/* This file contains a 3D replacement for the out_line function called by the decoder. The purpose is to apply various 3D transformations before displaying points. Called once per line of the original GIF file. Original Author Tim Wegner, with extensive help from Marc Reinig. */ #include #include #include #include #include #include "fractint.h" static int TOP = -1; static int BOT = -1; static int LEFT = -1; static int RIGHT = -1; static int line_length1; static int T_header_24 = 18; /* Size of current Targa-24 header */ extern unsigned char dacbox[256][3]; static FILE *File_Ptr1 = NULL; int Ambient; static unsigned int IAmbient; int RANDOMIZE; static int rand_factor; int haze; static int HAZE_MULT; int full_color; char light_name[80]; extern int warn; /* warnings on/off */ unsigned char back_color[3]; static unsigned char Real_Color; extern int dotmode; /* video access method, 11 if really disk video */ extern int calc_status; extern long calctime; int clipcolor(int,int,int); int clipcolor2(int,int,int); int interpcolor(int,int,int); int T_clipcolor(int,int,int); int T_interpcolor(int,int,int); int (*fillplot)(); int (*normalplot)(); int (*standardplot)(); char preview = 0; char showbox = 0; static int localpreviewfactor; int previewfactor = 20; int xadjust = 0; int yadjust = 0; int xxadjust; int yyadjust; int xshift; int yshift; extern int overflow; extern int filetype; extern char floatflag; extern int (*plot)(); extern int xdots, ydots, colors; extern int debugflag; extern void draw_line (int X1, int Y1, int X2, int Y2, int color); extern int extraseg; extern unsigned height; extern int rowcount; /* in general.asm */ extern int init3d[]; /* 3D arguments (FRACTINT.C) */ extern FILE *fp_pot; /* potential file pointer */ extern long far *lx0; extern int transparent[2]; /* transparency min/max */ static int zcoord = 256; static double aspect; /* aspect ratio */ static float far *sinthetaarray; /* all sine thetas go here */ static float far *costhetaarray; /* all cosine thetas go here */ static double rXrscale; /* precalculation factor */ static int persp; /* flag for indicating perspective transformations */ int bad_value = -10000; /* set bad values to this */ int bad_check = -1000; /* check values against this to determine if good */ /* this array remembers the previous line */ struct point { int x; int y; int color; } far *lastrow; static struct point p1,p2,p3; struct f_point { float x; float y; float color; } far *f_lastrow; /* array of min and max x values used in triangle fill */ struct minmax { int minx; int maxx; } far *minmax_x; VECTOR view; /* position of observer for perspective */ VECTOR cross; VECTOR tmpcross; line3d(unsigned char pixels[], unsigned linelen) { static FILE *out1; static int numsaves1=0; char File_Name[12]; int RND; char openfile[80], lightfiletype[10]; /* these values come from FRACTINT.C */ /* These variables must preserve their values across calls */ static float deltaphi; /* increment of latitude, longitude */ static float phi; static double rscale; /* surface roughness factor */ static long xcenter,ycenter; /* circle center */ static double sclx,scly,sclz; /* scale factors */ static double R; /* radius values */ static double Rfactor; /* for intermediate calculation */ static MATRIX m; /* transformation matrix */ static MATRIX lightm; /* m w/no trans, keeps obj. on screen */ static LMATRIX lm; /* "" */ static LVECTOR lview; /* for perspective views */ static double zcutoff; /* perspective backside cutoff value */ static float twocosdeltaphi; static float cosphi,sinphi; /* precalculated sin/cos of longitude */ static float oldcosphi1,oldsinphi1; static float oldcosphi2,oldsinphi2; double r; /* sphere radius */ double xval,yval,zval; /* rotation values */ float costheta,sintheta; /* precalculated sin/cos of latitude */ float twocosdeltatheta; int col; /* current column (original GIF) */ struct point cur; /* current pixels */ struct point old; /* old pixels */ struct point oldlast; /* old pixels */ static struct point bad; /* out of range value */ struct f_point f_cur; struct f_point f_old; static struct f_point f_bad; /* out of range value */ static float far *fpixels; /* float persion of pixels array */ VECTOR v; /* double vector */ VECTOR v1,v2; VECTOR crossavg; char crossnotinit; /* flag for crossavg init indication */ static VECTOR light_direction; double v_length; VECTOR origin, direct; LVECTOR lv; /* long equivalent of v */ LVECTOR lv0; /* long equivalent of v */ int color; /* current decoded color */ /* corners of transformed xdotx by ydots x colors box */ double xmin, ymin, zmin, xmax, ymax, zmax; int i,j; int lastdot; if(transparent[0] || transparent[1]) plot = normalplot = T_clipcolor; /* Use the transparent plot function */ else if(colors >= 16) plot = normalplot = clipcolor; /* the usual FRACTINT plot function with clipping */ else plot = normalplot = clipcolor2; /* This IF clause is executed ONCE per image. All precalculations are done here, with out any special concern about speed. DANGER - communication with the rest of the program is generally via static or global variables. */ if(rowcount == 0) { long check_extra; float theta,theta1,theta2; /* current,start,stop latitude */ float phi1,phi2; /* current start,stop longitude */ float deltatheta; /* increment of latitude */ /* plot_setup();*/ /* lastrow stores the previous row of the original GIF image for the purpose of filling in gaps with triangle procedure */ calctime = 0; calc_status = 1; /* mark as in-progress, and enable timer display */ if (dotmode == 11) { movecursor(2,0); printf("...mapping to 3d..."); } IAmbient = (unsigned int) 255 * (float)(100 - Ambient) / 100.0; if (full_color && FILLTYPE >= 5) { restart: strcpy(openfile,light_name); strcpy(lightfiletype,".tga"); /* Assume file ext. is ".tga" */ for (i = 0; i < strlen(openfile); i++) /* See if they supplied */ if (openfile[i] == '.') /* an extention */ { /* Yes! */ strcpy(lightfiletype,&openfile[i]); /* Capture it */ openfile[i] = 0; /* Del. the ext. from the filename */ } if (++numsaves1 > 1) /* Have we already saved this file on */ { /* Yes! */ updatesavename(openfile); /* secondary saves? new filename */ strncpy(light_name, openfile, strlen(openfile)); } strcat(openfile,lightfiletype); /* Rebuild filename with ext. */ /* Does file name exist? */ if (warn && (out1=fopen(openfile,"r")) != NULL) { /* Oops! */ fclose(out1); goto restart; } startdisk1(light_name); } rand_factor = 14 - RANDOMIZE; if(colors<16) zcoord = 256; else zcoord = colors; crossavg[0] = 0; crossavg[1] = 0; crossavg[2] = 0; /********************************************************************* Memory allocation - assumptions - a 64K segment starting at extraseg has been grabbed. It may have other purposes elsewhere, but it is assumed that it is totally free for use here. Our strategy is to assign all the far pointers needed here to various spots in the extra segment, depending on the pixel dimensions of the video mode, and check whether we have run out. There is basically one case where the extra segment is not big enough - SPHERE mode with a fill type that uses putatriangle() (array minmax_x) at the largest legal resolution of 2048x2048 or thereabouts. In that case we use farmemalloc to grab memory for minmax_x. This memory is never freed. *******************************************************************/ if(extraseg) { #ifdef __TURBOC__ lastrow = MK_FP(extraseg,0); #else FP_SEG(lastrow)=extraseg; FP_OFF(lastrow)=0; #endif }else return(-1); check_extra = sizeof(*lastrow)*xdots; if(SPHERE) { sinthetaarray = (float far *)(lastrow+xdots); check_extra += sizeof(*sinthetaarray)*xdots; costhetaarray = (float far *)(sinthetaarray+xdots); check_extra += sizeof(*costhetaarray)*xdots; f_lastrow = (struct f_point far *)(costhetaarray+xdots); } else f_lastrow = (struct f_point far *)(lastrow+xdots); check_extra += sizeof(*f_lastrow)*(xdots); fpixels = (float far *)(f_lastrow+xdots); check_extra += sizeof(*fpixels)*xdots; minmax_x = (struct minmax *)NULL; /* these fill types call putatriangle which uses minmax_x */ if( FILLTYPE == 2 || FILLTYPE == 3 || FILLTYPE == 5 || FILLTYPE == 6) { /* end of arrays if we use extra segement */ check_extra += sizeof(struct minmax)*ydots; if(check_extra > 1L<<16) /* run out of extra segment? */ { static struct minmax far *got_mem = NULL; /* not using extra segment so decrement check_extra */ check_extra -= sizeof(struct minmax)*ydots; if(got_mem == NULL) got_mem = (struct minmax far *)(farmemalloc(2048L*sizeof(struct minmax))); if(got_mem) minmax_x = got_mem; else return(-1); } else /* ok to use extra segment */ minmax_x = (struct minmax far *)(fpixels+xdots); } if(debugflag == 2222 || check_extra > 1L<<16) { printf("used %ld of extra segment\n",check_extra); getch(); } /* get scale factors */ sclx = XSCALE/100.0; scly = YSCALE/100.0; sclz = - ROUGH/100.0; /* aspect ratio calculation - assume screen is 4 x 3 */ aspect = (double)xdots*.75/(double)ydots; if(SPHERE==FALSE) /* skip this slow stuff in sphere case */ { /* What is done here is to create a single matrix, m, which has scale, rotation, and shift all combined. This allows us to use a single matrix to transform any point. Additionally, we create two perspective vectors. Start with a unit matrix. Add scale and rotation. Then calculate the perspective vectors. Finally add enough translation to center the final image plus whatever shift the user has set. */ /* start with identity */ identity (m); identity (lightm); /* translate so origin is in center of box, so that when we rotate it, we do so through the center */ trans ( (double)xdots/(-2.0),(double)ydots/(-2.0), (double)zcoord/(-2.0),m); trans ( (double)xdots/(-2.0),(double)ydots/(-2.0), (double)zcoord/(-2.0),lightm); /* apply scale factors */ scale(sclx,scly,sclz,m); scale(sclx,scly,sclz,lightm); /* rotation values - converting from degrees to radians */ xval = XROT / 57.29577; yval = YROT / 57.29577; zval = ZROT / 57.29577; xrot (xval,m); xrot (xval,lightm); yrot (yval,m); yrot (yval,lightm); zrot (zval,m); zrot (zval,lightm); /* Find values of translation that make all x,y,z negative */ /* m current matrix */ /* 0 means don't show box */ /* returns minimum and maximum values of x,y,z in fractal */ corners(m,0,&xmin,&ymin,&zmin,&xmax,&ymax,&zmax); } /* perspective 3D vector - lview[2] == 0 means no perspective */ /* set perspective flag */ persp = 0; if (ZVIEWER != 0) { persp = 1; if(ZVIEWER < 80) /* force float */ floatflag |= 2; /* turn on second bit */ } /* set up view vector, and put viewer in center of screen */ lview[0] = xdots >> 1; lview[1] = ydots >> 1; /* z value of user's eye - should be more negative than extreme negative part of image */ if(SPHERE) /* sphere case */ lview[2] = -(long)((double)ydots*(double)ZVIEWER/100.0); else /* non-sphere case */ lview[2] = (long)((zmin-zmax)*(double)ZVIEWER/100.0); view[0] = lview[0]; view[1] = lview[1]; view[2] = lview[2]; lview[0] = lview[0] << 