dos3d

annotate src/mingl.c @ 17:1e9f0b3616fa

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fixed the matrix multiplication order
author John Tsiombikas <nuclear@member.fsf.org>
date Wed, 30 Nov 2011 00:04:16 +0200
parents 7b574ba5758e
children 00d84ab1ef26
rev   line source
nuclear@0 1 /*
nuclear@0 2 256-color 3D graphics hack for real-mode DOS.
nuclear@0 3 Copyright (C) 2011 John Tsiombikas <nuclear@member.fsf.org>
nuclear@0 4
nuclear@0 5 This program is free software: you can redistribute it and/or modify
nuclear@0 6 it under the terms of the GNU General Public License as published by
nuclear@0 7 the Free Software Foundation, either version 3 of the License, or
nuclear@0 8 (at your option) any later version.
nuclear@0 9
nuclear@0 10 This program is distributed in the hope that it will be useful,
nuclear@0 11 but WITHOUT ANY WARRANTY; without even the implied warranty of
nuclear@0 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
nuclear@0 13 GNU General Public License for more details.
nuclear@0 14
nuclear@0 15 You should have received a copy of the GNU General Public License
nuclear@0 16 along with this program. If not, see <http://www.gnu.org/licenses/>.
nuclear@0 17 */
nuclear@0 18 #include <stdio.h>
nuclear@0 19 #include <stdlib.h>
nuclear@0 20 #include <string.h>
nuclear@0 21 #include <math.h>
nuclear@17 22 #include <limits.h>
nuclear@0 23 #include <assert.h>
nuclear@0 24 #include "mingl.h"
nuclear@0 25 #include "mglimpl.h"
nuclear@0 26
nuclear@3 27
nuclear@0 28 #define DOT(a, b) ((a).x * (b).x + (a).y * (b).y + (a).z * (b).z)
nuclear@0 29
nuclear@11 30 #define NORMALIZE(v) \
nuclear@11 31 do { \
nuclear@11 32 float mag = sqrt(DOT(v, v)); \
nuclear@11 33 if(fabs(mag) > 1e-6) { \
nuclear@11 34 float invmag = 1.0 / mag; \
nuclear@11 35 (v).x *= invmag; \
nuclear@11 36 (v).y *= invmag; \
nuclear@11 37 (v).z *= invmag; \
nuclear@11 38 } \
nuclear@11 39 } while(0)
nuclear@11 40
nuclear@0 41 static void transform(vec4_t *res, vec4_t *v, float *mat);
nuclear@0 42 static void transform3(vec3_t *res, vec3_t *v, float *mat);
nuclear@0 43 static void vertex_proc(struct vertex *vert);
nuclear@3 44 static int calc_shiftmask(int val, int *shiftp, unsigned int *maskp);
nuclear@0 45
nuclear@0 46 static struct state st;
nuclear@0 47 static struct framebuffer fb;
nuclear@0 48
nuclear@0 49 int mgl_init(int width, int height)
nuclear@0 50 {
nuclear@0 51 int i;
nuclear@0 52
nuclear@0 53 st.flags = 0;
nuclear@0 54 st.mmode = 0;
nuclear@0 55
nuclear@0 56 mgl_front_face(MGL_CCW);
nuclear@0 57 mgl_cull_face(MGL_BACK);
nuclear@0 58
nuclear@0 59 st.curv.cidx = 0;
nuclear@0 60 st.curv.energy = 1.0;
nuclear@0 61 st.curv.norm.x = st.curv.norm.y = st.curv.norm.z = 0.0;
nuclear@0 62
nuclear@0 63 if(!(fb.pixels = malloc(width * height))) {
nuclear@0 64 return -1;
