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authorrubidium <rubidium@openttd.org>2007-08-27 21:18:04 +0000
committerrubidium <rubidium@openttd.org>2007-08-27 21:18:04 +0000
commit5ce935c6ebf8ea88bb28909addbb0ccf937acaba (patch)
treed054ea6d02484291e1b3655d44f6dbc85a1c1f5d
parent68d385b77ca4026acaec6c789ed1ef2905632395 (diff)
downloadopenttd-5ce935c6ebf8ea88bb28909addbb0ccf937acaba.tar.xz
(svn r10991) -Codechange: add documentation, enumification and some code simplifications to the terraforming code. Patch by frosch.
-rw-r--r--src/clear_cmd.cpp166
-rw-r--r--src/industry_cmd.cpp4
-rw-r--r--src/main_gui.cpp4
-rw-r--r--src/town_cmd.cpp1
4 files changed, 122 insertions, 53 deletions
diff --git a/src/clear_cmd.cpp b/src/clear_cmd.cpp
index 134a04c7f..73ab18937 100644
--- a/src/clear_cmd.cpp
+++ b/src/clear_cmd.cpp
@@ -24,26 +24,34 @@
#include "industry.h"
#include "water_map.h"
+static const int TERRAFORMER_MODHEIGHT_SIZE = 576;
+static const int TERRAFORMER_TILE_TABLE_SIZE = 625;
+
struct TerraformerHeightMod {
- TileIndex tile;
- byte height;
+ TileIndex tile; ///< Referenced tile.
+ byte height; ///< New TileHeight (height of north corner) of the tile.
};
struct TerraformerState {
- int height[4];
uint32 flags;
int direction;
- int modheight_count;
- int tile_table_count;
+ int modheight_count; ///< amount of entries in "modheight".
+ int tile_table_count; ///< amount of entries in "tile_table".
CommandCost cost;
- TileIndex *tile_table;
- TerraformerHeightMod *modheight;
-
+ TileIndex tile_table[TERRAFORMER_TILE_TABLE_SIZE]; ///< Dirty tiles, i.e. at least one corner changed.
+ TerraformerHeightMod modheight[TERRAFORMER_MODHEIGHT_SIZE]; ///< Height modifications.
};
+/**
+ * Tests if a tile has already been terraformed.
+ *
+ * @param ts TerraformerState.
+ * @param tile Tile.
+ * @return Tile not yet terraformed (1), tile already terraformed (0), void land (-1).
+ */
static int TerraformAllowTileProcess(TerraformerState *ts, TileIndex tile)
{
TileIndex *t;
@@ -59,6 +67,13 @@ static int TerraformAllowTileProcess(TerraformerState *ts, TileIndex tile)
return 1;
}
+/**
+ * Gets the TileHeight (height of north corner) of a tile as of current terraforming progress.
+ *
+ * @param ts TerraformerState.
+ * @param tile Tile.
+ * @return TileHeight.
+ */
static int TerraformGetHeightOfTile(TerraformerState *ts, TileIndex tile)
{
TerraformerHeightMod *mod = ts->modheight;
@@ -68,9 +83,16 @@ static int TerraformGetHeightOfTile(TerraformerState *ts, TileIndex tile)
if (mod->tile == tile) return mod->height;
}
+ /* TileHeight unchanged so far, read value from map. */
return TileHeight(tile);
}
+/**
+ * Adds a tile to the "tile_table" in a TerraformerState.
+ *
+ * @param ts TerraformerState.
+ * @param tile Tile.
+ */
static void TerraformAddDirtyTile(TerraformerState *ts, TileIndex tile)
{
int count;
@@ -78,15 +100,21 @@ static void TerraformAddDirtyTile(TerraformerState *ts, TileIndex tile)
count = ts->tile_table_count;
- if (count >= 625) return;
-
for (t = ts->tile_table; count != 0; count--, t++) {
if (*t == tile) return;
}
+ assert(ts->tile_table_count < TERRAFORMER_TILE_TABLE_SIZE);
+
ts->tile_table[ts->tile_table_count++] = tile;
}
+/**
+ * Adds all tiles that incident with the north corner of a specific tile to the "tile_table" in a TerraformerState.