16; lview[1] = lview[1] << 16; lview[2] = lview[2] << 16; if(SPHERE==FALSE) /* sphere skips this */ { /* translate back exactly amount we translated earlier plus enough to center image so maximum values are non-positive */ trans(((double)xdots-xmax-xmin)/2,((double)ydots-ymax-ymin)/2,-zmax,m); /* Keep the box centered and on screen regardless of shifts */ trans(((double)xdots-xmax-xmin)/2,((double)ydots-ymax-ymin)/2, -zmax,lightm); trans((double)(xshift),(double)(-yshift),0.0,m); /* matrix m now contains ALL those transforms composed together !!!! */ /* convert m to long integers shifted 16 bits */ for (i = 0; i < 4; i++) for (j = 0; j < 4; j++) lm[i][j] = m[i][j] * 65536.0; } else /* sphere stuff goes here */ { float z; /* Sphere is on side - north pole on right. Top is -90 degrees latitude; bottom 90 degrees */ /* Map X to this LATITUDE range */ theta1 = THETA1*PI/180.0; theta2 = THETA2*PI/180.0; /* Map Y to this LONGITUDE range */ phi1 = PHI1*PI/180.0; phi2 = PHI2*PI/180.0; theta = theta1; phi = phi1; /* Thanks to Hugh Bray for the following idea: when calculating a table of evenly spaced sines or cosines, only a few initial values need be calculated, and the remaining values can be gotten from a derivative of the sine/cosine angle sum formula at the cost of one multiplication and one addition per value! This idea is applied once here to get a complete table for latitude, and near the bottom of this routine to incrementally calculate longitude. Precalculate 2*cos(deltaangle), sin(start) and sin(start+delta). Then apply recursively: sin(angle+2*delta) = sin(angle+delta) * 2cosdelta - sin(angle) Similarly for cosine. Neat! */ deltatheta = (float)(theta2 - theta1)/(float)linelen; /* initial sin,cos theta */ sinthetaarray[0] = sin((double)theta); costhetaarray[0] = cos((double)theta); sinthetaarray[1] = sin((double)(theta + deltatheta)); costhetaarray[1] = cos((double)(theta + deltatheta)); /* sin,cos delta theta */ twocosdeltatheta = 2.0*cos((double)deltatheta); /* build table of other sin,cos with trig identity */ for(i=2;i= 5 && showbox) { normalize_vector(direct); /* Set origin[] to be the center of the untransformed xy plane at z=0 */ /* and torigin[] to be the same */ origin[0] = (double)(xdots)/2.0; origin[1] = (double)(ydots)/2.0; origin[2] = 0.0; /* Set length of light direction vector to be convienient for viewing */ v_length = min ((xdots/2.0), min ((ydots/2.0), (float)(zcoord))); /* Set direct[] to point from origin[] in direction of untransformed light_direction (direct[]). */ direct[0] = origin[0] + direct[0] * v_length; direct[1] = origin[1] + direct[1] * v_length; direct[2] = origin[2] + direct[2] * v_length; /* Draw light source vector and box containing it, draw_light_box will transform them if necessary. */ draw_light_box (origin,direct,lightm); /* draw box around original field of view to help visualize effect of rotations */ /* 1 means show box - xmin etc. do nothing here */ corners(m,1,&xmin,&ymin,&zmin,&xmax,&ymax,&zmax); } /* bad has values caught by clipping */ f_bad.x = bad.x = bad_value; f_bad.y = bad.y = bad_value; f_bad.color = bad.color = bad_value; for(i=0;i= 5) if (haze != 0 && full_color) { HAZE_MULT = haze * (0.1 + 0.9 * (float)( ydots - 1 - rowcount)) / (float)(ydots - 1); HAZE_MULT = 100 - HAZE_MULT; } if (FILLTYPE == -1) { if (col != lastdot) /* if this is not the last col */ if (col % localpreviewfactor) /* if not the 1st or mod factor col*/ goto loopbottom; } cur.color = pixels[col]; f_cur.color = fpixels[col]; if (cur.color > 0 && cur.color < WATERLINE) f_cur.color = cur.color = WATERLINE; /* "lake" */ if(SPHERE) /* sphere case */ { sintheta = sinthetaarray[col]; costheta = costhetaarray[col]; /* if naked use of goto's offend you don't read next two lines! */ if(sinphi < 0) { cur = bad; f_cur = f_bad; goto loopbottom; /* another goto ! */ } /* KEEP THIS FOR DOCS - original formula -- if(rscale < 0.0) r = 1.0+((double)cur.color/(double)zcoord)*rscale; else r = 1.0-rscale+((double)cur.color/(double)zcoord)*rscale; R = (double)ydots/2; r = r*R; cur.x = xdots/2 + sclx*r*sintheta*aspect + xup ; cur.y = ydots/2 + scly*r*costheta*cosphi - yup ; */ if(rscale < 0.0) r = R + Rfactor*(double)f_cur.color*costheta; else if(rscale > 0.0) r = R -rXrscale + Rfactor*(double)f_cur.color*costheta; else r = R; if(persp) { /* NOTE: fudge was pre-calculated above in r and R */ lv[2] = -R - r*costheta*sinphi; /* (almost) guarantee negative */ if(lv[2] > zcutoff) { cur = bad; f_cur = f_bad; goto loopbottom; /* another goto ! */ } lv[0] = xcenter + sintheta*sclx*r; /* x */ lv[1] = ycenter + costheta*cosphi*scly*r; /* y */ if(FILLTYPE >= 5) /* calculate illumination normal before persp */ { double r0; int xcenter0,ycenter0; r0 = r/65536; xcenter0 = xcenter >> 16; ycenter0 = xcenter >> 16; f_cur.x = xcenter0 + sintheta*sclx*r0; f_cur.y = ycenter0 + costheta*cosphi*scly*r0; f_cur.color = -r0*costheta*sinphi; } if(!floatflag) { if(longpersp(lv,lview,16) == -1) { cur = bad; f_cur = f_bad; goto loopbottom; /* another goto ! */ } cur.x = ((lv[0]+32768L) >> 16) + xxadjust; cur.y = ((lv[1]+32768L) >> 16) + yyadjust; } if(floatflag||overflow) { VECTOR v; long fudge; fudge = 1L<<16; v[0] = lv[0]; v[1] = lv[1]; v[2] = lv[2]; v[0] /= fudge; v[1] /= fudge; v[2] /= fudge; perspective(v); cur.x = v[0]+.5 + xxadjust; cur.y = v[1]+.5 + yyadjust; } } else { cur.x = f_cur.x = xcenter + sintheta*sclx*r + xxadjust; cur.y = f_cur.y = ycenter + costheta*cosphi*scly*r + yyadjust; if(FILLTYPE >= 5) f_cur.color = -r*costheta*sinphi; } } else /* non-sphere 3D */ { if(!floatflag) { if(FILLTYPE >= 5) /* flag to save vector before perspective */ lv0[0] = 1; /* in longvmultpersp calculation */ else lv0[0] = 0; /* use 32-bit multiply math to snap this out */ lv[0] = col; lv[0] = lv[0] << 16; lv[1] = rowcount; lv[1] = lv[1] << 16; if(filetype) /* don't truncate fractional part */ lv[2] = f_cur.color*65536.0; else /* there IS no fractaional part here! */ { lv[2] = f_cur.color; lv[2] = lv[2] << 16; } if(longvmultpersp(lv,lm,lv0,lv,lview,16) == -1) { cur = bad; f_cur = f_bad; goto loopbottom; } cur.x = ((lv[0]+32768L) >> 16) + xxadjust; cur.y = ((lv[1]+32768L) >> 16) + yyadjust; if(FILLTYPE >= 5) { f_cur.x = lv0[0]; f_cur.x /= 65536.0; f_cur.y = lv0[1]; f_cur.y /= 65536.0; f_cur.color = lv0[2]; f_cur.color /= 65536.0; } } if(floatflag||overflow) /* do in float if integer math overflowed */ { /* slow float version for comparison */ v[0] = col; v[1] = rowcount; v[2] = f_cur.color; vmult(v,m,v); f_cur.x = v[0]; f_cur.y = v[1]; f_cur.color = v[2]; if(persp) perspective(v); cur.x = v[0] + xxadjust + .5; cur.y = v[1] + yyadjust + .5; } } if (RANDOMIZE) if (cur.color > WATERLINE) { RND = rand() >> 8; /* 7-bit number */ RND = RND * RND >> rand_factor; /* n-bit number */ if (rand() & 1) RND = -RND; /* Make +/- n-bit number */ if ((int)(cur.color) + RND >= colors) cur.color = colors-2; else if ((int)(cur.color) + RND <= WATERLINE) cur.color = WATERLINE + 1; else pixels[col] = cur.color = cur.color + RND; } switch(FILLTYPE) { case -1: if (col && old.x > bad_check && old.x < (xdots - bad_check)) draw_line (old.x, old.y, cur.x, cur.y, cur.color); if (rowcount && lastrow[col].x > bad_check && lastrow[col].y > bad_check && lastrow[col].x < (xdots - bad_check) && lastrow[col].y < (ydots - bad_check)) draw_line (lastrow[col].x,lastrow[col].y,cur.x, cur.y,cur.color); break; case 0: (*plot)(cur.x,cur.y,cur.color); break; case 1: /* connect-a-dot */ if ((old.x < xdots) && (col) && old.x > bad_check && old.y > bad_check) /* Don't draw from old to cur on col 0 */ draw_line(old.x,old.y,cur.x,cur.y,cur.color); old.x = cur.x; old.y = cur.y; break; case 2: /* with interpolation */ case 3: /* no interpolation */ /* "triangle fill" - consider four points: current point, previous point same row, point opposite current point in previous row, point after current point in previous row. The object is to fill all points inside the two triangles. lastrow[col].x/y___ lastrow[col+1] / 1 / / 1 / / 1 / oldrow/col _____ trow/col / */ if(rowcount && col) /* skip first row and first column */ { if(col == 1) putatriangle(lastrow[col],oldlast,old,old.color); if(col < lastdot) putatriangle(lastrow[col+1],lastrow[col],cur,cur.color); putatriangle(old, lastrow[col],cur,cur.color); /* make sure corner colors not overwritten */ (*plot)(cur.x,cur.y,cur.color); (*plot)(old.x,old.y,old.color); (*plot)(lastrow[col ].x,lastrow[col ].y,lastrow[col ].color); if(col < lastdot) (*plot)(lastrow[col+1].x,lastrow[col+1].y,lastrow[col+1].color); } break; case 4: /* "solid fill" */ if (SPHERE) { if (persp) { old.x = xcenter>>16; old.y = ycenter>>16; } else { old.x = xcenter; old.y = ycenter; } } else { lv[0] = col; lv[1] = rowcount; lv[2] = 0; /* apply fudge bit shift for integer math */ lv[0] = lv[0] << 16; lv[1] = lv[1] << 16; /* Since 0, unnecessary lv[2] = lv[2] << 16;*/ if(longvmultpersp(lv,lm,lv0,lv,lview,16)) { cur = bad; f_cur = f_bad; goto loopbottom; /* another goto ! */ } /* Round and fudge back to original */ old.x = (lv[0]+32768L) >> 16; old.y = (lv[1]+32768L) >> 16; } if (old.x < 0) old.x = 0; if (old.x >= xdots) old.x = xdots-1; if (old.y < 0) old.y = 0; if (old.y >= ydots) old.y = ydots-1; draw_line(old.x,old.y,cur.x,cur.y,cur.color); break; case 5: case 6: /* light-source modulated fill */ if(rowcount && col) /* skip first row and first column */ { if(f_cur.color < bad_check || f_old.color < bad_check || f_lastrow[col].color < bad_check) break; if(FILLTYPE==5) { v1[0] = 1; v1[1] = 0; v1[2] = f_cur.color - f_old.color; v2[0] = 0; v2[1] = 1; v2[2] = f_lastrow[col].color - f_cur.color; } else if(FILLTYPE==6) { if(f_lastrow[col].color < bad_check) break; v1[0] = f_cur.x - f_old.x; v1[1] = f_cur.y - f_old.y; v1[2] = f_cur.color - f_old.color; v2[0] = f_lastrow[col].x - f_cur.x; v2[1] = f_lastrow[col].y - f_cur.y; v2[2] = f_lastrow[col].color - f_cur.color; } cross_product (v1, v2, cross); /* normalize cross - and check if non-zero */ if(normalize_vector(cross)) cur.color = f_cur.color = bad.color; else { /* line-wise averaging scheme */ if(LIGHTAVG>0) { if(crossnotinit) { /* initialize array of old normal vectors */ crossavg[0] = cross[0]; crossavg[1] = cross[1]; crossavg[2] = cross[2]; crossnotinit = 0; } tmpcross[0] = (crossavg[0]*LIGHTAVG+cross[0])/(LIGHTAVG+1); tmpcross[1] = (crossavg[1]*LIGHTAVG+cross[1])/(LIGHTAVG+1); tmpcross[2] = (crossavg[2]*LIGHTAVG+cross[2])/(LIGHTAVG+1); cross[0] = tmpcross[0]; cross[1] = tmpcross[1]; cross[2] = tmpcross[2]; if(normalize_vector(cross)) { /* this shouldn't happen */ if(debugflag) { printf("normal vector error #2\r"); showfpoint(f_cur); showfpoint(f_lastrow[col]); showfpoint(f_lastrow[col-1]); getch(); } cur.color = f_cur.color = colors; } crossavg[0] = tmpcross[0]; crossavg[1] = tmpcross[1]; crossavg[2] = tmpcross[2]; } /* dot product of unit vectors is cos of angle between */ /* we will use this value to shade