7 #if defined(__WATCOMC__) || defined(_WIN32) || defined(__DJGPP__)
20 #define ENABLE_ZBUFFER
23 typedef float g3d_matrix[16];
27 #define IMM_VBUF_SIZE 256
29 #define NORMALIZE(v) \
31 float len = sqrt((v)[0] * (v)[0] + (v)[1] * (v)[1] + (v)[2] * (v)[2]); \
33 float s = 1.0 / len; \
40 enum {LT_POS, LT_DIR};
58 g3d_matrix mat[G3D_NUM_MATRICES][STACK_SIZE];
59 int mtop[G3D_NUM_MATRICES];
65 struct light lt[MAX_LIGHTS];
75 int imm_numv, imm_pcount;
76 struct g3d_vertex imm_curv;
77 struct g3d_vertex imm_vbuf[IMM_VBUF_SIZE];
80 static void imm_flush(void);
81 static __inline void xform4_vec3(const float *mat, float *vec);
82 static __inline void xform3_vec3(const float *mat, float *vec);
83 static void shade(struct g3d_vertex *v);
85 static struct g3d_state *st;
86 static const float idmat[] = {
95 if(!(st = calloc(1, sizeof *st))) {
96 fprintf(stderr, "failed to allocate G3D context\n");
104 void g3d_destroy(void)
106 #ifdef ENABLE_ZBUFFER
116 #ifdef ENABLE_ZBUFFER
119 memset(st, 0, sizeof *st);
121 st->opt = G3D_CLIP_FRUSTUM;
122 st->polymode = POLYFILL_FLAT;
124 for(i=0; i<G3D_NUM_MATRICES; i++) {
129 for(i=0; i<MAX_LIGHTS; i++) {
130 g3d_light_color(i, 1, 1, 1);
132 g3d_light_ambient(0.1, 0.1, 0.1);
134 g3d_mtl_diffuse(1, 1, 1);
137 void g3d_framebuffer(int width, int height, void *pixels)
139 static int max_height;
141 #ifdef ENABLE_ZBUFFER
142 static int max_npixels;
143 int npixels = width * height;
145 if(npixels > max_npixels) {
147 pfill_zbuf = malloc(npixels * sizeof *pfill_zbuf);
148 max_npixels = npixels;
152 if(height > max_height) {
153 polyfill_fbheight(height);
161 pfill_fb.pixels = pixels;
162 pfill_fb.width = width;
163 pfill_fb.height = height;
165 g3d_viewport(0, 0, width, height);
168 /* set the framebuffer pointer, without resetting the size */
169 void g3d_framebuffer_addr(void *pixels)
172 pfill_fb.pixels = pixels;
175 void g3d_viewport(int x, int y, int w, int h)
183 void g3d_enable(unsigned int opt)
188 void g3d_disable(unsigned int opt)
193 void g3d_setopt(unsigned int opt, unsigned int mask)
195 st->opt = (st->opt & ~mask) | (opt & mask);
198 unsigned int g3d_getopt(unsigned int mask)
200 return st->opt & mask;
203 void g3d_front_face(unsigned int order)
205 st->frontface = order;
208 void g3d_polygon_mode(int pmode)
210 st->polymode = pmode;
213 int g3d_get_polygon_mode(void)
218 void g3d_matrix_mode(int mmode)
223 void g3d_load_identity(void)
225 int top = st->mtop[st->mmode];
226 memcpy(st->mat[st->mmode][top], idmat, 16 * sizeof(float));
229 void g3d_load_matrix(const float *m)
231 int top = st->mtop[st->mmode];
232 memcpy(st->mat[st->mmode][top], m, 16 * sizeof(float));
235 #define M(i,j) (((i) << 2) + (j))
