deepstone: 00d84ab1ef26 src/mingl.c

deepstone

view src/mingl.c @ 21:00d84ab1ef26

switched to wacom

author	John Tsiombikas <nuclear@member.fsf.org>
date	Sat, 21 Sep 2013 18:17:55 +0300
parents	1e9f0b3616fa
children	11d14f688485

line source

1 #include <stdio.h>

2 #include <stdlib.h>

3 #include <string.h>

4 #include <math.h>

5 #include <limits.h>

6 #include <assert.h>

7 #include "vmath.h"

8 #include "mingl.h"

9 #include "mglimpl.h"

12 #define DOT(a, b) ((a).x * (b).x + (a).y * (b).y + (a).z * (b).z)

14 #define NORMALIZE(v) \

15 do { \

16 float mag = sqrt(DOT(v, v)); \

17 if(fabs(mag) > 1e-6) { \

18 float invmag = 1.0 / mag; \

19 (v).x *= invmag; \

20 (v).y *= invmag; \

21 (v).z *= invmag; \

22 } \

23 } while(0)

25 static void transform(vec4_t *res, vec4_t *v, float *mat);

26 static void transform3(vec3_t *res, vec3_t *v, float *mat);

27 static void vertex_proc(struct vertex *vert);

28 static int calc_shiftmask(int val, int *shiftp, unsigned int *maskp);

30 static struct state st;

31 static struct framebuffer fb;

33 int mgl_init(int width, int height)

34 {

35 int i;

37 st.flags = 0;

38 st.mmode = 0;

40 mgl_front_face(MGL_CCW);

41 mgl_cull_face(MGL_BACK);

43 st.curv.cidx = 0;

44 st.curv.energy = 1.0;

45 st.curv.norm.x = st.curv.norm.y = st.curv.norm.z = 0.0;

47 if(!(fb.pixels = malloc(width * height))) {

48 return -1;

49 }

50 fb.width = width;

51 fb.height = height;

52 fb.zbuf = 0;

54 if(mgl_rast_init(&st, &fb) == -1) {

55 free(fb.pixels);

56 return -1;

57 }

59 st.mtop[0] = st.mtop[1] = 0;

61 mgl_matrix_mode(MGL_MODELVIEW);

62 mgl_load_identity();

63 mgl_matrix_mode(MGL_PROJECTION);

64 mgl_load_identity();

66 /* initial viewport in the size of the framebuffer */

67 st.vp[0] = st.vp[1] = 0;

68 st.vp[2] = width;

69 st.vp[3] = height;

71 st.col_range = 256;

72 for(i=0; i<MAX_LIGHTS; i++) {

73 st.lpos[i].x = st.lpos[i].y = st.lpos[i].w = 0.0f;

74 st.lpos[i].z = 1.0f;

75 st.lint[i] = 0.0f;

76 }

78 return 0;

79 }

81 void mgl_free(void)

82 {

83 int i;

85 mgl_rast_cleanup();

86 free(fb.pixels);

87 fb.pixels = 0;

89 if(fb.zbuf) {

90 for(i=0; i<fb.num_ztiles; i++) {

91 free(fb.zbuf[i]);

92 }

93 free(fb.zbuf);

94 fb.zbuf = 0;

95 }

96 }

98 unsigned char *mgl_framebuffer(void)

99 {

100 return fb.pixels;

101 }

102

103 void mgl_clear(int cidx)

104 {

105 memset(fb.pixels, cidx, fb.width * fb.height);

106 }

107

108 void mgl_clear_depth(void)

109 {

110 int i;

111

112 if(!fb.zbuf) {

113 long num_pixels = (long)fb.width * (long)fb.height;

114 fb.num_ztiles = (num_pixels + ZTILE_SIZE - 1) / ZTILE_SIZE;

115

116 if(!(fb.zbuf = malloc(fb.num_ztiles * sizeof *fb.zbuf))) {

117 fprintf(stderr, "failed to allocate ztile array\n");

118 abort();

119 }

120

121 for(i=0; i<fb.num_ztiles; i++) {

122 if(!(fb.zbuf[i] = malloc(ZTILE_SIZE * 2))) {

123 fprintf(stderr, "failed to allocate ztile %d\n", i);

124 abort();

125 }

126 memset(fb.zbuf[i], 0xff, ZTILE_SIZE * 2);

127 }

128 return;

129 }

130

131 for(i=0; i<fb.num_ztiles; i++) {

132 memset(fb.zbuf[i], 0xff, ZTILE_SIZE * 2);

133 }

134 }

135

136 void mgl_enable(unsigned int bit)

137 {

138 st.flags |= bit;

