volray: b050ce167ff1 src/volray.c

volray

view src/volray.c @ 0:b050ce167ff1

foo

author	John Tsiombikas <nuclear@member.fsf.org>
date	Sat, 31 Mar 2012 02:08:42 +0300
parents
children	57072295eb83

line source

1 #include <stdio.h>

2 #include <stdlib.h>

3 #include <assert.h>

5 #include <GL/glew.h>

6 #ifndef __APPLE__

7 #include <GL/glut.h>

8 #else

9 #include <GLUT/glut.h>

10 #endif

12 #include <vmath/vmath.h>

13 #include <imago2.h>

14 #include "sdr.h"

16 struct slice_file {

17 char *name;

18 struct slice_file *next;

19 };

21 int init(void);

22 void disp(void);

23 void reshape(int x, int y);

24 void keyb(unsigned char key, int x, int y);

25 void mouse(int bn, int state, int x, int y);

26 void motion(int x, int y);

27 int parse_args(int argc, char **argv);

29 unsigned int create_ray_texture(int xsz, int ysz, float vfov, vec2_t *tex_scale);

30 static vec3_t get_primary_ray_dir(int x, int y, int w, int h, float vfov_deg);

31 static int round_pow2(int x);

33 float cam_theta = 0, cam_phi = 0, cam_dist = 4.0;

34 float cam_x, cam_y, cam_z;

36 vec2_t tex_scale;

37 struct slice_file *flist;

38 int nslices;

39 unsigned int sdr, vol_tex, ray_tex;

40 int win_xsz, win_ysz;

42 int main(int argc, char **argv)

43 {

44 glutInit(&argc, argv);

45 glutInitWindowSize(1280, 720);

46 glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE);

48 if(parse_args(argc, argv) == -1) {

49 return 1;

50 }

52 glutCreateWindow("Volume Raytracer");

54 glutDisplayFunc(disp);

55 glutReshapeFunc(reshape);

56 glutKeyboardFunc(keyb);

57 glutMouseFunc(mouse);

58 glutMotionFunc(motion);

60 glewInit();

62 if(init() == -1) {

63 return 1;

64 }

66 glutMainLoop();

67 return 0;

68 }

70 int init(void)

71 {

72 int i, vol_xsz, vol_ysz;

74 if(!(sdr = create_program_load("volray.v.glsl", "volray.p.glsl"))) {

75 return 1;

76 }

78 glGenTextures(1, &vol_tex);

79 glBindTexture(GL_TEXTURE_3D, vol_tex);

80 glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);

81 glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

82 glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);

83 glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);

84 glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE);

86 for(i=0; i<nslices; i++) {

87 int xsz, ysz;

88 void *pix;

89 struct slice_file *sfile = flist;

90 flist = flist->next;

92 if(!(pix = img_load_pixels(sfile->name, &xsz, &ysz, IMG_FMT_RGBA32))) {

93 fprintf(stderr, "failed to load image: %s\n", sfile->name);

94 return -1;

95 }

97 if(i == 0) {

98 /* allocate storage for the texture */

99 glTexImage3D(GL_TEXTURE_3D, 0, GL_RGBA, xsz, ysz, nslices, 0, GL_RGBA, GL_UNSIGNED_BYTE, 0);

100

101 vol_xsz = xsz;

102 vol_ysz = ysz;

103

104 } else {

105 if(xsz != vol_xsz || ysz != vol_ysz) {

106 fprintf(stderr, "%s: inconsistent slice size: %dx%d. expected: %dx%d\n",

107 sfile->name, xsz, ysz, vol_xsz, vol_ysz);

108 img_free_pixels(pix);

109 return -1;

110 }

111 }

112 free(sfile);

113

114 glTexSubImage3D(GL_TEXTURE_3D, 0, 0, 0, i, xsz, ysz, 1, GL_RGBA, GL_UNSIGNED_BYTE, pix);

115 img_free_pixels(pix);

116 }

117

118 return 0;

119 }

120

121 void disp(void)

122 {

123 glMatrixMode(GL_MODELVIEW);

124 glLoadIdentity();

125 glTranslatef(cam_x, cam_y, -cam_z);

126 glRotatef(cam_theta, 0, 1, 0);

127 glRotatef(cam_phi, 1, 0, 0);

128 glTranslatef(0, 0, -cam_dist);

129

130 glMatrixMode(GL_TEXTURE);

131 glPushMatrix();

132 glScalef(tex_scale.x, tex_scale.y, 1.0);

133

134 glActiveTexture(GL_TEXTURE0);

135 glEnable(GL_TEXTURE_3D);

136 glBindTexture(GL_TEXTURE_3D, vol_tex);

137

138 glActiveTexture(GL_TEXTURE1);

139 glEnable(GL_TEXTURE_2D);

140 glBindTexture(GL_TEXTURE_2D, ray_tex);

141

142 bind_program(sdr);

143 glBegin(GL_QUADS);

144 glColor3f(1, 1, 1);

145 glTexCoord2f(0, 1);

146 glVertex2f(-1, -1);

147 glTexCoord2f(1, 1);

148 glVertex2f(1, -1);

149 glTexCoord2f(1, 0);

150 glVertex2f(1, 1);

