00001 #include "zgl.h"
00002 #include <limits.h>
00003
00004
00005
00006
00007 #define CLIP_XMIN (1<<0)
00008 #define CLIP_XMAX (1<<1)
00009 #define CLIP_YMIN (1<<2)
00010 #define CLIP_YMAX (1<<3)
00011 #define CLIP_ZMIN (1<<4)
00012 #define CLIP_ZMAX (1<<5)
00013
00014 void gl_transform_to_viewport(GLContext *c,GLVertex *v)
00015 {
00016 PN_stdfloat winv;
00017
00018
00019 winv = 1.0f / v->pc.v[3];
00020 v->zp.x= (int) ( v->pc.v[0] * winv * c->viewport.scale.v[0]
00021 + c->viewport.trans.v[0] );
00022 v->zp.y= (int) ( v->pc.v[1] * winv * c->viewport.scale.v[1]
00023 + c->viewport.trans.v[1] );
00024 v->zp.z= (int) ( v->pc.v[2] * winv * c->viewport.scale.v[2]
00025 + c->viewport.trans.v[2] );
00026
00027
00028 int z = v->zp.z + (c->zbias << (ZB_POINT_Z_FRAC_BITS + 4));
00029 if (z < v->zp.z && c->zbias > 0) {
00030 v->zp.z = INT_MAX;
00031 } else if (z > v->zp.z && c->zbias < 0) {
00032 v->zp.z = -INT_MAX;
00033 } else {
00034 v->zp.z = z;
00035 }
00036
00037
00038 v->zp.r=(int)(v->color.v[0] * (ZB_POINT_RED_MAX - ZB_POINT_RED_MIN)
00039 + ZB_POINT_RED_MIN);
00040 v->zp.g=(int)(v->color.v[1] * (ZB_POINT_GREEN_MAX - ZB_POINT_GREEN_MIN)
00041 + ZB_POINT_GREEN_MIN);
00042 v->zp.b=(int)(v->color.v[2] * (ZB_POINT_BLUE_MAX - ZB_POINT_BLUE_MIN)
00043 + ZB_POINT_BLUE_MIN);
00044 v->zp.a=(int)(v->color.v[3] * (ZB_POINT_ALPHA_MAX - ZB_POINT_ALPHA_MIN)
00045 + ZB_POINT_ALPHA_MIN);
00046
00047
00048 if (c->num_textures_enabled >= 1) {
00049 static const int si = 0;
00050 v->zp.s = (int)(v->tex_coord[si].v[0] * c->current_textures[si]->s_max);
00051 v->zp.t = (int)(v->tex_coord[si].v[1] * c->current_textures[si]->t_max);
00052 }
00053 if (c->num_textures_enabled >= 2) {
00054 static const int si = 1;
00055 v->zp.sa = (int)(v->tex_coord[si].v[0] * c->current_textures[si]->s_max);
00056 v->zp.ta = (int)(v->tex_coord[si].v[1] * c->current_textures[si]->t_max);
00057 }
00058 if (c->num_textures_enabled >= 3) {
00059 static const int si = 2;
00060 v->zp.sb = (int)(v->tex_coord[si].v[0] * c->current_textures[si]->s_max);
00061 v->zp.tb = (int)(v->tex_coord[si].v[1] * c->current_textures[si]->t_max);
00062 }
00063 }
00064
00065
00066
00067
00068 void gl_draw_point(GLContext *c,GLVertex *p0)
00069 {
00070 if (p0->clip_code == 0) {
00071 ZB_plot(c->zb,&p0->zp);
00072 }
00073 }
00074
00075
00076
00077 static inline void interpolate(GLVertex *q,GLVertex *p0,GLVertex *p1,PN_stdfloat t)
00078 {