139 }

140

141 void mgl_disable(unsigned int bit)

142 {

143 st.flags &= ~bit;

144 }

145

146 int mgl_isenabled(unsigned int bit)

147 {

148 return (st.flags & bit) != 0;

149 }

150

151 void mgl_front_face(int ff)

152 {

153 st.frontface = ff;

154 }

155

156 void mgl_cull_face(int cf)

157 {

158 st.cullface = cf;

159 }

160

161 void mgl_color_range(int rng)

162 {

163 st.col_range = rng;

164 }

165

166 void mgl_light_intensity(int ltidx, float intens)

167 {

168 assert(ltidx >= 0 && ltidx < MAX_LIGHTS);

169 st.lint[ltidx] = intens;

170 }

171

172 void mgl_light_position(int ltidx, float x, float y, float z, float w)

173 {

174 vec4_t pos;

175 assert(ltidx >= 0 && ltidx < MAX_LIGHTS);

176

177 pos.x = x;

178 pos.y = y;

179 pos.z = z;

180 pos.w = w;

181 transform(&st.lpos[ltidx], &pos, st.matrix[MGL_MODELVIEW][st.mtop[MGL_MODELVIEW]]);

182

183 if(fabs(st.lpos[ltidx].w) < 1e-6) {

184 NORMALIZE(st.lpos[ltidx]);

185 } else {

186 st.lpos[ltidx].x /= st.lpos[ltidx].w;

187 st.lpos[ltidx].y /= st.lpos[ltidx].w;

188 st.lpos[ltidx].z /= st.lpos[ltidx].w;

189 }

190 }

191

192 void mgl_begin(int prim)

193 {

194 st.prim = prim;

195 st.vidx = 0;

196

197 st.ord = st.frontface;

198 if(st.cullface == MGL_FRONT) {

199 st.ord = st.frontface == MGL_CCW ? MGL_CW : MGL_CCW;

200 }

201

202 /* select the correct rasterizer according to state */

203 mgl_rast_prepare();

204 }

205

206 void mgl_end(void)

207 {

208 }

209

210 void mgl_vertex2f(float x, float y)

211 {

212 mgl_vertex4f(x, y, 0.0f, 1.0f);

213 }

214

215 void mgl_vertex3f(float x, float y, float z)

216 {

217 mgl_vertex4f(x, y, z, 1.0f);

218 }

219

220 void mgl_vertex4f(float x, float y, float z, float w)

221 {

222 st.v[st.vidx].pos.x = x;

223 st.v[st.vidx].pos.y = y;

224 st.v[st.vidx].pos.z = z;

225 st.v[st.vidx].pos.w = w;

226 st.v[st.vidx].cidx = st.curv.cidx;

227 st.v[st.vidx].energy = st.curv.energy;

228 st.v[st.vidx].norm = st.curv.norm;

229 st.v[st.vidx].tc = st.curv.tc;

230

231 vertex_proc(st.v + st.vidx);

232

233 if(++st.vidx >= st.prim) {

234 switch(st.prim) {

235 case MGL_POINTS:

236 mgl_draw_point(st.v);

237 break;

238 case MGL_LINES:

239 mgl_draw_line(st.v, st.v + 1);

240 break;

241 case MGL_TRIANGLES:

242 case MGL_QUADS:

243 mgl_draw_poly(st.v, st.prim);

244 break;

245 default:

246 fprintf(stderr, "invalid primitive: %d\n", st.prim);

247 abort();

248 }

249 st.vidx = 0;

250 }

251 }

252

253 void mgl_color1f(float energy)

254 {

255 st.curv.energy = energy;

256 }

257

258 void mgl_index(int c)

259 {

260 st.curv.cidx = c;

261 }

262

263 void mgl_normal(float x, float y, float z)

264 {

265 st.curv.norm.x = x;

266 st.curv.norm.y = y;

267 st.curv.norm.z = z;

268 }

269

270 void mgl_texcoord2f(float x, float y)

271 {

272 st.curv.tc.x = x;

273 st.curv.tc.y = y;

274 }

275

276 static void transform(vec4_t *res, vec4_t *v, float *mat)

277 {

278 res->x = mat[0] * v->x + mat[4] * v->y + mat[8] * v->z + mat[12] * v->w;

279 res->y = mat[1] * v->x + mat[5] * v->y + mat[9] * v->z + mat[13] * v->w;

280 res->z = mat[2] * v->x + mat[6] * v->y + mat[10] * v->z + mat[14] * v->w;

281 res->w = mat[3] * v->x + mat[7] * v->y + mat[11] * v->z + mat[15] * v->w;

