates (x1,y1,x2,y2), as defined in _vd.dpi.
+ * This function basically takes (x1,y1) (i.e. the upper left corner of that region)
+ * and returns the tile coordinate of the tile, which would be painted at (x1,y1)
+ * if one assumes height zero at that position.
+ *
+ * However, in detail: Imagine tiles being split up into their upper left,upper right,
+ * etc. isometric sections. We return a tile where the upper left corner of the
+ * mentioned region is either in its lower right section or in a neighbor tile
+ * below / right of that section. By doing so, we want to enforce that we can
+ * travel to east or south from that point without leaving the region again.
+ *
+ * @param x Some x screen coordinate, x1 in terms of the description above
+ * @param y Some y screen coordinate, y1 in terms of the description above
+ * @return Upper left corner of the region as tile coordinates.
+ */
+static Point GetMinTileCoordsIgnoringHeight(int x, int y)
+{
+ Point tile_coord = GetTileCoordFromScreenCoord(x, y);
+
+ /* Expand area to be painted in order to avoid situations
+ * where south or east of the to be painted point in dpi are tiles
+ * which will not be painted. */
+ tile_coord.y--;
+
+ return tile_coord;
+}
+
+/**
+ * Assume a region, given by screen coordinates (x1,y1,x2,y2), as defined in _vd.dpi.
+ * This function basically takes (x2,y2) (i.e. the lower right corner of that region)
+ * and returns the tile coordinate of the tile, which would be painted at (x2,y2)
+ * if one assumes height zero at that position.
+ *
+ * However, in detail: Imagine tiles being split up into their upper left,upper right,
+ * etc. isometric sections. We return a tile where the lower right corner of the
+ * mentioned region is either in its upper left section or in a neighbor tile
+ * above / left of that section. By doing so, we want to enforce that we can
+ * travel to north or west from that point without leaving the region again.
+ *
+ * @param x Some x screen coordinate, x2 in terms of the description above
+ * @param y Some y screen coordinate, y2 in terms of the description above
+ * @return Upper left corner of the region as tile coordinates.
+ */
+static Point GetMaxTileCoordsIgnoringHeight(int x, int y)
+{
+ Point tile_coord = GetTileCoordFromScreenCoord(x, y);
+
+ /* Expand area to be painted to southeast in order to avoid situations
+ * where north or east of the given to be painted point in dpi are
+ * tiles which will not be repainted. */
+ tile_coord.y++;
+
+ return tile_coord;
+}
+
+/**
+ * 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 int GetViewportY(Point tile)
+{
+ return (tile.y * TILE_SIZE + tile.x * TILE_SIZE - GetTileMaxPixelZOutsideMap(tile.x, tile.y)) << ZOOM_LVL_SHIFT;
+}
+
+/**
+ * Given a tile coordinate as returned by TileX / TileY, this returns its column.
+ *
+ * @param tile_coord The coordinate of the tile.
+ * @return The column index.
+ * @ingroup vp_column_row
+ */
+static int GetTileColumnFromTileCoord(Point tile_coord)
+{
+ return tile_coord.y - tile_coord.x;
+}
+
+/**
+ * Returns the position of the tile at the northern end of the column of the
+ * given tile.
+ * @param tile Any tile.
+ * @return Position of the tile at the northern end of the column as described.
+ * @ingroup vp_column_row
+ */
+static Point GetNorthernEndOfColumn(Point tile)
+{
+ Point northern_end;
+
+ if (tile.x < tile.y) {
+ northern_end.x = 0;
+ northern_end.y = tile.y - tile.x;
+ } else {
+ northern_end.x = tile.x - tile.y;
+ northern_end.y = 0;
}
- assert(width > 0);
- assert(height > 0);
+ return northern_end;
+}
+
+/**
+ * Returns the position of the tile at the southern end of the column of the
+ * given tile, if it is within the given limit expressed in number of tiles
+ * @param tile Any tile.
+ * @param limit Number of tiles to go to south at most, if the southern end is
+ * further away, stop after that number of tiles
+ * @return Position of the tile at the soutern end of the column as described.