nuclear@0 65 }
nuclear@0 66 fb.width = width;
nuclear@0 67 fb.height = height;
nuclear@0 68 fb.zbuf = 0;
nuclear@0 69
nuclear@0 70 if(mgl_rast_init(&st, &fb) == -1) {
nuclear@0 71 free(fb.pixels);
nuclear@0 72 return -1;
nuclear@0 73 }
nuclear@0 74
nuclear@0 75 st.mtop[0] = st.mtop[1] = 0;
nuclear@0 76
nuclear@0 77 mgl_matrix_mode(MGL_MODELVIEW);
nuclear@0 78 mgl_load_identity();
nuclear@0 79 mgl_matrix_mode(MGL_PROJECTION);
nuclear@0 80 mgl_load_identity();
nuclear@0 81
nuclear@0 82 /* initial viewport in the size of the framebuffer */
nuclear@0 83 st.vp[0] = st.vp[1] = 0;
nuclear@0 84 st.vp[2] = width;
nuclear@0 85 st.vp[3] = height;
nuclear@0 86
nuclear@0 87 st.col_range = 256;
nuclear@0 88 for(i=0; i<MAX_LIGHTS; i++) {
nuclear@11 89 st.lpos[i].x = st.lpos[i].y = st.lpos[i].w = 0.0f;
nuclear@11 90 st.lpos[i].z = 1.0f;
nuclear@0 91 st.lint[i] = 0.0f;
nuclear@0 92 }
nuclear@0 93
nuclear@0 94 return 0;
nuclear@0 95 }
nuclear@0 96
nuclear@0 97 void mgl_free(void)
nuclear@0 98 {
nuclear@9 99 int i;
nuclear@9 100
nuclear@0 101 mgl_rast_cleanup();
nuclear@0 102 free(fb.pixels);
nuclear@9 103 fb.pixels = 0;
nuclear@9 104
nuclear@9 105 if(fb.zbuf) {
nuclear@9 106 for(i=0; i<fb.num_ztiles; i++) {
nuclear@9 107 free(fb.zbuf[i]);
nuclear@9 108 }
nuclear@9 109 free(fb.zbuf);
nuclear@9 110 fb.zbuf = 0;
nuclear@9 111 }
nuclear@0 112 }
nuclear@0 113
nuclear@0 114 unsigned char *mgl_framebuffer(void)
nuclear@0 115 {
nuclear@0 116 return fb.pixels;
nuclear@0 117 }
nuclear@0 118
nuclear@0 119 void mgl_clear(int cidx)
nuclear@0 120 {
nuclear@0 121 memset(fb.pixels, cidx, fb.width * fb.height);
nuclear@0 122 }
nuclear@0 123
nuclear@9 124 void mgl_clear_depth(void)
nuclear@9 125 {
nuclear@9 126 int i;
nuclear@9 127
nuclear@9 128 if(!fb.zbuf) {
nuclear@9 129 long num_pixels = (long)fb.width * (long)fb.height;
nuclear@9 130 fb.num_ztiles = (num_pixels + ZTILE_SIZE - 1) / ZTILE_SIZE;
nuclear@9 131
nuclear@9 132 if(!(fb.zbuf = malloc(fb.num_ztiles * sizeof *fb.zbuf))) {
nuclear@9 133 fprintf(stderr, "failed to allocate ztile array\n");
nuclear@9 134 abort();
nuclear@9 135 }
nuclear@9 136
nuclear@9 137 for(i=0; i<fb.num_ztiles; i++) {
nuclear@9 138 if(!(fb.zbuf[i] = malloc(ZTILE_SIZE * 2))) {
nuclear@9 139 fprintf(stderr, "failed to allocate ztile %d\n", i);
nuclear@9 140 abort();
nuclear@9 141 }
nuclear@9 142 memset(fb.zbuf[i], 0xff, ZTILE_SIZE * 2);
nuclear@9 143 }
nuclear@9 144 return;
nuclear@9 145 }
nuclear@9 146
nuclear@9 147 for(i=0; i<fb.num_ztiles; i++) {
nuclear@9 148 memset(fb.zbuf[i], 0xff, ZTILE_SIZE * 2);
nuclear@9 149 }
nuclear@9 150 }
nuclear@9 151
nuclear@0 152 void mgl_enable(unsigned int bit)
nuclear@0 153 {
nuclear@0 154 st.flags |= bit;
nuclear@0 155 }
nuclear@0 156
nuclear@0 157 void mgl_disable(unsigned int bit)
nuclear@0 158 {
