animations
Haldean Brown
4 years ago
0 | #include <cstdint> | |
0 | 1 | #include <iostream> |
2 | #include <random> | |
1 | 3 | #include <vector> |
4 | ||
2 | 5 | #include <Eigen/Dense> |
3 | #include <cstdint> | |
4 | 6 | #include <png++/png.hpp> |
7 | ||
5 | 8 | #include "perspective.hpp" |
6 | 9 | |
7 | #define W 1200 | |
10 | using namespace Eigen; | |
11 | ||
12 | #define W 1000 | |
8 | 13 | #define H 400 |
9 | 14 | |
10 | static Eigen::Matrix<uint16_t, Eigen::Dynamic, Eigen::Dynamic> img; | |
15 | static Matrix<uint16_t, Dynamic, Dynamic> img; | |
11 | 16 | typedef png::basic_rgb_pixel<uint8_t> pixel; |
12 | 17 | |
13 | //int c[] { 255, 150, 100, 70, 50, 20, 0 }; | |
14 | 18 | uint8_t c[7][3] { |
15 | 19 | { 0, 0, 40 }, |
16 | 20 | { 140, 0, 0 }, |
21 | 25 | { 255, 255, 240 }, |
22 | 26 | }; |
23 | 27 | |
28 | Vector2f random_uv() | |
29 | { | |
30 | static std::random_device rd; | |
31 | static std::default_random_engine rande(rd()); | |
32 | static std::uniform_real_distribution<float> dist_u(0, 2 * M_PI); | |
33 | static std::normal_distribution<float> dist_v(M_PI / 2, M_PI / 6); | |
34 | ||
35 | float u = dist_u(rande); | |
36 | float v = dist_v(rande); | |
37 | return Vector2f(u, v); | |
38 | } | |
39 | ||
40 | void point(Vector2i p) | |
41 | { | |
42 | int x = p[0]; | |
43 | int y = p[1]; | |
44 | if (x >= 0 && x < img.rows() && y >= 0 && y < img.cols()) | |
45 | img(x, y)++; | |
46 | } | |
47 | ||
48 | void line(Vector2i start, Vector2i end) | |
49 | { | |
50 | if (start[0] > end[0]) | |
51 | std::swap(start, end); | |
52 | Vector2i delta = end - start; | |
53 | bool flip = false; | |
54 | if (fabs(delta[1]) > fabs(delta[0])) | |
55 | { | |
56 | int t; | |
57 | t = start[0]; start[0] = start[1]; start[1] = t; | |
58 | t = end[0]; end[0] = end[1]; end[1] = t; | |
59 | t = delta[0]; delta[0] = delta[1]; delta[1] = t; | |
60 | flip = true; | |
61 | } | |
62 | ||
63 | double derr = fabs((double) delta[1] / (double) delta[0]); | |
64 | double err = derr - 0.5; | |
65 | int y = start[1]; | |
66 | if (delta[0] == 0) | |
67 | { | |
68 | for (int y = start[0]; y <= start[1]; delta[1] > 0 ? y++ : y--) | |
69 | point(Vector2i(start[0], y)); | |
70 | return; | |
71 | } | |
72 | for (int x = start[0]; x <= end[0]; x++) | |
73 | { | |
74 | if (flip) | |
75 | point(Vector2i(y, x)); | |
76 | else | |
77 | point(Vector2i(x, y)); | |
78 | err += derr; | |
79 | while (err >= 0.5) | |
80 | { | |
81 | if (delta[1] > 0) y++; | |
82 | else y--; | |
83 | err -= 1.; | |
84 | } | |
85 | } | |
86 | } | |
87 | ||
88 | Vector2i uv2ss(Vector2f uv, float t) | |
89 | { | |
90 | static Matrix4f view = lookAt<float>( | |
91 | Vector3f(0, 10, 0), | |
92 | //Vector3f(0.75, 0.65, 0), | |
93 | Vector3f(0, 0, 0), | |
94 | Vector3f(0, 0, 1)); | |
95 | static Matrix4f proj = | |
96 | perspective<float>(M_PI / 7, 1., 0.1, 100); | |
97 | static Matrix4f mvp = proj * view; | |
98 | ||
99 | Vector4f h; | |
100 | h.block(0, 0, 3, 1) = | |
101 | AngleAxisf(4 * M_PI * t, Vector3f::UnitX()) * | |
102 | AngleAxisf(uv[0] + 2 * M_PI * t, Vector3f::UnitZ()) * | |
103 | AngleAxisf(uv[1], Vector3f::UnitY()) * | |