00079 q->pc.v[0]=p0->pc.v[0]+(p1->pc.v[0]-p0->pc.v[0])*t;
00080 q->pc.v[1]=p0->pc.v[1]+(p1->pc.v[1]-p0->pc.v[1])*t;
00081 q->pc.v[2]=p0->pc.v[2]+(p1->pc.v[2]-p0->pc.v[2])*t;
00082 q->pc.v[3]=p0->pc.v[3]+(p1->pc.v[3]-p0->pc.v[3])*t;
00083
00084 q->color.v[0]=p0->color.v[0] + (p1->color.v[0]-p0->color.v[0])*t;
00085 q->color.v[1]=p0->color.v[1] + (p1->color.v[1]-p0->color.v[1])*t;
00086 q->color.v[2]=p0->color.v[2] + (p1->color.v[2]-p0->color.v[2])*t;
00087 q->color.v[3]=p0->color.v[3] + (p1->color.v[3]-p0->color.v[3])*t;
00088 }
00089
00090
00091
00092
00093
00094
00095
00096 static inline int ClipLine1(PN_stdfloat denom,PN_stdfloat num,PN_stdfloat *tmin,PN_stdfloat *tmax)
00097 {
00098 PN_stdfloat t;
00099
00100 if (denom>0) {
00101 t=num/denom;
00102 if (t>*tmax) return 0;
00103 if (t>*tmin) *tmin=t;
00104 } else if (denom<0) {
00105 t=num/denom;
00106 if (t<*tmin) return 0;
00107 if (t<*tmax) *tmax=t;
00108 } else if (num>0) return 0;
00109 return 1;
00110 }
00111
00112 void gl_draw_line(GLContext *c,GLVertex *p1,GLVertex *p2)
00113 {
00114 PN_stdfloat dx,dy,dz,dw,x1,y1,z1,w1;
00115 PN_stdfloat tmin,tmax;
00116 GLVertex q1,q2;
00117 int cc1,cc2;
00118
00119 cc1=p1->clip_code;
00120 cc2=p2->clip_code;
00121
00122 if ( (cc1 | cc2) == 0) {
00123 if (c->depth_test)
00124 ZB_line_z(c->zb,&p1->zp,&p2->zp);
00125 else
00126 ZB_line(c->zb,&p1->zp,&p2->zp);
00127 } else if ( (cc1&cc2) != 0 ) {
00128 return;
00129 } else {
00130 dx=p2->pc.v[0]-p1->pc.v[0];
00131 dy=p2->pc.v[1]-p1->pc.v[1];
00132 dz=p2->pc.v[2]-p1->pc.v[2];
00133 dw=p2->pc.v[3]-p1->pc.v[3];
00134 x1=p1->pc.v[0];
00135 y1=p1->pc.v[1];
00136 z1=p1->pc.v[2];
00137 w1=p1->pc.v[3];
00138
00139 tmin=0;
00140 tmax=1;
00141 if (ClipLine1(dx+dw,-x1-w1,&tmin,&tmax) &&
00142 ClipLine1(-dx+dw,x1-w1,&tmin,&tmax) &&
00143 ClipLine1(dy+dw,-y1-w1,&tmin,&tmax) &&
00144 ClipLine1(-dy+dw,y1-w1,&tmin,&tmax) &&
00145 ClipLine1(dz+dw,-z1-w1,&tmin,&tmax) &&
00146 ClipLine1(-dz+dw,z1-w1,&tmin,&tmax)) {
00147
00148 interpolate(&q1,p1,p2,tmin);
00149 interpolate(&q2,p1,p2,tmax);
00150 gl_transform_to_viewport(c,&q1);
00151 gl_transform_to_viewport(c,&q2);
00152
00153 if (c->depth_test)
00154 ZB_line_z(c->zb,&q1.zp,&q2.zp);
00155 else
00156 ZB_line(c->zb,&q1.zp,&q2.zp);
00157 }
00158 }
00159 }
00160
00161
00162
00163
00164
00165
00166
00167
00168
00169
00170
00171
00172
00173 #define clip_func(name, sign, dir, dir1, dir2) \
00174 static PN_stdfloat name(V4 *c, V4 *a, V4 *b) \
00175 {\