236 void g3d_mult_matrix(const float *m2)
238 int i, j, top = st->mtop[st->mmode];
240 float *dest = st->mat[st->mmode][top];
242 memcpy(m1, dest, sizeof m1);
246 *dest++ = m1[M(0,j)] * m2[M(i,0)] +
247 m1[M(1,j)] * m2[M(i,1)] +
248 m1[M(2,j)] * m2[M(i,2)] +
249 m1[M(3,j)] * m2[M(i,3)];
254 void g3d_push_matrix(void)
256 int top = st->mtop[st->mmode];
257 if(top >= G3D_NUM_MATRICES) {
258 fprintf(stderr, "g3d_push_matrix overflow\n");
261 memcpy(st->mat[st->mmode][top + 1], st->mat[st->mmode][top], 16 * sizeof(float));
262 st->mtop[st->mmode] = top + 1;
265 void g3d_pop_matrix(void)
267 if(st->mtop[st->mmode] <= 0) {
268 fprintf(stderr, "g3d_pop_matrix underflow\n");
271 --st->mtop[st->mmode];
274 void g3d_translate(float x, float y, float z)
276 float m[16] = {1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1};
283 void g3d_rotate(float deg, float x, float y, float z)
287 float angle = M_PI * deg / 180.0f;
288 float sina = sin(angle);
289 float cosa = cos(angle);
290 float one_minus_cosa = 1.0f - cosa;
295 m[0] = nxsq + (1.0f - nxsq) * cosa;
296 m[4] = x * y * one_minus_cosa - z * sina;
297 m[8] = x * z * one_minus_cosa + y * sina;
298 m[1] = x * y * one_minus_cosa + z * sina;
299 m[5] = nysq + (1.0 - nysq) * cosa;
300 m[9] = y * z * one_minus_cosa - x * sina;
301 m[2] = x * z * one_minus_cosa - y * sina;
302 m[6] = y * z * one_minus_cosa + x * sina;
303 m[10] = nzsq + (1.0 - nzsq) * cosa;
309 void g3d_scale(float x, float y, float z)
319 void g3d_ortho(float left, float right, float bottom, float top, float znear, float zfar)
323 float dx = right - left;
324 float dy = top - bottom;
325 float dz = zfar - znear;
330 m[12] = -(right + left) / dx;
331 m[13] = -(top + bottom) / dy;
332 m[14] = -(zfar + znear) / dz;
338 void g3d_frustum(float left, float right, float bottom, float top, float nr, float fr)
342 float dx = right - left;
343 float dy = top - bottom;
346 float a = (right + left) / dx;
347 float b = (top + bottom) / dy;
348 float c = -(fr + nr) / dz;
349 float d = -2.0 * fr * nr / dz;
351 m[0] = 2.0 * nr / dx;
352 m[5] = 2.0 * nr / dy;
362 void g3d_perspective(float vfov_deg, float aspect, float znear, float zfar)
366 float vfov = M_PI * vfov_deg / 180.0f;
367 float s = 1.0f / tan(vfov * 0.5f);
368 float range = znear - zfar;
372 m[10] = (znear + zfar) / range;
374 m[14] = 2.0f * znear * zfar / range;
379 const float *g3d_get_matrix(int which, float *m)
381 int top = st->mtop[which];
384 memcpy(m, st->mat[which][top], 16 * sizeof(float));
386 return st->mat[which][top];
389 void g3d_light_pos(int idx, float x, float y, float z)
391 int mvtop = st->mtop[G3D_MODELVIEW];
393 st->lt[idx].type = LT_POS;
398 xform4_vec3(st->mat[G3D_MODELVIEW][mvtop], &st->lt[idx].x);
