qvolray: 57072295eb83 src/volray.c

qvolray

view src/volray.c @ 1:57072295eb83

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author	John Tsiombikas <nuclear@member.fsf.org>
date	Mon, 02 Apr 2012 02:11:35 +0300
parents	b050ce167ff1
children	0b73aa7317e1

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 static void 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;

41 int raytex_needs_recalc = 1;

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

44 {

45 glutInit(&argc, argv);

46 glutInitWindowSize(1280, 720);

47 glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE);

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

50 return 1;

51 }

53 glutCreateWindow("Volume Raytracer");

55 glutDisplayFunc(disp);

56 glutReshapeFunc(reshape);

57 glutKeyboardFunc(keyb);

58 glutMouseFunc(mouse);

59 glutMotionFunc(motion);

61 glewInit();

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

64 return 1;

65 }

67 glutMainLoop();

68 return 0;

69 }

71 int init(void)

72 {

73 int i, vol_xsz, vol_ysz;

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

76 return -1;

77 }

78 set_uniform_int(sdr, "volume", 0);

79 set_uniform_int(sdr, "ray_tex", 1);

81 glGenTextures(1, &vol_tex);

82 glBindTexture(GL_TEXTURE_3D, vol_tex);

83 glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);

84 glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

85 glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_S, GL_CLAMP);

86 glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_T, GL_CLAMP);

87 glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_R, GL_CLAMP);

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

90 int xsz, ysz;

91 void *pix;

92 struct slice_file *sfile = flist;

93 flist = flist->next;

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

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

97 return -1;

98 }

100 if(i == 0) {

101 /* allocate storage for the texture */

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

103

104 vol_xsz = xsz;

105 vol_ysz = ysz;

106

107 } else {

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

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

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

111 img_free_pixels(pix);

112 return -1;

113 }

114 }

115 free(sfile);

116

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

118 img_free_pixels(pix);

119 }

120 return 0;

121 }

122

123 void disp(void)

124 {

125 if(raytex_needs_recalc) {

126 create_ray_texture(win_xsz, win_ysz, 50.0, &tex_scale);

127 }

128

129 glMatrixMode(GL_MODELVIEW);

130 glLoadIdentity();

131 glRotatef(-90, 1, 0, 0);

132 glTranslatef(cam_x, cam_y, -cam_z);

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

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

135 glTranslatef(0, 0, -cam_dist);

136

137 glMatrixMode(GL_TEXTURE);

138 glLoadIdentity();

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

140

141 glActiveTexture(GL_TEXTURE0);

142 glBindTexture(GL_TEXTURE_3D, vol_tex);

143 glEnable(GL_TEXTURE_3D);

144

145 glActiveTexture(GL_TEXTURE1);

146 glBindTexture(GL_TEXTURE_2D, ray_tex);

147 glEnable(GL_TEXTURE_2D);

148

149 bind_program(sdr);

150 glBegin(GL_QUADS);

151 glColor3f(1, 1, 1);

152 glTexCoord2f(0, 1); glVertex2f(-1, -1);

153 glTexCoord2f(1, 1); glVertex2f(1, -1);

154 glTexCoord2f(1, 0); glVertex2f(1, 1);

155 glTexCoord2f(0, 0); glVertex2f(-1, 1);

156 glEnd();

157 bind_program(0);

158

159 glActiveTexture(GL_TEXTURE1);

160 glDisable(GL_TEXTURE_2D);

161 glActiveTexture(GL_TEXTURE0);

162 glDisable(GL_TEXTURE_3D);

163

164 glMatrixMode(GL_TEXTURE);

165 glLoadIdentity();

166

167 glutSwapBuffers();

168 assert(glGetError() == GL_NO_ERROR);

169 }

170

171 void reshape(int x, int y)

172 {

173 printf("reshape: %dx%d\n", x, y);

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

175

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

177 raytex_needs_recalc = 1;

178 win_xsz = x;

179 win_ysz = y;

180 }

181 }

182

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

184 {

185 switch(key) {

186 case 27:

187 exit(0);

188 }

189 }

190

191 static int bnstate[32];

192 static int prev_x, prev_y;

193

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

195 {

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

197 prev_x = x;

198 prev_y = y;

199 }

200

201 void motion(int x, int y)

202 {

203 int dx = x - prev_x;

204 int dy = y - prev_y;

205

206 prev_x = x;

207 prev_y = y;

208

209 if(bnstate[0]) {

210 cam_theta += dx * 0.5;

211 cam_phi += dy * 0.5;

212

213 if(cam_phi <= -90) cam_phi = -89;

214 if(cam_phi >= 90) cam_phi = 89;

215

216 glutPostRedisplay();

217 }

218

219 if(bnstate[1]) {

220 cam_x += dx * 0.025;

221 cam_y += dy * 0.025;

222 glutPostRedisplay();

223 }

224

225 if(bnstate[2]) {

226 cam_dist += dy * 0.025;

227 if(cam_dist < 0.0) cam_dist = 0.0;

228 glutPostRedisplay();

229 }

230 }

231

232

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

234 {

235 int i;

236 struct slice_file *tail;

237

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

239 struct slice_file *sfile;

240

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

242 perror("failed to allocate memory");

243 return -1;

244 }

245 sfile->name = argv[i];

246 sfile->next = 0;

247

248 if(!flist) {

249 flist = tail = sfile;

250 } else {

251 tail->next = sfile;

252 tail = sfile;

253 }

254 nslices++;

255 }

256

257 if(!nslices) {

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

259 return -1;

260 }

261

262 return 0;

263 }

264

265

266 static void create_ray_texture(int xsz, int ysz, float vfov, vec2_t *tex_scale)

267 {

268 int i, j;

269 int cur_tex_xsz, cur_tex_ysz;

270 int tex_xsz = round_pow2(xsz);

271 int tex_ysz = round_pow2(ysz);

272 float *teximg, *dir;

273

274 if(!(teximg = malloc(3 * xsz * ysz * sizeof *teximg))) {

275 return;

276 }

277 dir = teximg;

278

279 for(i=0; i<ysz; i++) {

280 for(j=0; j<xsz; j++) {

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

282 *dir++ = rdir.x;

283 *dir++ = rdir.y;

284 *dir++ = rdir.z;

285 }

286 }

287

288 if(!ray_tex) {

289 glGenTextures(1, &ray_tex);

290 }

291

292 glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_WIDTH, &cur_tex_xsz);

293 glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_HEIGHT, &cur_tex_ysz);

294

295 if(tex_xsz > cur_tex_xsz || tex_ysz > cur_tex_ysz) {

296 glBindTexture(GL_TEXTURE_2D, ray_tex);

297 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);

298 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);

299 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);

300 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);

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

302 }

303

304 glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, xsz, ysz, GL_RGB, GL_FLOAT, teximg);

305 free(teximg);

306

307 if(tex_scale) {

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

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

310 }

311 raytex_needs_recalc = 0;

312 }

313

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

315 {

316 float vfov = M_PI * vfov_deg / 180.0;

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

318

319 float ysz = 2.0;

320 float xsz = aspect * ysz;

321

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

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

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

325

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

327

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

329 }

330

331 static int round_pow2(int x)

332 {

333 x--;

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

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

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

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

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

339 return x + 1;

340 }

341