00176 PN_stdfloat t,den;\
00177 PN_stdfloat d[4];\
00178 d[0] = (b->v[0] - a->v[0]);\
00179 d[1] = (b->v[1] - a->v[1]);\
00180 d[2] = (b->v[2] - a->v[2]);\
00181 d[3] = (b->v[3] - a->v[3]);\
00182 den = -(sign d[dir]) + d[3];\
00183 if (den == 0) t=0;\
00184 else t = ( sign a->v[dir] - a->v[3]) / den;\
00185 c->v[dir1] = a->v[dir1] + t * d[dir1];\
00186 c->v[dir2] = a->v[dir2] + t * d[dir2];\
00187 c->v[3] = a->v[3] + t * d[3];\
00188 c->v[dir] = sign c->v[3];\
00189 return t;\
00190 }
00191
00192
00193 clip_func(clip_xmin, -, 0, 1, 2)
00194
00195 clip_func(clip_xmax, +, 0, 1, 2)
00196
00197 clip_func(clip_ymin, -, 1, 0, 2)
00198
00199 clip_func(clip_ymax, +, 1, 0, 2)
00200
00201 clip_func(clip_zmin, -, 2, 0, 1)
00202
00203 clip_func(clip_zmax, +, 2, 0, 1)
00204
00205
00206 PN_stdfloat (*clip_proc[6])(V4 *,V4 *,V4 *)= {
00207 clip_xmin,clip_xmax,
00208 clip_ymin,clip_ymax,
00209 clip_zmin,clip_zmax
00210 };
00211
00212 static inline void updateTmp(GLContext *c,
00213 GLVertex *q,GLVertex *p0,GLVertex *p1,PN_stdfloat t)
00214 {
00215 if (c->smooth_shade_model) {
00216 q->color.v[0]=p0->color.v[0] + (p1->color.v[0]-p0->color.v[0])*t;
00217 q->color.v[1]=p0->color.v[1] + (p1->color.v[1]-p0->color.v[1])*t;
00218 q->color.v[2]=p0->color.v[2] + (p1->color.v[2]-p0->color.v[2])*t;
00219 q->color.v[3]=p0->color.v[3] + (p1->color.v[3]-p0->color.v[3])*t;
00220 } else {
00221 q->color.v[0]=p0->color.v[0];
00222 q->color.v[1]=p0->color.v[1];
00223 q->color.v[2]=p0->color.v[2];
00224 q->color.v[3]=p0->color.v[3];
00225 }
00226
00227 for (int si = 0; si < c->num_textures_enabled; ++si) {
00228 q->tex_coord[si].v[0]=p0->tex_coord[si].v[0] + (p1->tex_coord[si].v[0]-p0->tex_coord[si].v[0])*t;
00229 q->tex_coord[si].v[1]=p0->tex_coord[si].v[1] + (p1->tex_coord[si].v[1]-p0->tex_coord[si].v[1])*t;
00230 }
00231
00232 q->clip_code=gl_clipcode(q->pc.v[0],q->pc.v[1],q->pc.v[2],q->pc.v[3]);
00233 if (q->clip_code==0) {
00234 gl_transform_to_viewport(c,q);
00235 }
00236 }
00237
00238 static void gl_draw_triangle_clip(GLContext *c,
00239 GLVertex *p0,GLVertex *p1,GLVertex *p2,int clip_bit);
00240
00241 void gl_draw_triangle(GLContext *c,
00242 GLVertex *p0,GLVertex *p1,GLVertex *p2)
00243 {
00244 int co,c_and,cc[3],front;
00245 PN_stdfloat norm;
00246
00247 cc[0]=p0->clip_code;
00248 cc[1]=p1->clip_code;
00249 cc[2]=p2->clip_code;
00250
00251 co=cc[0] | cc[1] | cc[2];
00252
00253
00254 if (co==0) {
00255