+ *
+ * @param ts TerraformerState.
+ * @param tile Tile.
+ */
static void TerraformAddDirtyTileAround(TerraformerState *ts, TileIndex tile)
{
TerraformAddDirtyTile(ts, tile + TileDiffXY( 0, -1));
@@ -95,6 +123,15 @@ static void TerraformAddDirtyTileAround(TerraformerState *ts, TileIndex tile)
TerraformAddDirtyTile(ts, tile);
}
+/**
+ * Checks if a tile can be terraformed.
+ * Extra costs for terraforming (like clearing the tile) are added to ts->cost.
+ *
+ * @param ts TerraformerState.
+ * @param tile Tile.
+ * @param mode Affected corner: 0 = north, 1 = east, 2 = south, 3 = west.
+ * @return 0 on success, else -1
+ */
static int TerraformProc(TerraformerState *ts, TileIndex tile, int mode)
{
int r;
@@ -102,9 +139,11 @@ static int TerraformProc(TerraformerState *ts, TileIndex tile, int mode)
assert(tile < MapSize());
+ /* Check for void land, and if the tile was already involved in a terraforming step, (i.e. is already cleared). */
r = TerraformAllowTileProcess(ts, tile);
if (r <= 0) return r;
+ /* Check if a tile can be terraformed. */
if (IsTileType(tile, MP_RAILWAY)) {
static const TrackBits safe_track[] = { TRACK_BIT_LOWER, TRACK_BIT_LEFT, TRACK_BIT_UPPER, TRACK_BIT_RIGHT };
static const Slope unsafe_slope[] = { SLOPE_S, SLOPE_W, SLOPE_N, SLOPE_E };
@@ -138,6 +177,10 @@ static int TerraformProc(TerraformerState *ts, TileIndex tile, int mode)
_error_message = STR_1002_EXCAVATION_WOULD_DAMAGE;
return -1;
}
+ /* Allow terraforming.
+ * The tile is not added to the "dirty"-list, because it needs to be checked again in further terraforming steps.
+ * However in the end it is missing in the list, so we have to add it later.
+ */
return 0;
}
}
@@ -149,6 +192,7 @@ static int TerraformProc(TerraformerState *ts, TileIndex tile, int mode)
return -1;
}
+ /* Try to clear the tile. If the tile can be cleared, add the cost to the terraforming cost, else the terraforming fails. */
ret = DoCommand(tile, 0, 0, ts->flags & ~DC_EXEC, CMD_LANDSCAPE_CLEAR);
if (CmdFailed(ret)) {
@@ -158,20 +202,26 @@ static int TerraformProc(TerraformerState *ts, TileIndex tile, int mode)
ts->cost.AddCost(ret.GetCost());
- if (ts->tile_table_count >= 625) return -1;
+ /* Add the tile to the "dirty" list. We know already that it is not there, so append it at the end. */
+ assert(ts->tile_table_count < TERRAFORMER_TILE_TABLE_SIZE);
ts->tile_table[ts->tile_table_count++] = tile;
return 0;
}
+/**
+ * Terraform the north corner of a tile to a specific height.
+ *
+ * @param ts TerraformerState.
+ * @param tile Tile.
+ * @param height Aimed height.
+ * @param return true on success.
+ */
static bool TerraformTileHeight(TerraformerState *ts, TileIndex tile, int height)
{
- int nh;
- TerraformerHeightMod *mod;
- int count;
-
assert(tile < MapSize());
+ /* Check range of destination height */
if (height < 0) {
_error_message = STR_1003_ALREADY_AT_SEA_LEVEL;
return false;
@@ -181,50 +231,67 @@ static bool TerraformTileHeight(TerraformerState *ts, TileIndex tile, int height
if (height > MAX_TILE_HEIGHT) return false;
- nh = TerraformGetHeightOfTile(ts, tile);
- if (nh < 0 || height == nh) return false;
+ /*
+ * Check if the terraforming has any effect.