282 }

283

284 /* the matrix is 4x4 (16 floats), just ignoring anything out of the 3x3 */

285 static void transform3(vec3_t *res, vec3_t *v, float *mat)

286 {

287 res->x = mat[0] * v->x + mat[4] * v->y + mat[8] * v->z;

288 res->y = mat[1] * v->x + mat[5] * v->y + mat[9] * v->z;

289 res->z = mat[2] * v->x + mat[6] * v->y + mat[10] * v->z;

290 }

291

292 static void vertex_proc(struct vertex *vert)

293 {

294 vec4_t pview, pclip;

295

296 float *mvmat = st.matrix[MGL_MODELVIEW][st.mtop[MGL_MODELVIEW]];

297 float *pmat = st.matrix[MGL_PROJECTION][st.mtop[MGL_PROJECTION]];

298

299 /* modelview transformation */

300 transform(&pview, &vert->pos, mvmat);

301

302 if(st.flags & MGL_LIGHTING) {

303 if((st.flags & MGL_SMOOTH) || st.vidx == 0) {

304 int i;

305 vec3_t norm;

306 float irrad = 0.0f;

307

308 transform3(&norm, &vert->norm, mvmat);

309

310 for(i=0; i<MAX_LIGHTS; i++) {

311 if(st.lint[i] > 1e-6f) {

312 float ndotl;

313 vec3_t ldir;

314

315 if(st.lpos[i].w == 0.0) {

316 ldir.x = st.lpos[i].x;

317 ldir.y = st.lpos[i].y;

318 ldir.z = st.lpos[i].z;

319 } else {

320 ldir.x = st.lpos[i].x - pview.x;

321 ldir.y = st.lpos[i].y - pview.y;

322 ldir.z = st.lpos[i].z - pview.z;

323

324 NORMALIZE(ldir);

325 }

326

327 ndotl = DOT(norm, ldir);

328 if(ndotl < 0.0) {

329 ndotl = 0.0;

330 }

331 irrad += ndotl * st.lint[i];

332 }

333 }

334 vert->energy = irrad;

335 } else {

336 vert->energy = st.v[0].energy;

337 }

338 }

339

340 transform(&pclip, &pview, pmat);

341 /* TODO clipping in homogenous clip space */

342

343 if(pclip.w < 1e-6 && pclip.w > -1e-6) {

344 vert->pos.x = vert->pos.y = vert->pos.z = vert->pos.w = 0.0f;

345 return;

346 }

347

348 /* perspective division */

349 vert->pos.x = pclip.x / pclip.w;

350 vert->pos.y = pclip.y / pclip.w;

351 vert->pos.z = pclip.z / pclip.w;

352 vert->pos.w = pclip.w;

353

354 /* viewport transformation */

355 vert->pos.x = st.vp[0] + st.vp[2] * (vert->pos.x * 0.5 + 0.5);

356 vert->pos.y = st.vp[1] + st.vp[3] * (-vert->pos.y * 0.5 + 0.5);

357 }

358

359 void mgl_viewport(int x, int y, int width, int height)

360 {

361 st.vp[0] = x;

362 st.vp[1] = y;

363 st.vp[2] = width;

364 st.vp[3] = height;

365 }

366

367 void mgl_matrix_mode(int mmode)

368 {

369 st.mmode = mmode;

370 }

371

372 void mgl_push_matrix(void)

373 {

374 float *topmat;

375 if(st.mtop[st.mmode] >= MATRIX_STACK_SIZE - 1) {

376 fprintf(stderr, "mgl_push_matrix: stack overflow\n");

377 abort();

378 }

379

380 topmat = st.matrix[st.mmode][st.mtop[st.mmode]];

381 memcpy(topmat + 16, topmat, 16 * sizeof *topmat);

382 st.mmode++;

383 }

384

385 void mgl_pop_matrix(void)

386 {

387 if(st.mtop[st.mmode] <= 0) {

388 fprintf(stderr, "mgl_pop_matrix: stack underflow\n");

389 abort();

390 }

391 st.mtop[st.mmode]--;

392 }

393

394 void mgl_load_matrix(float *mat)

395 {

396 float *dest = st.matrix[st.mmode][st.mtop[st.mmode]];

397 memcpy(dest, mat, 16 * sizeof *dest);

398 }

399

400 #define M(i,j) (((i) << 2) + (j))

401 void mgl_mult_matrix(float *m2)

402 {

403 int i, j;

404 float m1[16];

405 float *dest = st.matrix[st.mmode][st.mtop[st.mmode]];

406

407 memcpy(m1, dest, sizeof m1);