00256 norm=(PN_stdfloat)(p1->zp.x-p0->zp.x)*(PN_stdfloat)(p2->zp.y-p0->zp.y)-
00257 (PN_stdfloat)(p2->zp.x-p0->zp.x)*(PN_stdfloat)(p1->zp.y-p0->zp.y);
00258
00259 if (norm == 0) return;
00260
00261 front = norm < 0.0;
00262
00263
00264 if (c->cull_face_enabled) {
00265
00266 if (c->cull_clockwise) {
00267 if (front == 0) return;
00268 c->draw_triangle_front(c,p0,p1,p2);
00269 } else {
00270 if (front != 0) return;
00271 c->draw_triangle_back(c,p0,p1,p2);
00272 }
00273 } else {
00274
00275 if (front) {
00276 c->draw_triangle_front(c,p0,p1,p2);
00277 } else {
00278 c->draw_triangle_back(c,p0,p1,p2);
00279 }
00280 }
00281 } else {
00282 c_and=cc[0] & cc[1] & cc[2];
00283 if (c_and==0) {
00284 gl_draw_triangle_clip(c,p0,p1,p2,0);
00285 }
00286 }
00287 }
00288
00289 static void gl_draw_triangle_clip(GLContext *c,
00290 GLVertex *p0,GLVertex *p1,GLVertex *p2,int clip_bit)
00291 {
00292 int co,c_and,co1,cc[3],edge_flag_tmp,clip_mask;
00293 GLVertex tmp1,tmp2,*q[3];
00294 PN_stdfloat tt;
00295
00296 cc[0]=p0->clip_code;
00297 cc[1]=p1->clip_code;
00298 cc[2]=p2->clip_code;
00299
00300 co=cc[0] | cc[1] | cc[2];
00301 if (co == 0) {
00302 gl_draw_triangle(c,p0,p1,p2);
00303 } else {
00304 c_and=cc[0] & cc[1] & cc[2];
00305
00306 if (c_and!=0) return;
00307
00308
00309 while (clip_bit < 6 && (co & (1 << clip_bit)) == 0) {
00310 clip_bit++;
00311 }
00312
00313
00314 if (clip_bit == 6) {
00315 #if 0
00316 printf("Error:\n");
00317 printf("%f %f %f %f\n",p0->pc.v[0],p0->pc.v[1],p0->pc.v[2],p0->pc.v[3]);
00318 printf("%f %f %f %f\n",p1->pc.v[0],p1->pc.v[1],p1->pc.v[2],p1->pc.v[3]);
00319 printf("%f %f %f %f\n",p2->pc.v[0],p2->pc.v[1],p2->pc.v[2],p2->pc.v[3]);
00320 #endif
00321 return;
00322 }
00323
00324 clip_mask = 1 << clip_bit;
00325 co1=(cc[0] ^ cc[1] ^ cc[2]) & clip_mask;
00326
00327 if (co1) {
00328
00329
00330 if (cc[0] & clip_mask) { q[0]=p0; q[1]=p1; q[2]=p2; }
00331 else if (cc[1] & clip_mask) { q[0]=p1; q[1]=p2; q[2]=p0; }
00332 else { q[0]=p2; q[1]=p0; q[2]=p1; }
00333
00334 tt=clip_proc[clip_bit](&tmp1.pc,&q[0]->pc,&q[1]->pc);
00335 updateTmp(c,&tmp1,q[0],q[1],tt);
00336
00337 tt=clip_proc[clip_bit](&tmp2.pc,&q[0]->pc,&q[2]->pc);
00338 updateTmp(c,&tmp2,q[0],q[2],tt);
00339
00340 tmp1.edge_flag=q[0]->edge_flag;
00341 edge_flag_tmp=q[2]->edge_flag;
00342 q[2]->edge_flag=0;
00343 gl_draw_triangle_clip(c,&tmp1,q[1],q[2],clip_bit+1);
00344
00345 tmp2.edge_flag=1;
00346 tmp1.edge_flag=0;
00347 q[2]->edge_flag=edge_flag_tmp;