401 void g3d_light_dir(int idx, float x, float y, float z)
403 int mvtop = st->mtop[G3D_MODELVIEW];
405 st->lt[idx].type = LT_DIR;
410 /* calc the normal matrix */
411 memcpy(st->norm_mat, st->mat[G3D_MODELVIEW][mvtop], 16 * sizeof(float));
412 st->norm_mat[12] = st->norm_mat[13] = st->norm_mat[14] = 0.0f;
414 xform4_vec3(st->norm_mat, &st->lt[idx].x);
416 NORMALIZE(&st->lt[idx].x);
419 void g3d_light_color(int idx, float r, float g, float b)
426 void g3d_light_ambient(float r, float g, float b)
433 void g3d_mtl_diffuse(float r, float g, float b)
440 void g3d_mtl_specular(float r, float g, float b)
447 void g3d_mtl_shininess(float shin)
452 static INLINE int calc_shift(unsigned int x)
462 static INLINE int calc_mask(unsigned int x)
467 void g3d_set_texture(int xsz, int ysz, void *pixels)
469 pfill_tex.pixels = pixels;
470 pfill_tex.width = xsz;
471 pfill_tex.height = ysz;
473 pfill_tex.xshift = calc_shift(xsz);
474 pfill_tex.yshift = calc_shift(ysz);
475 pfill_tex.xmask = calc_mask(xsz);
476 pfill_tex.ymask = calc_mask(ysz);
479 void g3d_draw(int prim, const struct g3d_vertex *varr, int varr_size)
481 g3d_draw_indexed(prim, varr, varr_size, 0, 0);
484 void g3d_draw_indexed(int prim, const struct g3d_vertex *varr, int varr_size,
485 const uint16_t *iarr, int iarr_size)
487 int i, j, vnum, nfaces, fill_mode;
488 struct pvertex pv[16];
489 struct g3d_vertex v[16];
490 int mvtop = st->mtop[G3D_MODELVIEW];
491 int ptop = st->mtop[G3D_PROJECTION];
492 struct g3d_vertex *tmpv;
494 tmpv = alloca(prim * 6 * sizeof *tmpv);
496 /* calc the normal matrix */
497 memcpy(st->norm_mat, st->mat[G3D_MODELVIEW][mvtop], 16 * sizeof(float));
498 st->norm_mat[12] = st->norm_mat[13] = st->norm_mat[14] = 0.0f;
500 nfaces = (iarr ? iarr_size : varr_size) / prim;
502 for(j=0; j<nfaces; j++) {
503 vnum = prim; /* reset vnum for each iteration */
505 for(i=0; i<vnum; i++) {
506 v[i] = iarr ? varr[*iarr++] : *varr++;
508 xform4_vec3(st->mat[G3D_MODELVIEW][mvtop], &v[i].x);
509 xform3_vec3(st->norm_mat, &v[i].nx);
511 if(st->opt & G3D_LIGHTING) {
514 if(st->opt & G3D_TEXTURE_GEN) {
515 v[i].u = v[i].nx * 0.5 + 0.5;
516 v[i].v = 0.5 - v[i].ny * 0.5;
518 if(st->opt & G3D_TEXTURE_MAT) {
519 float *mat = st->mat[G3D_TEXTURE][st->mtop[G3D_TEXTURE]];
520 float x = mat[0] * v[i].u + mat[4] * v[i].v + mat[12];
521 float y = mat[1] * v[i].u + mat[5] * v[i].v + mat[13];
522 float w = mat[3] * v[i].u + mat[7] * v[i].v + mat[15];
526 xform4_vec3(st->mat[G3D_PROJECTION][ptop], &v[i].x);
530 if(st->opt & G3D_CLIP_FRUSTUM) {
532 memcpy(tmpv, v, vnum * sizeof *v);
534 if(clip_frustum(v, &vnum, tmpv, vnum, i) < 0) {
535 /* polygon completely outside of view volume. discard */
