Files
snejk/src/shared/grid.c
2025-12-11 15:11:01 +01:00

101 lines
2.5 KiB
C

#include "grid.h"
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#define GRID_MIN_WIDTH 8
#define GRID_MIN_HEIGHT 8
static bool from_grid_index(Grid *grid, uint16_t grid_index, uint16_t *out_x, uint16_t *out_y) {
assert(grid != NULL);
assert(out_x != NULL);
assert(out_y != NULL);
if (!grid || !out_x || !out_y) return false;
if (grid_index >= grid->width * grid->height) return false;
*out_x = grid_index % grid->width;
*out_y = grid_index / grid->width;
return true;
}
bool grid_initialize(Grid *grid, uint16_t width, uint16_t height) {
assert(grid != NULL);
if(width < GRID_MIN_WIDTH || height < GRID_MIN_HEIGHT) {
return false;
}
grid->width = width;
grid->height = height;
grid->cells = calloc(width * height, sizeof(Grid_Cell));
for(uint16_t i = 0; i < (width * height); i++) {
Grid_Cell *cell = &grid->cells[i];
assert(from_grid_index(grid, i, &cell->x, &cell->y));
}
return true;
}
void grid_dispose(Grid *grid) {
assert(grid != NULL);
free(grid->cells);
memset(grid, 0, sizeof(Grid));
}
static bool to_grid_index(Grid *grid, uint16_t x, uint16_t y, uint16_t *out_grid_index) {
assert(grid != NULL);
assert(out_grid_index != NULL);
if (!grid || !out_grid_index) return false;
if (x >= grid->width || y >= grid->height) return false;
*out_grid_index = y * grid->width + x;
return true;
}
Grid_Cell *grid_get_cell(Grid *grid, uint16_t x, uint16_t y) {
assert(grid != NULL);
if(x >= grid->width || y >= grid->height) return NULL;
uint16_t grid_index = 0;
if(!to_grid_index(grid, x, y, &grid_index)) {
return NULL;
}
return &grid->cells[grid_index];
}
bool grid_try_add_entity_to_cell(Grid_Cell *cell, Entity *entity) {
assert(cell != NULL);
assert(entity != NULL);
// TODO: SS - Could check what type of cell it is to determine if
// we're allowed to place an entity here. Is it a wall? Lava?
if(cell->entity != NULL) {
return false;
}
cell->entity = entity;
entity->x = cell->x;
entity->y = cell->y;
return true;
}
bool grid_try_remove_entity_from_cell(Grid_Cell *cell) {
assert(cell != NULL);
if(cell->entity == NULL) {
return false;
}
cell->entity->x = 0;
cell->entity->y = 0;
cell->entity = NULL;
return true;
}