/* * zbuf.c * * Add Z buffer support to Rayshade 4.0, by Mark W. Maimone (mwm@cs.cmu.edu) * * Rayshade is a rendering package by Craig Kolb, et al * Copyright (C) 1989, 1991, Craig E. Kolb * All rights reserved. * * This software may be freely copied, modified, and redistributed * provided that this copyright notice is preserved on all copies. * * You may not distribute this software, in whole or in part, as part of * any commercial product without the express consent of the authors. * * There is no warranty or other guarantee of fitness of this software * for any purpose. It is provided solely "as is". * * $Id$ * * $Log$ */ #include "rayshade.h" #include "options.h" #include "zbuf.h" #include "viewing.h" typedef struct { char *s; int i; } PairT; RSZbuf zbuffer; /* Must set the proper window size before calling ZbufSetup() */ void ZbufSetup() { int horiz = Screen.xsize; int vert = Screen.ysize; int i, j; if (Options.zbufname == (char *)NULL) return; if ((zbuffer.fzbuf = fopen (Options.zbufname, "w")) == NULL) RLerror(RL_PANIC, "Cannot open Z buffer file \"%s\".\n", Options.zbufname); zbuffer.array = (Float **) Malloc (vert * sizeof (Float *)); /* Initialize all depths to Infinity */ for (i = 0; i < vert; i++) { zbuffer.array[i] = (Float *) Malloc (horiz * sizeof (Float)); for (j = 0; j < horiz; j++) zbuffer.array[i][j] = ZBUF_INF; } /* for */ } /* ZbufSetup */ /* ZbufAdd -- Some object in pixel (x,y) is distance dist from the eye. Add it to the Z buffer if it's nearer than all other objects seen so far. This simple-minded storage scheme relies on the anti-aliasing to sample the pixel at appropriate places. It also assumes you want the distance of the *nearest* object touching the pixel as the final distance measure. */ void ZbufAdd (x, y, dist) Float x, y, dist; { int j = ((int) (x + 0.5)) - Screen.minx; int i = ((int) (y + 0.5)) - Screen.miny; if (zbuffer.array && i >= 0 && j >= 0 && i < Screen.ysize && j < Screen.xsize) { Float before = zbuffer.array[i][j]; if (before == ZBUF_INF || dist < before) zbuffer.array[i][j] = dist; } } /* ZbufAdd */ /* ZbufPrint -- Write the Z buffer data to a file. Output format is determined by the filename, or by DEFAULT_ZBUF_TYPE. Three formats are available: HF -- Output is written in Heightfield format TXT -- After some opening comments, distances are written in ascii. Each line in the output file contains distances for the corresponding image line, separated by a single space. TXT3 -- After some opening comments, distances are output as a triple: pixel coordinate and distance (e.g.: 0 3 3.14146 means at position (0,3) the depth is 3.13146. This is very space-inefficient, but is quite portable, and can be directly read by GNUplot for easy viewing. % rayshade -R 50 50 -z zbuf.dat Examples/balls.ray > balls.rle % gnuplot gnuplot> set term x11 [or whatever you're on] gnuplot> set sample 2500 [for a 50x50 image] gnuplot> set parametric [needed to plot 3D data] gnuplot> splot 'zbuf.dat' with lines [gives a nice height map grid] gnuplot> help set view [info on changing viewpoint] gnuplot> set view 45, 45 [a sample viewpoint] gnuplot> quit Warning! Distances are expected to always be positive, so background pixels are represented by a distance of ZBUF_INF (i.e., -1000). To get nice looking GNUplot output you should replace all -1's with the maximum distance. On UNIX: % rayshade -R 50 50 -z zbuf.dat Examples/planet.ray > balls.rle % awk 'BEGIN {max = -1} NF == 3 { if ($3 > max) max = $3} END \ {print max}' < zbuf.dat [this gives you the max] 3.69359 % sed s/-1000/3.69359/g < zbuf.dat | awk 'NF == 3 { print $1" "$2" -"$3 \ ; next} {print}' > zbuf.plot [replace -1 with max, make all distances negative so the plot appears rightside up] % gnuplot . . gnuplot> set zrange [-3.7:0] gnuplot> splot 'zbuf.plot' */ static PairT exts[] = { "hf", ZBUF_HF, "rle", ZBUF_RLE, "txt", ZBUF_TXT, "txt3", ZBUF_TXT3, /* silly suffix, for backward compatability */ "etxt", ZBUF_TXT3, }; /* exts */ void ZbufPrint () { int type = ZsetOutputType (Options.zbufname); int len = Screen.xsize; int y; FILE *fp = zbuffer.fzbuf; char *filename = Options.zbufname; if (PrepareForOutput (type, fp, filename) == 0) return; #ifdef URT for (y = Screen.ysize-1; y >= 0; y--) #else for (y = 0; y < Screen.ysize; y++) #endif WriteRow (type, y + Screen.miny, fp, filename, zbuffer.array[y], len); NoMoreThisImage (type, fp, filename); } /* ZbufPrint */ int PrepareForOutput (type, fp, filename) int type; FILE *fp; char *filename; { HEIGHTFIELD_SIZE i; if (fp == NULL) return 0; switch (type) { case ZBUF_HF: i = Screen.xsize; if (i < Screen.ysize) i = Screen.ysize; fwrite (&i, sizeof (HEIGHTFIELD_SIZE), 1, fp); zbuffer.pad = i - Screen.xsize; break; case ZBUF_RLE: fprintf (stderr, "Sorry, RLE output not available\n"); return 0; case ZBUF_TXT: case ZBUF_TXT3: fprintf (fp, "# Rayshade Z-buffer output file for command:\n"); fprintf (fp, "# "); ZwriteArgv (fp, zbuffer.argv); if (zbuffer.rayfile) fprintf (fp, "\n# Input RAY file: \"%s\"\n", zbuffer.rayfile); if (zbuffer.outfile) fprintf (fp, "# Output file: \"%s\"\n", zbuffer.outfile); fprintf (fp, "# Resolution for this rendering is %dx%d\n", Screen.xres, Screen.yres); fprintf (fp, "# window from (%d,%d) to (%d,%d)\n", Screen.minx, Screen.miny, Screen.maxx, Screen.maxy); break; default: fprintf (stderr, "Error! Unknown Z buffer type '%d'\n", type); return 0; } /* switch */ return 1; } /* PrepareForOutput */ WriteRow (type, y, fp, filename, row, len) int type, y; FILE *fp; char *filename; Float *row; int len; { int i; char *sep = ""; static float *padding = NULL; static int pad_len = 0, vec_len = 0; static float *vec = NULL; switch (type) { case ZBUF_HF: if (vec_len < len) { if (vec) free (vec); vec_len = ((len+9) / 10) * 10; vec = (float *) malloc (sizeof (float) * vec_len); } for (i = 0; i < len; i++) vec[i] = (float) row[i]; fwrite (vec, sizeof (float), len, fp); if (zbuffer.pad) { if (pad_len < zbuffer.pad) { if (padding) free (padding); pad_len = ((zbuffer.pad+9) / 10) * 10; padding = (float *) malloc (sizeof (float) * pad_len); for (i = 0; i < pad_len; i++) padding[i] = ZBUF_INF; } /* if */ fwrite (padding, sizeof (float), zbuffer.pad, fp); } break; case ZBUF_TXT: for (i = 0; i < len; i++) { fprintf (fp, "%s%g", sep, row[i]); sep = " "; } /* for */ fprintf (fp, "\n"); break; case ZBUF_TXT3: for (i = 0; i < len; i++) fprintf (fp, "%d %d %g\n", i + Screen.minx, y, row[i]); fprintf (fp, "\n"); break; default: fprintf (stderr, "*Invalid type %d in WriteRow\n", type); break; } /* switch */ } /* WriteRow */ NoMoreThisImage (type, fp, filename) int type; FILE *fp; char *filename; { if (type == ZBUF_HF) if (Screen.xsize > Screen.ysize) { int len = Screen.xsize - Screen.ysize; int i; float *padding = (float *) malloc (sizeof (float) * Screen.xsize); for (i = 0; i < Screen.xsize; i++) padding[i] = ZBUF_INF; while (len-- > 0) fwrite (padding, sizeof (float), Screen.xsize, fp); free (padding); } /* if */ fclose (fp); zbuffer.fzbuf = NULL; } /* NoMoreThisImage */ ZwriteArgv (fp, argv) FILE *fp; char **argv; { char *sep = ""; if (fp == NULL || argv == NULL) return; while (*argv) { fprintf (fp, "%s%s", sep, *argv); sep = " "; argv++; } } /* ZwriteArgv */ int ZsetOutputType (filename) char *filename; { int i, len; int type = DEFAULT_ZBUF_TYPE; if (filename != NULL) { len = strlen (filename); for (i = 0; i < sizeof (exts) / sizeof (PairT); i++) if (len >= strlen (exts[i].s) && strcmp (exts[i].s, filename + len - strlen (exts[i].s)) == 0) { type = exts[i].i; break; } /* if */ } /* if */ /* No RLE output yet */ if (type == ZBUF_RLE) { fprintf (stderr, " (Z buffer not in available in RLE format yet, sorry)\n"); type = DEFAULT_ZBUF_TYPE; } /* if */ if (type) { fprintf (stderr, "Z buffer will be written in "); switch (type) { case ZBUF_HF: fprintf (stderr, "HEIGHTFIELD"); break; case ZBUF_TXT: fprintf (stderr, "TEXT"); break; case ZBUF_TXT3: fprintf (stderr, "EXPANDED TEXT"); break; case ZBUF_RLE: fprintf (stderr, "UTAH RASTER TOOLKIT"); break; default: fprintf (stderr, "UNKNOWN!!"); type = 0; break; } /* switch */ fprintf (stderr, " format to \"%s\"\n", Options.zbufname); } /* if */ return type; } /* ZsetOutputType */ #ifdef SDfl void ZbufPrint () { FILE *fp = zbuffer.fzbuf; int minx = Screen.minx, maxx = Screen.maxx; int miny = Screen.miny, maxy = Screen.maxy; int horiz = Screen.xsize; int vert = Screen.ysize; int x, y; if (fp == NULL) return; fprintf (fp, "# Depth Map for Rayshade output file\n"); if (zbuffer.rayfile) fprintf (fp, "# Input RAY file: \"%s\"\n", zbuffer.rayfile); if (zbuffer.outfile) fprintf (fp, "# Output file: \"%s\"\n", zbuffer.outfile); fprintf (fp, "# Resolution for this rendering is %dx%d\n", Screen.xres, Screen.yres); fprintf (fp, "# window from (%d,%d) to (%d,%d)\n", minx, miny, maxx, maxy); fprintf (fp, "# Screen X unit vector: (%g,%g,%g)\n", Screen.scrnx.x, Screen.scrnx.y, Screen.scrnx.z); fprintf (fp, "# Screen Y unit vector: (%g,%g,%g)\n", Screen.scrny.x, Screen.scrny.y, Screen.scrny.z); /* Would be nice to save command-line options too */ for (x = 0; x < horiz; x++) { for (y = 0; y < vert; y++) fprintf (fp, "%d %d %g\n", x, y, zbuffer.array[x][y]); fprintf (fp, "\n"); } /* for */ fclose (fp); zbuffer.fzbuf = NULL; } /* ZbufPrint */ #endif