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#include "sandbox.hpp"
#include "common.hpp"
#include <cstring>
#include <utility>
// Copied from IM_COL32
#define COL_U32(r, g, b, a) (((uint32_t)(A) << IM_COL32_A_SHIFT) | ((uint32_t)(B) << IM_COL32_B_SHIFT) | ((uint32_t)(G) << IM_COL32_G_SHIFT) | ((uint32_t)(R) << IM_COL32_R_SHIFT))
// Correct byte order for this platform
constexpr uint32_t bo(uint32_t n) {
if (std::endian::native == std::endian::little)
return std::byteswap(n);
return n;
}
static constexpr uint32_t TILE_COLORS_LUT[] = {
#define X(_0, _1, color) bo(color),
#include "x/tile_types.inc"
#undef X
};
static constexpr uint32_t FLUID_COLORS_LUT[] = {
#define X(_0, _1, color) bo(color),
#include "x/fluid_types.inc"
#undef X
};
uint32_t Tile::get_color() const {
return TILE_COLORS_LUT[std::to_underlying(so)];
}
Sandbox::Sandbox(int w, int h, RandomState rand)
: bitmap(new uint32_t[w * h])
, tiles(new Tile[w * h])
, _rand(std::move(rand))
, _wall_tile{ Tile::Ti_Rock }
, width{ w }
, height{ h } //
{
memset(bitmap, 0xff, (w * h) * sizeof(bitmap[0]));
}
Sandbox::~Sandbox() {
delete[] bitmap;
delete[] tiles;
}
static void simulate_sand_tile(Sandbox& self, int x, int y) {
const auto at0 = self.gs(x, y);
if (at0.updated) {
return;
}
switch (at0.so) {
case Tile::Ti_Air: break;
case Tile::Ti_Rock: break;
case Tile::Ti_Sand: {
const auto below = self.gs(x, y - 1);
if (below.so == Tile::Ti_Air) {
self.set_sand(x, y, below);
self.set_sand(x, y - 1, at0);
} else {
Pt loc1[]{ Pt(x - 1, y - 1), Pt(x + 1, y - 1) };
auto bound = 2;
auto which = self._rand.next_u32(bound);
for (int i = 0; i < bound; ++i) {
// Try going to a side
auto at1 = self.gs(loc1[i].x, loc1[i].y);
if (at1.so == Tile::Ti_Air) {
self.set_sand(x, y, at1);
self.set_sand(loc1[i].x, loc1[i].y, at0);
}
which = (which + 1) % bound;
}
}
} break;
}
if (at0.so == Tile::Ti_Air)
switch (at0.fl) {
case Tile::Fl_Nothing: break;
case Tile::Fl_Water: {
// Pt neighs[]{ Pt(x - 1, y), Pt(x + 1, y), Pt(x, y + 1), Pt(x, y - 1) };
// int max_pressure = 0;
// for (auto [x1, y1] : neighs) {
// auto& neigh = self.gs(x1, y1);
// if (neigh.fl == Tile::Fl_Water) {
// auto p = neigh.fmass;
// max_pressure = max_pressure > p ? max_pressure : p;
// }
// }
} break;
}
}
void Sandbox::simulate_step() {
dirty_curr = dirty_writeto;
dirty_writeto = {};
const auto [x0, y0] = dirty_curr.bl;
const auto [x1, y1] = dirty_curr.tr;
// Clear update bit for this cycle
for (_y = y0; _y <= y1; ++_y) {
for (_x = x0; _x <= x1; ++_x) {
gs(_x, _y).updated = false;
}
}
for (_y = y0; _y <= y1; ++_y) {
for (_x = x0; _x <= x1; ++_x) {
simulate_sand_tile(*this, _x, _y);
}
}
++ncycle;
}
Tile& Sandbox::gs(int x, int y) {
if (x < 0 || x >= width || y < 0 || y >= height)
return _wall_tile;
return tiles[y * width + x];
}
void Sandbox::set_sand(int x, int y, Tile sand) {
auto& target = tiles[y * width + x];
target = sand;
// Set update bit if the target is after cursor
if (y < _y || x > _x)
target.updated = true;
bitmap[y * width + x] = sand.get_color();
if (dirty_writeto == Rect())
dirty_writeto = Rect(x, y, x, y);
else
dirty_writeto = rect_union(dirty_writeto, Pt(x, y));
}
// std::vector<uint32_t> Sandbox::to_bitmap() const {
// // TODO
// }
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