nuclear@0 159 st.flags &= ~bit;
nuclear@0 160 }
nuclear@0 161
nuclear@3 162 int mgl_isenabled(unsigned int bit)
nuclear@3 163 {
nuclear@3 164 return (st.flags & bit) != 0;
nuclear@3 165 }
nuclear@3 166
nuclear@0 167 void mgl_front_face(int ff)
nuclear@0 168 {
nuclear@0 169 st.frontface = ff;
nuclear@0 170 }
nuclear@0 171
nuclear@0 172 void mgl_cull_face(int cf)
nuclear@0 173 {
nuclear@0 174 st.cullface = cf;
nuclear@0 175 }
nuclear@0 176
nuclear@0 177 void mgl_color_range(int rng)
nuclear@0 178 {
nuclear@0 179 st.col_range = rng;
nuclear@0 180 }
nuclear@0 181
nuclear@0 182 void mgl_light_intensity(int ltidx, float intens)
nuclear@0 183 {
nuclear@0 184 assert(ltidx >= 0 && ltidx < MAX_LIGHTS);
nuclear@0 185 st.lint[ltidx] = intens;
nuclear@0 186 }
nuclear@0 187
nuclear@11 188 void mgl_light_position(int ltidx, float x, float y, float z, float w)
nuclear@0 189 {
nuclear@11 190 vec4_t pos;
nuclear@0 191 assert(ltidx >= 0 && ltidx < MAX_LIGHTS);
nuclear@0 192
nuclear@11 193 pos.x = x;
nuclear@11 194 pos.y = y;
nuclear@11 195 pos.z = z;
nuclear@11 196 pos.w = w;
nuclear@11 197 transform(&st.lpos[ltidx], &pos, st.matrix[MGL_MODELVIEW][st.mtop[MGL_MODELVIEW]]);
nuclear@0 198
nuclear@11 199 if(fabs(st.lpos[ltidx].w) < 1e-6) {
nuclear@11 200 NORMALIZE(st.lpos[ltidx]);
nuclear@11 201 } else {
nuclear@11 202 st.lpos[ltidx].x /= st.lpos[ltidx].w;
nuclear@11 203 st.lpos[ltidx].y /= st.lpos[ltidx].w;
nuclear@11 204 st.lpos[ltidx].z /= st.lpos[ltidx].w;
nuclear@0 205 }
nuclear@0 206 }
nuclear@0 207
nuclear@0 208 void mgl_begin(int prim)
nuclear@0 209 {
nuclear@0 210 st.prim = prim;
nuclear@0 211 st.vidx = 0;
nuclear@0 212
nuclear@0 213 st.ord = st.frontface;
nuclear@0 214 if(st.cullface == MGL_FRONT) {
nuclear@0 215 st.ord = st.frontface == MGL_CCW ? MGL_CW : MGL_CCW;
nuclear@0 216 }
nuclear@0 217
nuclear@0 218 /* select the correct rasterizer according to state */
nuclear@0 219 mgl_rast_prepare();
nuclear@0 220 }
nuclear@0 221
nuclear@0 222 void mgl_end(void)
nuclear@0 223 {
nuclear@0 224 }
nuclear@0 225
nuclear@0 226 void mgl_vertex2f(float x, float y)
nuclear@0 227 {
nuclear@0 228 mgl_vertex4f(x, y, 0.0f, 1.0f);
nuclear@0 229 }
nuclear@0 230
nuclear@0 231 void mgl_vertex3f(float x, float y, float z)
nuclear@0 232 {
nuclear@0 233 mgl_vertex4f(x, y, z, 1.0f);
nuclear@0 234 }
nuclear@0 235
nuclear@0 236 void mgl_vertex4f(float x, float y, float z, float w)
nuclear@0 237 {
nuclear@0 238 st.v[st.vidx].pos.x = x;
nuclear@0 239 st.v[st.vidx].pos.y = y;
nuclear@0 240 st.v[st.vidx].pos.z = z;
nuclear@0 241 st.v[st.vidx].pos.w = w;
nuclear@0 242 st.v[st.vidx].cidx = st.curv.cidx;
nuclear@0 243 st.v[st.vidx].energy = st.curv.energy;
nuclear@0 244 st.v[st.vidx].norm = st.curv.norm;
nuclear@0 245 st.v[st.vidx].tc = st.curv.tc;
nuclear@0 246
nuclear@0 247 vertex_proc(st.v + st.vidx);
