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

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frosch
2018-03-11 13:23:26 +00:00
parent 07d841d0ef
commit 5558899621
2 changed files with 37 additions and 12 deletions
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2
src/tile_type.h
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@@ -18,6 +18,8 @@ static const uint TILE_PIXELS = 32; ///< Pixel distan
static const uint TILE_HEIGHT = 8; ///< Height of a height level in world coordinate AND in pixels in #ZOOM_LVL_BASE. 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 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 static const uint MAX_TILE_HEIGHT = 255; ///< Maximum allowed tile height

47
src/vehicle.cpp
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@@ -57,7 +57,30 @@
#include "safeguards.h" #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; VehicleID _new_vehicle_id;
uint16 _returned_refit_capacity; ///< Stores the capacity after a refit operation. uint16 _returned_refit_capacity; ///< Stores the capacity after a refit operation.
@@ -618,7 +641,7 @@ static void UpdateVehicleTileHash(Vehicle *v, bool remove)
v->hash_tile_current = new_hash; 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) static void UpdateVehicleViewportHash(Vehicle *v, int x, int y)
{ {
@@ -1088,26 +1111,26 @@ void ViewportAddVehicles(DrawPixelInfo *dpi)
/* The hash area to scan */ /* The hash area to scan */
int xl, xu, yl, yu; int xl, xu, yl, yu;
if (dpi->width + (70 * ZOOM_LVL_BASE) < (1 << (7 + 6 + ZOOM_LVL_SHIFT))) { if (dpi->width + (MAX_VEHICLE_PIXEL_X * ZOOM_LVL_BASE) < GEN_HASHX_SIZE) {
xl = GB(l - (70 * ZOOM_LVL_BASE), 7 + ZOOM_LVL_SHIFT, 6); xl = GEN_HASHX(l - MAX_VEHICLE_PIXEL_X * ZOOM_LVL_BASE);
xu = GB(r, 7 + ZOOM_LVL_SHIFT, 6); xu = GEN_HASHX(r);
} else { } else {
/* scan whole hash row */ /* scan whole hash row */
xl = 0; xl = 0;
xu = 0x3F; xu = GEN_HASHX_MASK;
} }
if (dpi->height + (70 * ZOOM_LVL_BASE) < (1 << (6 + 6 + ZOOM_LVL_SHIFT))) { if (dpi->height + (MAX_VEHICLE_PIXEL_Y * ZOOM_LVL_BASE) < GEN_HASHY_SIZE) {
yl = GB(t - (70 * ZOOM_LVL_BASE), 6 + ZOOM_LVL_SHIFT, 6) << 6; yl = GEN_HASHY(t - MAX_VEHICLE_PIXEL_Y * ZOOM_LVL_BASE);
yu = GB(b, 6 + ZOOM_LVL_SHIFT, 6) << 6; yu = GEN_HASHY(b);
} else { } else {
/* scan whole column */ /* scan whole column */
yl = 0; yl = 0;
yu = 0x3F << 6; yu = GEN_HASHY_MASK;
} }
for (int y = yl;; y = (y + (1 << 6)) & (0x3F << 6)) { for (int y = yl;; y = (y + GEN_HASHY_INC) & GEN_HASHY_MASK) {
for (int x = xl;; x = (x + 1) & 0x3F) { for (int x = xl;; x = (x + GEN_HASHX_INC) & GEN_HASHX_MASK) {
const Vehicle *v = _vehicle_viewport_hash[x + y]; // already masked & 0xFFF const Vehicle *v = _vehicle_viewport_hash[x + y]; // already masked & 0xFFF
while (v != NULL) { while (v != NULL) {