15 typedef float g3d_matrix[16];
17 #define MAX_VBUF_SIZE 256
36 g3d_matrix mat[G3D_NUM_MATRICES][STACK_SIZE];
37 int mtop[G3D_NUM_MATRICES];
43 struct light lt[MAX_LIGHTS];
52 static void xform4_vec3(const float *mat, float *vec);
53 static void xform3_vec3(const float *mat, float *vec);
54 static void shade(struct g3d_vertex *v);
56 static struct g3d_state *st;
57 static const float idmat[] = {
68 if(!(st = calloc(1, sizeof *st))) {
69 fprintf(stderr, "failed to allocate G3D context\n");
72 st->fill_mode = POLYFILL_FLAT;
74 for(i=0; i<G3D_NUM_MATRICES; i++) {
79 for(i=0; i<MAX_LIGHTS; i++) {
80 g3d_light_color(i, 1, 1, 1);
82 g3d_light_ambient(0.1, 0.1, 0.1);
84 g3d_mtl_diffuse(1, 1, 1);
88 void g3d_destroy(void)
93 void g3d_framebuffer(int width, int height, void *pixels)
99 pfill_fb.pixels = pixels;
100 pfill_fb.width = width;
101 pfill_fb.height = height;
103 g3d_viewport(0, 0, width, height);
106 void g3d_viewport(int x, int y, int w, int h)
114 void g3d_enable(unsigned int opt)
119 void g3d_disable(unsigned int opt)
124 void g3d_setopt(unsigned int opt, unsigned int mask)
126 st->opt = (st->opt & ~mask) | (opt & mask);
129 unsigned int g3d_getopt(unsigned int mask)
131 return st->opt & mask;
134 void g3d_front_face(unsigned int order)
136 st->frontface = order;
139 void g3d_polygon_mode(int pmode)
141 st->fill_mode = pmode;
144 void g3d_matrix_mode(int mmode)
149 void g3d_load_identity(void)
151 int top = st->mtop[st->mmode];
152 memcpy(st->mat[st->mmode][top], idmat, 16 * sizeof(float));
155 void g3d_load_matrix(const float *m)
157 int top = st->mtop[st->mmode];
158 memcpy(st->mat[st->mmode][top], m, 16 * sizeof(float));
161 #define M(i,j) (((i) << 2) + (j))
162 void g3d_mult_matrix(const float *m2)
164 int i, j, top = st->mtop[st->mmode];
166 float *dest = st->mat[st->mmode][top];
168 memcpy(m1, dest, sizeof m1);
172 *dest++ = m1[M(0,j)] * m2[M(i,0)] +
173 m1[M(1,j)] * m2[M(i,1)] +
174 m1[M(2,j)] * m2[M(i,2)] +
175 m1[M(3,j)] * m2[M(i,3)];
180 void g3d_push_matrix(void)
182 int top = st->mtop[st->mmode];
183 if(top >= G3D_NUM_MATRICES) {
184 fprintf(stderr, "g3d_push_matrix overflow\n");
187 memcpy(st->mat[st->mmode][top + 1], st->mat[st->mmode][top], 16 * sizeof(float));
188 st->mtop[st->mmode] = top + 1;
191 void g3d_pop_matrix(void)
193 if(st->mtop[st->mmode] <= 0) {
194 fprintf(stderr, "g3d_pop_matrix underflow\n");
197 --st->mtop[st->mmode];
200 void g3d_translate(float x, float y, float z)
202 float m[] = {1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1};
209 void g3d_rotate(float deg, float x, float y, float z)
211 float m[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
213 float angle = M_PI * deg / 180.0f;
214 float sina = sin(angle);
215 float cosa = cos(angle);
216 float one_minus_cosa = 1.0f - cosa;
221 m[0] = nxsq + (1.0f - nxsq) * cosa;
222 m[4] = x * y * one_minus_cosa - z * sina;
223 m[8] = x * z * one_minus_cosa + y * sina;
224 m[1] = x * y * one_minus_cosa + z * sina;
225 m[5] = nysq + (1.0 - nysq) * cosa;
226 m[9] = y * z * one_minus_cosa - x * sina;
227 m[2] = x * z * one_minus_cosa - y * sina;
228 m[6] = y * z * one_minus_cosa + x * sina;
229 m[10] = nzsq + (1.0 - nzsq) * cosa;
235 void g3d_scale(float x, float y, float z)
