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C/C++ Source or Header  |  2001-01-08  |  7.8 KB  |  395 lines
  1. #include <stdlib.h>
  2. #include "zbuffer.h"
  3.  
  4. #define ZCMP(z,zpix) ((z) >= (zpix))
  5.  
  6. void ZB_fillTriangleFlat(ZBuffer *zb,
  7.              ZBufferPoint *p0,ZBufferPoint *p1,ZBufferPoint *p2)
  8. {
  9. #if TGL_FEATURE_RENDER_BITS == 24
  10.     unsigned char colorR, colorG, colorB;
  11. #else
  12.     int color;
  13. #endif
  14.  
  15. #define INTERP_Z
  16.  
  17. #if TGL_FEATURE_RENDER_BITS == 24 
  18.  
  19. #define DRAW_INIT()                \
  20. {                        \
  21.   colorR=p2->r>>8; \
  22.   colorG=p2->g>>8; \
  23.   colorB=p2->b>>8; \
  24. }
  25.  
  26. #define PUT_PIXEL(_a)        \
  27. {                        \
  28.     zz=z >> ZB_POINT_Z_FRAC_BITS;        \
  29.     if (ZCMP(zz,pz[_a])) {                \
  30.       pp[3 * _a]=colorR;\
  31.       pp[3 * _a + 1]=colorG;\
  32.       pp[3 * _a + 2]=colorB;\
  33.       pz[_a]=zz;                \
  34.     }\
  35.     z+=dzdx;                    \
  36. }
  37.  
  38. #else
  39.  
  40. #define DRAW_INIT()                \
  41. {                        \
  42.   color=RGB_TO_PIXEL(p2->r,p2->g,p2->b);    \
  43. }
  44.   
  45. #define PUT_PIXEL(_a)                \
  46. {                        \
  47.     zz=z >> ZB_POINT_Z_FRAC_BITS;        \
  48.     if (ZCMP(zz,pz[_a])) {                \
  49.       pp[_a]=color;                \
  50.       pz[_a]=zz;                \
  51.     }                        \
  52.     z+=dzdx;                    \
  53. }
  54. #endif /* TGL_FEATURE_RENDER_BITS == 24 */
  55.  
  56. #include "ztriangle.h"
  57. }
  58.  
  59. /*
  60.  * Smooth filled triangle.
  61.  * The code below is very tricky :)
  62.  */
  63.  
  64. void ZB_fillTriangleSmooth(ZBuffer *zb,
  65.                ZBufferPoint *p0,ZBufferPoint *p1,ZBufferPoint *p2)
  66. {
  67. #if TGL_FEATURE_RENDER_BITS == 16
  68.         int _drgbdx;
  69. #endif
  70.  
  71. #define INTERP_Z
  72. #define INTERP_RGB
  73.  
  74. #define SAR_RND_TO_ZERO(v,n) (v / (1<<n))
  75.  
  76. #if TGL_FEATURE_RENDER_BITS == 24
  77.  
  78. #define DRAW_INIT()                 \
  79. {                        \
  80. }
  81.  
  82. #define PUT_PIXEL(_a)                \
  83. {                        \
  84.     zz=z >> ZB_POINT_Z_FRAC_BITS;        \
  85.     if (ZCMP(zz,pz[_a])) {                \
  86.       pp[3 * _a]=or1 >> 8;\
  87.       pp[3 * _a + 1]=og1 >> 8;\
  88.       pp[3 * _a + 2]=ob1 >> 8;\
  89.       pz[_a]=zz;                \
  90.     }\
  91.     z+=dzdx;                    \
  92.     og1+=dgdx;                    \
  93.     or1+=drdx;                    \
  94.     ob1+=dbdx;                    \
  95. }
  96.  
  97. #elif TGL_FEATURE_RENDER_BITS == 16
  98.  
