13 typedef float g3d_matrix[16];
15 #define MAX_VBUF_SIZE 256
34 g3d_matrix mat[G3D_NUM_MATRICES][STACK_SIZE];
35 int mtop[G3D_NUM_MATRICES];
41 struct light lt[MAX_LIGHTS];
50 static void xform4_vec3(const float *mat, float *vec);
51 static void xform3_vec3(const float *mat, float *vec);
52 static void shade(struct g3d_vertex *v);
54 static struct g3d_state *st;
55 static const float idmat[] = {
66 if(!(st = calloc(1, sizeof *st))) {
67 fprintf(stderr, "failed to allocate G3D context\n");
70 st->fill_mode = POLYFILL_FLAT;
72 for(i=0; i<G3D_NUM_MATRICES; i++) {
77 for(i=0; i<MAX_LIGHTS; i++) {
78 g3d_light_color(i, 1, 1, 1);
80 g3d_light_ambient(0.1, 0.1, 0.1);
82 g3d_mtl_diffuse(1, 1, 1);
86 void g3d_destroy(void)
91 void g3d_framebuffer(int width, int height, void *pixels)
97 pfill_fb.pixels = pixels;
98 pfill_fb.width = width;
99 pfill_fb.height = height;
101 g3d_viewport(0, 0, width, height);
104 void g3d_viewport(int x, int y, int w, int h)
112 void g3d_enable(unsigned int opt)
117 void g3d_disable(unsigned int opt)
122 void g3d_setopt(unsigned int opt, unsigned int mask)
124 st->opt = (st->opt & ~mask) | (opt & mask);
127 unsigned int g3d_getopt(unsigned int mask)
129 return st->opt & mask;
132 void g3d_front_face(unsigned int order)
134 st->frontface = order;
137 void g3d_polygon_mode(int pmode)
139 st->fill_mode = pmode;
142 void g3d_matrix_mode(int mmode)
147 void g3d_load_identity(void)
149 int top = st->mtop[st->mmode];
150 memcpy(st->mat[st->mmode][top], idmat, 16 * sizeof(float));
153 void g3d_load_matrix(const float *m)
155 int top = st->mtop[st->mmode];
156 memcpy(st->mat[st->mmode][top], m, 16 * sizeof(float));
159 #define M(i,j) (((i) << 2) + (j))
160 void g3d_mult_matrix(const float *m2)
162 int i, j, top = st->mtop[st->mmode];
164 float *dest = st->mat[st->mmode][top];
166 memcpy(m1, dest, sizeof m1);
170 *dest++ = m1[M(0,j)] * m2[M(i,0)] +
171 m1[M(1,j)] * m2[M(i,1)] +
172 m1[M(2,j)] * m2[M(i,2)] +
173 m1[M(3,j)] * m2[M(i,3)];
178 void g3d_push_matrix(void)
180 int top = st->mtop[st->mmode];
181 if(top >= G3D_NUM_MATRICES) {
182 fprintf(stderr, "g3d_push_matrix overflow\n");
185 memcpy(st->mat[st->mmode][top + 1], st->mat[st->mmode][top], 16 * sizeof(float));
186 st->mtop[st->mmode] = top + 1;
189 void g3d_pop_matrix(void)
191 if(st->mtop[st->mmode] <= 0) {
192 fprintf(stderr, "g3d_pop_matrix underflow\n");
195 --st->mtop[st->mmode];
198 void g3d_translate(float x, float y, float z)
200 float m[] = {1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1};
207 void g3d_rotate(float deg, float x, float y, float z)
209 float m[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
211 float angle = M_PI * deg / 180.0f;
212 float sina = sin(angle);
213 float cosa = cos(angle);
214 float one_minus_cosa = 1.0f - cosa;
219 m[0] = nxsq + (1.0f - nxsq) * cosa;
220 m[4] = x * y * one_minus_cosa - z * sina;
221 m[8] = x * z * one_minus_cosa + y * sina;
222 m[1] = x * y * one_minus_cosa + z * sina;
223 m[5] = nysq + (1.0 - nysq) * cosa;
224 m[9] = y * z * one_minus_cosa - x * sina;