237 float m[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
245 void g3d_ortho(float left, float right, float bottom, float top, float znear, float zfar)
247 float m[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
249 float dx = right - left;
250 float dy = top - bottom;
251 float dz = zfar - znear;
256 m[12] = -(right + left) / dx;
257 m[13] = -(top + bottom) / dy;
258 m[14] = -(zfar + znear) / dz;
263 void g3d_frustum(float left, float right, float bottom, float top, float nr, float fr)
265 float m[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
267 float dx = right - left;
268 float dy = top - bottom;
271 float a = (right + left) / dx;
272 float b = (top + bottom) / dy;
273 float c = -(fr + nr) / dz;
274 float d = -2.0 * fr * nr / dz;
276 m[0] = 2.0 * nr / dx;
277 m[5] = 2.0 * nr / dy;
287 void g3d_perspective(float vfov_deg, float aspect, float znear, float zfar)
289 float m[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
291 float vfov = M_PI * vfov_deg / 180.0f;
292 float s = 1.0f / tan(vfov * 0.5f);
293 float range = znear - zfar;
297 m[10] = (znear + zfar) / range;
299 m[14] = 2.0f * znear * zfar / range;
304 const float *g3d_get_matrix(int which, float *m)
306 int top = st->mtop[which];
309 memcpy(m, st->mat[which][top], 16 * sizeof(float));
311 return st->mat[which][top];
314 void g3d_light_pos(int idx, float x, float y, float z)
316 int mvtop = st->mtop[G3D_MODELVIEW];
322 xform4_vec3(st->mat[G3D_MODELVIEW][mvtop], &st->lt[idx].x);
325 void g3d_light_color(int idx, float r, float g, float b)
332 void g3d_light_ambient(float r, float g, float b)
339 void g3d_mtl_diffuse(float r, float g, float b)
346 void g3d_mtl_specular(float r, float g, float b)
353 void g3d_mtl_shininess(float shin)
358 static INLINE int calc_shift(unsigned int x)
368 static INLINE int calc_mask(unsigned int x)
373 void g3d_set_texture(int xsz, int ysz, void *pixels)
375 pfill_tex.pixels = pixels;
376 pfill_tex.width = xsz;
377 pfill_tex.height = ysz;
379 pfill_tex.xshift = calc_shift(xsz);
380 pfill_tex.yshift = calc_shift(ysz);
381 pfill_tex.xmask = calc_mask(xsz);
382 pfill_tex.ymask = calc_mask(ysz);
385 void g3d_draw(int prim, const struct g3d_vertex *varr, int varr_size)
387 g3d_draw_indexed(prim, varr, varr_size, 0, 0);
390 void g3d_draw_indexed(int prim, const struct g3d_vertex *varr, int varr_size,
391 const int16_t *iarr, int iarr_size)
394 struct pvertex pv[16];
395 struct g3d_vertex v[16];
396 int vnum = prim; /* primitive vertex counts correspond to enum values */
397 int mvtop = st->mtop[G3D_MODELVIEW];
398 int ptop = st->mtop[G3D_PROJECTION];
400 /* calc the normal matrix */
401 memcpy(st->norm_mat, st->mat[G3D_MODELVIEW][mvtop], 16 * sizeof(float));
402 st->norm_mat[12] = st->norm_mat[13] = st->norm_mat[14] = 0.0f;
404 nfaces = (iarr ? iarr_size : varr_size) / vnum;
406 for(j=0; j<nfaces; j++) {
407 vnum = prim; /* reset vnum for each iteration */
409 for(i=0; i<vnum; i++) {
410 v[i] = iarr ? varr[*iarr++] : *varr++;
412 xform4_vec3(st->mat[G3D_MODELVIEW][mvtop], &v[i].x);
413 xform3_vec3(st->norm_mat, &v[i].nx);
415 if(st->opt & G3D_LIGHTING) {
418 xform4_vec3(st->mat[G3D_PROJECTION][ptop], &v[i].x);