+ * @ingroup vp_column_row
+ */
+static Point GetSouthernEndOfColumnWithLimit(Point tile, uint limit)
+{
+ Point distance_to_end;
+ distance_to_end.x = (int)MapMaxX() - tile.x;
+ distance_to_end.y = (int)MapMaxY() - tile.y;
+
+ Point southern_end;
+ if (distance_to_end.x < distance_to_end.y) {
+ int number_of_steps = min(limit, distance_to_end.x);
+ southern_end.x = tile.x + number_of_steps;
+ southern_end.y = tile.y + number_of_steps;
+ } else {
+ int number_of_steps = min(limit, distance_to_end.y);
+ southern_end.x = tile.x + number_of_steps;
+ southern_end.y = tile.y + number_of_steps;
+ }
+
+ return southern_end;
+}
+
+/**
+ * Returns the position of the tile at the southern end of the column of the
+ * given tile.
+ * @param tile Any tile.
+ * @return Position of the tile at the soutern end of the column as described.
+ * @ingroup vp_column_row
+ */
+static Point GetSouthernEndOfColumn(Point tile)
+{
+ return GetSouthernEndOfColumnWithLimit(tile, UINT32_MAX);
+}
+
+/**
+ * Returns the tile exactly in the middle between two given tiles.
+ *
+ * @param tile Point upper_tile, any tile.
+ * @param tile Point lower_tile, any tile.
+ * @return The tile in the middle of Point upper_tile and Point lower_tile.
+ */
+static Point GetMiddleTile(Point upper_tile, Point lower_tile)
+{
+ Point middle_tile;
+ middle_tile.x = (lower_tile.x + upper_tile.x) / 2;
+ middle_tile.y = (lower_tile.y + upper_tile.y) / 2;
+ return middle_tile;
+}
- direction = false;
+/**
+ * Given a tile coordinate assuming height zero, this returns the row actually
+ * painted at this tile coordinate if one recognizes height.
+ *
+ * The problem concerning this calculation is that we have not enough
+ * information to calculate this in one closed formula. Which row we
+ * search rather depends on the height distribution on the map. So
+ * we have to search.
+ *
+ * First, the searched tile may be located outside map. Then, we know
+ * that we are not too far outside map, so we can step tile by tile,
+ * starting at the given tile, until we have passed the searched tile.
+ *
+ * If the searched tile is inside map, searching is more difficult. A
+ * linear search on some thousand tiles would be not that efficient. But,
+ * we can solve the problem by interval intersection. We know for sure,
+ * that the searched tile is south of the given tile, simply because
+ * mountains of height > 0 (and we have only such mountains) are always
+ * painted north of their tile. So we choose a tile half way between the
+ * given tile and the southern end of the map, have a look whether it is
+ * north or south of the given position, and intersect again. Until
+ * our interval has length 1, then we take the upper one.
+ *
+ * @param viewport_y The viewport y corresponding to tile, if one assumes height zero for that tile
+ * @param tile Some tile coordinate assuming height zero.
+ * @param bridge_correct If true, consider bridges south of the calculated tile, and if the bridge
+ * visually intersect the calculated tile, shift it southwards.
+ * @return The row which is painted at this coordinate, according to the discussion above.
+ * @ingroup vp_column_row
+ */
+int GetRowAtTile(int viewport_y, Point tile, bool bridge_correct)
+{
+ Point northern_tile = GetNorthernEndOfColumn(tile);
+ Point southern_tile = GetSouthernEndOfColumn(tile);
- int min_xy = _settings_game.construction.freeform_edges ? TILE_SIZE : 0;
+ int northern_tile_viewport_y = GetViewportY(northern_tile);
+ int southern_tile_viewport_y = GetViewportY(southern_tile);
+
+ if (northern_tile_viewport_y >= viewport_y) {
+ /* We are north of the map, search tile by tile with direction north. */
+ while (northern_tile_viewport_y >= viewport_y) {
+ northern_tile.x--;
+ northern_tile.y--;
+ northern_tile_viewport_y = GetViewportY(northern_tile);
+ }
+ return northern_tile.x + northern_tile.y;
+ }
+
+ if (southern_tile_viewport_y <= viewport_y) {
+ /* We are south of the map, search tile by tile with direction south. */
+ while (southern_tile_viewport_y <= viewport_y) {
+ southern_tile.x++;
+ southern_tile.y++;
+ southern_tile_viewport_y = GetViewportY(southern_tile);
+ }
+ return southern_tile.x + southern_tile.y;
+ }
+
+ /*
+ * We are inside the map. The searched tile is at most
+ * <maximum heightlevel / 4> tiles south of the given tile (as one tile
+ * painted on the screen needs as much vertical space as painting a tile
+ * by 4 heightlevels ascended). Add one to avoid rounding errors to the
+ * wrong side.
