8 void hsv2rgb(float h, float s, float v, float *r, float *g, float *b)
14 float hp = (h * 180.0 / M_PI) / 60.0;
15 float x = c * (1 - fabs(fmod(hp, 2.0f) - 1.0f));
17 if (hp >= 0 && hp < 1) {
21 } else if (hp >= 1 && hp < 2) {
25 } else if (hp >= 2 && hp < 3) {
29 } else if (hp >= 3 && hp < 4) {
33 } else if (hp >= 4 && hp < 5) {
49 std::string read_file(const std::string &filename)
51 static char buf[131072];
52 FILE *fp = fopen(filename.c_str(), "r");
54 perror(filename.c_str());
58 int len = fread(buf, 1, sizeof(buf), fp);
61 return std::string(buf, len);
64 GLuint compile_shader(const std::string &shader_src, GLenum type)
66 GLuint obj = glCreateShader(type);
67 const GLchar* source[] = { shader_src.data() };
68 const GLint length[] = { (GLint)shader_src.size() };
69 glShaderSource(obj, 1, source, length);
72 GLchar info_log[4096];
73 GLsizei log_length = sizeof(info_log) - 1;
74 glGetShaderInfoLog(obj, log_length, &log_length, info_log);
75 info_log[log_length] = 0;
76 printf("shader compile log: %s\n", info_log);
79 glGetShaderiv(obj, GL_COMPILE_STATUS, &status);
80 if (status == GL_FALSE) {
87 void multiply_3x3_matrices(const Matrix3x3 a, const Matrix3x3 b, Matrix3x3 result)
89 result[0] = a[0] * b[0] + a[3] * b[1] + a[6] * b[2];
90 result[1] = a[1] * b[0] + a[4] * b[1] + a[7] * b[2];
91 result[2] = a[2] * b[0] + a[5] * b[1] + a[8] * b[2];
93 result[3] = a[0] * b[3] + a[3] * b[4] + a[6] * b[5];
94 result[4] = a[1] * b[3] + a[4] * b[4] + a[7] * b[5];
95 result[5] = a[2] * b[3] + a[5] * b[4] + a[8] * b[5];
97 result[6] = a[0] * b[6] + a[3] * b[7] + a[6] * b[8];
98 result[7] = a[1] * b[6] + a[4] * b[7] + a[7] * b[8];
99 result[8] = a[2] * b[6] + a[5] * b[7] + a[8] * b[8];
102 void invert_3x3_matrix(const Matrix3x3 m, Matrix3x3 result)
104 double inv_det = 1.0 / (
105 m[6] * m[1] * m[5] - m[6] * m[2] * m[4] -
106 m[3] * m[1] * m[8] + m[3] * m[2] * m[7] +
107 m[0] * m[4] * m[8] - m[0] * m[5] * m[7]);
109 result[0] = inv_det * (m[4] * m[8] - m[5] * m[7]);
110 result[1] = inv_det * (m[2] * m[7] - m[1] * m[8]);
111 result[2] = inv_det * (m[1] * m[5] - m[2] * m[4]);
113 result[3] = inv_det * (m[6] * m[5] - m[3] * m[8]);
114 result[4] = inv_det * (m[0] * m[8] - m[6] * m[2]);
115 result[5] = inv_det * (m[3] * m[2] - m[0] * m[5]);
117 result[6] = inv_det * (m[3] * m[7] - m[6] * m[4]);
118 result[7] = inv_det * (m[6] * m[1] - m[0] * m[7]);
119 result[8] = inv_det * (m[0] * m[4] - m[3] * m[1]);
122 void print_3x3_matrix(const Matrix3x3 m)
124 printf("%6.4f %6.4f %6.4f\n", m[0], m[3], m[6]);
125 printf("%6.4f %6.4f %6.4f\n", m[1], m[4], m[7]);
126 printf("%6.4f %6.4f %6.4f\n", m[2], m[5], m[8]);