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];
73 uint16_t clear_color, clear_depth;
77 int imm_numv, imm_pcount;
78 struct g3d_vertex imm_curv;
79 struct g3d_vertex imm_vbuf[IMM_VBUF_SIZE];
82 static void imm_flush(void);
83 static __inline void xform4_vec3(const float *mat, float *vec);
84 static __inline void xform3_vec3(const float *mat, float *vec);
85 static void shade(struct g3d_vertex *v);
87 static struct g3d_state *st;
88 static const float idmat[] = {
97 if(!(st = calloc(1, sizeof *st))) {
98 fprintf(stderr, "failed to allocate G3D context\n");
106 void g3d_destroy(void)
108 #ifdef ENABLE_ZBUFFER
118 #ifdef ENABLE_ZBUFFER
121 memset(st, 0, sizeof *st);
123 st->opt = G3D_CLIP_FRUSTUM;
124 st->polymode = POLYFILL_FLAT;
126 for(i=0; i<G3D_NUM_MATRICES; i++) {
131 for(i=0; i<MAX_LIGHTS; i++) {
132 g3d_light_color(i, 1, 1, 1);
134 g3d_light_ambient(0.1, 0.1, 0.1);
136 g3d_mtl_diffuse(1, 1, 1);
138 st->clear_depth = 65535;
141 void g3d_framebuffer(int width, int height, void *pixels)
143 static int max_height;
145 #ifdef ENABLE_ZBUFFER
146 static int max_npixels;
147 int npixels = width * height;
149 if(npixels > max_npixels) {
151 pfill_zbuf = malloc(npixels * sizeof *pfill_zbuf);
152 max_npixels = npixels;
156 if(height > max_height) {
157 polyfill_fbheight(height);
164 pfill_fb.pixels = pixels;
165 pfill_fb.width = width;
166 pfill_fb.height = height;
168 g3d_viewport(0, 0, width, height);
171 /* set the framebuffer pointer, without resetting the size */
172 void g3d_framebuffer_addr(void *pixels)
174 pfill_fb.pixels = pixels;
177 void g3d_viewport(int x, int y, int w, int h)
185 void g3d_clear_color(unsigned char r, unsigned char g, unsigned char b)
187 st->clear_color = PACK_RGB16(r, g, b);
190 void g3d_clear_depth(uint16_t zval)
192 st->clear_depth = zval;
195 void g3d_clear(unsigned int mask)
197 if(mask & G3D_COLOR_BUFFER_BIT) {
198 memset16(pfill_fb.pixels, st->clear_color, pfill_fb.width * pfill_fb.height);
200 if(mask & G3D_DEPTH_BUFFER_BIT) {
201 memset16(pfill_zbuf, st->clear_depth, pfill_fb.width * pfill_fb.height);
205 void g3d_enable(unsigned int opt)
210 void g3d_disable(unsigned int opt)
215 void g3d_setopt(unsigned int opt, unsigned int mask)
217 st->opt = (st->opt & ~mask) | (opt & mask);
220 unsigned int g3d_getopt(unsigned int mask)
222 return st->opt & mask;
225 void g3d_front_face(unsigned int order)
227 st->frontface = order;
230 void g3d_polygon_mode(int pmode)
232 st->polymode = pmode;
235 int g3d_get_polygon_mode(void)
240 void g3d_matrix_mode(int mmode)
245 void g3d_load_identity(void)
247 int top = st->mtop[st->mmode];
248 memcpy(st->mat[st->mmode][top], idmat, 16 * sizeof(float));
251 void g3d_load_matrix(const float *m)
253 int top = st->mtop[st->mmode];
254 memcpy(st->mat[st->mmode][top], m, 16 * sizeof(float));