00348 gl_draw_triangle_clip(c,&tmp2,&tmp1,q[2],clip_bit+1);
00349 } else {
00350
00351
00352 if ((cc[0] & clip_mask)==0) { q[0]=p0; q[1]=p1; q[2]=p2; }
00353 else if ((cc[1] & clip_mask)==0) { q[0]=p1; q[1]=p2; q[2]=p0; }
00354 else { q[0]=p2; q[1]=p0; q[2]=p1; }
00355
00356 tt=clip_proc[clip_bit](&tmp1.pc,&q[0]->pc,&q[1]->pc);
00357 updateTmp(c,&tmp1,q[0],q[1],tt);
00358
00359 tt=clip_proc[clip_bit](&tmp2.pc,&q[0]->pc,&q[2]->pc);
00360 updateTmp(c,&tmp2,q[0],q[2],tt);
00361
00362 tmp1.edge_flag=1;
00363 tmp2.edge_flag=q[2]->edge_flag;
00364 gl_draw_triangle_clip(c,q[0],&tmp1,&tmp2,clip_bit+1);
00365 }
00366 }
00367 }
00368
00369
00370 #ifdef PROFILE
00371 int count_triangles,count_triangles_textured,count_pixels;
00372 #endif
00373
00374 void gl_draw_triangle_fill(GLContext *c,
00375 GLVertex *p0,GLVertex *p1,GLVertex *p2)
00376 {
00377 #ifdef PROFILE
00378 {
00379 int norm;
00380 assert(p0->zp.x >= 0 && p0->zp.x < c->zb->xsize);
00381 assert(p0->zp.y >= 0 && p0->zp.y < c->zb->ysize);
00382 assert(p1->zp.x >= 0 && p1->zp.x < c->zb->xsize);
00383 assert(p1->zp.y >= 0 && p1->zp.y < c->zb->ysize);
00384 assert(p2->zp.x >= 0 && p2->zp.x < c->zb->xsize);
00385 assert(p2->zp.y >= 0 && p2->zp.y < c->zb->ysize);
00386
00387 norm=(p1->zp.x-p0->zp.x)*(p2->zp.y-p0->zp.y)-
00388 (p2->zp.x-p0->zp.x)*(p1->zp.y-p0->zp.y);
00389 count_pixels+=abs(norm)/2;
00390 count_triangles++;
00391 }
00392 #endif
00393
00394 #ifdef PROFILE
00395 if (c->num_textures_enabled != 0) {
00396 count_triangles_textured++;
00397 }
00398 #endif
00399
00400 (*c->zb_fill_tri)(c->zb,&p0->zp,&p1->zp,&p2->zp);
00401 }
00402
00403
00404
00405 void gl_draw_triangle_line(GLContext *c,
00406 GLVertex *p0,GLVertex *p1,GLVertex *p2)
00407 {
00408 if (c->depth_test) {
00409 if (p0->edge_flag) ZB_line_z(c->zb,&p0->zp,&p1->zp);
00410 if (p1->edge_flag) ZB_line_z(c->zb,&p1->zp,&p2->zp);
00411 if (p2->edge_flag) ZB_line_z(c->zb,&p2->zp,&p0->zp);
00412 } else {
00413 if (p0->edge_flag) ZB_line(c->zb,&p0->zp,&p1->zp);
00414 if (p1->edge_flag) ZB_line(c->zb,&p1->zp,&p2->zp);
00415 if (p2->edge_flag) ZB_line(c->zb,&p2->zp,&p0->zp);
00416 }
00417 }
00418
00419
00420
00421
00422 void gl_draw_triangle_point(GLContext *c,
00423 GLVertex *p0,GLVertex *p1,GLVertex *p2)
00424 {
00425 if (p0->edge_flag) ZB_plot(c->zb,&p0->zp);
00426 if (p1->edge_flag) ZB_plot(c->zb,&p1->zp);
00427 if (p2->edge_flag) ZB_plot(c->zb,&p2->zp);
00428 }
00429
00430
00431
00432