The next little game in the series where I make a fancy rogue game.
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roguish/pathing.cpp

99 lines
2.6 KiB

#include "constants.hpp"
#include "pathing.hpp"
#include "dbc.hpp"
#include <vector>
using std::vector;
inline void add_neighbors(PointList &neighbors, Matrix &closed, size_t y, size_t x, size_t w, size_t h) {
vector<size_t> rows{y - 1, y, y + 1};
vector<size_t> cols{x - 1, x, x + 1};
for(size_t row : rows) {
for(size_t col : cols) {
if((0 <= row && row < h) &&
(0 <= col && col < w) &&
closed[row][col] == 0)
{
closed[row][col] = 1;
neighbors.push_back({.x=col, .y=row});
}
}
}
}
/*
* Used https://github.com/HenrYxZ/dijkstra-map as a reference.
*/
void Pathing::compute_paths(Matrix &walls) {
INVARIANT();
// Initialize the new array with every pixel at limit distance
matrix::assign($paths, WALL_PATH_LIMIT);
Matrix closed = walls;
PointList starting_pixels;
PointList open_pixels;
// First pass: Add starting pixels and put them in closed
for(size_t counter = 0; counter < $height * $width; counter++) {
size_t x = counter % $width;
size_t y = counter / $width;
if($input[y][x] == 0) {
$paths[y][x] = 0;
closed[y][x] = 1;
starting_pixels.push_back({x,y});
}
}
// Second pass: Add border to open
for(auto sp : starting_pixels) {
add_neighbors(open_pixels, closed, sp.y, sp.x, $width, $height);
}
// Third pass: Iterate filling in the open list
int counter = 1; // leave this here so it's available below
for(; counter < WALL_PATH_LIMIT && !open_pixels.empty(); ++counter) {
PointList next_open;
for(auto sp : open_pixels) {
$paths[sp.y][sp.x] = counter;
add_neighbors(next_open, closed, sp.y, sp.x, $width, $height);
}
open_pixels = next_open;
}
// Last pass: flood last pixels
for(auto sp : open_pixels) {
$paths[sp.y][sp.x] = counter;
}
}
void Pathing::set_target(const Point &at, int value) {
// FUTURE: I'll eventually allow setting this to negatives for priority
$input[at.y][at.x] = value;
}
void Pathing::clear_target(const Point &at) {
$input[at.y][at.x] = 1;
}
void Pathing::random_flood(const Point from, std::function<void(Point at, int dnum)> cb) {
// quick hack to try the idea
matrix::each_cell it{$paths};
it.x = from.x;
it.y = from.y;
while(it.next()) {
cb({it.x, it.y}, $paths[it.y][it.x]);
}
}
bool Pathing::INVARIANT() {
using dbc::check;
check($paths.size() == $height, "paths wrong height");
check($paths[0].size() == $width, "paths wrong width");
check($input.size() == $height, "input wrong height");
check($input[0].size() == $width, "input wrong width");
return true;
}