goat3dgfx: 25bf39105c82 src/curve.cc

goat3dgfx

view src/curve.cc @ 13:25bf39105c82

lalal

author	John Tsiombikas <nuclear@member.fsf.org>
date	Wed, 27 Nov 2013 08:08:59 +0200
parents
children	7d6b667821cf

line source

1 #include <float.h>

2 #include <assert.h>

3 #include "curve.h"

4 #include "opengl.h"

5 #include "shader.h"

6 #include "logger.h"

8 #define DEF_THICKNESS 0.075

9 #define DEF_SEGM_SUB 3

10 #define DEF_RING_SUB 6

12 Curve::Curve()

13 {

14 thickness = DEF_THICKNESS;

15 mesh_valid = false;

16 lengths_valid = false;

18 bbox_valid = false;

20 segm_subdiv = DEF_SEGM_SUB;

21 ring_subdiv = DEF_RING_SUB;

22 }

24 Curve::Curve(const Vector3 *points, int num_points)

25 {

26 thickness = DEF_THICKNESS;

27 mesh_valid = false;

28 lengths_valid = false;

30 bbox_valid = false;

32 segm_subdiv = DEF_SEGM_SUB;

33 ring_subdiv = DEF_RING_SUB;

35 for(int i=0; i<num_points; i++) {

36 add_point(points[i]);

37 }

38 }

40 Curve::Curve(const Vector2 *points, int num_points)

41 {

42 thickness = DEF_THICKNESS;

43 mesh_valid = false;

44 lengths_valid = false;

46 bbox_valid = false;

48 segm_subdiv = DEF_SEGM_SUB;

49 ring_subdiv = DEF_RING_SUB;

51 for(int i=0; i<num_points; i++) {

52 add_point(Vector3(points[i].x, points[i].y, 0.0));

53 }

54 }

56 void Curve::set_name(const char *name)

57 {

58 this->name = name;

59 }

61 const char *Curve::get_name() const

62 {

63 return name.c_str();

64 }

66 bool Curve::empty() const

67 {

68 return cv.empty();

69 }

71 void Curve::set_thickness(float thickness)

72 {

73 this->thickness = thickness;

74 }

76 void Curve::set_subdiv(int seg, int ring)

77 {

78 if(seg < 1) seg = 1;

79 if(ring < 3) ring = 3;

81 segm_subdiv = seg;

82 ring_subdiv = ring;

83 }

85 void Curve::clear()

86 {

87 mesh_valid = false;

88 lengths_valid = false;

89 bbox_valid = false;

90 cv.clear();

91 }

93 void Curve::add_point(const Vector3 &pt)

94 {

95 cv.push_back(pt);

96 mesh_valid = false;

97 lengths_valid = false;

98 bbox_valid = false;

99 }

100

101 Vector3 &Curve::get_point(int idx)

102 {

103 mesh_valid = false;

104 lengths_valid = false;

105 bbox_valid = false;

106 return cv[idx];

107 }

108

109 const Vector3 &Curve::get_point(int idx) const

110 {

111 return cv[idx];

112 }

113

114 int Curve::get_count() const

115 {

116 return (int)cv.size();

117 }

118

119 Vector3 &Curve::operator[] (int idx)

120 {

121 return get_point(idx);

122 }

123

124 const Vector3 &Curve::operator[] (int idx) const

125 {

126 return get_point(idx);

127 }

128

129 void Curve::get_bbox(Vector3 *bbmin, Vector3 *bbmax) const

130 {

131 if(!bbox_valid) {

132 this->bbmin = Vector3(FLT_MAX, FLT_MAX, FLT_MAX);

133 this->bbmax = -this->bbmin;

134

135 for(size_t i=0; i<cv.size(); i++) {

136 for(int j=0; j<3; j++) {

137 if(cv[i][j] < this->bbmin[j]) {

138 this->bbmin[j] = cv[i][j];

139 }

140 if(cv[i][j] > this->bbmax[j]) {

141 this->bbmax[j] = cv[i][j];

142 }

143 }

144 }

145 bbox_valid = true;

146 }

147

148 if(bbmin) *bbmin = this->bbmin;

149 if(bbmax) *bbmax = this->bbmax;

150 }

151

152 void Curve::normalize()

153 {

154 get_bbox(0, 0); // force validation of the bounding box

155

156 float len = (bbmax - bbmin).length() * 0.5;

157 if(len == 0.0) {

158 return;

159 }

160

161 for(size_t i=0; i<cv.size(); i++) {

162 get_point(i) /= len;

163 }

164 }

165

166 Vector3 Curve::get_pos(float t) const

167 {

168 if(cv.empty()) {

169 return Vector3(0, 0, 0);

170 }

171 if(cv.size() == 1 || t <= 0.0) {

172 return cv[0];