+ * This can only be true, if multiple corners of the start-tile are terraformed (i.e. the terraforming is done by towns/industries etc.).
+ * In this case the terraforming should fail. (Don't know why.)
+ */
+ if (height == TerraformGetHeightOfTile(ts, tile)) return false;
+ /* Check if the incident tiles of the corner can be terraformed. Compute extra costs (like tile clearing) */
if (TerraformProc(ts, tile, 0) < 0) return false;
if (TerraformProc(ts, tile + TileDiffXY( 0, -1), 1) < 0) return false;
if (TerraformProc(ts, tile + TileDiffXY(-1, -1), 2) < 0) return false;
if (TerraformProc(ts, tile + TileDiffXY(-1, 0), 3) < 0) return false;
- mod = ts->modheight;
- count = ts->modheight_count;
+ /* Store the height modification */
- for (;;) {
- if (count == 0) {
- if (ts->modheight_count >= 576) return false;
- ts->modheight_count++;
- break;
- }
- if (mod->tile == tile) break;
+ /* Find tile in the "modheight" table.
+ * Note: In a normal user-terraform command the tile will not be found in the "modheight" table.
+ * But during house- or industry-construction multiple corners can be terraformed at once. */
+ TerraformerHeightMod *mod = ts->modheight;
+ int count = ts->modheight_count;
+ while ((count > 0) && (mod->tile != tile)) {
mod++;
count--;
}
+ /* New entry? */
+ if (count == 0) {
+ assert(ts->modheight_count < TERRAFORMER_MODHEIGHT_SIZE);
+ ts->modheight_count++;
+ }
+
+ /* Finally store the new value */
mod->tile = tile;
mod->height = (byte)height;
+ /* Increment cost */
ts->cost.AddCost(_price.terraform);
+ /* Recurse to neighboured corners if height difference is larger than 1 */
{
- int direction = ts->direction, r;
const TileIndexDiffC *ttm;
static const TileIndexDiffC _terraform_tilepos[] = {
- { 1, 0},
- {-2, 0},
- { 1, 1},
- { 0, -2}
+ { 1, 0}, // move to tile in SE
+ {-2, 0}, // undo last move, and move to tile in NW
+ { 1, 1}, // undo last move, and move to tile in SW
+ { 0, -2} // undo last move, and move to tile in NE
};
for (ttm = _terraform_tilepos; ttm != endof(_terraform_tilepos); ttm++) {
tile += ToTileIndexDiff(*ttm);
- r = TerraformGetHeightOfTile(ts, tile);
- if (r != height && r - direction != height && r + direction != height) {
- if (!TerraformTileHeight(ts, tile, r + direction))
+ /* Get TileHeight of neighboured tile as of current terraform progress */
+ int r = TerraformGetHeightOfTile(ts, tile);
+ int height_diff = height - r;
+
+ /* Is the height difference to the neighboured corner greater than 1? */
+ if (abs(height_diff) > 1) {
+ /* Terraform the neighboured corner. The resulting height difference should be 1. */
+ height_diff += (height_diff < 0 ? 1 : -1);
+ if (!TerraformTileHeight(ts, tile, r + height_diff))
return false;
}
}
@@ -236,8 +303,8 @@ static bool TerraformTileHeight(TerraformerState *ts, TileIndex tile, int height
/** Terraform land
* @param tile tile to terraform
* @param flags for this command type
- * @param p1 corners to terraform.