257 #define M(i,j) (((i) << 2) + (j))
258 void g3d_mult_matrix(const float *m2)
260 int i, j, top = st->mtop[st->mmode];
262 float *dest = st->mat[st->mmode][top];
264 memcpy(m1, dest, sizeof m1);
268 *dest++ = m1[M(0,j)] * m2[M(i,0)] +
269 m1[M(1,j)] * m2[M(i,1)] +
270 m1[M(2,j)] * m2[M(i,2)] +
271 m1[M(3,j)] * m2[M(i,3)];
276 void g3d_push_matrix(void)
278 int top = st->mtop[st->mmode];
279 if(top >= G3D_NUM_MATRICES) {
280 fprintf(stderr, "g3d_push_matrix overflow\n");
283 memcpy(st->mat[st->mmode][top + 1], st->mat[st->mmode][top], 16 * sizeof(float));
284 st->mtop[st->mmode] = top + 1;
287 void g3d_pop_matrix(void)
289 if(st->mtop[st->mmode] <= 0) {
290 fprintf(stderr, "g3d_pop_matrix underflow\n");
293 --st->mtop[st->mmode];
296 void g3d_translate(float x, float y, float z)
298 float m[16] = {1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1};
305 void g3d_rotate(float deg, float x, float y, float z)
309 float angle = M_PI * deg / 180.0f;
310 float sina = sin(angle);
311 float cosa = cos(angle);
312 float one_minus_cosa = 1.0f - cosa;
317 m[0] = nxsq + (1.0f - nxsq) * cosa;
318 m[4] = x * y * one_minus_cosa - z * sina;
319 m[8] = x * z * one_minus_cosa + y * sina;
320 m[1] = x * y * one_minus_cosa + z * sina;
321 m[5] = nysq + (1.0 - nysq) * cosa;
322 m[9] = y * z * one_minus_cosa - x * sina;
323 m[2] = x * z * one_minus_cosa - y * sina;
324 m[6] = y * z * one_minus_cosa + x * sina;
325 m[10] = nzsq + (1.0 - nzsq) * cosa;
331 void g3d_scale(float x, float y, float z)
341 void g3d_ortho(float left, float right, float bottom, float top, float znear, float zfar)
345 float dx = right - left;
346 float dy = top - bottom;
347 float dz = zfar - znear;
352 m[12] = -(right + left) / dx;
353 m[13] = -(top + bottom) / dy;
354 m[14] = -(zfar + znear) / dz;
360 void g3d_frustum(float left, float right, float bottom, float top, float nr, float fr)
364 float dx = right - left;
365 float dy = top - bottom;
368 float a = (right + left) / dx;
369 float b = (top + bottom) / dy;
370 float c = -(fr + nr) / dz;
371 float d = -2.0 * fr * nr / dz;
373 m[0] = 2.0 * nr / dx;
374 m[5] = 2.0 * nr / dy;
384 void g3d_perspective(float vfov_deg, float aspect, float znear, float zfar)
388 float vfov = M_PI * vfov_deg / 180.0f;
389 float s = 1.0f / tan(vfov * 0.5f);
390 float range = znear - zfar;
394 m[10] = (znear + zfar) / range;
396 m[14] = 2.0f * znear * zfar / range;
401 const float *g3d_get_matrix(int which, float *m)
403 int top = st->mtop[which];
406 memcpy(m, st->mat[which][top], 16 * sizeof(float));
408 return st->mat[which][top];
411 void g3d_light_pos(int idx, float x, float y, float z)
413 int mvtop = st->mtop[G3D_MODELVIEW];
415 st->lt[idx].type = LT_POS;
420 xform4_vec3(st->mat[G3D_MODELVIEW][mvtop], &st->lt[idx].x);
423 void g3d_light_dir(int idx, float x, float y, float z)