104 | Vector3f::UnitZ(); | |
105 | h[3] = 1; | |
106 | Vector4f p = mvp * h; | |
107 | int x = int(roundf(p[0] * 100)) + W / 2; | |
108 | int y = int(roundf(p[1] * 100)) + H / 2; | |
109 | return Vector2i(x, y); | |
110 | } | |
111 | ||
24 | 112 | int main() { |
25 | 113 | img.resize(W, H); |
26 | img.setZero(); | |
27 | 114 | |
28 | Eigen::Vector3f r3; | |
29 | Eigen::Vector4f p; | |
115 | Vector3f r3; | |
116 | Vector4f p; | |
30 | 117 | size_t i, j; |
118 | float u, v; | |
119 | Vector2i s, e; | |
31 | 120 | |
32 | Eigen::Matrix4f view = lookAt<float>( | |
33 | Eigen::Vector3f(2, 6, 3), | |
34 | Eigen::Vector3f(0.75, 0.65, 0), | |
35 | Eigen::Vector3f(0, 0, 1)); | |
36 | Eigen::Matrix4f proj = perspective<float>(M_PI / 32, 1, 0.1, 100); | |
37 | Eigen::Matrix4f mvp = proj * view; | |
121 | std::vector<std::pair<Vector2f, Vector2f>> edges; | |
122 | for (int i = 0; i < 1000; i++) | |
123 | { | |
124 | Vector2f uv1 = random_uv(); | |
125 | Vector2f uv2 = random_uv(); | |
126 | edges.push_back(std::make_pair(uv1, uv2)); | |
127 | } | |
38 | 128 | |
39 | const float step = 0.0002; | |
40 | for (float u = 0; u < 2 * M_PI; u += step) | |
129 | const int framecount = 200; | |
130 | for (int f = 0; f < framecount; f++) | |
41 | 131 | { |
42 | for (float v = 0; v < M_PI; v += step) | |
132 | float t = (float) f / framecount; | |
133 | img.setZero(); | |
134 | if (true) | |
43 | 135 | { |
44 | Eigen::Vector4f h; | |
45 | h.block(0, 0, 3, 1) = | |
46 | Eigen::AngleAxisf(u, Eigen::Vector3f::UnitZ()) * | |
47 | Eigen::AngleAxisf(v, Eigen::Vector3f::UnitY()) * | |
48 | Eigen::Vector3f::UnitZ(); | |
49 | h[3] = 1; | |
50 | p = mvp * 2 * h; | |
51 | i = size_t(p[0] * 100) + W / 2; | |
52 | j = size_t(p[1] * 100) + H / 2; | |
53 | if (i >= 0 && i < img.rows() && j >= 0 && j < img.cols()) | |
54 | img(i, j) += 1; | |
136 | for (const auto &pp : edges) | |
137 | { | |
138 | s = uv2ss(pp.first, t); | |
139 | e = uv2ss(pp.second, t); | |
140 | line(s, e); | |
141 | } | |
55 | 142 | } |
143 | if (false) | |
144 | { | |
145 | const float step = 0.01; | |
146 | for (float u = 0; u < 2 * M_PI; u += step) | |
147 | { | |
148 | for (float v = 0; v < M_PI; v += step) | |
149 | { | |
150 | e = uv2ss(Vector2f(u, v), t); | |
151 | point(e); | |
152 | } | |
153 | } | |
154 | } | |
155 | ||
156 | png::image<pixel> out(W, H); | |
157 | for (i = 0; i < W; i++) | |
158 | { | |
159 | for (j = 0; j < H; j++) | |
160 | { | |
161 | uint16_t step = img(i, j); | |
162 | if (step > 6) | |
163 | step = 6; | |
164 | auto px = pixel( | |
165 | c[step][0], c[step][1], c[step][2]); | |
166 | out.set_pixel(i, j, px); | |
167 | } | |
168 | } | |
169 | char buf[32]; | |
170 | sprintf(buf, "output-%06d.png", f); | |
171 | out.write(buf); | |
56 | 172 | } |
57 | png::image<pixel> out(W, H); | |
58 | for (i = 0; i < W; i++) | |
59 | { | |
60 | for (j = 0; j < H; j++) | |
61 | { | |
62 | uint16_t step = img(i, j); | |
63 | if (step > 6) | |
64 | step = 6; | |
65 | out.set_pixel(i, j, pixel(c[step][0], c[step][1], c[step][2])); | |
66 | } | |
67 | } | |
68 | out.write("output.png"); | |
69 | 173 | return 0; |
70 | 174 | } |