Files
PixelDefense/engine/breeze/util/spatial_grid.c

284 lines
8.6 KiB
C

#include "spatial_grid.h"
#include "../memory/memory.h"
#include "array.h"
#include "object_pool.h"
#include <math.h>
typedef struct BzSpatialGrid {
BzSpatialGridID **cells;
BzObjectPool *entriesPool;
i32 width;
i32 height;
i32 cellWidth;
i32 cellHeight;
i32 userDataSize;
i32 queryCount;
} BzSpatialGrid;
static BzSpatialGridID **getCell(const BzSpatialGrid *grid, i32 x, i32 y);
BzSpatialGrid *bzSpatialGridCreate(const BzSpatialGridDesc *desc) {
i32 width = (desc->maxWidth + desc->cellWidth - 1) / desc->cellWidth;
i32 height = (desc->maxHeight + desc->cellHeight - 1) / desc->cellHeight;
size_t cellsNumBytes = width * height * sizeof(BzSpatialGridID *);
size_t numBytes = sizeof(BzSpatialGrid) + cellsNumBytes;
BzSpatialGrid *grid = bzAlloc(numBytes);
grid->width = width;
grid->height = height;
grid->cellWidth = desc->cellWidth;
grid->cellHeight = desc->cellHeight;
grid->userDataSize = desc->userDataSize;
grid->queryCount = 0;
grid->cells = (BzSpatialGridID **) (grid + 1);
for (i32 y = 0; y < grid->height; y++) {
for (i32 x = 0; x < grid->width; x++) {
BzSpatialGridID **cell = getCell(grid, x, y);
*cell = bzArrayCreate(BzSpatialGridID, 4);
}
}
grid->entriesPool = bzObjectPoolCreate(&(BzObjectPoolDesc) {
.objectSize=sizeof(BzSpatialGridEntry) + desc->userDataSize,
.objectsPerPage=1024,
});
return grid;
}
void bzSpatialGridDestroy(BzSpatialGrid *grid) {
bzObjectPoolDestroy(grid->entriesPool);
grid->entriesPool = NULL;
for (i32 y = 0; y < grid->height; y++) {
for (i32 x = 0; x < grid->width; x++) {
BzSpatialGridID **cell = getCell(grid, x, y);
bzArrayDestroy(*cell);
*cell = NULL;
}
}
grid->cells = NULL;
bzFree(grid);
}
void *bzSpatialGridGetData(const BzSpatialGrid *grid, BzSpatialGridID id) {
return (u8 *)bzObjectPoolGetObject(grid->entriesPool, id) + sizeof(BzSpatialGridEntry);
}
static BzSpatialGridID **getCell(const BzSpatialGrid *grid, i32 x, i32 y) {
BZ_ASSERT(x >= 0 && y >= 0 && x < grid->width && y < grid->height);
return grid->cells + y * grid->width + x;
}
static void insertCell(BzSpatialGrid *grid, BzSpatialGridID id, i32 x, i32 y) {
BzSpatialGridID **cell = getCell(grid, x, y);
bzArrayPush(*cell, id);
}
static void removeCell(BzSpatialGrid *grid, BzSpatialGridID id, i32 x, i32 y) {
BzSpatialGridID **cell = getCell(grid, x, y);
i32 i;
for (i = 0; i < bzArraySize(*cell); i++) {
if (id == (*cell)[i]) {
break;
}
}
if (i < bzArraySize(*cell)) {
BzSpatialGridID lastID = bzArrayPop(*cell);
(*cell)[i] = lastID;
}
}
static BzSpatialGridIndex calculateGridIndex(BzSpatialGrid *grid, f32 posX, f32 posY, f32 sizeX, f32 sizeY) {
i32 minX = (i32) floorf(posX);
i32 minY = (i32) floorf(posY);
i32 maxX = (i32) ceilf(posX + sizeX);
i32 maxY = (i32) ceilf(posY + sizeY);
BzSpatialGridIndex index = {
(i16) (minX / grid->cellWidth),
(i16) (minY / grid->cellHeight),
(i16) (maxX / grid->cellWidth),
(i16) (maxY / grid->cellHeight),
};
if (index.minX > index.maxX) {
i32 tmp = index.minX;
index.minX = index.maxX;
index.maxX = tmp;
}
if (index.minY > index.maxY) {
i32 tmp = index.minY;
index.minY = index.maxY;
index.maxX = tmp;
}
if (index.minX < 0) index.minX = 0;
if (index.minY < 0) index.minY = 0;
if (index.maxX >= grid->width) index.maxX = grid->width - 1;
if (index.maxY >= grid->height) index.maxY = grid->height - 1;
return index;
}
BzSpatialGridID bzSpatialGridInsert(BzSpatialGrid *grid, void *data, f32 posX, f32 posY, f32 sizeX, f32 sizeY) {
BzSpatialGridEntry *entry = bzObjectPool(grid->entriesPool);
BZ_ASSERT(entry);
BzSpatialGridIndex index = calculateGridIndex(grid, posX, posY, sizeX, sizeY);
BzSpatialGridID id = bzObjectPoolGetIdx(grid->entriesPool, entry);
for (i32 y = index.minY; y <= index.maxY; y++) {