surface */ cur.color = 1+(colors-2)*(1.0-dot_product(cross,light_direction)); } /* if colors out of range, set them to min or max color index but avoid background index. This makes colors "opaque" so SOMETHING plots */ if(cur.color <= 0) /* prevent transparent colors */ cur.color = 1; /* avoid background */ if(cur.color >= colors) cur.color = colors-1; /* why "col < 2"? So we have sufficient geometry for the fill algorithm, which needs previous point in same row to have already been calculated (variable old) */ if(col < 2 || rowcount < 2) /* don't have valid colors yet */ break; Real_Color = pixels[col]; if(col < lastdot) putatriangle(lastrow[col+1],lastrow[col],cur,cur.color); putatriangle(old,lastrow[col],cur,cur.color); /* make sure corner colors not overwritten */ plot=standardplot; } break; } /* End of CASE statement for fill type */ loopbottom: if (FILLTYPE == -1 || (FILLTYPE >= 2 && FILLTYPE != 4)) { /* for triangle and grid fill purposes */ oldlast = lastrow[col]; old = lastrow[col] = cur; if(FILLTYPE >= 5) { /* for illumination model purposes */ f_old = f_lastrow[col] = f_cur; } } col++; } /* End of while statement for plotting line */ /* Done with the row (line). Now, increment rowcount and see if you are done with image */ reallythebottom: if(++rowcount >= ydots) { if (full_color && FILLTYPE >= 5) enddisk(); /* We done! */ /* end of image mopup stuff */ /* done - make sure pot file is closed */ if(fp_pot) { fclose(fp_pot); fp_pot = NULL; } if(preview && !SPHERE && showbox) { /* draw box to help visualize effect of rotations */ /* 1 means show box - xmin etc. do nothing here */ corners(m,1,&xmin,&ymin,&zmin,&xmax,&ymax,&zmax); } /* reset floatflag */ floatflag &= 1; /* strip second bit */ } /* stuff that HAS to be done, even in preview mode, goes here */ if(SPHERE) { /* incremental sin/cos phi calc */ if(rowcount == 1) { sinphi = oldsinphi2; cosphi = oldcosphi2; }else { sinphi = twocosdeltaphi*oldsinphi2 - oldsinphi1; cosphi = twocosdeltaphi*oldcosphi2 - oldcosphi1; oldsinphi1 = oldsinphi2; oldsinphi2 = sinphi; oldcosphi1 = oldcosphi2; oldcosphi2 = cosphi; } } return(0); /* decoder needs to know all is well !!! */ } /* Bresenham's algorithm for drawing line */ void draw_line (int X1, int Y1, int X2, int Y2, int color) { /* uses Bresenham algorithm to draw a line */ int dX, dY; /* vector components */ int row, col, final, /* final row or column number */ G, /* used to test for new row or column */ inc1, /* G increment when row or column doesn't change */ inc2; /* G increment when row or column changes */ char pos_slope; extern int xdots,ydots; extern int (*plot)(); dX = X2 - X1; /* find vector components */ dY = Y2 - Y1; pos_slope = (dX > 0); /* is slope positive? */ if (dY < 0) pos_slope = !pos_slope; if (abs (dX) > abs (dY)) /* shallow line case */ { if (dX > 0) /* determine start point and last column */ { col = X1; row = Y1; final = X2; } else { col = X2; row = Y2; final = X1; } inc1 = 2 * abs (dY); /* determine increments and initial G */ G = inc1 - abs (dX); inc2 = 2 * (abs (dY) - abs (dX)); if (pos_slope) while (col <= final) /* step through columns checking for new row */ { (*plot) (col, row, color); col++; if (G >= 0) /* it's time to change rows */ { row++; /* positive slope so increment through the rows */ G += inc2; } else /* stay at the same row */ G += inc1; } else while (col <= final) /* step through columns checking for new row */ { (*plot) (col, row, color); col++; if (G > 0) /* it's time to change rows */ { row--; /* negative slope so decrement through the rows */ G += inc2; } else /* stay at the same row */ G += inc1; } } /* if |dX| > |dY| */ else /* steep line case */ { if (dY > 0) /* determine start point and last row */ { col = X1; row = Y1; final = Y2; } else { col = X2; row = Y2; final = Y1; } inc1 = 2 * abs (dX); /* determine increments and initial G */ G = inc1 - abs (dY); inc2 = 2 * (abs (dX) - abs (dY)); if (pos_slope) while (row <= final) /* step through rows checking for new column */ { (*plot) (col, row, color); row++; if (G >= 0) /* it's time to change columns */ { col++; /* positive slope so increment through the columns */ G += inc2; } else /* stay at the same column */ G += inc1; } else while (row <= final) /* step through rows checking for new column */ { (*plot) (col, row, color); row++; if (G > 0) /* it's time to change columns */ { col--; /* negative slope so decrement through the columns */ G += inc2; } else /* stay at the same column */ G += inc1; } } } /* draw_line */ /* vector version of line draw */ void vdraw_line(v1,v2,color) double *v1,*v2; int color; { int x1,y1,x2,y2; x1 = (int)v1[0]; y1 = (int)v1[1]; x2 = (int)v2[0]; y2 = (int)v2[1]; draw_line(x1,y1,x2,y2,color); } /* This bizarre function has two purposes. The main purpose is to determine the extreme values of a transformed box containing a fractal for centering purposes. As a side effect it can also plot the transformed box as an aid in setting reasonable rotation parameters */ corners(m,show,pxmin,pymin,pzmin,pxmax,pymax,pzmax) MATRIX m; int show; /* turns on box-showing feature */ double *pxmin,*pymin,*pzmin,*pxmax,*pymax,*pzmax; { extern int xdots,ydots,zcoord; VECTOR b1,b2,b3,b4,t1,t2,t3,t4; *pxmin = *pymin = *pzmin = INT_MAX; *pxmax = *pymax = *pzmax = INT_MIN; /* define corners of box fractal is in in x,y,z plane */ /* "b" stands for "bottom" - these points are the corners of the screen in the x-y plane. The "t"'s stand for Top - they are the top of