1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
|
#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 material_color_lut[] = {
bo(0xffffff'ff), // AIR
bo(0xababab'ff), // SOLID
bo(0xe3dd24'ff), // SAND
bo(0x435bf7'ff), // WATER
};
uint32_t Tile::get_color() const {
return material_color_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::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::AIR: break;
case Tile::ROCK: break;
case Tile::SAND: {
const auto below = self.gs(x, y - 1);
if (below.so == Tile::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::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::AIR)
switch (at0.fl) {
case Tile::NOTHING: break;
case Tile::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::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
// }
|