- * @param p2 direction; eg up or down
+ * @param p1 corners to terraform (SLOPE_xxx)
+ * @param p2 direction; eg up (non-zero) or down (zero)
* @return error or cost of terraforming
*/
CommandCost CmdTerraformLand(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
@@ -246,9 +313,6 @@ CommandCost CmdTerraformLand(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
TileIndex t;
int direction;
- TerraformerHeightMod modheight_data[576];
- TileIndex tile_table_data[625];
-
SET_EXPENSES_TYPE(EXPENSES_CONSTRUCTION);
_terraform_err_tile = 0;
@@ -257,48 +321,48 @@ CommandCost CmdTerraformLand(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
ts.flags = flags;
ts.modheight_count = ts.tile_table_count = 0;
ts.cost = CommandCost();
- ts.modheight = modheight_data;
- ts.tile_table = tile_table_data;
/* Make an extra check for map-bounds cause we add tiles to the originating tile */
if (tile + TileDiffXY(1, 1) >= MapSize()) return CMD_ERROR;
- if (p1 & 1) {
+ /* Compute the costs and the terraforming result in a model of the landscape */
+ if ((p1 & SLOPE_W) != 0) {
t = tile + TileDiffXY(1, 0);
if (!TerraformTileHeight(&ts, t, TileHeight(t) + direction)) {
return CMD_ERROR;
}
}
- if (p1 & 2) {
+ if ((p1 & SLOPE_S) != 0) {
t = tile + TileDiffXY(1, 1);
if (!TerraformTileHeight(&ts, t, TileHeight(t) + direction)) {
return CMD_ERROR;
}
}
- if (p1 & 4) {
+ if ((p1 & SLOPE_E) != 0) {
t = tile + TileDiffXY(0, 1);
if (!TerraformTileHeight(&ts, t, TileHeight(t) + direction)) {
return CMD_ERROR;
}
}
- if (p1 & 8) {
+ if ((p1 & SLOPE_N) != 0) {
t = tile + TileDiffXY(0, 0);
if (!TerraformTileHeight(&ts, t, TileHeight(t) + direction)) {
return CMD_ERROR;
}
}
+ /* Check if the terraforming is valid wrt. tunnels and bridges */
{
- /* Check if tunnel would take damage */
int count;
TileIndex *ti = ts.tile_table;
for (count = ts.tile_table_count; count != 0; count--, ti++) {
TileIndex tile = *ti;
+ /* Find min and max height of tile */
uint z_min = TerraformGetHeightOfTile(&ts, tile + TileDiffXY(0, 0));
uint z_max = z_min;
uint t = TerraformGetHeightOfTile(&ts, tile + TileDiffXY(1, 0));
@@ -311,11 +375,15 @@ CommandCost CmdTerraformLand(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
z_min = min(z_min, t);
z_max = max(z_max, t);
+ /* Check if bridge would take damage */
if (direction == 1 && MayHaveBridgeAbove(tile) && IsBridgeAbove(tile) &&
GetBridgeHeight(GetSouthernBridgeEnd(tile)) <= z_max * TILE_HEIGHT) {
+ _terraform_err_tile = *ti; // highlight the tile under the bridge
return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);
}
+ /* Check if tunnel would take damage */
if (direction == -1 && IsTunnelInWay(tile, z_min * TILE_HEIGHT)) {
+ _terraform_err_tile = *ti; // highlight the tile above the tunnel
return_cmd_error(STR_1002_EXCAVATION_WOULD_DAMAGE);
}
}
@@ -341,7 +409,7 @@ CommandCost CmdTerraformLand(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
TileIndex til = mod->tile;
SetTileHeight(til, mod->height);
- TerraformAddDirtyTileAround(&ts, til);
+ TerraformAddDirtyTileAround(&ts, til); // add the dirty tiles, we forgot above
}
}
@@ -400,7 +468,7 @@ CommandCost CmdLevelLand(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
BEGIN_TILE_LOOP(tile2, size_x, size_y, tile) {
curh = TileHeight(tile2);
while (curh != h) {
- ret = DoCommand(tile2, 8, (curh > h) ? 0 : 1, flags & ~DC_EXEC, CMD_TERRAFORM_LAND);
+ ret = DoCommand(tile2, SLOPE_N, (curh > h) ? 0 : 1, flags & ~DC_EXEC, CMD_TERRAFORM_LAND);
if (CmdFailed(ret)) break;
if (flags & DC_EXEC) {
@@ -409,7 +477,7 @@ CommandCost CmdLevelLand(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
_additional_cash_required = ret.GetCost();
return cost;
}
- DoCommand(tile2, 8, (curh > h) ? 0 : 1, flags, CMD_TERRAFORM_LAND);
+ DoCommand(tile2, SLOPE_N, (curh > h) ? 0 : 1, flags, CMD_TERRAFORM_LAND);
}
cost.AddCost(ret);
diff --git a/src/industry_cmd.cpp b/src/industry_cmd.cpp
index ea9d8401d..6f9eeb8b0 100644
--- a/src/industry_cmd.cpp
+++ b/src/industry_cmd.cpp
@@ -1339,7 +1339,7 @@ static bool CheckIfCanLevelIndustryPlatform(TileIndex tile, uint32 flags, const
if (!CheckCanTerraformSurroundingTiles(tile_walk, h, 0)) return false;
/* This is not 100% correct check, but the best we can do without modifying the map.