nuclear@0 248
nuclear@0 249 if(++st.vidx >= st.prim) {
nuclear@0 250 switch(st.prim) {
nuclear@0 251 case MGL_POINTS:
nuclear@0 252 mgl_draw_point(st.v);
nuclear@0 253 break;
nuclear@0 254 case MGL_LINES:
nuclear@0 255 mgl_draw_line(st.v, st.v + 1);
nuclear@0 256 break;
nuclear@0 257 case MGL_TRIANGLES:
nuclear@0 258 case MGL_QUADS:
nuclear@0 259 mgl_draw_poly(st.v, st.prim);
nuclear@0 260 break;
nuclear@0 261 default:
nuclear@0 262 fprintf(stderr, "invalid primitive: %d\n", st.prim);
nuclear@0 263 abort();
nuclear@0 264 }
nuclear@0 265 st.vidx = 0;
nuclear@0 266 }
nuclear@0 267 }
nuclear@0 268
nuclear@0 269 void mgl_color1f(float energy)
nuclear@0 270 {
nuclear@0 271 st.curv.energy = energy;
nuclear@0 272 }
nuclear@0 273
nuclear@0 274 void mgl_index(int c)
nuclear@0 275 {
nuclear@0 276 st.curv.cidx = c;
nuclear@0 277 }
nuclear@0 278
nuclear@0 279 void mgl_normal(float x, float y, float z)
nuclear@0 280 {
nuclear@0 281 st.curv.norm.x = x;
nuclear@0 282 st.curv.norm.y = y;
nuclear@0 283 st.curv.norm.z = z;
nuclear@0 284 }
nuclear@0 285
nuclear@0 286 void mgl_texcoord2f(float x, float y)
nuclear@0 287 {
nuclear@0 288 st.curv.tc.x = x;
nuclear@0 289 st.curv.tc.y = y;
nuclear@0 290 }
nuclear@0 291
nuclear@0 292 static void transform(vec4_t *res, vec4_t *v, float *mat)
nuclear@0 293 {
nuclear@0 294 res->x = mat[0] * v->x + mat[4] * v->y + mat[8] * v->z + mat[12] * v->w;
nuclear@0 295 res->y = mat[1] * v->x + mat[5] * v->y + mat[9] * v->z + mat[13] * v->w;
nuclear@0 296 res->z = mat[2] * v->x + mat[6] * v->y + mat[10] * v->z + mat[14] * v->w;
nuclear@0 297 res->w = mat[3] * v->x + mat[7] * v->y + mat[11] * v->z + mat[15] * v->w;
nuclear@0 298 }
nuclear@0 299
nuclear@0 300 /* the matrix is 4x4 (16 floats), just ignoring anything out of the 3x3 */
nuclear@0 301 static void transform3(vec3_t *res, vec3_t *v, float *mat)
nuclear@0 302 {
nuclear@0 303 res->x = mat[0] * v->x + mat[4] * v->y + mat[8] * v->z;
nuclear@0 304 res->y = mat[1] * v->x + mat[5] * v->y + mat[9] * v->z;
nuclear@0 305 res->z = mat[2] * v->x + mat[6] * v->y + mat[10] * v->z;
nuclear@0 306 }
nuclear@0 307
nuclear@0 308 static void vertex_proc(struct vertex *vert)
nuclear@0 309 {
nuclear@0 310 vec4_t pview, pclip;
nuclear@0 311
nuclear@0 312 float *mvmat = st.matrix[MGL_MODELVIEW][st.mtop[MGL_MODELVIEW]];
nuclear@0 313 float *pmat = st.matrix[MGL_PROJECTION][st.mtop[MGL_PROJECTION]];
nuclear@0 314
nuclear@0 315 /* modelview transformation */
nuclear@0 316 transform(&pview, &vert->pos, mvmat);
nuclear@0 317
nuclear@0 318 if(st.flags & MGL_LIGHTING) {
nuclear@0 319 if((st.flags & MGL_SMOOTH) || st.vidx == 0) {
nuclear@0 320 int i;
nuclear@0 321 vec3_t norm;
nuclear@0 322 float irrad = 0.0f;
nuclear@0 323
nuclear@0 324 transform3(&norm, &vert->norm, mvmat);
nuclear@0 325