425 int mvtop = st->mtop[G3D_MODELVIEW];
427 st->lt[idx].type = LT_DIR;
432 /* calc the normal matrix */
433 memcpy(st->norm_mat, st->mat[G3D_MODELVIEW][mvtop], 16 * sizeof(float));
434 st->norm_mat[12] = st->norm_mat[13] = st->norm_mat[14] = 0.0f;
436 xform4_vec3(st->norm_mat, &st->lt[idx].x);
438 NORMALIZE(&st->lt[idx].x);
441 void g3d_light_color(int idx, float r, float g, float b)
448 void g3d_light_ambient(float r, float g, float b)
455 void g3d_mtl_diffuse(float r, float g, float b)
462 void g3d_mtl_specular(float r, float g, float b)
469 void g3d_mtl_shininess(float shin)
474 static INLINE int calc_shift(unsigned int x)
484 static INLINE int calc_mask(unsigned int x)
489 void g3d_set_texture(int xsz, int ysz, void *pixels)
491 pfill_tex.pixels = pixels;
492 pfill_tex.width = xsz;
493 pfill_tex.height = ysz;
495 pfill_tex.xshift = calc_shift(xsz);
496 pfill_tex.yshift = calc_shift(ysz);
497 pfill_tex.xmask = calc_mask(xsz);
498 pfill_tex.ymask = calc_mask(ysz);
501 void g3d_draw(int prim, const struct g3d_vertex *varr, int varr_size)
503 g3d_draw_indexed(prim, varr, varr_size, 0, 0);
506 #define NEED_NORMALS (st->opt & (G3D_LIGHTING | G3D_TEXTURE_GEN))
508 void g3d_draw_indexed(int prim, const struct g3d_vertex *varr, int varr_size,
509 const uint16_t *iarr, int iarr_size)
511 int i, j, vnum, nfaces, fill_mode;
512 struct pvertex pv[16];
513 struct g3d_vertex v[16];
514 int mvtop = st->mtop[G3D_MODELVIEW];
515 int ptop = st->mtop[G3D_PROJECTION];
516 struct g3d_vertex *tmpv;
518 tmpv = alloca(prim * 6 * sizeof *tmpv);
520 /* calc the normal matrix */
522 memcpy(st->norm_mat, st->mat[G3D_MODELVIEW][mvtop], 16 * sizeof(float));
523 st->norm_mat[12] = st->norm_mat[13] = st->norm_mat[14] = 0.0f;
526 nfaces = (iarr ? iarr_size : varr_size) / prim;
528 for(j=0; j<nfaces; j++) {
529 vnum = prim; /* reset vnum for each iteration */
531 for(i=0; i<vnum; i++) {
532 v[i] = iarr ? varr[*iarr++] : *varr++;
534 xform4_vec3(st->mat[G3D_MODELVIEW][mvtop], &v[i].x);
537 xform3_vec3(st->norm_mat, &v[i].nx);
538 if(st->opt & G3D_LIGHTING) {
541 if(st->opt & G3D_TEXTURE_GEN) {
542 v[i].u = v[i].nx * 0.5 + 0.5;
543 v[i].v = 0.5 - v[i].ny * 0.5;
546 if(st->opt & G3D_TEXTURE_MAT) {
547 float *mat = st->mat[G3D_TEXTURE][st->mtop[G3D_TEXTURE]];
548 float x = mat[0] * v[i].u + mat[4] * v[i].v + mat[12];
549 float y = mat[1] * v[i].u + mat[5] * v[i].v + mat[13];
550 float w = mat[3] * v[i].u + mat[7] * v[i].v + mat[15];
554 xform4_vec3(st->mat[G3D_PROJECTION][ptop], &v[i].x);
558 if(st->opt & G3D_CLIP_FRUSTUM) {
560 memcpy(tmpv, v, vnum * sizeof *v);
562 if(clip_frustum(v, &vnum, tmpv, vnum, i) < 0) {
563 /* polygon completely outside of view volume. discard */
572 for(i=0; i<vnum; i++) {
576 #ifdef ENABLE_ZBUFFER
577 if(st->opt & G3D_DEPTH_TEST) {
