12 typedef float g3d_matrix[16];
14 #define MAX_VBUF_SIZE 256
33 g3d_matrix mat[G3D_NUM_MATRICES][STACK_SIZE];
34 int mtop[G3D_NUM_MATRICES];
40 struct light lt[MAX_LIGHTS];
47 static void xform4_vec3(const float *mat, float *vec);
48 static void xform3_vec3(const float *mat, float *vec);
49 static void shade(struct g3d_vertex *v);
51 static struct g3d_state *st;
52 static const float idmat[] = {
63 if(!(st = calloc(1, sizeof *st))) {
64 fprintf(stderr, "failed to allocate G3D context\n");
67 st->fill_mode = POLYFILL_FLAT;
69 for(i=0; i<G3D_NUM_MATRICES; i++) {
74 for(i=0; i<MAX_LIGHTS; i++) {
75 g3d_light_color(i, 1, 1, 1);
77 g3d_light_ambient(0.1, 0.1, 0.1);
79 g3d_mtl_diffuse(1, 1, 1);
83 void g3d_destroy(void)
88 void g3d_framebuffer(int width, int height, void *pixels)
94 pfill_fb.pixels = pixels;
95 pfill_fb.width = width;
96 pfill_fb.height = height;
99 void g3d_enable(unsigned int opt)
104 void g3d_disable(unsigned int opt)
109 void g3d_setopt(unsigned int opt, unsigned int mask)
111 st->opt = (st->opt & ~mask) | (opt & mask);
114 unsigned int g3d_getopt(unsigned int mask)
116 return st->opt & mask;
119 void g3d_front_face(unsigned int order)
121 st->frontface = order;
124 void g3d_polygon_mode(int pmode)
126 st->fill_mode = pmode;
129 void g3d_matrix_mode(int mmode)
134 void g3d_load_identity(void)
136 int top = st->mtop[st->mmode];
137 memcpy(st->mat[st->mmode][top], idmat, 16 * sizeof(float));
140 void g3d_load_matrix(const float *m)
142 int top = st->mtop[st->mmode];
143 memcpy(st->mat[st->mmode][top], m, 16 * sizeof(float));
146 #define M(i,j) (((i) << 2) + (j))
147 void g3d_mult_matrix(const float *m2)
149 int i, j, top = st->mtop[st->mmode];
151 float *dest = st->mat[st->mmode][top];
153 memcpy(m1, dest, sizeof m1);
157 *dest++ = m1[M(0,j)] * m2[M(i,0)] +
158 m1[M(1,j)] * m2[M(i,1)] +
159 m1[M(2,j)] * m2[M(i,2)] +
160 m1[M(3,j)] * m2[M(i,3)];
165 void g3d_push_matrix(void)
167 int top = st->mtop[st->mmode];
168 if(top >= G3D_NUM_MATRICES) {
169 fprintf(stderr, "g3d_push_matrix overflow\n");
172 memcpy(st->mat[st->mmode][top + 1], st->mat[st->mmode][top], 16 * sizeof(float));
173 st->mtop[st->mmode] = top + 1;
176 void g3d_pop_matrix(void)
178 if(st->mtop[st->mmode] <= 0) {
179 fprintf(stderr, "g3d_pop_matrix underflow\n");
182 --st->mtop[st->mmode];
185 void g3d_translate(float x, float y, float z)
187 float m[] = {1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1};
194 void g3d_rotate(float deg, float x, float y, float z)
196 float m[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
198 float angle = M_PI * deg / 180.0f;
199 float sina = sin(angle);
200 float cosa = cos(angle);
201 float one_minus_cosa = 1.0f - cosa;
206 m[0] = nxsq + (1.0f - nxsq) * cosa;
207 m[4] = x * y * one_minus_cosa - z * sina;
208 m[8] = x * z * one_minus_cosa + y * sina;
209 m[1] = x * y * one_minus_cosa + z * sina;
210 m[5] = nysq + (1.0 - nysq) * cosa;