nuclear@0 326 for(i=0; i<MAX_LIGHTS; i++) {
nuclear@0 327 if(st.lint[i] > 1e-6f) {
nuclear@11 328 float ndotl;
nuclear@11 329 vec3_t ldir;
nuclear@11 330
nuclear@11 331 if(st.lpos[i].w == 0.0) {
nuclear@11 332 ldir.x = st.lpos[i].x;
nuclear@11 333 ldir.y = st.lpos[i].y;
nuclear@11 334 ldir.z = st.lpos[i].z;
nuclear@11 335 } else {
nuclear@11 336 ldir.x = st.lpos[i].x - pview.x;
nuclear@11 337 ldir.y = st.lpos[i].y - pview.y;
nuclear@11 338 ldir.z = st.lpos[i].z - pview.z;
nuclear@11 339
nuclear@11 340 NORMALIZE(ldir);
nuclear@11 341 }
nuclear@11 342
nuclear@11 343 ndotl = DOT(norm, ldir);
nuclear@0 344 if(ndotl < 0.0) {
nuclear@0 345 ndotl = 0.0;
nuclear@0 346 }
nuclear@0 347 irrad += ndotl * st.lint[i];
nuclear@0 348 }
nuclear@0 349 }
nuclear@0 350 vert->energy = irrad;
nuclear@0 351 } else {
nuclear@0 352 vert->energy = st.v[0].energy;
nuclear@0 353 }
nuclear@0 354 }
nuclear@0 355
nuclear@0 356 transform(&pclip, &pview, pmat);
nuclear@0 357 /* TODO clipping in homogenous clip space */
nuclear@0 358
nuclear@0 359 if(pclip.w < 1e-6 && pclip.w > -1e-6) {
nuclear@0 360 vert->pos.x = vert->pos.y = vert->pos.z = vert->pos.w = 0.0f;
nuclear@0 361 return;
nuclear@0 362 }
nuclear@0 363
nuclear@0 364 /* perspective division */
nuclear@0 365 vert->pos.x = pclip.x / pclip.w;
nuclear@0 366 vert->pos.y = pclip.y / pclip.w;
nuclear@0 367 vert->pos.z = pclip.z / pclip.w;
nuclear@0 368 vert->pos.w = pclip.w;
nuclear@0 369
nuclear@0 370 /* viewport transformation */
nuclear@0 371 vert->pos.x = st.vp[0] + st.vp[2] * (vert->pos.x * 0.5 + 0.5);
nuclear@0 372 vert->pos.y = st.vp[1] + st.vp[3] * (-vert->pos.y * 0.5 + 0.5);
nuclear@0 373 }
nuclear@0 374
nuclear@0 375 void mgl_viewport(int x, int y, int width, int height)
nuclear@0 376 {
nuclear@0 377 st.vp[0] = x;
nuclear@0 378 st.vp[1] = y;
nuclear@0 379 st.vp[2] = width;
nuclear@0 380 st.vp[3] = height;
nuclear@0 381 }
nuclear@0 382
nuclear@0 383 void mgl_matrix_mode(int mmode)
nuclear@0 384 {
nuclear@0 385 st.mmode = mmode;
nuclear@0 386 }
nuclear@0 387
nuclear@0 388 void mgl_push_matrix(void)
nuclear@0 389 {
nuclear@0 390 float *topmat;
nuclear@0 391 if(st.mtop[st.mmode] >= MATRIX_STACK_SIZE - 1) {
nuclear@0 392 fprintf(stderr, "mgl_push_matrix: stack overflow\n");
nuclear@0 393 abort();
nuclear@0 394 }
nuclear@0 395
nuclear@0 396 topmat = st.matrix[st.mmode][st.mtop[st.mmode]];
nuclear@0 397 memcpy(topmat + 16, topmat, 16 * sizeof *topmat);
nuclear@0 398 st.mmode++;
nuclear@0 399 }
nuclear@0 400
nuclear@0 401 void mgl_pop_matrix(void)
nuclear@0 402 {
nuclear@0 403 if(st.mtop[st.mmode] <= 0) {
nuclear@0 404 fprintf(stderr, "mgl_pop_matrix: stack underflow\n");
nuclear@0 405 abort();
nuclear@0 406 }
nuclear@0 407 st.mtop[st.mmode]--;
nuclear@0 408 }
nuclear@0 409
nuclear@0 410 void mgl_load_matrix(float *mat)
nuclear@0 411 {