583 /* viewport transformation */
584 v[i].x = (v[i].x * 0.5f + 0.5f) * (float)st->vport[2] + st->vport[0];
585 v[i].y = (0.5f - v[i].y * 0.5f) * (float)st->vport[3] + st->vport[1];
587 /* convert pos to 24.8 fixed point */
588 pv[i].x = cround64(v[i].x * 256.0f);
589 pv[i].y = cround64(v[i].y * 256.0f);
590 #ifdef ENABLE_ZBUFFER
591 if(st->opt & G3D_DEPTH_TEST) {
592 /* after div/w z is in [-1, 1], remap it to [0, 65535] */
593 pv[i].z = cround64(v[i].z * 32767.5f + 32767.5f);
596 /* convert tex coords to 16.16 fixed point */
597 pv[i].u = cround64(v[i].u * 65536.0f);
598 pv[i].v = cround64(v[i].v * 65536.0f);
599 /* pass the color through as is */
606 /* backface culling */
607 if(vnum > 2 && st->opt & G3D_CULL_FACE) {
608 int32_t ax = pv[1].x - pv[0].x;
609 int32_t ay = pv[1].y - pv[0].y;
610 int32_t bx = pv[2].x - pv[0].x;
611 int32_t by = pv[2].y - pv[0].y;
612 int32_t cross_z = (ax >> 4) * (by >> 4) - (ay >> 4) * (bx >> 4);
613 int sign = (cross_z >> 31) & 1;
615 if(!(sign ^ st->frontface)) {
616 continue; /* back-facing */
622 if(st->opt & (G3D_ALPHA_BLEND | G3D_ADD_BLEND)) {
623 int r, g, b, inv_alpha;
624 g3d_pixel *dest = pfill_fb.pixels + (pv[0].y >> 8) * st->width + (pv[0].x >> 8);
625 if(st->opt & G3D_ALPHA_BLEND) {
626 inv_alpha = 255 - pv[0].a;
627 r = ((int)pv[0].r * pv[0].a + G3D_UNPACK_R(*dest) * inv_alpha) >> 8;
628 g = ((int)pv[0].g * pv[0].a + G3D_UNPACK_G(*dest) * inv_alpha) >> 8;
629 b = ((int)pv[0].b * pv[0].a + G3D_UNPACK_B(*dest) * inv_alpha) >> 8;
631 r = (int)pv[0].r + G3D_UNPACK_R(*dest);
632 g = (int)pv[0].g + G3D_UNPACK_G(*dest);
633 b = (int)pv[0].b + G3D_UNPACK_B(*dest);
638 *dest++ = G3D_PACK_RGB(r, g, b);
640 g3d_pixel *dest = pfill_fb.pixels + (pv[0].y >> 8) * st->width + (pv[0].x >> 8);
641 *dest = G3D_PACK_RGB(pv[0].r, pv[0].g, pv[0].b);
647 g3d_pixel col = G3D_PACK_RGB(pv[0].r, pv[0].g, pv[0].b);
648 draw_line(pv[0].x >> 8, pv[0].y >> 8, pv[1].x >> 8, pv[1].y >> 8, col);
653 fill_mode = st->polymode;
654 if(st->opt & G3D_TEXTURE_2D) {
655 fill_mode |= POLYFILL_TEX_BIT;
657 if(st->opt & G3D_ALPHA_BLEND) {
658 fill_mode |= POLYFILL_ALPHA_BIT;
659 } else if(st->opt & G3D_ADD_BLEND) {
660 fill_mode |= POLYFILL_ADD_BIT;
662 #ifdef ENABLE_ZBUFFER
663 if(st->opt & G3D_DEPTH_TEST) {
664 fill_mode |= POLYFILL_ZBUF_BIT;
667 polyfill(fill_mode, pv, vnum);
672 void g3d_begin(int prim)
675 st->imm_pcount = prim;
684 static void imm_flush(void)
686 int numv = st->imm_numv;
688 g3d_draw_indexed(st->imm_prim, st->imm_vbuf, numv, 0, 0);
691 void g3d_vertex(float x, float y, float z)
693 struct g3d_vertex *vptr = st->imm_vbuf + st->imm_numv++;
694 *vptr = st->imm_curv;
700 if(!--st->imm_pcount) {
701 if(st->imm_numv >= IMM_VBUF_SIZE - st->imm_prim) {
704 st->imm_pcount = st->imm_prim;
708 void g3d_normal(float x, float y, float z)