  99. #define DRAW_INIT()                 \
  100. {                        \
  101.   _drgbdx=(SAR_RND_TO_ZERO(drdx,6) << 22) & 0xFFC00000;        \
  102.   _drgbdx|=SAR_RND_TO_ZERO(dgdx,5) & 0x000007FF;        \
  103.   _drgbdx|=(SAR_RND_TO_ZERO(dbdx,7) << 12) & 0x001FF000;     \
  104. }
  105.  
  106.  
  107. #define PUT_PIXEL(_a)                \
  108. {                        \
  109.     zz=z >> ZB_POINT_Z_FRAC_BITS;        \
  110.     if (ZCMP(zz,pz[_a])) {                \
  111.       tmp=rgb & 0xF81F07E0;            \
  112.       pp[_a]=tmp | (tmp >> 16);            \
  113.       pz[_a]=zz;                \
  114.     }                        \
  115.     z+=dzdx;                    \
  116.     rgb=(rgb+drgbdx) & ( ~ 0x00200800);        \
  117. }
  118.  
  119. #define DRAW_LINE()                               \
  120. {                                       \
  121.   register unsigned short *pz;                       \
  122.   register PIXEL *pp;                       \
  123.   register unsigned int tmp,z,zz,rgb,drgbdx;                   \
  124.   register int n;                               \
  125.   n=(x2 >> 16) - x1;                               \
  126.   pp=pp1+x1;                                   \
  127.   pz=pz1+x1;                                   \
  128.   z=z1;                                       \
  129.   rgb=(r1 << 16) & 0xFFC00000;                           \
  130.   rgb|=(g1 >> 5) & 0x000007FF;                           \
  131.   rgb|=(b1 << 5) & 0x001FF000;                           \
  132.   drgbdx=_drgbdx;                               \
  133.   while (n>=3) {                               \
  134.     PUT_PIXEL(0);                               \
  135.     PUT_PIXEL(1);                               \
  136.     PUT_PIXEL(2);                               \
  137.     PUT_PIXEL(3);                               \
  138.     pz+=4;                                   \
  139.     pp+=4;                                   \
  140.     n-=4;                                   \
  141.   }                                       \
  142.   while (n>=0) {                               \
  143.     PUT_PIXEL(0);                               \
  144.     pz+=1;                                   \
  145.     pp+=1;                                   \
  146.     n-=1;                                   \
  147.   }                                       \
  148. }
  149.  
  150. #else
  151.  
  152. #define DRAW_INIT()                 \
  153. {                        \
  154. }
  155.  
  156. #define PUT_PIXEL(_a)                \
  157. {                        \
  158.     zz=z >> ZB_POINT_Z_FRAC_BITS;        \
  159.     if (ZCMP(zz,pz[_a])) {                \
  160.       pp[_a] = RGB_TO_PIXEL(or1, og1, ob1);\
  161.       pz[_a]=zz;                \
  162.     }\
  163.     z+=dzdx;                    \
  164.     og1+=dgdx;                    \
  165.     or1+=drdx;                    \
  166.     ob1+=dbdx;                    \
  167. }
  168.  
  169. #endif /* TGL_FEATURE_RENDER_BITS */
  170.  
  171. #include "ztriangle.h"
  172. }
  173.  
  174. void ZB_setTexture(ZBuffer *zb,PIXEL *texture)
  175. {
  176.     zb->current_texture=texture;
  177. }
  178.  
  179. void ZB_fillTriangleMapping(ZBuffer *zb,
  180.                 ZBufferPoint *p0,ZBufferPoint *p1,ZBufferPoint *p2)
  181. {
  182.     PIXEL *texture;
  183.  
  184. #define INTERP_Z
  185. #define INTERP_ST
  186.  
  187. #define DRAW_INIT()                \
  188. {                        \
  189.   texture=zb->current_texture;            \
  190. }
  191.  
  192. #if TGL_FEATURE_RENDER_BITS == 24
  193.  
