13 #include <simgear/compiler.h>
14 #if defined( __APPLE__)
15 # include <OpenGL/OpenGL.h>
16 # include <GLUT/glut.h>
26 unsigned char env_map[TEXRES_X][TEXRES_Y][4];
28 int window_x = 640, window_y = 480;
29 float alpha = 0.0, beta = 0.0;
31 /*****************************************************************/
32 /*****************************************************************/
33 /*****************************************************************/
34 void setColor(float x, float y, float z, float angular_size, float r, float g, float b, float a)
37 float inv_length = 1.0 / sqrt(x*x + y*y + z*z);
38 x *= inv_length; y *= inv_length; z *= inv_length;
39 printf("x = %f, y = %f, z = %f\n", x, y, z);
41 float cos_angular_size = cos(angular_size*3.1415/180.0);
42 printf("cos_angular_size = %f\n", cos_angular_size);
44 for(float tz_sign = -1.0; tz_sign < 3.0; tz_sign += 2.0)
46 for(float tx = -1.0; tx <= 1.0; tx += 0.01)
48 for(float ty = -1.0; ty <= 1.0; ty += 0.01)
50 if ((1.0 - tx*tx - ty*ty)<0.0)
53 float tz = tz_sign * sqrt(1.0 - tx*tx - ty*ty);
55 float cos_phi = x*tx + y*ty + z*tz;
57 if (cos_angular_size < cos_phi)
59 float rx = tx; //mirroring on the z=0 plane
63 float inv_m = 1.0 / (2.0 * sqrt(rx*rx + ry*ry + (rz + 1)*(rz + 1)));
64 int s = (int)(TEXRES_X * (rx * inv_m + 0.5));
65 int t = (int)(TEXRES_Y * (ry * inv_m + 0.5));
67 //seg_fault protection:
69 if (s>=TEXRES_X) s=TEXRES_X-1;
72 if (t>=TEXRES_Y) t=TEXRES_Y-1;
74 env_map[s][t][0] = (unsigned char)(r * 255);
75 env_map[s][t][1] = (unsigned char)(g * 255);
76 env_map[s][t][2] = (unsigned char)(b * 255);
77 env_map[s][t][3] = (unsigned char)(a * 255);
83 /*****************************************************************/
84 /*****************************************************************/
85 /*****************************************************************/
89 glClearColor(0.0, 0.0, 0.0, 0.0);
90 glShadeModel(GL_FLAT);
91 glEnable(GL_DEPTH_TEST);
93 for(int x=0; x<TEXRES_X; x++)
95 for(int y=0; y<TEXRES_Y; y++)
97 env_map[x][y][0] = x; //a few colors
99 env_map[x][y][2] = 128;
100 env_map[x][y][3] = 128;
104 /*****************************************************************/
105 /*****************************************************************/
106 /*****************************************************************/
108 setColor(0.0, 0.0, -1.0 , 23.0, 1.0, 1.0, 1.0, 1.0);
109 setColor(0.7071067, 0.0, -0.7071067, 23.0, 1.0, 0.0, 0.0, 1.0);
110 /*****************************************************************/
111 /*****************************************************************/
112 /*****************************************************************/
114 glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
115 glGenTextures(1, &texName);
116 glBindTexture(GL_TEXTURE_2D, texName);
118 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
119 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
120 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
121 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
122 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, TEXRES_X, TEXRES_Y, 0, GL_RGBA, GL_UNSIGNED_BYTE, env_map);
125 void reshape(int w, int h)
127 window_x = w; window_y = h;
128 glViewport(0, 0, (GLsizei) w, (GLsizei) h);
129 glMatrixMode(GL_PROJECTION);
131 gluPerspective((GLdouble) 60.0, ((GLdouble)w)/((GLdouble)h), (GLdouble) 10.0, (GLdouble) 1000.0);
132 glMatrixMode(GL_MODELVIEW);
134 glTranslatef(0.0, 0.0, -20.0);
139 glClear ( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT ) ;
142 glMatrixMode(GL_PROJECTION);
144 gluPerspective((GLdouble) 60.0, (float)window_x/window_y, (GLdouble) 1.0, (GLdouble) 100.0);
145 glMatrixMode(GL_MODELVIEW);
148 glTranslatef(0.0, 0.0, -10.0);
150 glRotatef(alpha, 1.0, 0.0, 0.0);
151 glRotatef(beta, 0.0, 1.0, 0.0);
154 glColor3f(1.0, 1.0, 1.0);
155 glVertex3f(0.0, 0.0, 0.0);
156 glVertex3f(0.0, 0.0, 1.0);
159 /*****************************************************************/
160 /*****************************************************************/
161 /*****************************************************************/
162 glEnable(GL_TEXTURE_2D);
163 glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
164 glBindTexture(GL_TEXTURE_2D, texName);
166 glTexGeni(GL_S, GL_TEXTURE_GEN_MODE, GL_SPHERE_MAP);
167 glTexGeni(GL_T, GL_TEXTURE_GEN_MODE, GL_SPHERE_MAP);
168 glEnable(GL_TEXTURE_GEN_S);
169 glEnable(GL_TEXTURE_GEN_T);
172 glNormal3f(0.0, 0.0, 1.0);
173 glVertex3f(1.0, 1.0, 0.0);
174 glVertex3f(-1.0, 1.0, 0.0);
175 glVertex3f(-1.0, -1.0, 0.0);
176 glVertex3f(1.0, -1.0, 0.0);
182 glNormal3f(0.0, 0.0, 1.0);
183 glVertex3f(0.0, 0.0, 0.0);
187 glDisable(GL_TEXTURE_GEN_S);
188 glDisable(GL_TEXTURE_GEN_T);
189 glDisable(GL_TEXTURE_2D);
190 /*****************************************************************/
191 /*****************************************************************/
192 /*****************************************************************/
194 //show how the map looks like
195 glMatrixMode(GL_PROJECTION);
197 //gluOrtho2D(0.0 -10.0, 1.0 +10.0, -(float)window_x/window_y -10.0,0.0 +10.0);
198 //glOrtho(0.0, 5.0, -5.0, 0.0, -10.0, 10.0);
199 glOrtho(0.0, 5.0*((float)window_x/window_y), -5.0, 0.0, -10.0, 10.0);
200 glMatrixMode(GL_MODELVIEW);
202 glEnable(GL_TEXTURE_2D);
203 glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
204 glBindTexture(GL_TEXTURE_2D, texName);
207 glTexCoord2f(0.0, 0.0); glVertex3f(0.0, 0.0, 0.0);
208 glTexCoord2f(0.0, 1.0); glVertex3f(0.0, -1.0, 0.0);
209 glTexCoord2f(1.0, 1.0); glVertex3f(1.0, -1.0, 0.0);
210 glTexCoord2f(1.0, 0.0); glVertex3f(1.0, 0.0, 0.0);
213 glDisable(GL_TEXTURE_2D);
215 glutPostRedisplay () ;
219 void keyboard (unsigned char key, int x, int y)
228 if (alpha >= 360.0) alpha -= 360.0;
233 if (alpha < 0.0) alpha += 360.0;
238 if (beta <= -90.0) beta = -90.0;
243 if (beta >= 90.0) beta = 90.0;
247 alpha = 0.0; beta = 0.0;
252 int main(int argc, char** argv)
254 glutInitWindowSize(window_x, window_y);
255 glutInit(&argc, argv);
256 glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
257 glutCreateWindow(argv[0]);
259 glutDisplayFunc(display);
260 glutReshapeFunc(reshape);
261 glutKeyboardFunc(keyboard);