715 #define CLAMP(x, a, b) ((x) < (a) ? (a) : ((x) > (b) ? (b) : (x)))
716 #define MIN(a, b) ((a) < (b) ? (a) : (b))
718 void g3d_color3b(unsigned char r, unsigned char g, unsigned char b)
720 st->imm_curv.r = MIN(r, 255);
721 st->imm_curv.g = MIN(g, 255);
722 st->imm_curv.b = MIN(b, 255);
723 st->imm_curv.a = 255;
726 void g3d_color4b(unsigned char r, unsigned char g, unsigned char b, unsigned char a)
728 st->imm_curv.r = MIN(r, 255);
729 st->imm_curv.g = MIN(g, 255);
730 st->imm_curv.b = MIN(b, 255);
731 st->imm_curv.a = MIN(a, 255);
734 void g3d_color3f(float r, float g, float b)
739 st->imm_curv.r = CLAMP(ir, 0, 255);
740 st->imm_curv.g = CLAMP(ig, 0, 255);
741 st->imm_curv.b = CLAMP(ib, 0, 255);
742 st->imm_curv.a = 255;
745 void g3d_color4f(float r, float g, float b, float a)
751 st->imm_curv.r = CLAMP(ir, 0, 255);
752 st->imm_curv.g = CLAMP(ig, 0, 255);
753 st->imm_curv.b = CLAMP(ib, 0, 255);
754 st->imm_curv.a = CLAMP(ia, 0, 255);
757 void g3d_texcoord(float u, float v)
763 static __inline void xform4_vec3(const float *mat, float *vec)
765 float x = mat[0] * vec[0] + mat[4] * vec[1] + mat[8] * vec[2] + mat[12];
766 float y = mat[1] * vec[0] + mat[5] * vec[1] + mat[9] * vec[2] + mat[13];
767 float z = mat[2] * vec[0] + mat[6] * vec[1] + mat[10] * vec[2] + mat[14];
768 vec[3] = mat[3] * vec[0] + mat[7] * vec[1] + mat[11] * vec[2] + mat[15];
774 static __inline void xform3_vec3(const float *mat, float *vec)
776 float x = mat[0] * vec[0] + mat[4] * vec[1] + mat[8] * vec[2];
777 float y = mat[1] * vec[0] + mat[5] * vec[1] + mat[9] * vec[2];
778 vec[2] = mat[2] * vec[0] + mat[6] * vec[1] + mat[10] * vec[2];
783 static void shade(struct g3d_vertex *v)
788 color[0] = st->ambient[0] * st->mtl.kd[0];
789 color[1] = st->ambient[1] * st->mtl.kd[1];
790 color[2] = st->ambient[2] * st->mtl.kd[2];
792 for(i=0; i<MAX_LIGHTS; i++) {
796 if(!(st->opt & (G3D_LIGHT0 << i))) {
800 ldir[0] = st->lt[i].x;
801 ldir[1] = st->lt[i].y;
802 ldir[2] = st->lt[i].z;
804 if(st->lt[i].type != LT_DIR) {
811 if((ndotl = v->nx * ldir[0] + v->ny * ldir[1] + v->nz * ldir[2]) < 0.0f) {
815 color[0] += st->mtl.kd[0] * st->lt[i].r * ndotl;
816 color[1] += st->mtl.kd[1] * st->lt[i].g * ndotl;
817 color[2] += st->mtl.kd[2] * st->lt[i].b * ndotl;
820 if(st->opt & G3D_SPECULAR) {
824 if((ndoth = v->nx * ldir[0] + v->ny * ldir[1] + v->nz * ldir[2]) < 0.0f) {
827 ndoth = pow(ndoth, st->mtl.shin);
829 color[0] += st->mtl.ks[0] * st->lt[i].r * ndoth;
830 color[1] += st->mtl.ks[1] * st->lt[i].g * ndoth;
831 color[2] += st->mtl.ks[2] * st->lt[i].b * ndoth;
836 r = cround64(color[0] * 255.0);
837 g = cround64(color[1] * 255.0);
838 b = cround64(color[2] * 255.0);
840 v->r = r > 255 ? 255 : r;
841 v->g = g > 255 ? 255 : g;
842 v->b = b > 255 ? 255 : b;
845 #endif /* !def BUILD_OPENGL */