544 for(i=0; i<vnum; i++) {
548 /*v[i].z /= v[i].w;*/
551 /* viewport transformation */
552 v[i].x = (v[i].x * 0.5f + 0.5f) * (float)st->vport[2] + st->vport[0];
553 v[i].y = (0.5f - v[i].y * 0.5f) * (float)st->vport[3] + st->vport[1];
555 /* convert pos to 24.8 fixed point */
556 pv[i].x = cround64(v[i].x * 256.0f);
557 pv[i].y = cround64(v[i].y * 256.0f);
558 /* convert tex coords to 16.16 fixed point */
559 pv[i].u = cround64(v[i].u * 65536.0f);
560 pv[i].v = cround64(v[i].v * 65536.0f);
561 /* pass the color through as is */
568 /* backface culling */
569 if(vnum > 2 && st->opt & G3D_CULL_FACE) {
570 int32_t ax = pv[1].x - pv[0].x;
571 int32_t ay = pv[1].y - pv[0].y;
572 int32_t bx = pv[2].x - pv[0].x;
573 int32_t by = pv[2].y - pv[0].y;
574 int32_t cross_z = (ax >> 4) * (by >> 4) - (ay >> 4) * (bx >> 4);
575 int sign = (cross_z >> 31) & 1;
577 if(!(sign ^ st->frontface)) {
578 continue; /* back-facing */
584 if(st->opt & (G3D_ALPHA_BLEND | G3D_ADD_BLEND)) {
585 int r, g, b, inv_alpha;
586 g3d_pixel *dest = st->pixels + (pv[0].y >> 8) * st->width + (pv[0].x >> 8);
587 if(st->opt & G3D_ALPHA_BLEND) {
588 inv_alpha = 255 - pv[0].a;
589 r = ((int)pv[0].r * pv[0].a + G3D_UNPACK_R(*dest) * inv_alpha) >> 8;
590 g = ((int)pv[0].g * pv[0].a + G3D_UNPACK_G(*dest) * inv_alpha) >> 8;
591 b = ((int)pv[0].b * pv[0].a + G3D_UNPACK_B(*dest) * inv_alpha) >> 8;
593 r = (int)pv[0].r + G3D_UNPACK_R(*dest);
594 g = (int)pv[0].g + G3D_UNPACK_G(*dest);
595 b = (int)pv[0].b + G3D_UNPACK_B(*dest);
600 *dest++ = G3D_PACK_RGB(r, g, b);
602 g3d_pixel *dest = st->pixels + (pv[0].y >> 8) * st->width + (pv[0].x >> 8);
603 *dest = G3D_PACK_RGB(pv[0].r, pv[0].g, pv[0].b);
609 g3d_pixel col = G3D_PACK_RGB(pv[0].r, pv[0].g, pv[0].b);
610 draw_line(pv[0].x >> 8, pv[0].y >> 8, pv[1].x >> 8, pv[1].y >> 8, col);
615 fill_mode = st->polymode;
616 if(st->opt & G3D_TEXTURE_2D) {
617 fill_mode |= POLYFILL_TEX_BIT;
619 if(st->opt & G3D_ALPHA_BLEND) {
620 fill_mode |= POLYFILL_ALPHA_BIT;
621 } else if(st->opt & G3D_ADD_BLEND) {
622 fill_mode |= POLYFILL_ADD_BIT;
624 polyfill(fill_mode, pv, vnum);
629 void g3d_begin(int prim)
632 st->imm_pcount = prim;
641 static void imm_flush(void)
643 int numv = st->imm_numv;
645 g3d_draw_indexed(st->imm_prim, st->imm_vbuf, numv, 0, 0);
648 void g3d_vertex(float x, float y, float z)
650 struct g3d_vertex *vptr = st->imm_vbuf + st->imm_numv++;
651 *vptr = st->imm_curv;
657 if(!--st->imm_pcount) {
658 if(st->imm_numv >= IMM_VBUF_SIZE - st->imm_prim) {
661 st->imm_pcount = st->imm_prim;
665 void g3d_normal(float x, float y, float z)
672 #define CLAMP(x, a, b) ((x) < (a) ? (a) : ((x) > (b) ? (b) : (x)))
673 #define MIN(a, b) ((a) < (b) ? (a) : (b))
