cpp/openttd-patchpack/source Changeset - r22758:0aeaa5bf84b8

Changeset - r22758:0aeaa5bf84b8

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frosch - 6 years ago 2018-03-11 13:23:26
frosch@openttd.org

(svn r27986) -Codechange: Name magic constants in the vehicle position hash functions.

2 files changed with 37 insertions and 12 deletions:

src/tile_type.h

src/vehicle.cpp

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src/tile_type.h

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@@ @@ -18,6 +18,8 @@ static const uint TILE_PIXELS = @@
 static const uint TILE_HEIGHT         =  8;                    ///< Height of a height level in world coordinate AND in pixels in #ZOOM_LVL_BASE.
 static const uint MAX_BUILDING_PIXELS = 200;                   ///< Maximum height of a building in pixels in #ZOOM_LVL_BASE. (Also applies to "bridge buildings" on the bridge floor.)
 static const int MAX_VEHICLE_PIXEL_X  = 70;                    ///< Maximum width of a vehicle in pixels in #ZOOM_LVL_BASE.
 static const int MAX_VEHICLE_PIXEL_Y  = 70;                    ///< Maximum height of a vehicle in pixels in #ZOOM_LVL_BASE.
 static const uint MAX_TILE_HEIGHT     = 255;                   ///< Maximum allowed tile height

src/vehicle.cpp

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@@ @@ -57,7 +57,30 @@ @@
 #include "safeguards.h"
 #define GEN_HASH(x, y) ((GB((y), 6 + ZOOM_LVL_SHIFT, 6) << 6) + GB((x), 7 + ZOOM_LVL_SHIFT, 6))
 /* Number of bits in the hash to use from each vehicle coord */
 static const uint GEN_HASHX_BITS = 6;
 static const uint GEN_HASHY_BITS = 6;
 /* Size of each hash bucket */
 static const uint GEN_HASHX_BUCKET_BITS = 7;
 static const uint GEN_HASHY_BUCKET_BITS = 6;
 /* Compute hash for vehicle coord */
 #define GEN_HASHX(x)    GB((x), GEN_HASHX_BUCKET_BITS + ZOOM_LVL_SHIFT, GEN_HASHX_BITS)
 #define GEN_HASHY(y)   (GB((y), GEN_HASHY_BUCKET_BITS + ZOOM_LVL_SHIFT, GEN_HASHY_BITS) << GEN_HASHX_BITS)
 #define GEN_HASH(x, y) (GEN_HASHY(y) + GEN_HASHX(x))
 /* Maximum size until hash repeats */
 static const int GEN_HASHX_SIZE = 1 << (GEN_HASHX_BUCKET_BITS + GEN_HASHX_BITS + ZOOM_LVL_SHIFT);
 static const int GEN_HASHY_SIZE = 1 << (GEN_HASHY_BUCKET_BITS + GEN_HASHY_BITS + ZOOM_LVL_SHIFT);
 /* Increments to reach next bucket in hash table */
 static const int GEN_HASHX_INC = 1;
 static const int GEN_HASHY_INC = 1 << GEN_HASHX_BITS;
 /* Mask to wrap-around buckets */
 static const uint GEN_HASHX_MASK =  (1 << GEN_HASHX_BITS) - 1;
 static const uint GEN_HASHY_MASK = ((1 << GEN_HASHY_BITS) - 1) << GEN_HASHX_BITS;
 VehicleID _new_vehicle_id;
 uint16 _returned_refit_capacity;      ///< Stores the capacity after a refit operation.
@@ @@ -618,7 +641,7 @@ static void UpdateVehicleTileHash(Vehicl @@
 	v->hash_tile_current = new_hash;
+}
-static Vehicle *_vehicle_viewport_hash[0x1000];
+static Vehicle *_vehicle_viewport_hash[1 << (GEN_HASHX_BITS + GEN_HASHY_BITS)];
 static void UpdateVehicleViewportHash(Vehicle *v, int x, int y)
+{
@@ @@ -1088,26 +1111,26 @@ void ViewportAddVehicles(DrawPixelInfo * @@
 	/* The hash area to scan */
 	int xl, xu, yl, yu;
 	if (dpi->width + (70 * ZOOM_LVL_BASE) < (1 << (7 + 6 + ZOOM_LVL_SHIFT))) {
 		xl = GB(l - (70 * ZOOM_LVL_BASE), 7 + ZOOM_LVL_SHIFT, 6);
 		xu = GB(r,                        7 + ZOOM_LVL_SHIFT, 6);
 	if (dpi->width + (MAX_VEHICLE_PIXEL_X * ZOOM_LVL_BASE) < GEN_HASHX_SIZE) {
 		xl = GEN_HASHX(l - MAX_VEHICLE_PIXEL_X * ZOOM_LVL_BASE);
 		xu = GEN_HASHX(r);
 	} else {
 		/* scan whole hash row */
 		xl = 0;
-		xu = 0x3F;
+		xu = GEN_HASHX_MASK;
+	}
 	if (dpi->height + (70 * ZOOM_LVL_BASE) < (1 << (6 + 6 + ZOOM_LVL_SHIFT))) {
 		yl = GB(t - (70 * ZOOM_LVL_BASE), 6 + ZOOM_LVL_SHIFT, 6) << 6;
 		yu = GB(b,                        6 + ZOOM_LVL_SHIFT, 6) << 6;
 	if (dpi->height + (MAX_VEHICLE_PIXEL_Y * ZOOM_LVL_BASE) < GEN_HASHY_SIZE) {
 		yl = GEN_HASHY(t - MAX_VEHICLE_PIXEL_Y * ZOOM_LVL_BASE);
 		yu = GEN_HASHY(b);
 	} else {
 		/* scan whole column */
 		yl = 0;
-		yu = 0x3F << 6;
+		yu = GEN_HASHY_MASK;
+	}
 	for (int y = yl;; y = (y + (1 << 6)) & (0x3F << 6)) {
 		for (int x = xl;; x = (x + 1) & 0x3F) {
 	for (int y = yl;; y = (y + GEN_HASHY_INC) & GEN_HASHY_MASK) {
 		for (int x = xl;; x = (x + GEN_HASHX_INC) & GEN_HASHX_MASK) {
 			const Vehicle *v = _vehicle_viewport_hash[x + y]; // already masked & 0xFFF
 			while (v != NULL) {

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