225 m[2] = x * z * one_minus_cosa - y * sina;
226 m[6] = y * z * one_minus_cosa + x * sina;
227 m[10] = nzsq + (1.0 - nzsq) * cosa;
233 void g3d_scale(float x, float y, float z)
235 float m[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
243 void g3d_ortho(float left, float right, float bottom, float top, float znear, float zfar)
245 float m[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
247 float dx = right - left;
248 float dy = top - bottom;
249 float dz = zfar - znear;
254 m[12] = -(right + left) / dx;
255 m[13] = -(top + bottom) / dy;
256 m[14] = -(zfar + znear) / dz;
261 void g3d_frustum(float left, float right, float bottom, float top, float nr, float fr)
263 float m[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
265 float dx = right - left;
266 float dy = top - bottom;
269 float a = (right + left) / dx;
270 float b = (top + bottom) / dy;
271 float c = -(fr + nr) / dz;
272 float d = -2.0 * fr * nr / dz;
274 m[0] = 2.0 * nr / dx;
275 m[5] = 2.0 * nr / dy;
285 void g3d_perspective(float vfov_deg, float aspect, float znear, float zfar)
287 float m[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
289 float vfov = M_PI * vfov_deg / 180.0f;
290 float s = 1.0f / tan(vfov * 0.5f);
291 float range = znear - zfar;
295 m[10] = (znear + zfar) / range;
297 m[14] = 2.0f * znear * zfar / range;
302 const float *g3d_get_matrix(int which, float *m)
304 int top = st->mtop[which];
307 memcpy(m, st->mat[which][top], 16 * sizeof(float));
309 return st->mat[which][top];
312 void g3d_light_pos(int idx, float x, float y, float z)
314 int mvtop = st->mtop[G3D_MODELVIEW];
320 xform4_vec3(st->mat[G3D_MODELVIEW][mvtop], &st->lt[idx].x);
323 void g3d_light_color(int idx, float r, float g, float b)
330 void g3d_light_ambient(float r, float g, float b)
337 void g3d_mtl_diffuse(float r, float g, float b)
344 void g3d_mtl_specular(float r, float g, float b)
351 void g3d_mtl_shininess(float shin)
356 static INLINE int calc_shift(unsigned int x)
366 static INLINE int calc_mask(unsigned int x)
371 void g3d_set_texture(int xsz, int ysz, void *pixels)
373 pfill_tex.pixels = pixels;
374 pfill_tex.width = xsz;
375 pfill_tex.height = ysz;
377 pfill_tex.xshift = calc_shift(xsz);
378 pfill_tex.yshift = calc_shift(ysz);
379 pfill_tex.xmask = calc_mask(xsz);
380 pfill_tex.ymask = calc_mask(ysz);
383 void g3d_draw(int prim, const struct g3d_vertex *varr, int varr_size)
385 g3d_draw_indexed(prim, varr, varr_size, 0, 0);
388 void g3d_draw_indexed(int prim, const struct g3d_vertex *varr, int varr_size,
389 const int16_t *iarr, int iarr_size)
392 struct pvertex pv[16];
393 struct g3d_vertex v[16];
394 int vnum = prim; /* primitive vertex counts correspond to enum values */
395 int mvtop = st->mtop[G3D_MODELVIEW];
396 int ptop = st->mtop[G3D_PROJECTION];
398 /* calc the normal matrix */
399 memcpy(st->norm_mat, st->mat[G3D_MODELVIEW][mvtop], 16 * sizeof(float));
400 st->norm_mat[12] = st->norm_mat[13] = st->norm_mat[14] = 0.0f;
402 nfaces = (iarr ? iarr_size : varr_size) / vnum;
