--- ray/src/px/pinterp.c 1990/01/04 17:47:37 1.14 +++ ray/src/px/pinterp.c 1990/01/05 11:34:27 1.15 @@ -26,6 +26,8 @@ static char SCCSid[] = "$SunId$ LBL"; #define ABS(x) ((x)>0?(x):-(x)) +struct position {int x,y; float z;}; + VIEW ourview = STDVIEW(512); /* desired view */ double zeps = .02; /* allowed z epsilon */ @@ -192,10 +194,8 @@ char *argv[]; /* allocate frame */ ourpict = (COLR *)malloc(ourview.hresolu*ourview.vresolu*sizeof(COLR)); ourzbuf = (float *)calloc(ourview.hresolu*ourview.vresolu,sizeof(float)); - if (ourpict == NULL || ourzbuf == NULL) { - perror(progname); - exit(1); - } + if (ourpict == NULL || ourzbuf == NULL) + syserror(); /* get input */ for ( ; i < argc; i += 2) addpicture(argv[i], argv[i+1]); @@ -254,8 +254,8 @@ char *pfile, *zspec; FILE *pfp, *zfp; char *err; COLR *scanin; - float *zin, *zlast; - int *plast; + float *zin; + struct position *plast; int y; /* open picture file */ if ((pfp = fopen(pfile, "r")) == NULL) { @@ -280,12 +280,10 @@ char *pfile, *zspec; /* allocate scanlines */ scanin = (COLR *)malloc(theirview.hresolu*sizeof(COLR)); zin = (float *)malloc(theirview.hresolu*sizeof(float)); - plast = (int *)calloc(theirview.hresolu, sizeof(int)); - zlast = (float *)calloc(theirview.hresolu, sizeof(float)); - if (scanin == NULL || zin == NULL || plast == NULL || zlast == NULL) { - perror(progname); - exit(1); - } + plast = (struct position *)calloc(theirview.hresolu, + sizeof(struct position)); + if (scanin == NULL || zin == NULL || plast == NULL) + syserror(); /* get z specification or file */ if ((zfp = fopen(zspec, "r")) == NULL) { double zvalue; @@ -309,13 +307,12 @@ char *pfile, *zspec; fprintf(stderr, "%s: read error\n", zspec); exit(1); } - addscanline(y, scanin, zin, plast, zlast); + addscanline(y, scanin, zin, plast); } /* clean up */ free((char *)scanin); free((char *)zin); free((char *)plast); - free((char *)zlast); fclose(pfp); if (zfp != NULL) fclose(zfp); @@ -358,19 +355,15 @@ register VIEW *vw1, *vw2; } -addscanline(y, pline, zline, lasty, lastyz) /* add scanline to output */ +addscanline(y, pline, zline, lasty) /* add scanline to output */ int y; COLR *pline; float *zline; -int *lasty; /* input/output */ -float *lastyz; /* input/output */ +struct position *lasty; /* input/output */ { extern double sqrt(); double pos[3]; - int lastx = 0; - double lastxz = 0; - double zt; - int xpos, ypos; + struct position lastx, newpos; register int x; for (x = theirview.hresolu-1; x >= 0; x--) { @@ -386,58 +379,82 @@ float *lastyz; /* input/output */ pos[1] *= pos[2]; } multp3(pos, pos, theirs2ours); - if (pos[2] <= 0) + if (pos[2] <= 0) { + lasty[x].z = lastx.z = 0; /* mark invalid */ continue; + } if (ourview.type == VT_PER) { pos[0] /= pos[2]; pos[1] /= pos[2]; } pos[0] += .5*ourview.hresolu; pos[1] += .5*ourview.vresolu; - if (pos[0] < 0 || (xpos = pos[0]) >= ourview.hresolu - || pos[1] < 0 || (ypos = pos[1]) >= ourview.vresolu) - continue; + newpos.x = pos[0]; + newpos.y = pos[1]; + newpos.z = zline[x]; /* add pixel to our image */ - zt = 2.