423 struct g3d_vertex tmpv[16];
424 memcpy(tmpv, v, vnum * sizeof *v);
426 if(clip_frustum(v, &vnum, tmpv, vnum, i) < 0) {
427 /* polygon completely outside of view volume. discard */
435 for(i=0; i<vnum; i++) {
439 /*v[i].z /= v[i].w;*/
442 /* viewport transformation */
443 v[i].x = (v[i].x * 0.5f + 0.5f) * (float)st->vport[2] + st->vport[0];
444 v[i].y = (0.5f - v[i].y * 0.5f) * (float)st->vport[3] + st->vport[1];
446 /* convert pos to 24.8 fixed point */
447 pv[i].x = cround64(v[i].x * 256.0f);
448 pv[i].y = cround64(v[i].y * 256.0f);
449 /* convert tex coords to 16.16 fixed point */
450 pv[i].u = cround64(v[i].u * 65536.0f);
451 pv[i].v = cround64(v[i].v * 65536.0f);
452 /* pass the color through as is */
459 /* backface culling */
460 if(vnum > 2 && st->opt & G3D_CULL_FACE) {
461 int32_t ax = pv[1].x - pv[0].x;
462 int32_t ay = pv[1].y - pv[0].y;
463 int32_t bx = pv[2].x - pv[0].x;
464 int32_t by = pv[2].y - pv[0].y;
465 int32_t cross_z = ax * (by >> 8) - ay * (bx >> 8);
466 int sign = (cross_z >> 31) & 1;
468 if(!(sign ^ st->frontface)) {
469 continue; /* back-facing */
475 if(st->opt & G3D_BLEND) {
477 int inv_alpha = 255 - pv[0].a;
478 uint16_t *dest = fb_pixels + (pv[0].y >> 8) * fb_width + (pv[0].x >> 8);
479 r = ((int)pv[0].r * pv[0].a + UNPACK_R16(*dest) * inv_alpha) >> 8;
480 g = ((int)pv[0].g * pv[0].a + UNPACK_G16(*dest) * inv_alpha) >> 8;
481 b = ((int)pv[0].b * pv[0].a + UNPACK_B16(*dest) * inv_alpha) >> 8;
482 *dest++ = PACK_RGB16(r, g, b);
484 uint16_t *dest = fb_pixels + (pv[0].y >> 8) * fb_width + (pv[0].x >> 8);
485 *dest = PACK_RGB16(pv[0].r, pv[0].g, pv[0].b);
490 /* TODO: draw line */
494 polyfill(st->fill_mode, pv, vnum);
499 static void xform4_vec3(const float *mat, float *vec)
501 float x = mat[0] * vec[0] + mat[4] * vec[1] + mat[8] * vec[2] + mat[12];
502 float y = mat[1] * vec[0] + mat[5] * vec[1] + mat[9] * vec[2] + mat[13];
503 float z = mat[2] * vec[0] + mat[6] * vec[1] + mat[10] * vec[2] + mat[14];
504 float w = mat[3] * vec[0] + mat[7] * vec[1] + mat[11] * vec[2] + mat[15];
512 static void xform3_vec3(const float *mat, float *vec)
514 float x = mat[0] * vec[0] + mat[4] * vec[1] + mat[8] * vec[2];
515 float y = mat[1] * vec[0] + mat[5] * vec[1] + mat[9] * vec[2];
516 float z = mat[2] * vec[0] + mat[6] * vec[1] + mat[10] * vec[2];
523 #define NORMALIZE(v) \
525 float len = sqrt(v[0] * v[0] + v[1] * v[1] + v[2] * v[2]); \
527 float s = 1.0 / len; \
534 static void shade(struct g3d_vertex *v)
539 color[0] = st->ambient[0] * st->mtl.kd[0];
540 color[1] = st->ambient[1] * st->mtl.kd[1];
541 color[2] = st->ambient[2] * st->mtl.kd[2];
543 for(i=0; i<MAX_LIGHTS; i++) {
547 if(!(st->opt & (G3D_LIGHT0 << i))) {
551 ldir[0] = st->lt[i].x - v->x;
552 ldir[1] = st->lt[i].y - v->y;
553 ldir[2] = st->lt[i].z - v->z;
556 if((ndotl = v->nx * ldir[0] + v->ny * ldir[1] + v->nz * ldir[2]) < 0.0f) {
560 color[0] += st->mtl.kd[0] * st->lt[i].r * ndotl;
561 color[1] += st->mtl.kd[1] * st->lt[i].g * ndotl;
562 color[2] += st->mtl.kd[2] * st->lt[i].b * ndotl;
565 r = cround64(color[0] * 255.0);
566 g = cround64(color[1] * 255.0);
567 b = cround64(color[2] * 255.0);
569 v->r = r > 255 ? 255 : r;
570 v->g = g > 255 ? 255 : g;
571 v->b = b > 255 ? 255 : b;