the cube where 255 color points hit. */ b1[0] = 0; b1[1] = 0; b1[2] = 0; b2[0] = xdots-1; b2[1] = 0; b2[2] = 0; b3[0] = xdots-1; b3[1] = ydots-1; b3[2] = 0; b4[0] = 0; b4[1] = ydots-1; b4[2] = 0; t1[0] = 0; t1[1] = 0; t1[2] = zcoord-1; t2[0] = xdots-1; t2[1] = 0; t2[2] = zcoord-1; t3[0] = xdots-1; t3[1] = ydots-1; t3[2] = zcoord-1; t4[0] = 0; t4[1] = ydots-1; t4[2] = zcoord-1; /* transform points */ vmult(b1,m,b1); vmult(b2,m,b2); vmult(b3,m,b3); vmult(b4,m,b4); vmult(t1,m,t1); vmult(t2,m,t2); vmult(t3,m,t3); vmult(t4,m,t4); /* find minimum x */ if(b1[0] <= *pxmin) *pxmin = b1[0]; if(b2[0] <= *pxmin) *pxmin = b2[0]; if(b3[0] <= *pxmin) *pxmin = b3[0]; if(b4[0] <= *pxmin) *pxmin = b4[0]; if(t1[0] <= *pxmin) *pxmin = t1[0]; if(t2[0] <= *pxmin) *pxmin = t2[0]; if(t3[0] <= *pxmin) *pxmin = t3[0]; if(t4[0] <= *pxmin) *pxmin = t4[0]; /* find minimum y */ if(b1[1] <= *pymin) *pymin = b1[1]; if(b2[1] <= *pymin) *pymin = b2[1]; if(b3[1] <= *pymin) *pymin = b3[1]; if(b4[1] <= *pymin) *pymin = b4[1]; if(t1[1] <= *pymin) *pymin = t1[1]; if(t2[1] <= *pymin) *pymin = t2[1]; if(t3[1] <= *pymin) *pymin = t3[1]; if(t4[1] <= *pymin) *pymin = t4[1]; /* find minimum z */ if(b1[2] <= *pzmin) *pzmin = b1[2]; if(b2[2] <= *pzmin) *pzmin = b2[2]; if(b3[2] <= *pzmin) *pzmin = b3[2]; if(b4[2] <= *pzmin) *pzmin = b4[2]; if(t1[2] <= *pzmin) *pzmin = t1[2]; if(t2[2] <= *pzmin) *pzmin = t2[2]; if(t3[2] <= *pzmin) *pzmin = t3[2]; if(t4[2] <= *pzmin) *pzmin = t4[2]; /* find maximum x */ if(b1[0] >= *pxmax) *pxmax = b1[0]; if(b2[0] >= *pxmax) *pxmax = b2[0]; if(b3[0] >= *pxmax) *pxmax = b3[0]; if(b4[0] >= *pxmax) *pxmax = b4[0]; if(t1[0] >= *pxmax) *pxmax = t1[0]; if(t2[0] >= *pxmax) *pxmax = t2[0]; if(t3[0] >= *pxmax) *pxmax = t3[0]; if(t4[0] >= *pxmax) *pxmax = t4[0]; /* find maximum y */ if(b1[1] >= *pymax) *pymax = b1[1]; if(b2[1] >= *pymax) *pymax = b2[1]; if(b3[1] >= *pymax) *pymax = b3[1]; if(b4[1] >= *pymax) *pymax = b4[1]; if(t1[1] >= *pymax) *pymax = t1[1]; if(t2[1] >= *pymax) *pymax = t2[1]; if(t3[1] >= *pymax) *pymax = t3[1]; if(t4[1] >= *pymax) *pymax = t4[1]; /* find maximum z */ if(b1[2] >= *pzmax) *pzmax = b1[2]; if(b2[2] >= *pzmax) *pzmax = b2[2]; if(b3[2] >= *pzmax) *pzmax = b3[2]; if(b4[2] >= *pzmax) *pzmax = b4[2]; if(t1[2] >= *pzmax) *pzmax = t1[2]; if(t2[2] >= *pzmax) *pzmax = t2[2]; if(t3[2] >= *pzmax) *pzmax = t3[2]; if(t4[2] >= *pzmax) *pzmax = t4[2]; if(show) { if(persp) { /* bottom */ perspective(b1); perspective(b2); perspective(b3); perspective(b4); perspective(t1); perspective(t2); perspective(t3); perspective(t4); } /* draw box connecting transformed points. NOTE COLORS */ /* Keep the box surrounding the fractal */ b1[0] = b1[0] + xxadjust; t1[0] = t1[0] + xxadjust; b2[0] = b2[0] + xxadjust; t2[0] = t2[0] + xxadjust; b3[0] = b3[0] + xxadjust; t3[0] = t3[0] + xxadjust; b4[0] = b4[0] + xxadjust; t4[0] = t4[0] + xxadjust; b1[1] = b1[1] + yyadjust; t1[1] = t1[1] + yyadjust; b2[1] = b2[1] + yyadjust; t2[1] = t2[1] + yyadjust; b3[1] = b3[1] + yyadjust; t3[1] = t3[1] + yyadjust; b4[1] = b4[1] + yyadjust; t4[1] = t4[1] + yyadjust; /* bottom */ vdraw_line (b1,b2,2); vdraw_line (b2,b3,2); vdraw_line (b3,b4,2); vdraw_line (b4,b1,2); /* top */ vdraw_line (t1,t2,3); vdraw_line (t2,t3,3); vdraw_line (t3,t4,3); vdraw_line (t4,t1,3); /* sides */ vdraw_line (b1,t1,4); /* these pixels written first - want in BACK */ vdraw_line (b2,t2,5); vdraw_line (b3,t3,6); /* these pixels written last - want in FRONT */ vdraw_line (b4,t4,7); } } /* This function draws a vector from origin[] to direct[] and a box around it. The vector and box are transformed or not depending on FILLTYPE. Will consolidate this and corners if the feature is used. Also, will be adding hidded line capability to this and/or corners. */ draw_light_box(origin,direct,m) double *origin, *direct; MATRIX m; { VECTOR b1,b2,b3,b4,t1,t2,t3,t4; int i; double temp; /* Initialize the arrays */ for (i=0;i<=2;i++) t1[i] = b1[i] = origin[i]; /* "x" "y" "z" */ b2[0] = b1[0]; b2[1] = direct[1]; b2[2] = b1[2]; b3[0] = direct[0]; b3[1] = b2[1]; b3[2] = b1[2]; b4[0] = b3[0]; b4[1] = b1[1]; b4[2] = b1[2]; t1[2] = direct[2]; t2[0] = t1[0]; t2[1] = direct[1]; t2[2] = t1[2]; t3[0] = direct[0]; t3[1] = t2[1]; t3[2] = t1[2]; t4[0] = t3[0]; t4[1] = t1[1]; t4[2] = t1[2]; /* transform the corners if necessary */ if (FILLTYPE == 6) { /* Transform the coordinates */ /* bottom */ /* top */ vmult(b1,m,b1); vmult(t1,m,t1); vmult(b2,m,b2); vmult(t2,m,t2); vmult(b3,m,b3); vmult(t3,m,t3); vmult(b4,m,b4); vmult(t4,m,t4); } if(persp) /* Adjust for perspective if set */ { perspective(b1); perspective(t1); perspective(b2); perspective(t2); perspective(b3); perspective(t3); perspective(b4); perspective(t4); } /* Adjust for aspect and shift back to origin (b1[]) */ temp = b1[0] * aspect; temp = temp - b1[0]; b1[0] = b1[0] * aspect - temp; t1[0] = t1[0] * aspect - temp; b2[0] = b2[0] * aspect - temp; t2[0] = t2[0] * aspect - temp; b3[0] = b3[0] * aspect - temp; t3[0] = t3[0] * aspect - temp; b4[0] = b4[0] * aspect - temp; t4[0] = t4[0] * aspect - temp; /* draw box connecting transformed points. NOTE COLORS */ /* bottom */ /* top */ vdraw_line (b1,b2,2); vdraw_line (t1,t2,3); vdraw_line (b2,b3,2); vdraw_line (t2,t3,3); vdraw_line (b3,b4,2); vdraw_line (t3,t4,3); vdraw_line (b4,b1,2); vdraw_line (t4,t1,3); /* sides */ vdraw_line (b1,t1,4); /* these pixels written first - want in BACK */ vdraw_line (b2,t2,5); vdraw_line (b3,t3,6); /* these pixels written last - want