  194. #define PUT_PIXEL(_a)                \
  195. {                        \
  196.    unsigned char *ptr;\
  197.    zz=z >> ZB_POINT_Z_FRAC_BITS;        \
  198.      if (ZCMP(zz,pz[_a])) {                \
  199.        ptr = texture + (((t & 0x3FC00000) | s) >> 14) * 3; \
  200.        pp[3 * _a]= ptr[0];\
  201.        pp[3 * _a + 1]= ptr[1];\
  202.        pp[3 * _a + 2]= ptr[2];\
  203.        pz[_a]=zz;                \
  204.     }                        \
  205.     z+=dzdx;                    \
  206.     s+=dsdx;                    \
  207.     t+=dtdx;                    \
  208. }
  209.  
  210. #else
  211.  
  212. #define PUT_PIXEL(_a)                \
  213. {                        \
  214.    zz=z >> ZB_POINT_Z_FRAC_BITS;        \
  215.      if (ZCMP(zz,pz[_a])) {                \
  216.        pp[_a]=texture[((t & 0x3FC00000) | s) >> 14];    \
  217.        pz[_a]=zz;                \
  218.     }                        \
  219.     z+=dzdx;                    \
  220.     s+=dsdx;                    \
  221.     t+=dtdx;                    \
  222. }
  223.  
  224. #endif
  225.  
  226. #include "ztriangle.h"
  227. }
  228.  
  229. /*
  230.  * Texture mapping with perspective correction.
  231.  * We use the gradient method to make less divisions.
  232.  * TODO: pipeline the division
  233.  */
  234. #if 1
  235.  
  236. void ZB_fillTriangleMappingPerspective(ZBuffer *zb,
  237.                             ZBufferPoint *p0,ZBufferPoint *p1,ZBufferPoint *p2)
  238. {
  239.     PIXEL *texture;
  240.     float fdzdx,fndzdx,ndszdx,ndtzdx;
  241.  
  242. #define INTERP_Z
  243. #define INTERP_STZ
  244.  
  245. #define NB_INTERP 8
  246.  
  247. #define DRAW_INIT()                \
  248. {                        \
  249.   texture=zb->current_texture;\
  250.   fdzdx=(float)dzdx;\
  251.   fndzdx=NB_INTERP * fdzdx;\
  252.   ndszdx=NB_INTERP * dszdx;\
  253.   ndtzdx=NB_INTERP * dtzdx;\
  254. }
  255.  
  256.  
  257. #if TGL_FEATURE_RENDER_BITS == 24
  258.  
  259. #define PUT_PIXEL(_a)                \
  260. {                        \
  261.    unsigned char *ptr;\
  262.    zz=z >> ZB_POINT_Z_FRAC_BITS;        \
  263.      if (ZCMP(zz,pz[_a])) {                \
  264.        ptr = texture + (((t & 0x3FC00000) | (s & 0x003FC000)) >> 14) * 3;\
  265.        pp[3 * _a]= ptr[0];\
  266.        pp[3 * _a + 1]= ptr[1];\
  267.        pp[3 * _a + 2]= ptr[2];\
  268.        pz[_a]=zz;                \
  269.     }                        \
  270.     z+=dzdx;                    \
  271.     s+=dsdx;                    \
  272.     t+=dtdx;                    \
  273. }
  274.  
  275. #else
  276.  
  277. #define PUT_PIXEL(_a)                \
  278. {                        \
  279.    zz=z >> ZB_POINT_Z_FRAC_BITS;        \
  280.      if (ZCMP(zz,pz[_a])) {                \
  281.        pp[_a]=*(PIXEL *)((char *)texture+ \
  282.                (((t & 0x3FC00000) | (s & 0x003FC000)) >> (17 - PSZSH)));\
  283.        pz[_a]=zz;                \
  284.     }                        \
  285.     z+=dzdx;                    \
  286.     s+=dsdx;                    \
  287.     t+=dtdx;                    \
  288. }
  289.  
  290. #endif
  291.  