*zeps*zline[x]; - addpixel(xpos, ypos, - (fill&F_FORE && ABS(zline[x]-lastxz) <= zt) - ? lastx - xpos : 1, - (fill&F_FORE && ABS(zline[x]-lastyz[x]) <= zt) - ? lasty[x] - ypos : 1, - pline[x], pos[2]); - lastx = xpos; - lasty[x] = ypos; - lastxz = lastyz[x] = zline[x]; + if (pos[0] >= 0 && newpos.x < ourview.hresolu + && pos[1] >= 0 && newpos.y < ourview.vresolu) { + addpixel(&newpos, &lastx, &lasty[x], pline[x], pos[2]); + lasty[x].x = lastx.x = newpos.x; + lasty[x].y = lastx.y = newpos.y; + lasty[x].z = lastx.z = newpos.z; + } else + lasty[x].z = lastx.z = 0; /* mark invalid */ } } -addpixel(xstart, ystart, width, height, pix, z) /* fill in area for pixel */ -int xstart, ystart; -int width, height; +addpixel(p0, p1, p2, pix, z) /* fill in pixel parallelogram */ +struct position *p0, *p1, *p2; COLR pix; double z; { - register int x, y; - /* make width and height positive */ - if (width < 0) { - width = -width; - xstart = xstart-width+1; - } else if (width == 0) - width = 1; - if (height < 0) { - height = -height; - ystart = ystart-height+1; - } else if (height == 0) - height = 1; - /* fill pixel(s) within rectangle */ - for (y = ystart; y < ystart+height; y++) - for (x = xstart; x < xstart+width; x++) - if (zscan(y)[x] <= 0 - || zscan(y)[x]-z > zeps*zscan(y)[x]) { + double zt = 2.*zeps*p0->z; /* threshold */ + int s1x, s1y, s2x, s2y; /* step sizes */ + int l1, l2, c1, c2; /* side lengths and counters */ + int p1isy; /* p0p1 along y? */ + int x1, y1; /* p1 position */ + register int x, y; /* final position */ + + /* compute vector p0p1 */ + if (fill&F_FORE && ABS(p1->z-p0->z) <= zt) { + s1x = p1->x - p0->x; + s1y = p1->y - p0->y; + l1 = ABS(s1x); + if (p1isy = (ABS(s1y) > l1)) + l1 = ABS(s1y); + } else { + l1 = s1x = s1y = 1; + p1isy = -1; + } + /* compute vector p0p2 */ + if (fill&F_FORE && ABS(p2->z-p0->z) <= zt) { + s2x = p2->x - p0->x; + s2y = p2->y - p0->y; + if (p1isy == 1) + l2 = ABS(s2x); + else { + l2 = ABS(s2y); + if (p1isy != 0 && ABS(s2x) > l2) + l2 = ABS(s2x); + } + } else + l2 = s2x = s2y = 1; + /* fill the parallelogram */ + for (c1 = l1; c1-- > 0; ) { + x1 = p0->x + c1*s1x/l1; + y1 = p0->y + c1*s1y/l1; + for (c2 = l2; c2-- > 0; ) { + x = x1 + c2*s2x/l2; + y = y1 + c2*s2y/l2; + if (zscan(y)[x] <= 0 || zscan(y)[x]-z + > zeps*zscan(y)[x]) { zscan(y)[x] = z; copycolr(pscan(y)[x], pix); } + } + } } @@ -449,10 +466,8 @@ backpicture() /* background fill algorithm */ register int x, i; /* get back buffer */ yback = (int *)malloc(ourview.hresolu*sizeof(int)); - if (yback == NULL) { - perror(progname); - return; - } + if (yback == NULL) + syserror(); for (x = 0; x < ourview.hresolu; x++) yback[x] = -2; /* @@ -542,10 +557,8 @@ writepicture() /* write out picture */ fputresolu(YMAJOR|YDECR, ourview.hresolu, ourview.vresolu, stdout); for (y = ourview.vresolu-1; y >= 0; y--) - if (fwritecolrs(pscan(y), ourview.hresolu, stdout) < 0) { - perror(progname); - exit(1); - } + if (fwritecolrs(pscan(y), ourview.hresolu, stdout) < 0) + syserror(); } @@ -563,10 +576,8 @@ char *fname; exit(1); } if (donorm - && (zout = (float *)malloc(ourview.hresolu*sizeof(float))) == NULL) { - perror(progname); - exit(1); - } + && (zout = (float *)malloc(ourview.hresolu*sizeof(float))) == NULL) + syserror(); for (y = ourview.vresolu-1; y >= 0; y--) { if (donorm) { double vx, yzn2;