404 for(j=0; j<nfaces; j++) {
405 vnum = prim; /* reset vnum for each iteration */
407 for(i=0; i<vnum; i++) {
408 v[i] = iarr ? varr[*iarr++] : *varr++;
410 xform4_vec3(st->mat[G3D_MODELVIEW][mvtop], &v[i].x);
411 xform3_vec3(st->norm_mat, &v[i].nx);
413 if(st->opt & G3D_LIGHTING) {
416 xform4_vec3(st->mat[G3D_PROJECTION][ptop], &v[i].x);
421 struct g3d_vertex tmpv[16];
422 memcpy(tmpv, v, vnum * sizeof *v);
424 if(clip_frustum(v, &vnum, tmpv, vnum, i) < 0) {
425 /* polygon completely outside of view volume. discard */
433 for(i=0; i<vnum; i++) {
437 /*v[i].z /= v[i].w;*/
440 /* viewport transformation */
441 v[i].x = (v[i].x * 0.5f + 0.5f) * (float)st->vport[2] + st->vport[0];
442 v[i].y = (0.5f - v[i].y * 0.5f) * (float)st->vport[3] + st->vport[1];
444 /* convert pos to 24.8 fixed point */
445 pv[i].x = cround64(v[i].x * 256.0f);
446 pv[i].y = cround64(v[i].y * 256.0f);
447 /* convert tex coords to 16.16 fixed point */
448 pv[i].u = cround64(v[i].u * 65536.0f);
449 pv[i].v = cround64(v[i].v * 65536.0f);
450 /* pass the color through as is */
456 /* backface culling */
457 if(vnum > 2 && st->opt & G3D_CULL_FACE) {
458 int32_t ax = pv[1].x - pv[0].x;
459 int32_t ay = pv[1].y - pv[0].y;
460 int32_t bx = pv[2].x - pv[0].x;
461 int32_t by = pv[2].y - pv[0].y;
462 int32_t cross_z = ax * (by >> 8) - ay * (bx >> 8);
463 int sign = (cross_z >> 31) & 1;
465 if(!(sign ^ st->frontface)) {
466 continue; /* back-facing */
470 polyfill(st->fill_mode, pv, vnum);
474 static void xform4_vec3(const float *mat, float *vec)
476 float x = mat[0] * vec[0] + mat[4] * vec[1] + mat[8] * vec[2] + mat[12];
477 float y = mat[1] * vec[0] + mat[5] * vec[1] + mat[9] * vec[2] + mat[13];
478 float z = mat[2] * vec[0] + mat[6] * vec[1] + mat[10] * vec[2] + mat[14];
479 float w = mat[3] * vec[0] + mat[7] * vec[1] + mat[11] * vec[2] + mat[15];
487 static void xform3_vec3(const float *mat, float *vec)
489 float x = mat[0] * vec[0] + mat[4] * vec[1] + mat[8] * vec[2];
490 float y = mat[1] * vec[0] + mat[5] * vec[1] + mat[9] * vec[2];
491 float z = mat[2] * vec[0] + mat[6] * vec[1] + mat[10] * vec[2];
498 #define NORMALIZE(v) \
500 float len = sqrt(v[0] * v[0] + v[1] * v[1] + v[2] * v[2]); \
502 float s = 1.0 / len; \
509 static void shade(struct g3d_vertex *v)
514 color[0] = st->ambient[0] * st->mtl.kd[0];
515 color[1] = st->ambient[1] * st->mtl.kd[1];
516 color[2] = st->ambient[2] * st->mtl.kd[2];
518 for(i=0; i<MAX_LIGHTS; i++) {
522 if(!(st->opt & (G3D_LIGHT0 << i))) {
526 ldir[0] = st->lt[i].x - v->x;
527 ldir[1] = st->lt[i].y - v->y;
528 ldir[2] = st->lt[i].z - v->z;
531 if((ndotl = v->nx * ldir[0] + v->ny * ldir[1] + v->nz * ldir[2]) < 0.0f) {
535 color[0] += st->mtl.kd[0] * st->lt[i].r * ndotl;
536 color[1] += st->mtl.kd[1] * st->lt[i].g * ndotl;
537 color[2] += st->mtl.kd[2] * st->lt[i].b * ndotl;
540 r = cround64(color[0] * 255.0);
541 g = cround64(color[1] * 255.0);
542 b = cround64(color[2] * 255.0);
544 v->r = r > 255 ? 255 : r;
545 v->g = g > 255 ? 255 : g;
546 v->b = b > 255 ? 255 : b;