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(svn r26910) -Fix: account for the height of the landscape at the edge of the map to determine the scroll boundaries (based on patch by ic111)

release/1.5
rubidium 2014-09-22 18:14:44 +00:00
parent 56ebc4d06e
commit a229fb79b5
1 changed files with 105 additions and 4 deletions
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109
src/viewport.cpp
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@ -1990,8 +1990,97 @@ void Window::DrawViewport() const
dpi->top -= this->top;
}
/**
* Continue criteria for the SearchMapEdge function.
* @param iter Value to check.
* @param iter_limit Maximum value for the iter
* @param sy Screen y coordinate calculated for the tile at hand
* @param sy_limit Limit to the screen y coordinate
* @return True when we should continue searching.
*/
typedef bool ContinueMapEdgeSearch(int iter, int iter_limit, int sy, int sy_limit);
/** Continue criteria for searching a no-longer-visible tile in negative direction, starting at some tile. */
static inline bool ContinueLowerMapEdgeSearch(int iter, int iter_limit, int sy, int sy_limit) { return iter > 0 && sy > sy_limit; }
/** Continue criteria for searching a no-longer-visible tile in positive direction, starting at some tile. */
static inline bool ContinueUpperMapEdgeSearch(int iter, int iter_limit, int sy, int sy_limit) { return iter < iter_limit && sy < sy_limit; }
/**
* Searches, starting at the given tile, by applying the given offset to iter, for a no longer visible tile.
* The whole sense of this function is keeping the to-be-written code small, thus it is a little bit abstracted
* so the same function can be used for both the X and Y locations. As such a reference to one of the elements
* in curr_tile was needed.
* @param curr_tile A tile
* @param iter Reference to either the X or Y of curr_tile.
* @param iter_limit Upper search limit for the iter value.
* @param offset Search in steps of this size
* @param sy_limit Search limit to be passed to the criteria
* @param continue_criteria Search as long as this criteria is true
* @return The final value of iter.
*/
static int SearchMapEdge(Point &curr_tile, int &iter, int iter_limit, int offset, int sy_limit, ContinueMapEdgeSearch continue_criteria)
{
int sy;
do {
iter = Clamp(iter + offset, 0, iter_limit);
sy = GetViewportY(curr_tile);
} while (continue_criteria(iter, iter_limit, sy, sy_limit));
return iter;
}
/**
* Determine the clamping of either the X or Y coordinate to the map.
* @param curr_tile A tile
* @param iter Reference to either the X or Y of curr_tile.
* @param iter_limit Upper search limit for the iter value.
* @param start Start value for the iteration.
* @param other_ref Reference to the opposite axis in curr_tile than of iter.
* @param other_value Start value for of the opposite axis
* @param vp_value Value of the viewport location in the opposite axis as for iter.
* @param other_limit Limit for the other value, so if iter is X, then other_limit is for Y.
* @param vp_top Top of the viewport.
* @param vp_bottom Bottom of the viewport.
* @return Clamped version of vp_value.