211 m[9] = y * z * one_minus_cosa - x * sina;
212 m[2] = x * z * one_minus_cosa - y * sina;
213 m[6] = y * z * one_minus_cosa + x * sina;
214 m[10] = nzsq + (1.0 - nzsq) * cosa;
220 void g3d_scale(float x, float y, float z)
222 float m[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
230 void g3d_ortho(float left, float right, float bottom, float top, float znear, float zfar)
232 float m[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
234 float dx = right - left;
235 float dy = top - bottom;
236 float dz = zfar - znear;
241 m[12] = -(right + left) / dx;
242 m[13] = -(top + bottom) / dy;
243 m[14] = -(zfar + znear) / dz;
248 void g3d_frustum(float left, float right, float bottom, float top, float nr, float fr)
250 float m[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
252 float dx = right - left;
253 float dy = top - bottom;
256 float a = (right + left) / dx;
257 float b = (top + bottom) / dy;
258 float c = -(fr + nr) / dz;
259 float d = -2.0 * fr * nr / dz;
261 m[0] = 2.0 * nr / dx;
262 m[5] = 2.0 * nr / dy;
272 void g3d_perspective(float vfov_deg, float aspect, float znear, float zfar)
274 float m[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
276 float vfov = M_PI * vfov_deg / 180.0f;
277 float s = 1.0f / tan(vfov * 0.5f);
278 float range = znear - zfar;
282 m[10] = (znear + zfar) / range;
284 m[14] = 2.0f * znear * zfar / range;
289 const float *g3d_get_matrix(int which, float *m)
291 int top = st->mtop[which];
294 memcpy(m, st->mat[which][top], 16 * sizeof(float));
296 return st->mat[which][top];
299 void g3d_light_pos(int idx, float x, float y, float z)
301 int mvtop = st->mtop[G3D_MODELVIEW];
307 xform4_vec3(st->mat[G3D_MODELVIEW][mvtop], &st->lt[idx].x);
310 void g3d_light_color(int idx, float r, float g, float b)
317 void g3d_light_ambient(float r, float g, float b)
324 void g3d_mtl_diffuse(float r, float g, float b)
331 void g3d_mtl_specular(float r, float g, float b)
338 void g3d_mtl_shininess(float shin)
343 static INLINE int calc_shift(unsigned int x)
353 static INLINE int calc_mask(unsigned int x)
358 void g3d_set_texture(int xsz, int ysz, void *pixels)
360 pfill_tex.pixels = pixels;
361 pfill_tex.width = xsz;
362 pfill_tex.height = ysz;
364 pfill_tex.xshift = calc_shift(xsz);
365 pfill_tex.yshift = calc_shift(ysz);
366 pfill_tex.xmask = calc_mask(xsz);
367 pfill_tex.ymask = calc_mask(ysz);
370 void g3d_draw(int prim, const struct g3d_vertex *varr, int varr_size)
372 g3d_draw_indexed(prim, varr, varr_size, 0, 0);
375 void g3d_draw_indexed(int prim, const struct g3d_vertex *varr, int varr_size,
376 const int16_t *iarr, int iarr_size)
379 struct pvertex pv[4];
380 struct g3d_vertex v[4];
381 int vnum = prim; /* primitive vertex counts correspond to enum values */
382 int mvtop = st->mtop[G3D_MODELVIEW];
383 int ptop = st->mtop[G3D_PROJECTION];
385 /* calc the normal matrix */