675 void g3d_color3b(unsigned char r, unsigned char g, unsigned char b)
677 st->imm_curv.r = MIN(r, 255);
678 st->imm_curv.g = MIN(g, 255);
679 st->imm_curv.b = MIN(b, 255);
680 st->imm_curv.a = 255;
683 void g3d_color4b(unsigned char r, unsigned char g, unsigned char b, unsigned char a)
685 st->imm_curv.r = MIN(r, 255);
686 st->imm_curv.g = MIN(g, 255);
687 st->imm_curv.b = MIN(b, 255);
688 st->imm_curv.a = MIN(a, 255);
691 void g3d_color3f(float r, float g, float b)
696 st->imm_curv.r = CLAMP(ir, 0, 255);
697 st->imm_curv.g = CLAMP(ig, 0, 255);
698 st->imm_curv.b = CLAMP(ib, 0, 255);
699 st->imm_curv.a = 255;
702 void g3d_color4f(float r, float g, float b, float a)
708 st->imm_curv.r = CLAMP(ir, 0, 255);
709 st->imm_curv.g = CLAMP(ig, 0, 255);
710 st->imm_curv.b = CLAMP(ib, 0, 255);
711 st->imm_curv.a = CLAMP(ia, 0, 255);
714 void g3d_texcoord(float u, float v)
720 static __inline void xform4_vec3(const float *mat, float *vec)
722 float x = mat[0] * vec[0] + mat[4] * vec[1] + mat[8] * vec[2] + mat[12];
723 float y = mat[1] * vec[0] + mat[5] * vec[1] + mat[9] * vec[2] + mat[13];
724 float z = mat[2] * vec[0] + mat[6] * vec[1] + mat[10] * vec[2] + mat[14];
725 vec[3] = mat[3] * vec[0] + mat[7] * vec[1] + mat[11] * vec[2] + mat[15];
731 static __inline void xform3_vec3(const float *mat, float *vec)
733 float x = mat[0] * vec[0] + mat[4] * vec[1] + mat[8] * vec[2];
734 float y = mat[1] * vec[0] + mat[5] * vec[1] + mat[9] * vec[2];
735 vec[2] = mat[2] * vec[0] + mat[6] * vec[1] + mat[10] * vec[2];
740 static void shade(struct g3d_vertex *v)
745 color[0] = st->ambient[0] * st->mtl.kd[0];
746 color[1] = st->ambient[1] * st->mtl.kd[1];
747 color[2] = st->ambient[2] * st->mtl.kd[2];
749 for(i=0; i<MAX_LIGHTS; i++) {
753 if(!(st->opt & (G3D_LIGHT0 << i))) {
757 ldir[0] = st->lt[i].x;
758 ldir[1] = st->lt[i].y;
759 ldir[2] = st->lt[i].z;
761 if(st->lt[i].type != LT_DIR) {
768 if((ndotl = v->nx * ldir[0] + v->ny * ldir[1] + v->nz * ldir[2]) < 0.0f) {
772 color[0] += st->mtl.kd[0] * st->lt[i].r * ndotl;
773 color[1] += st->mtl.kd[1] * st->lt[i].g * ndotl;
774 color[2] += st->mtl.kd[2] * st->lt[i].b * ndotl;
777 if(st->opt & G3D_SPECULAR) {
781 if((ndoth = v->nx * ldir[0] + v->ny * ldir[1] + v->nz * ldir[2]) < 0.0f) {
784 ndoth = pow(ndoth, st->mtl.shin);
786 color[0] += st->mtl.ks[0] * st->lt[i].r * ndoth;
787 color[1] += st->mtl.ks[1] * st->lt[i].g * ndoth;
788 color[2] += st->mtl.ks[2] * st->lt[i].b * ndoth;
793 r = cround64(color[0] * 255.0);
794 g = cround64(color[1] * 255.0);
795 b = cround64(color[2] * 255.0);
797 v->r = r > 255 ? 255 : r;
798 v->g = g > 255 ? 255 : g;
799 v->b = b > 255 ? 255 : b;
802 #endif /* !def BUILD_OPENGL */