+ *
+ * Invariant in the code below: The searched tile shown at viewport_y
+ * always is between upper_tile and lower_tile.
+ */
+ Point upper_tile = tile;
+ Point lower_tile = GetSouthernEndOfColumnWithLimit(upper_tile, _settings_game.construction.max_heightlevel / 4 + 1);
+ int middle_bound;
do {
- int width_cur = width;
- int x_cur = x;
- int y_cur = y;
+ Point middle_tile = GetMiddleTile(upper_tile, lower_tile);
+ middle_bound = GetViewportY(middle_tile);
- do {
- TileType tt;
- ti.x = x_cur;
- ti.y = y_cur;
-
- if (IsInsideMM(x_cur, min_xy, MapMaxX() * TILE_SIZE) &&
- IsInsideMM(y_cur, min_xy, MapMaxY() * TILE_SIZE)) {
- ti.tile = TileVirtXY(x_cur, y_cur);
- ti.tileh = GetTilePixelSlope(ti.tile, &ti.z);
- tt = GetTileType(ti.tile);
- } else {
- /* We are outside the map => paint black. */
- ti.tile = 0;
- ti.tileh = GetTilePixelSlopeOutsideMap(x_cur / (int)TILE_SIZE, y_cur / (int)TILE_SIZE, &ti.z);
- tt = MP_VOID;
+ if (middle_bound >= viewport_y) {
+ /* The tile shown at viewport_y is somewhere in the upper half of
+ * the currently observed section. */
+ lower_tile = middle_tile;
+ } else {
+ /* The tile shown at viewport_y is somewhere in the lower half of
+ * the currently observed section. */
+ upper_tile = middle_tile;
+ }
+ }
+ while (lower_tile.y - upper_tile.y > 1);
+
+ /* Now our interval has length 1, so only contains two tiles, and we take the upper one.
+ * However, there is one problem left: Tiles being located southwards, containing a high bridge.
+ * They may, though not high enough in terms of landscape, intersect the drawing area with parts
+ * of the bridge.
+ * Luckily, there is a guaranteed upper bound for bridge height, thus we know how far we have to
+ * search southwards whether such a bridge exists.
+ */
+ int correction_step = 0;
+ if (bridge_correct) {
+ /* Calculate, how many tiles below upper_tile, a worst case bridge intersecting upper_tile in
+ * terms of painting can be located. Lets inspect that formula in detail:
+ * ... - 5: The magic constant near the beginning of ViewportAddLandscape accounts for 5 harmless heightlevels a bridge can have. Thus subtract them.
+ * ... / 2: Four heightlevels account for one tile height. On the other hand, if landscape ascends from upper_tile southwards, this can account for
+ * as many additional heightlevels as we step southwards. In combination: A division by two gains the number of tiles to step southwards.
+ * ... + 1: Avoid rounding errors, and fall back to the safe side.
+ */
+ int worst_case_steps_southwards = max(0, ((int)_settings_game.construction.max_bridge_height - 5) / 2 + 1);
+ for (int n = 0; n < worst_case_steps_southwards; n++) {
+ TileIndex potential_bridge_tile = TileXY(upper_tile.x + n, upper_tile.y + n);
+ if (IsValidTile(potential_bridge_tile) && IsBridgeAbove(potential_bridge_tile)) {
+ /* There is a bridge. */
+ TileIndex bridge_start = GetNorthernBridgeEnd(potential_bridge_tile);
+ int bridge_height = GetBridgeHeight(bridge_start);
+ int upper_tile_height = GetTileZ(TileXY(upper_tile.x, upper_tile.y));
+
+ /* Start at the bridge level, descend by the number of heightlevels equivalent to our steps southwards (in worst case), subtract the harmless
+ * bridge heightlevels, and compare whether we are still above the height of the upper_tile. If yes, we need to paint that tile, to avoid glitches.