* What is missing, is if the difference in height is more than 1.. */
- if (CmdFailed(DoCommand(tile_walk, 8, (curh > h) ? 0 : 1, flags & ~DC_EXEC, CMD_TERRAFORM_LAND))) return false;
+ if (CmdFailed(DoCommand(tile_walk, SLOPE_N, (curh > h) ? 0 : 1, flags & ~DC_EXEC, CMD_TERRAFORM_LAND))) return false;
}
} END_TILE_LOOP(tile_walk, size_x, size_y, cur_tile)
@@ -1351,7 +1351,7 @@ static bool CheckIfCanLevelIndustryPlatform(TileIndex tile, uint32 flags, const
/* We give the terraforming for free here, because we can't calculate
* exact cost in the test-round, and as we all know, that will cause
* a nice assert if they don't match ;) */
- DoCommand(tile_walk, 8, (curh > h) ? 0 : 1, flags, CMD_TERRAFORM_LAND);
+ DoCommand(tile_walk, SLOPE_N, (curh > h) ? 0 : 1, flags, CMD_TERRAFORM_LAND);
curh += (curh > h) ? -1 : 1;
}
} END_TILE_LOOP(tile_walk, size_x, size_y, cur_tile)
diff --git a/src/main_gui.cpp b/src/main_gui.cpp
index e4e20c317..0e0498283 100644
--- a/src/main_gui.cpp
+++ b/src/main_gui.cpp
@@ -1086,7 +1086,7 @@ static void CommonRaiseLowerBigLand(TileIndex tile, int mode)
StringID msg =
mode ? STR_0808_CAN_T_RAISE_LAND_HERE : STR_0809_CAN_T_LOWER_LAND_HERE;
- DoCommandP(tile, 8, (uint32)mode, CcTerraform, CMD_TERRAFORM_LAND | CMD_AUTO | CMD_MSG(msg));
+ DoCommandP(tile, SLOPE_N, (uint32)mode, CcTerraform, CMD_TERRAFORM_LAND | CMD_AUTO | CMD_MSG(msg));
} else {
SndPlayTileFx(SND_1F_SPLAT, tile);
@@ -1113,7 +1113,7 @@ static void CommonRaiseLowerBigLand(TileIndex tile, int mode)
BEGIN_TILE_LOOP(tile2, sizex, sizey, tile) {
if (TileHeight(tile2) == h) {
- DoCommandP(tile2, 8, (uint32)mode, NULL, CMD_TERRAFORM_LAND | CMD_AUTO);
+ DoCommandP(tile2, SLOPE_N, (uint32)mode, NULL, CMD_TERRAFORM_LAND | CMD_AUTO);
}
} END_TILE_LOOP(tile2, sizex, sizey, tile)
}
diff --git a/src/town_cmd.cpp b/src/town_cmd.cpp
index 48b20ffc7..a5247150b 100644
--- a/src/town_cmd.cpp
+++ b/src/town_cmd.cpp
@@ -706,6 +706,7 @@ no_slope:
res = DoCommand(tile, slope, 0, DC_EXEC | DC_AUTO | DC_NO_WATER,
CMD_TERRAFORM_LAND);
} else {
+ /* Note: Do not replace " ^ 0xF" with ComplementSlope(). The slope might be steep. */
res = DoCommand(tile, slope ^ 0xF, 1, DC_EXEC | DC_AUTO | DC_NO_WATER,
CMD_TERRAFORM_LAND);
}