151 glTexCoord2f(0, 0);

152 glVertex2f(-1, 1);

153 glEnd();

154 bind_program(0);

155

156 glDisable(GL_TEXTURE_2D);

157 glActiveTexture(GL_TEXTURE0);

158 glDisable(GL_TEXTURE_3D);

159

160 glMatrixMode(GL_TEXTURE);

161 glPopMatrix();

162

163 glutSwapBuffers();

164 assert(glGetError() == GL_NO_ERROR);

165 }

166

167 void reshape(int x, int y)

168 {

169 glViewport(0, 0, x, y);

170

171 if(x != win_xsz || y != win_ysz) {

172 ray_tex = create_ray_texture(x, y, 50.0, &tex_scale);

173 win_xsz = x;

174 win_ysz = y;

175 }

176 }

177

178 void keyb(unsigned char key, int x, int y)

179 {

180 switch(key) {

181 case 27:

182 exit(0);

183 }

184 }

185

186 static int bnstate[32];

187 static int prev_x, prev_y;

188

189 void mouse(int bn, int state, int x, int y)

190 {

191 bnstate[bn - GLUT_LEFT_BUTTON] = state == GLUT_DOWN;

192 prev_x = x;

193 prev_y = y;

194 }

195

196 void motion(int x, int y)

197 {

198 int dx = x - prev_x;

199 int dy = y - prev_y;

200

201 prev_x = x;

202 prev_y = y;

203

204 if(bnstate[0]) {

205 cam_theta += dx * 0.5;

206 cam_phi += dy * 0.5;

207

208 if(cam_phi < -90) cam_phi = -90;

209 if(cam_phi > 90) cam_phi = 90;

210

211 glutPostRedisplay();

212 }

213

214 if(bnstate[1]) {

215 cam_y += dy * 0.1;

216 glutPostRedisplay();

217 }

218

219 if(bnstate[2]) {

220 cam_dist += dy * 0.1;

221 if(cam_dist < 0.0) cam_dist = 0.0;

222 glutPostRedisplay();

223 }

224 }

225

226

227 int parse_args(int argc, char **argv)

228 {

229 int i;

230 struct slice_file *tail;

231

232 for(i=1; i<argc; i++) {

233 struct slice_file *sfile;

234

235 if(!(sfile = malloc(sizeof *sfile))) {

236 perror("failed to allocate memory");

237 return -1;

238 }

239 sfile->name = argv[i];

240 sfile->next = 0;

241

242 if(!flist) {

243 flist = tail = sfile;

244 } else {

245 tail->next = sfile;

246 tail = sfile;

247 }

248 nslices++;

249 }

250

251 if(!nslices) {

252 fprintf(stderr, "pass the slice filenames\n");

253 return -1;

254 }

255

256 return 0;

257 }

258

259

260 unsigned int create_ray_texture(int xsz, int ysz, float vfov, vec2_t *tex_scale)

261 {

262 int i, j;

263 unsigned int tex;

264 int tex_xsz = round_pow2(xsz);

265 int tex_ysz = round_pow2(ysz);

266 float *teximg, *dir;

267

268 if(!(teximg = malloc(3 * tex_xsz * tex_ysz * sizeof *teximg))) {

269 return 0;

270 }

271 dir = teximg;

272

273 for(i=0; i<tex_ysz; i++) {

274 for(j=0; j<tex_xsz; j++) {

275 if(j < xsz && i < ysz) {

276 vec3_t rdir = get_primary_ray_dir(j, i, xsz, ysz, vfov);

277 dir[0] = rdir.x;

278 dir[1] = rdir.y;

279 dir[2] = rdir.z;

280 } else {

281 dir[0] = dir[1] = 0.0f;

282 dir[2] = 1.0f;

283 }

284

285 dir += 3;

286 }

287 }

288

289 glGenTextures(1, &tex);

290 glBindTexture(GL_TEXTURE_2D, tex);

291 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);

292 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);

293 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);

294 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);

295 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB32F_ARB, tex_xsz, tex_ysz, 0, GL_RGB, GL_FLOAT, teximg);

296 free(teximg);

297

298 if(tex_scale) {

299 tex_scale->x = (float)xsz / (float)tex_xsz;

300 tex_scale->y = (float)ysz / (float)tex_ysz;

301 }

302 return tex;

303 }

304

305 static vec3_t get_primary_ray_dir(int x, int y, int w, int h, float vfov_deg)

306 {

307 float vfov = M_PI * vfov_deg / 180.0;

308 float aspect = (float)w / (float)h;

309

310 float ysz = 2.0;

311 float xsz = aspect * ysz;

312

313 float px = ((float)x / (float)w) * xsz - xsz / 2.0;

314 float py = 1.0 - ((float)y / (float)h) * ysz;

315 float pz = 1.0 / tan(0.5 * vfov);

316

317 float mag = sqrt(px * px + py * py + pz * pz);

318

319 return v3_cons(px / mag, py / mag, pz / mag);

320 }

321

322 static int round_pow2(int x)

323 {

324 x--;

325 x = (x >> 1) | x;

326 x = (x >> 2) | x;

327 x = (x >> 4) | x;

328 x = (x >> 8) | x;

329 x = (x >> 16) | x;

330 return x + 1;

331 }

332