Infrastructure for generating POV-Ray output (not useful yet)

- solidify/Makefile: added solid.o
- solidify/solid.h, solidify.c (height_field, povray): output the part as
  the intersection of two height fields
- solidify/solidify.c (main): generate POV-Ray output if stdout is
  redirected
- solidify/Makefile (run, pov, disp): targets to run a test setup, render
  it, and display the result
- solidify/main.pov: simple scene showing the test part

solidify/Makefile

@@ -12,7 +12,8 @@
 
 SHELL = /bin/bash
 
-OBJS = array.o face.o histo.o level.o overlap.o solidify.o style.o util.o
+OBJS = array.o face.o histo.o level.o overlap.o solid.o solidify.o style.o \
+       util.o
 
 CFLAGS_WARN = -Wall -Wshadow -Wmissing-prototypes \
 	      -Wmissing-declarations -Wno-format-zero-length
@@ -50,6 +51,25 @@ clean:
 spotless:	clean
 		rm -f solidify
 
+# ----- Experimental execution ------------------------------------------------
+
+PRJ=http://projects.qi-hardware.com/index.php/p/ben-scans/source/tree/master
+DIR=$(PRJ)/data/csv
+FACE_A=$(DIR)/ben-batcvr-outside-100um.txt.bz2
+FACE_B=$(DIR)/ben-batcvr-inside-100um.txt.bz2
+D=1.16
+
+.PHONY:		run pov disp
+
+run:		solidify
+		./solidify $(FACE_A) $(FACE_B) $(D) >batcvr.inc
+
+pov:
+		povray +A -W1280 -H1024 main.pov
+
+disp:
+		display main.png
+
 # ----- Dependencies ----------------------------------------------------------
 
 # compile and generate dependencies, from fped, based on

solidify/main.pov

@@ -0,0 +1,27 @@
+#include "colors.inc"
+#include "batcvr.inc"
+
+camera {
+    location < 2, 2, 3>
+    look_at < 0, 0, 0>
+    right -4/3*x
+    sky x
+}
+
+background { color White }
+
+light_source {
+    < 4, 7, 4>
+    color White
+}
+
+union {
+    Part
+    pigment { rgb <0.9, 0.9, 0.9> }
+    finish {
+        brilliance 2
+        phong 0.8
+        phong_size 100
+        metallic
+    }
+}

solidify/solid.c

@@ -0,0 +1,71 @@
+/*
+ * solid.c - Data structure and handling of a solid made of two opposing faces
+ *
+ * Written 2010 by Werner Almesberger
+ * Copyright 2010 by Werner Almesberger
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+#include "face.h"
+#include "solid.h"
+
+
+static void height_field(const char *name, const struct face *f,
+    const struct matrix *m)
+{
+	FILE *file;
+	int x, y;
+	int z;
+	uint16_t g;
+	uint8_t v[2];
+
+	file = fopen(name, "w");
+	if (!file) {
+		perror(name);
+		exit(1);
+	}
+	fprintf(file, "P5\n%d %d\n65535\n", f->sx, f->sy);
+	for (y = 0; y != f->sy; y++)
+		for (x = 0; x != f->sx; x++) {
+			z = get(f->a, x+f->a->min_x, y+f->a->min_y);
+			g = z == UNDEF ? 0 :
+			    65535*(z-f->a->min_z)/(f->a->max_z-f->a->min_z);
+			v[0] = g >> 8;
+			v[1] = g;
+			fwrite(v, 2, 1, file);
+		}
+	fclose(file);
+}
+
+
+void povray(const struct solid *s)
+{
+	struct matrix m;
+
+	m.a[0][0] = m.a[1][1] = 1;
+	m.a[0][1] = m.a[1][0] = 0;
+	m.b[0] = m.b[1] = 0;
+
+	height_field("top.pgm", s->a, &m);
+	height_field("bot.pgm", s->b, &m);
+
+	/*
+	 * 1/65535 = 0.000015..., so we set the water level a bit lower, e.g.,
+	 * to 0.0001
+	 */
+	printf(
+"#declare Part =\n"
+"    intersection {\n"
+"        height_field { pgm \"top.pgm\" water_level 0.00001 smooth }\n"
+"        height_field { pgm \"bot.pgm\" water_level 0.00001 smooth }\n"
+"    }\n");
+}

solidify/solid.h

@@ -18,4 +18,7 @@ struct solid {
 	double dist;
 };
 
+
+void povray(const struct solid *s);
+
 #endif /* SOLID_H */

solidify/solidify.c

@@ -13,6 +13,7 @@
 
 #include <stdlib.h>
 #include <stdio.h>
+#include <unistd.h>
 #include <locale.h>
 #include <gtk/gtk.h>
 
@@ -137,6 +138,8 @@ int main(int argc, char **argv)
 	solid.b = read_face(argv[2]);
 	solid.dist = atof(argv[3])/0.025; /* @@@ hack */
 	gui();
+	if (!isatty(1))
+		povray(&solid);
 
 	return 0;
 }