408

409 for(i=0; i<4; i++) {

410 for(j=0; j<4; j++) {

411 dest[M(i,j)] = m1[M(0,j)] * m2[M(i,0)] +

412 m1[M(1,j)] * m2[M(i,1)] +

413 m1[M(2,j)] * m2[M(i,2)] +

414 m1[M(3,j)] * m2[M(i,3)];

415 }

416 }

417 }

418

419 void mgl_load_identity(void)

420 {

421 static float id[] = {1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1};

422 mgl_load_matrix((float*)id);

423 }

424

425 void mgl_translate(float x, float y, float z)

426 {

427 float xform[] = {1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1};

428 xform[12] = x;

429 xform[13] = y;

430 xform[14] = z;

431 mgl_mult_matrix(xform);

432 }

433

434 void mgl_rotate(float deg, float x, float y, float z)

435 {

436 float xform[] = {1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1};

437

438 float angle = M_PI * deg / 180.0f;

439 float sina = sin(angle);

440 float cosa = cos(angle);

441 float one_minus_cosa = 1.0f - cosa;

442 float nxsq = x * x;

443 float nysq = y * y;

444 float nzsq = z * z;

445

446 xform[0] = nxsq + (1.0f - nxsq) * cosa;

447 xform[4] = x * y * one_minus_cosa - z * sina;

448 xform[8] = x * z * one_minus_cosa + y * sina;

449 xform[1] = x * y * one_minus_cosa + z * sina;

450 xform[5] = nysq + (1.0 - nysq) * cosa;

451 xform[9] = y * z * one_minus_cosa - x * sina;

452 xform[2] = x * z * one_minus_cosa - y * sina;

453 xform[6] = y * z * one_minus_cosa + x * sina;

454 xform[10] = nzsq + (1.0 - nzsq) * cosa;

455

456 mgl_mult_matrix(xform);

457 }

458

459 void mgl_scale(float x, float y, float z)

460 {

461 float xform[] = {1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1};

462 xform[0] = x;

463 xform[5] = y;

464 xform[10] = z;

465 mgl_mult_matrix(xform);

466 }

467

468 void gl_ortho(float left, float right, float bottom, float top, float nr, float fr)

469 {

470 float xform[] = {1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1};

471

472 float dx = right - left;

473 float dy = top - bottom;

474 float dz = fr - nr;

475

476 float tx = -(right + left) / dx;

477 float ty = -(top + bottom) / dy;

478 float tz = -(fr + nr) / dz;

479

480 float sx = 2.0 / dx;

481 float sy = 2.0 / dy;

482 float sz = -2.0 / dz;

483

484 xform[0] = sx;

485 xform[5] = sy;

486 xform[10] = sz;

487 xform[12] = tx;

488 xform[13] = ty;

489 xform[14] = tz;

490

491 mgl_mult_matrix(xform);

492 }

493

494 void mgl_frustum(float left, float right, float bottom, float top, float nr, float fr)

495 {

496 float xform[] = {1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1};

497

498 float dx = right - left;

499 float dy = top - bottom;

500 float dz = fr - nr;

501

502 float a = (right + left) / dx;

503 float b = (top + bottom) / dy;

504 float c = -(fr + nr) / dz;

505 float d = -2.0 * fr * nr / dz;

506

507 xform[0] = 2.0 * nr / dx;

508 xform[5] = 2.0 * nr / dy;

509 xform[8] = a;

510 xform[9] = b;

511 xform[10] = c;

512 xform[11] = -1.0f;

513 xform[14] = d;

514

515 mgl_mult_matrix(xform);

516 }

517

518 void mgl_perspective(float vfov, float aspect, float nr, float fr)

519 {

520 float vfov_rad = M_PI * vfov / 180.0;

521 float x = nr * tan(vfov_rad / 2.0);

522 mgl_frustum(-aspect * x, aspect * x, -x, x, nr, fr);

523 }

524

525 void mgl_teximage(int width, int height, unsigned char *pixels)

526 {

527 st.tex.width = width;

528 st.tex.height = height;

529 st.tex.pixels = pixels;

530

531 if(calc_shiftmask(width, &st.tex.xshift, &st.tex.xmask) == -1 ||

532 calc_shiftmask(height, &st.tex.yshift, &st.tex.ymask) == -1) {

533 st.tex.pixels = 0;

534 }

535 }

536

537 #define MAX_SHIFT 12

538 static int calc_shiftmask(int val, int *shiftp, unsigned int *maskp)

539 {

540 int i;

541

542 for(i=0; i<MAX_SHIFT; i++) {

543 if((val >> i) == 1) {

544 *shiftp = i;

545 *maskp = ~(UINT_MAX << i);

546 return 0;

547 }

548 }

549 return -1;

550 }