386 memcpy(st->norm_mat, st->mat[G3D_MODELVIEW][mvtop], 16 * sizeof(float));
387 st->norm_mat[12] = st->norm_mat[13] = st->norm_mat[14] = 0.0f;
389 nfaces = (iarr ? iarr_size : varr_size) / vnum;
391 for(j=0; j<nfaces; j++) {
393 for(i=0; i<vnum; i++) {
394 v[i] = iarr ? varr[*iarr++] : *varr++;
396 xform4_vec3(st->mat[G3D_MODELVIEW][mvtop], &v[i].x);
397 xform3_vec3(st->norm_mat, &v[i].nx);
399 if(st->opt & G3D_LIGHTING) {
402 xform4_vec3(st->mat[G3D_PROJECTION][ptop], &v[i].x);
407 for(i=0; i<vnum; i++) {
411 /*v[i].z /= v[i].w;*/
414 /* viewport transformation */
415 v[i].x = (v[i].x * 0.5f + 0.5f) * (float)st->width;
416 v[i].y = (0.5f - v[i].y * 0.5f) * (float)st->height;
418 /* convert pos to 24.8 fixed point */
419 pv[i].x = cround64(v[i].x * 256.0f);
420 pv[i].y = cround64(v[i].y * 256.0f);
421 /* convert tex coords to 16.16 fixed point */
422 pv[i].u = cround64(v[i].u * 65536.0f);
423 pv[i].v = cround64(v[i].v * 65536.0f);
424 /* pass the color through as is */
430 /* backface culling */
431 if(vnum > 2 && st->opt & G3D_CULL_FACE) {
432 int32_t ax = pv[1].x - pv[0].x;
433 int32_t ay = pv[1].y - pv[0].y;
434 int32_t bx = pv[2].x - pv[0].x;
435 int32_t by = pv[2].y - pv[0].y;
436 int32_t cross_z = ax * (by >> 8) - ay * (bx >> 8);
437 int sign = (cross_z >> 31) & 1;
439 if(!(sign ^ st->frontface)) {
440 continue; /* back-facing */
444 polyfill(st->fill_mode, pv, vnum);
448 static void xform4_vec3(const float *mat, float *vec)
450 float x = mat[0] * vec[0] + mat[4] * vec[1] + mat[8] * vec[2] + mat[12];
451 float y = mat[1] * vec[0] + mat[5] * vec[1] + mat[9] * vec[2] + mat[13];
452 float z = mat[2] * vec[0] + mat[6] * vec[1] + mat[10] * vec[2] + mat[14];
453 float w = mat[3] * vec[0] + mat[7] * vec[1] + mat[11] * vec[2] + mat[15];
461 static void xform3_vec3(const float *mat, float *vec)
463 float x = mat[0] * vec[0] + mat[4] * vec[1] + mat[8] * vec[2];
464 float y = mat[1] * vec[0] + mat[5] * vec[1] + mat[9] * vec[2];
465 float z = mat[2] * vec[0] + mat[6] * vec[1] + mat[10] * vec[2];
472 #define NORMALIZE(v) \
474 float len = sqrt(v[0] * v[0] + v[1] * v[1] + v[2] * v[2]); \
476 float s = 1.0 / len; \
483 static void shade(struct g3d_vertex *v)
488 color[0] = st->ambient[0] * st->mtl.kd[0];
489 color[1] = st->ambient[1] * st->mtl.kd[1];
490 color[2] = st->ambient[2] * st->mtl.kd[2];
492 for(i=0; i<MAX_LIGHTS; i++) {
496 if(!(st->opt & (G3D_LIGHT0 << i))) {
500 ldir[0] = st->lt[i].x - v->x;
501 ldir[1] = st->lt[i].y - v->y;
502 ldir[2] = st->lt[i].z - v->z;
505 if((ndotl = v->nx * ldir[0] + v->ny * ldir[1] + v->nz * ldir[2]) < 0.0f) {
509 color[0] += st->mtl.kd[0] * st->lt[i].r * ndotl;
510 color[1] += st->mtl.kd[1] * st->lt[i].g * ndotl;
511 color[2] += st->mtl.kd[2] * st->lt[i].b * ndotl;
514 r = cround64(color[0] * 255.0);
515 g = cround64(color[1] * 255.0);
516 b = cround64(color[2] * 255.0);
518 v->r = r > 255 ? 255 : r;
519 v->g = g > 255 ? 255 : g;
520 v->b = b > 255 ? 255 : b;