173 }

174 if(t >= 1.0) {

175 return cv.back();

176 }

177

178 t = reparametrize(t);

179

180 int numcv = (int)cv.size();

181 int idx0 = t * (numcv - 1);

182 int idx1 = idx0 + 1;

183

184 int idx_prev = idx0 <= 0 ? idx0 : idx0 - 1;

185 int idx_next = idx1 >= numcv - 1 ? idx1 : idx1 + 1;

186

187 float dt = 1.0 / (float)(numcv - 1);

188

189 float t0 = (float)idx0 * dt;

190 float t1 = (float)idx1 * dt;

191

192 t = (t - t0) / (t1 - t0);

193 if(t < 0.0) t = 0.0;

194 if(t > 1.0) t = 1.0;

195

196 //return catmull_rom_spline(cv[idx_prev], cv[idx0], cv[idx1], cv[idx_next], t);

197 return bspline(cv[idx_prev], cv[idx0], cv[idx1], cv[idx_next], t);

198 }

199

200 Vector3 Curve::operator() (float t) const

201 {

202 return get_pos(t);

203 }

204

205 void Curve::draw() const

206 {

207 update_mesh();

208 if(!mesh_valid) {

209 return;

210 }

211

212 mesh.draw();

213 }

214

215

216 float Curve::reparametrize(float t) const

217 {

218 calc_cvlengths();

219 return t; // TODO

220 }

221

222 void Curve::calc_cvlengths() const

223 {

224 if(lengths_valid || cv.empty()) {

225 return;

226 }

227

228 length.clear();

229 length.resize(cv.size());

230

231 length[0] = 0;

232 for(size_t i=1; i<cv.size(); i++) {

233 length[i] = length[i - 1] + (cv[i] - cv[i - 1]).length();

234 }

235

236 lengths_valid = true;

237 }

238

239 void Curve::update_mesh() const

240 {

241 if(mesh_valid) return;

242

243 if(cv.size() < 2) {

244 return;

245 }

246

247 mesh.clear();

248

249 int nsub = segm_subdiv * (cv.size() - 1);

250 int num_rings = nsub + 1;

251

252 int num_verts = ring_subdiv * num_rings;

253 int num_quads = ring_subdiv * nsub;

254 int num_tri = num_quads * 2;

255 int num_idx = num_tri * 3;

256

257 float *varr = mesh.set_attrib_data(MESH_ATTR_VERTEX, 3, num_verts);

258 float *narr = mesh.set_attrib_data(MESH_ATTR_NORMAL, 3, num_verts);

259 float *tcarr = mesh.set_attrib_data(MESH_ATTR_TEXCOORD, 2, num_verts);

260 unsigned int *idxarr = mesh.set_index_data(num_idx);

261

262 float t = 0.0;

263 float dt = 1.0 / (float)(num_rings - 1);

264

265 for(int i=0; i<num_rings; i++) {

266 Vector3 p = get_pos(t);

267 Vector3 dir = (get_pos(t + dt) - p).normalized();

268

269 Vector3 up = Vector3(0, 0, 1);

270 float updotdir = dot_product(up, dir);

271 if(1.0 - fabs(updotdir) < 1e-4) {

272 up = Vector3(0, 1, 0);

273 }

274 Vector3 right = cross_product(up, dir).normalized();

275 up = cross_product(dir, right);

276

277 for(int j=0; j<ring_subdiv; j++) {

278 float u = (float)j / (float)ring_subdiv * M_PI * 2.0;

279 Quaternion qrot(dir, u);

280 Vector3 v = p + right.transformed(qrot) * thickness;

281

282 *varr++ = v.x;

283 *varr++ = v.y;

284 *varr++ = v.z;

285

286 Vector3 norm = (v - p).normalized();

287 *narr++ = norm.x;

288 *narr++ = norm.y;

289 *narr++ = norm.z;

290

291 *tcarr++ = u;

292 *tcarr++ = t;

293

294 if(i < nsub) {

295 int quad = i * ring_subdiv + j;

296

297 int v0 = quad;

298 int v1 = i * ring_subdiv + ((j + 1) % ring_subdiv);

299 int v2 = (i + 1) * ring_subdiv + ((j + 1) % ring_subdiv);

300 int v3 = (i + 1) * ring_subdiv + j;

301

302 idxarr[quad * 6] = v0;

303 idxarr[quad * 6 + 1] = v1;

304 idxarr[quad * 6 + 2] = v2;

305

306 idxarr[quad * 6 + 3] = v0;

307 idxarr[quad * 6 + 4] = v2;

308 idxarr[quad * 6 + 5] = v3;

309 }

310 }

311

312 t += dt;

313 }

314

315 mesh_valid = true;

316 }