*/
static inline int ClampXYToMap(Point &curr_tile, int &iter, int iter_limit, int start, int &other_ref, int other_value, int vp_value, int other_limit, int vp_top, int vp_bottom)
{
bool upper_edge = other_value < _settings_game.construction.max_heightlevel / 4;
/*
* First get an estimate of the tiles relevant for us at that edge. Relevant in the sense
* "at least close to the visible area".Thus, we don´t look at exactly each tile, inspecting
* e.g. every tenth should be enough. After all, the desired screen limit is set such that
* the bordermost tiles are painted in the middle of the screen when one hits the limit,
* i.e. it is no harm if there is some small error in that calculation
*/
other_ref = upper_edge ? 0 : other_limit;
iter = start;
int min_iter = SearchMapEdge(curr_tile, iter, iter_limit, upper_edge ? -10 : +10, vp_top, upper_edge ? ContinueLowerMapEdgeSearch : ContinueUpperMapEdgeSearch);
iter = start;
int max_iter = SearchMapEdge(curr_tile, iter, iter_limit, upper_edge ? +10 : -10, vp_bottom, upper_edge ? ContinueUpperMapEdgeSearch : ContinueLowerMapEdgeSearch);
max_iter = min(max_iter + _settings_game.construction.max_heightlevel / 4, iter_limit);
min_iter = min(min_iter, max_iter);
/* Now, calculate the highest heightlevel of these tiles. Again just as an estimate. */
int max_heightlevel_at_edge = 0;
for (iter = min_iter; iter <= max_iter; iter += 10) {
max_heightlevel_at_edge = max(max_heightlevel_at_edge, (int)TileHeight(TileXY(curr_tile.x, curr_tile.y)));
}
/* Based on that heightlevel, calculate the limit. For the upper edge a tile with height zero would
* get a limit of zero, on the other side it depends on the number of tiles along the axis. */
return upper_edge ?
max(vp_value, -max_heightlevel_at_edge * (int)(TILE_HEIGHT * 2 * ZOOM_LVL_BASE)) :
min(vp_value, (other_limit * TILE_SIZE * 4 - max_heightlevel_at_edge * TILE_HEIGHT * 2) * ZOOM_LVL_BASE);
}
static inline void ClampViewportToMap(const ViewPort *vp, int &x, int &y)
{
int original_y = y;
/* Centre of the viewport is hot spot */
x += vp->virtual_width / 2;
y += vp->virtual_height / 2;
@ -2001,9 +2090,14 @@ static inline void ClampViewportToMap(const ViewPort *vp, int &x, int &y)
int vx = -x + y * 2;
int vy = x + y * 2;
/* clamp to size of map */
vx = Clamp(vx, 0, MapMaxX() * TILE_SIZE * 4 * ZOOM_LVL_BASE);
vy = Clamp(vy, 0, MapMaxY() * TILE_SIZE * 4 * ZOOM_LVL_BASE);
/* Find out which tile corresponds to (vx,vy) if one assumes height zero. The cast is necessary to prevent C++ from
* converting the result to an uint, which gives an overflow instead of a negative result... */
int tx = vx / (int)(TILE_SIZE * 4 * ZOOM_LVL_BASE);
int ty = vy / (int)(TILE_SIZE * 4 * ZOOM_LVL_BASE);
Point curr_tile;
vx = ClampXYToMap(curr_tile, curr_tile.y, MapMaxY(), ty, curr_tile.x, tx, vx, MapMaxX(), original_y, original_y + vp->virtual_height);
vy = ClampXYToMap(curr_tile, curr_tile.x, MapMaxX(), tx, curr_tile.y, ty, vy, MapMaxY(), original_y, original_y + vp->virtual_height);
/* Convert map coordinates to viewport coordinates */
x = (-vx + vy) / 2;
@ -2450,7 +2544,14 @@ void RebuildViewportOverlay(Window *w)
bool ScrollWindowTo(int x, int y, int z, Window *w, bool instant)
{
/* The slope cannot be acquired outside of the map, so make sure we are always within the map. */
if (z == -1) z = GetSlopePixelZ(Clamp(x, 0, MapSizeX() * TILE_SIZE - 1), Clamp(y, 0, MapSizeY() * TILE_SIZE - 1));
if (z == -1) {
if ( x >= 0 && x <= (int)MapSizeX() * (int)TILE_SIZE - 1
&& y >= 0 && y <= (int)MapSizeY() * (int)TILE_SIZE - 1) {
z = GetSlopePixelZ(x, y);
} else {
z = TileHeightOutsideMap(x / TILE_SIZE, y / TILE_SIZE);
}
}
Point pt = MapXYZToViewport(w->viewport, x, y, z);
w->viewport->follow_vehicle = INVALID_VEHICLE;