+ */
+ if (bridge_height - 2 * n - 1 > upper_tile_height) {
+ correction_step = n;
+ }
}
+ }
+ }
- _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;
+ /* The biggest recorded correction_step defines, which tile we actually return. */
+ upper_tile.x += correction_step;
+ upper_tile.y += correction_step;
- _tile_type_procs[tt]->draw_tile_proc(&ti);
+ /* Returns its row. */
+ return upper_tile.x + upper_tile.y;
+}
- if (((uint)x_cur == MapMaxX() * TILE_SIZE && IsInsideMM(y_cur, 0, MapMaxY() * TILE_SIZE + 1)) ||
- ((uint)y_cur == MapMaxY() * TILE_SIZE && IsInsideMM(x_cur, 0, MapMaxX() * TILE_SIZE + 1))) {
- TileIndex tile = TileVirtXY(x_cur, y_cur);
- ti.tile = tile;
- ti.tileh = GetTilePixelSlope(tile, &ti.z);
- tt = GetTileType(tile);
- }
- if (ti.tile != INVALID_TILE) DrawTileSelection(&ti);
+/**
+ * Returns the bottom tile of the column of upper_tile shown on the viewport,
+ * given upper_tile and the lower right tile shown on the viewport.
+ *
+ * @param upper_tile Sny tile inside the map.
+ * @param lower_right_tile The tile shown at the southeast edge of the viewport
+ * (ignoring height). Note that this tile may be located
+ * northeast of the upper_tile, because upper_tile is usually
+ * calculated by shifting a tile southwards until we reach
+ * the northern map border.
+ * @return The lowest existing tile located in the column defined by upper_tile,
+ * which is in the same row as lower_right_tile or above that row
+ * If lower_right_tile was northeast of upper_tile, (-1,-1) is returned.
+ * @ingroup vp_column_row
+ */
+static Point GetBottomTileOfColumn(Point upper_tile, Point lower_right_tile)
+{
+ int upper_row = upper_tile.x + upper_tile.y;
+ int lower_row = lower_right_tile.x + lower_right_tile.y;
+
+ assert(upper_row <= lower_row);
+
+ int number_of_rows = lower_row - upper_row;
+
+ if (number_of_rows % 2 != 0) {
+ /* Avoid 0.5 being rounded down to zero; painting too much is better than
+ * painting too little. */
+ number_of_rows++;
+ }
+
+ Point bottom_tile;
+ bottom_tile.x = upper_tile.x + number_of_rows / 2;
+ bottom_tile.y = upper_tile.y + number_of_rows / 2;
+
+ int bottom_row = bottom_tile.x + bottom_tile.y;
- y_cur += 0x10;
- x_cur -= 0x10;
- } while (--width_cur);
+ assert(bottom_row >= lower_row);
- if ((direction ^= 1) != 0) {
- y += 0x10;
+ return bottom_tile;
+}
+
+/**
+ * Add the landscape to the viewport, i.e. all ground tiles and buildings.
+ */
+static void ViewportAddLandscape()
+{
+ assert(_vd.dpi.top <= _vd.dpi.top + _vd.dpi.height);
+ assert(_vd.dpi.left <= _vd.dpi.left + _vd.dpi.width);
+
+ /* The upper and lower edge of the viewport part to paint. Add some number
+ * of pixels to the lower end in order to ensure that we also take tiles
+ * south of the given area, but with high buildings intersecting the area.
+ * Subtract some pixels from the upper end in order to avoid glitches at the
+ * upper end of the top be painted area. */
+ int viewport_top = _vd.dpi.top - 16;
+ int viewport_bottom = _vd.dpi.top + _vd.dpi.height + 116;
+
+ /* First get the position of the tile at the upper left / lower right edge,
+ * for now ignoring the height. (i.e. assuming height zero.) */
+ Point upper_left_tile = GetMinTileCoordsIgnoringHeight(_vd.dpi.left, viewport_top);
+ Point lower_right_tile = GetMaxTileCoordsIgnoringHeight(_vd.dpi.left + _vd.dpi.width, viewport_bottom);
+
+ /* Calculate the bounding columns. We won't need to draw anything
+ * left / right of them. */
+ int left_column = GetTileColumnFromTileCoord(upper_left_tile);
+ /* Correction to avoid glitches when approaching the left edge of the map. */
+ left_column--;
+ int right_column = GetTileColumnFromTileCoord(lower_right_tile);
+ right_column++;
+
+ /* For each column, calculate the top and the bottom row. These are the
+ * bounding rows for that specific column. */
+ int *top_row = AllocaM(int, right_column - left_column + 1); // Pre-allocate memory for visual studio/express to be able to compile.