in FRONT */ vdraw_line (b4,t4,7); /* draw light source vector */ vdraw_line (b1,t3,8); } /* replacement for plot - builds a table of min and max x's instead of plot */ /* called by draw_line as part of triangle fill routine */ int putminmax(int x,int y,int color) { if(y < 0 || y >= ydots) return(-1); if(x < minmax_x[y].minx) minmax_x[y].minx = x; if(x > minmax_x[y].maxx) minmax_x[y].maxx = x; return(0); } /* This routine fills in a triangle. Extreme left and right values for each row are calculated by calling the line function for the sides. Then rows are filled in with horizontal lines */ #define MAXOFFSCREEN 2 /* allow two of three points to be off screen */ putatriangle(pt1,pt2,pt3,color) struct point pt1,pt2,pt3; int color; { extern struct point p1,p2,p3; int miny,maxy,minx,maxx; int y; p1 = pt1; p2 = pt2; p3 = pt3; /* are these all good points? */ if(-abs(p1.x) <= bad_check) return(-1); if(-abs(p1.y) <= bad_check) return(-1); if(-abs(p2.x) <= bad_check) return(-1); if(-abs(p2.y) <= bad_check) return(-1); if(-abs(p3.x) <= bad_check) return(-1); if(-abs(p3.y) <= bad_check) return(-1); /* Too many points off the screen? */ if(offscreen(&p1) + offscreen(&p2) + offscreen(&p3) > MAXOFFSCREEN) return(-1); /* bail out if points are equal */ if (pt1.x == pt2.x) if (pt2.x == pt3.x) if (pt1.y == pt2.y) if (pt2.y == pt3.y) { plot(p3.x, p3.y, color); return(-1); } /* find min max y */ miny = INT_MAX; maxy = INT_MIN; if(p1.y < miny) miny = p1.y; if(p2.y < miny) miny = p2.y; if(p3.y < miny) miny = p3.y; if(p1.y > maxy) maxy = p1.y; if(p2.y > maxy) maxy = p2.y; if(p3.y > maxy) maxy = p3.y; if(maxy < 0 || miny >= ydots) /* bail out if totally off screen */ return(-1); if(maxy - miny <= 1) { /* find min max x */ minx = INT_MAX; maxx = INT_MIN; if(p1.x < minx) minx = p1.x; if(p2.x < minx) minx = p2.x; if(p3.x < minx) minx = p3.x; if(p1.x > maxx) maxx = p1.x; if(p2.x > maxx) maxx = p2.x; if(p3.x > maxx) maxx = p3.x; if(maxx < 0 || minx >= xdots) /* bail out if totally off screen */ return(-1); } /* only worried about values on screen */ miny = max(0,miny); maxy = min(ydots-1,maxy); for(y=miny;y<=maxy;y++) { minmax_x[y].minx = INT_MAX; minmax_x[y].maxx = INT_MIN; } /* set plot to "fake" plot function */ plot = putminmax; /* build table of extreme x's of triangle */ draw_line(p1.x,p1.y,p2.x,p2.y,0); draw_line(p2.x,p2.y,p3.x,p3.y,0); draw_line(p3.x,p3.y,p1.x,p1.y,0); plot = fillplot; for(y=miny;y<=maxy;y++) draw_line(minmax_x[y].minx,y,minmax_x[y].maxx,y,color); plot = normalplot; return(0); /* zero means ok */ } offscreen(struct point *pt) { if(pt->x >= 0) if(pt->x < xdots) if(pt->y >= 0) if(pt->y < ydots) return(0); /* point is ok */ return(1); /* point is off the screen */ } clipcolor(int x,int y,int color) { if(0 <= x && x < xdots && 0 <= y && y < ydots && 0 <= color && color < colors) { standardplot(x,y,color); return(0); } else return(-1); } clipcolor2(int x,int y,int color) { if(0 <= x && x < xdots && 0 <= y && y < ydots && 0 <= color) { standardplot(x,y,color&1); return(0); } else return(-1); } T_clipcolor(int x,int y,int color) /* This function is the same as clipcolor but checks for color being in transparent range. Intended to be called only if transparency has been enabled. */ { if(0 <= x && x < xdots && /* is the point on screen? */ 0 <= y && y < ydots && /* Yes? */ 0 <= color && color < colors && /* Colors in valid range? */ /* Lets make sure its not a transparent color */ (transparent[0] > color || color > transparent[1])) { standardplot(x,y,color); /* I guess we can plot then */ return(0); /* Done */ } else return(-1); /* Sorry, can't plot that */ } /* A substitute for plotcolor that interpolates the colors according to the x and y values of three points (p1,p2,p3) which are static in this routine */ int interpcolor(int x,int y,int color) { unsigned char R1, G, B; unsigned long H, S, V; unsigned char RGB[3]; int D,d1,d2,d3; /* this distance formula is not the usual one - but it has the virtue that it uses ONLY additions (almost) and it DOES go to zero as the points get close. */ d1 = abs(p1.x-x)+abs(p1.y-y); d2 = abs(p2.x-x)+abs(p2.y-y); d3 = abs(p3.x-x)+abs(p3.y-y); D = (d1 + d2 + d3) << 1; if(D) { /* calculate a weighted average of colors - long casts prevent integer overflow */ color = ((long)(d2+d3)*(long)p1.color + (long)(d1+d3)*(long)p2.color + (long)(d1+d2)*(long)p3.color) / D; } if(0 <= x && x < xdots && 0 <= y && y < ydots && 0 < color && color < colors) { if (full_color) { /* Get the color triplet for the original untransformed pixel */ RGB[0] = dacbox [Real_Color] [0]; RGB[1] = dacbox [Real_Color] [1]; RGB[2] = dacbox [Real_Color] [2]; /* Now lets convert it to hsv */ R_H(RGB[0], RGB[1], RGB[2], &H, &S, &V); /* Modify H, S and V components */ V = (65280 - color * IAmbient); if (haze != 0) { S = (unsigned long)(S * HAZE_MULT) / 100; if (V >= 32640) { V = V - 32640; V = (unsigned long)(V * (HAZE_MULT >> 1) / 100); V = V + 32640; } else { V = 32640 - V; V = (unsigned long)(V * (HAZE_MULT >> 1) / 100); V = 32640 - V; } } /* Now lets convert it back to RGB */ H_R(&RGB[0], &RGB[1], &RGB[2], H, S, V); /* Now write the color triple to its transformed location on the disk. */ targa_writedisk (x, y, RGB[0], RGB[1], RGB[2]); } if (FILLTYPE >= 5) color = (color * IAmbient)/255; standardplot(x,y,color); return(0); } else return(-1); } int T_interpcolor(int x,int y,int color) /* A substitute for interpcolor that interpolates the colors according to the x and y values