nuclear@0 412 float *dest = st.matrix[st.mmode][st.mtop[st.mmode]];
nuclear@0 413 memcpy(dest, mat, 16 * sizeof *dest);
nuclear@0 414 }
nuclear@0 415
nuclear@17 416 #define M(i,j) (((i) << 2) + (j))
nuclear@0 417 void mgl_mult_matrix(float *m2)
nuclear@0 418 {
nuclear@0 419 int i, j;
nuclear@0 420 float m1[16];
nuclear@0 421 float *dest = st.matrix[st.mmode][st.mtop[st.mmode]];
nuclear@0 422
nuclear@0 423 memcpy(m1, dest, sizeof m1);
nuclear@0 424
nuclear@0 425 for(i=0; i<4; i++) {
nuclear@0 426 for(j=0; j<4; j++) {
nuclear@0 427 dest[M(i,j)] = m1[M(0,j)] * m2[M(i,0)] +
nuclear@0 428 m1[M(1,j)] * m2[M(i,1)] +
nuclear@0 429 m1[M(2,j)] * m2[M(i,2)] +
nuclear@0 430 m1[M(3,j)] * m2[M(i,3)];
nuclear@0 431 }
nuclear@0 432 }
nuclear@0 433 }
nuclear@0 434
nuclear@0 435 void mgl_load_identity(void)
nuclear@0 436 {
nuclear@0 437 static float id[] = {1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1};
nuclear@0 438 mgl_load_matrix((float*)id);
nuclear@0 439 }
nuclear@0 440
nuclear@0 441 void mgl_translate(float x, float y, float z)
nuclear@0 442 {
nuclear@0 443 float xform[] = {1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1};
nuclear@0 444 xform[12] = x;
nuclear@0 445 xform[13] = y;
nuclear@0 446 xform[14] = z;
nuclear@0 447 mgl_mult_matrix(xform);
nuclear@0 448 }
nuclear@0 449
nuclear@0 450 void mgl_rotate(float deg, float x, float y, float z)
nuclear@0 451 {
nuclear@0 452 float xform[] = {1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1};
nuclear@0 453
nuclear@0 454 float angle = M_PI * deg / 180.0f;
nuclear@0 455 float sina = sin(angle);
nuclear@0 456 float cosa = cos(angle);
nuclear@0 457 float one_minus_cosa = 1.0f - cosa;
nuclear@0 458 float nxsq = x * x;
nuclear@0 459 float nysq = y * y;
nuclear@0 460 float nzsq = z * z;
nuclear@0 461
nuclear@0 462 xform[0] = nxsq + (1.0f - nxsq) * cosa;
nuclear@0 463 xform[4] = x * y * one_minus_cosa - z * sina;
nuclear@0 464 xform[8] = x * z * one_minus_cosa + y * sina;
nuclear@0 465 xform[1] = x * y * one_minus_cosa + z * sina;
nuclear@0 466 xform[5] = nysq + (1.0 - nysq) * cosa;
nuclear@0 467 xform[9] = y * z * one_minus_cosa - x * sina;
nuclear@0 468 xform[2] = x * z * one_minus_cosa - y * sina;
nuclear@0 469 xform[6] = y * z * one_minus_cosa + x * sina;
nuclear@0 470 xform[10] = nzsq + (1.0 - nzsq) * cosa;
nuclear@0 471
nuclear@0 472 mgl_mult_matrix(xform);
nuclear@0 473 }
nuclear@0 474
nuclear@0 475 void mgl_scale(float x, float y, float z)
nuclear@0 476 {
nuclear@0 477 float xform[] = {1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1};
nuclear@0 478 xform[0] = x;
nuclear@0 479 xform[5] = y;
nuclear@0 480 xform[10] = z;
nuclear@0 481 mgl_mult_matrix(xform);
nuclear@0 482 }
nuclear@0 483
nuclear@0 484 void gl_ortho(float left, float right, float bottom, float top, float nr, float fr)