  292. #define DRAW_LINE()                \
  293. {                        \
  294.   register unsigned short *pz;        \
  295.   register PIXEL *pp;        \
  296.   register unsigned int s,t,z,zz;    \
  297.   register int n,dsdx,dtdx;        \
  298.   float sz,tz,fz,zinv; \
  299.   n=(x2>>16)-x1;                             \
  300.   fz=(float)z1;\
  301.   zinv=1.0 / fz;\
  302.   pp=(PIXEL *)((char *)pp1 + x1 * PSZB); \
  303.   pz=pz1+x1;                    \
  304.   z=z1;                        \
  305.   sz=sz1;\
  306.   tz=tz1;\
  307.   while (n>=(NB_INTERP-1)) {                           \
  308.     {\
  309.       float ss,tt;\
  310.       ss=(sz * zinv);\
  311.       tt=(tz * zinv);\
  312.       s=(int) ss;\
  313.       t=(int) tt;\
  314.       dsdx= (int)( (dszdx - ss*fdzdx)*zinv );\
  315.       dtdx= (int)( (dtzdx - tt*fdzdx)*zinv );\
  316.       fz+=fndzdx;\
  317.       zinv=1.0 / fz;\
  318.     }\
  319.     PUT_PIXEL(0);                               \
  320.     PUT_PIXEL(1);                               \
  321.     PUT_PIXEL(2);                               \
  322.     PUT_PIXEL(3);                               \
  323.     PUT_PIXEL(4);                               \
  324.     PUT_PIXEL(5);                               \
  325.     PUT_PIXEL(6);                               \
  326.     PUT_PIXEL(7);                               \
  327.     pz+=NB_INTERP;                               \
  328.     pp=(PIXEL *)((char *)pp + NB_INTERP * PSZB);\
  329.     n-=NB_INTERP;                               \
  330.     sz+=ndszdx;\
  331.     tz+=ndtzdx;\
  332.   }                                       \
  333.     {\
  334.       float ss,tt;\
  335.       ss=(sz * zinv);\
  336.       tt=(tz * zinv);\
  337.       s=(int) ss;\
  338.       t=(int) tt;\
  339.       dsdx= (int)( (dszdx - ss*fdzdx)*zinv );\
  340.       dtdx= (int)( (dtzdx - tt*fdzdx)*zinv );\
  341.     }\
  342.   while (n>=0) {                               \
  343.     PUT_PIXEL(0);                               \
  344.     pz+=1;                                   \
  345.     pp=(PIXEL *)((char *)pp + PSZB);\
  346.     n-=1;                                   \
  347.   }                                       \
  348. }
  349.   
  350. #include "ztriangle.h"
  351. }
  352.  
  353. #endif
  354.  
  355. #if 0
  356.  
  357. /* slow but exact version (only there for reference, incorrect for 24
  358.    bits) */
  359.  
  360. void ZB_fillTriangleMappingPerspective(ZBuffer *zb,
  361.                             ZBufferPoint *p0,ZBufferPoint *p1,ZBufferPoint *p2)
  362. {
  363.     PIXEL *texture;
  364.  
  365. #define INTERP_Z
  366. #define INTERP_STZ
  367.  
  368. #define DRAW_INIT()                \
  369. {                        \
  370.   texture=zb->current_texture;            \
  371. }
  372.  
  373. #define PUT_PIXEL(_a)                \
  374. {                        \
  375.    float zinv; \
  376.    int s,t; \
  377.    zz=z >> ZB_POINT_Z_FRAC_BITS;        \
  378.      if (ZCMP(zz,pz[_a])) {                \
  379.        zinv= 1.0 / (float) z; \
  380.        s= (int) (sz * zinv); \
  381.        t= (int) (tz * zinv); \
  382.        pp[_a]=texture[((t & 0x3FC00000) | s) >> 14];    \
  383.        pz[_a]=zz;                \
  384.     }                        \
  385.     z+=dzdx;                    \
  386.     sz+=dszdx;                    \
  387.     tz+=dtzdx;                    \
  388. }
  389.  
  390. #include "ztriangle.h"
  391. }
  392.  
  393.  
  394. #endif
  395.