+ int *bottom_row = AllocaM(int, right_column - left_column + 1); // Pre-allocate memory for visual studio/express to be able to compile.
+ int min_top_row = MapMaxX() + MapMaxY();
+ int max_bottom_row = 0;
+ Point top_tile_of_column = upper_left_tile;
+
+ /* And now for each column, determine the top and the bottom row we must paint. */
+ bool south_east_direction = false;
+ for (int x = left_column; x <= right_column; x++) {
+ Point bottom_tile_of_column = GetBottomTileOfColumn(top_tile_of_column, lower_right_tile);
+
+ /* And then actually find out the top and the bottom row. Note that
+ * top_tile_of_column and bottom_tile_of_column may be outside the map here.
+ * This possibility is needed, otherwise we couldn't paint the black area
+ * outside the map (and in particular the edge of map) properly.
+ * Subtract three / add one to avoid glitches. */
+ top_row[x - left_column] = GetRowAtTile(viewport_top, top_tile_of_column, false);
+
+ top_row[x - left_column] -= 3;
+ bottom_row[x - left_column] = GetRowAtTile(viewport_bottom, bottom_tile_of_column, true);
+ bottom_row[x - left_column]++;
+
+ /* We never paint things in rows < min_top_row or > max_bottom_row. */
+ min_top_row = min(min_top_row, top_row[x - left_column]);
+ max_bottom_row = max(max_bottom_row, bottom_row[x - left_column]);
+
+ /* Go to next column in the east. */
+ if (south_east_direction) {
+ top_tile_of_column.y++;
} else {
- x += 0x10;
+ top_tile_of_column.x--;
}
- } while (--height);
+
+ /* Switch between directions southeast and northeast. */
+ south_east_direction = !south_east_direction;
+ }
+
+ for (int row = min_top_row; row <= max_bottom_row; row++) {
+ for (int column = left_column; column <= right_column; column++) {
+ /* For each column, we only paint the interval top_row .. bottom_row.
+ * Due to the division by two below, even and odd values of row + column map to
+ * the same (x,y) combinations. Thus, we only paint one of them. */
+ if (((row + column) % 2 == 0) &&
+ (top_row[column - left_column] <= row) &&
+ (row <= bottom_row[column - left_column])) {
+ TileType tile_type;
+ TileInfo tile_info;
+ _cur_ti = &tile_info;
+
+ /* column = y - x; row = x + y; now solve the equation system
+ * for x and y. */
+ int x = (row - column) / 2;
+ int y = (row + column) / 2;
+ tile_info.x = x;
+ tile_info.y = y;
+
+ /* For some strange reason, those fields inside tile_info are uints. However,
+ * in the old code their copies in an int variable where compared against zero. */
+ if (0 < x && x < (int)MapMaxX() && 0 < y && y < (int)MapMaxY()) {
+ /* We are inside the map => paint landscape. */
+ tile_info.tile = TileXY(tile_info.x, tile_info.y);
+ tile_info.tileh = GetTilePixelSlope(tile_info.tile, &tile_info.z);
+ tile_type = GetTileType(tile_info.tile);
+ } else {
+ /* We are outside the map => paint black. */
+ tile_info.tile = INVALID_TILE;
+ tile_info.tileh = GetTilePixelSlopeOutsideMap(tile_info.x, tile_info.y, &tile_info.z);
+ tile_type = MP_VOID;
+ }
+
+ /* Scale to 16x16 tiles, needed for the drawing procedures called below. */
+ tile_info.x *= TILE_SIZE;
+ tile_info.y *= TILE_SIZE;
+
+ _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);
+ DrawTileSelection(&tile_info);
+ }
+ }
+ }
}
/**
diff --git a/src/viewport_func.h b/src/viewport_func.h
index 7d86dda98..7eba50853 100644
--- a/src/viewport_func.h
+++ b/src/viewport_func.h
@@ -79,6 +79,8 @@ extern Point _tile_fract_coords;
void MarkTileDirtyByTile(TileIndex tile);
+int GetRowAtTile(int viewport_y, Point tile, bool bridge_correct);
+
Point GetViewportStationMiddle(const ViewPort *vp, const Station *st);
#endif /* VIEWPORT_FUNC_H */