nuclear@0 485 {
nuclear@0 486 float xform[] = {1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1};
nuclear@0 487
nuclear@0 488 float dx = right - left;
nuclear@0 489 float dy = top - bottom;
nuclear@0 490 float dz = fr - nr;
nuclear@0 491
nuclear@0 492 float tx = -(right + left) / dx;
nuclear@0 493 float ty = -(top + bottom) / dy;
nuclear@0 494 float tz = -(fr + nr) / dz;
nuclear@0 495
nuclear@0 496 float sx = 2.0 / dx;
nuclear@0 497 float sy = 2.0 / dy;
nuclear@0 498 float sz = -2.0 / dz;
nuclear@0 499
nuclear@0 500 xform[0] = sx;
nuclear@0 501 xform[5] = sy;
nuclear@0 502 xform[10] = sz;
nuclear@0 503 xform[12] = tx;
nuclear@0 504 xform[13] = ty;
nuclear@0 505 xform[14] = tz;
nuclear@0 506
nuclear@0 507 mgl_mult_matrix(xform);
nuclear@0 508 }
nuclear@0 509
nuclear@0 510 void mgl_frustum(float left, float right, float bottom, float top, float nr, float fr)
nuclear@0 511 {
nuclear@0 512 float xform[] = {1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1};
nuclear@0 513
nuclear@0 514 float dx = right - left;
nuclear@0 515 float dy = top - bottom;
nuclear@0 516 float dz = fr - nr;
nuclear@0 517
nuclear@0 518 float a = (right + left) / dx;
nuclear@0 519 float b = (top + bottom) / dy;
nuclear@0 520 float c = -(fr + nr) / dz;
nuclear@0 521 float d = -2.0 * fr * nr / dz;
nuclear@0 522
nuclear@0 523 xform[0] = 2.0 * nr / dx;
nuclear@0 524 xform[5] = 2.0 * nr / dy;
nuclear@0 525 xform[8] = a;
nuclear@0 526 xform[9] = b;
nuclear@0 527 xform[10] = c;
nuclear@0 528 xform[11] = -1.0f;
nuclear@0 529 xform[14] = d;
nuclear@0 530
nuclear@0 531 mgl_mult_matrix(xform);
nuclear@0 532 }
nuclear@0 533
nuclear@0 534 void mgl_perspective(float vfov, float aspect, float nr, float fr)
nuclear@0 535 {
nuclear@0 536 float vfov_rad = M_PI * vfov / 180.0;
nuclear@0 537 float x = nr * tan(vfov_rad / 2.0);
nuclear@0 538 mgl_frustum(-aspect * x, aspect * x, -x, x, nr, fr);
nuclear@0 539 }
nuclear@3 540
nuclear@3 541 void mgl_teximage(int width, int height, unsigned char *pixels)
nuclear@3 542 {
nuclear@3 543 st.tex.width = width;
nuclear@3 544 st.tex.height = height;
nuclear@3 545 st.tex.pixels = pixels;
nuclear@3 546
nuclear@3 547 if(calc_shiftmask(width, &st.tex.xshift, &st.tex.xmask) == -1 ||
nuclear@3 548 calc_shiftmask(height, &st.tex.yshift, &st.tex.ymask) == -1) {
nuclear@3 549 st.tex.pixels = 0;
nuclear@3 550 }
nuclear@3 551 }
nuclear@3 552
nuclear@3 553 #define MAX_SHIFT 12
nuclear@3 554 static int calc_shiftmask(int val, int *shiftp, unsigned int *maskp)
nuclear@3 555 {
nuclear@3 556 int i;
nuclear@3 557
nuclear@3 558 for(i=0; i<MAX_SHIFT; i++) {
nuclear@3 559 if((val >> i) == 1) {
nuclear@3 560 *shiftp = i;
nuclear@17 561 *maskp = ~(UINT_MAX << i);
nuclear@3 562 return 0;
nuclear@3 563 }
nuclear@3 564 }
nuclear@3 565 return -1;
nuclear@3 566 }