for (i32 x = index.minX; x <= index.maxX; x++) {
insertCell(grid, id, x, y);
}
}
entry->id = id;
entry->queryIdx = 0;
entry->index = index;
if (grid->userDataSize) {
bzMemCpy(entry + 1, data, grid->userDataSize);
}
return id;
}
static bool indexContains(BzSpatialGridIndex index, i32 x, i32 y) {
return x >= index.minX && x <= index.maxX && y >= index.minY && y <= index.maxY;
}
void bzSpatialGridUpdate(BzSpatialGrid *grid, BzSpatialGridID id, f32 posX, f32 posY, f32 sizeX, f32 sizeY) {
BzSpatialGridEntry *entry = bzObjectPoolGetObject(grid->entriesPool, id);
BZ_ASSERT(entry && entry->id == id);
BzSpatialGridIndex oldIndex = entry->index;
BzSpatialGridIndex newIndex = calculateGridIndex(grid, posX, posY, sizeX, sizeY);
if (oldIndex.minX == newIndex.minX &&
oldIndex.minY == newIndex.minY &&
oldIndex.maxX == newIndex.maxX &&
oldIndex.maxY == newIndex.maxY) {
return;
}
for (i32 y = oldIndex.minY; y <= oldIndex.maxY; y++) {
for (i32 x = oldIndex.minX; x <= oldIndex.maxX; x++) {
bool inNew = indexContains(newIndex, x, y);
if (!inNew) removeCell(grid, id, x, y);
}
}
for (i32 y = newIndex.minY; y <= newIndex.maxY; y++) {
for (i32 x = newIndex.minX; x <= newIndex.maxX; x++) {
bool inOld = indexContains(oldIndex, x, y);
if (!inOld) insertCell(grid, id, x, y);
}
}
entry->index = newIndex;
}
void bzSpatialGridRemove(BzSpatialGrid *grid, BzSpatialGridID id) {
BzSpatialGridEntry *entry = bzObjectPoolGetObject(grid->entriesPool, id);
BZ_ASSERT(entry && entry->id == id);
BzSpatialGridIndex index = entry->index;
for (i32 y = index.minY; y <= index.maxY; y++) {
for (i32 x = index.minX; x <= index.maxX; x++) {
removeCell(grid, id, x, y);
}
}
bzObjectPoolRelease(grid->entriesPool, entry);
}
BzSpatialGridIter bzSpatialGridIter(BzSpatialGrid *grid, f32 posX, f32 posY, f32 sizeX, f32 sizeY) {
BzSpatialGridIndex index = calculateGridIndex(grid, posX, posY, sizeX, sizeY);
BzSpatialGridIter it = {
.index=index,
._grid=grid,
._queryIdx=grid->queryCount++,
._x=index.minX,
._y=index.minY,
._cellIdx=0
};
return it;
}
bool bzSpatialGridQueryNext(BzSpatialGridIter *it) {
BzSpatialGridID **cell = getCell(it->_grid, it->_x, it->_y);
BzSpatialGridID id;
BzSpatialGridEntry *entry;
bool foundUnprocessed = false;
while (!foundUnprocessed) {
while (it->_cellIdx >= bzArraySize(*cell)) {
it->_cellIdx = 0;
it->_x++;
if (it->_x > it->index.maxX) {
it->_x = it->index.minX;
it->_y++;
if (it->_y > it->index.maxY) {
return false;
}
}
cell = getCell(it->_grid, it->_x, it->_y);
}
id = bzArrayGet(*cell, it->_cellIdx);
entry = bzObjectPoolGetObject(it->_grid->entriesPool, id);
BZ_ASSERT(entry && id == entry->id);
if (entry->queryIdx != it->_queryIdx) {
entry->queryIdx = it->_queryIdx;
foundUnprocessed = true;
}
it->_cellIdx++;
}
it->entry = *entry;
it->data = (void *) (entry + 1);
return true;
}
#include <raylib.h>
#include <stdio.h>
void bzSpatialGridDrawDebugGrid(const BzSpatialGrid *grid) {
// Draw lines
i32 posX = 0;
i32 posY = 0;
for (i32 x = 0; x <= grid->width; x++) {
DrawLine(posX, 0, posX, grid->height * grid->cellHeight, BLACK);
posX += grid->cellWidth;
}
for (i32 y = 0; y <= grid->height; y++) {
DrawLine(0, posY, grid->width * grid->cellWidth, posY, BLACK);
posY += grid->cellHeight;
}
posX = 0;
posY = 0;
for (i32 y = 0; y < grid->height; y++) {
for (i32 x = 0; x < grid->width; x++) {
BzSpatialGridID **cell = getCell(grid, x, y);
i32 numEntries = 0;
if (*cell)
numEntries = bzArraySize(*cell);
Color color = WHITE;
i32 tint = numEntries;
if (tint > 10) tint = 10;
tint = 10 - tint;
color.g = 25 * tint;
color.b = 25 * tint;
char buf[8];
snprintf(buf, sizeof(buf), "%d", numEntries);
DrawText(buf, posX + 1, posY + 1, 6, color);
posX += grid->cellWidth;
}
posX = 0;
posY += grid->cellHeight;
}
}