of three points (p1,p2,p3) which are static in this routine AND additionally checks for transparent colors */ { int d1,d2,d3; /* this distance formula is not the usual one - put it has the virtue that it uses ONLY additions (almost) and it DOES go to zero as the points get close. */ d1 = abs(p1.x-x)+abs(p1.y-y); d2 = abs(p2.x-x)+abs(p2.y-y); d3 = abs(p3.x-x)+abs(p3.y-y); /* calculate a weighted average of colors - long casts prevent integer overflow */ color = ((long)(d2+d3)*(long)p1.color + (long)(d1+d3)*(long)p2.color + (long)(d1+d2)*(long)p3.color) /(d2+d3+d1+d3+d1+d2); /* Checking for on-screen x,y might be moved to top of routine if it would speed things significantly for values of perspective <100 */ if(0 <= x && x < xdots && /* is the point on screen? */ 0 <= y && y < ydots && /* Yes? */ 0 <= color && color < colors && /* Colors in valid range? */ /* Lets make sure its not a transparent color */ (transparent[0] > color || color > transparent[1])) { standardplot(x,y,color); /* I guess we can plot then */ return(0); /* Done */ } else return(-1); /* Sorry, can't plot that */ } int set_pixel_buff(unsigned char *pixels,float far *fpixels,unsigned linelen) { unsigned int *intbuf; int i; switch(filetype) { case 2: /* TARGA type 10 (RGB 16 bit) */ case 1: /* TIW 16 bit */ intbuf = (unsigned int *)pixels; for(i=0;i\n",File_Name1); return(-1); } if (status == -2) { printf("\nOOPS - Ran Out Of Disk Space\n\n"); printf("You Will Need A Min Of\n\n < %ld Bytes >\n\n", (3L*(long)xdots*(long)ydots)+18L); printf("Of Disk Space To Create \n\n"); printf(" < %s >\n\n",File_Name1); printf("Press Any Key To Cont. With Screen Only"); getch(); return(-1); } printf("Press Any Key To Cont. With Screen Only"); getch(); return(-1); } int Open_T_24(File_Name2) char *File_Name2; /********************************************************** Open Targa 24 uncompressed file write header, verify there is enough disk space, and leave the file pointer at the start of the display data area. If there is an error close the file. return (0) successfull return (-1) Open failure return (-2) Out of disk space return (-3) Out of memory **********************************************************/ { int i,j; extern xdots; extern ydots; /* Open File for both reading and writing */ if ((File_Ptr1=fopen(File_Name2,"w+b"))==NULL) return(-1); /* Oops, somethings wrong! */ else /* File opened successfully, now write TARGA header */ for (i = 0; i < 12; i++) { if (i == 2) putc(i,File_Ptr1); else putc(0,File_Ptr1); } /* Write image size */ putc((unsigned char)(xdots & 0xff),File_Ptr1); putc((unsigned char)(xdots >> 8), File_Ptr1); putc((unsigned char)(ydots & 0xff),File_Ptr1); putc((unsigned char)(ydots >> 8), File_Ptr1); /* Write TARGA 24 ID */ putc(24,File_Ptr1); putc(32,File_Ptr1); /* Finished with the header, now lets work on the display area */ line_length1 = 3 * xdots; /* length of a line @ 3 bytes per pixel */ for (i = 0; i < ydots; i++) /* "clear the screen" (write to the disk) */ for (j = 0; j < line_length1; j=j+3) /* clear the line to some color */ { putc(back_color[2], File_Ptr1); /* Targa order (B, G, R) */ putc(back_color[1], File_Ptr1); putc(back_color[0], File_Ptr1); } if (ferror (File_Ptr1)) { /* Almost certainly not enough disk space */ fclose (File_Ptr1); remove (light_name); return(-2); } if (targa_startdisk(File_Ptr1, T_header_24) != 0) { enddisk(); remove (light_name); return(-3); } return(0); } int R_H (R, G, B, H, S, V) unsigned char R,G,B; unsigned long *H, *S, *V; /*********************************************************************** ***********************************************************************/ { unsigned long H1, R1, G1, B1, DENOM; unsigned char MIN; *V = R; MIN = G; if (R < G) { *V = G; MIN = R; if (G < B) *V = B; if (B < R) MIN = B; } else { if (B < G) MIN = B; if (R < B) *V = B; } DENOM = *V - MIN; if (*V != 0 && DENOM !=0) { *S = ((DENOM << 16) / *V) - 1; if (*S < 0) *S = 0; } else *S = 0;/* Color is black! and Sat has no meaning */ if(*S == 0) /* R=G=B => shade of grey and Hue has no meaning */ { *H = 0; *V = *V << 8; return(1); /* v or s or both are 0 */ } if (*V == MIN) { *H = 0; *V = *V << 8; return(0); } R1 = (((*V - R) * 60) << 6) / DENOM; /* distance of color from red */ G1 = (((*V - G) * 60) << 6) / DENOM; /* distance of color from green */ B1 = (((*V - B) * 60) << 6) / DENOM; /* distance of color from blue */ if(*V == R) if (MIN == G) *H = (300 << 6) + B1; else *H = (60 << 6) - G1; if(*V == G) if (MIN == B) *H = (60 << 6) + R1; else *H = (180 << 6) - B1; if(*V == B) if(MIN == R) *H = (180 << 6) + G1; else *H = (300 << 6) - R1; *V = *V << 8; return(0); } int H_R (R, G, B, H, S, V) unsigned char *R, *G, *B; unsigned long H, S, V; /******************************************************************** ********************************************************************/ { unsigned long P1, P2, P3; int RMD, I; if(H >= 23040) H = H % 23040; /* Makes h circular */ I = H / 3840; RMD = H % 3840; /* RMD = fractional part of H */ P1 = ((V * (65535 - S)) / 65280) >> 8; P2 = (((V * (65535 - (S * RMD) / 3840)) / 65280) - 1) >> 8; P3 = (((V * (65535 - (S * (3840 - RMD)) / 3840)) / 65280)) >> 8; V = V >> 8; switch (I) { case 0: *R = V; *G = P3; *B = P1; break; case 1: *R = P2; *G = V; *B = P1; break; case 2: *R = P1; *G = V; *B = P3; break; case 3: *R = P1; *G = P2; *B = V; break; case 4: *R = P3; *G = P1; *B = V; break; case 5: *R = V ; *G = P1; *B = P2; break; } return(0); }