Introduce a solid data type and use it, mainly in overlap()

- solidify/solid.h: definition of a solid made from two opposing faces
- solidify/overlap.h (overlap), solidify/overlap.c (draw_image,
  scroll_event, overlap): operate on solid instead of face
- solidify/overlap.c (sx, sy, draw_image, overlap): helper functions sx()
  and sy() to determine canvas size
- solidify/overlap.c (BORDER, sx, sy): added a border around the piece,
  to help with positioning
- solidify/solidify.c (clicked, gui_buttons, gui, main): use solid instead
  of faces

solidify/overlap.c

@@ -18,10 +18,24 @@
 #include <gtk/gtk.h>
 
 #include "face.h"
+#include "solid.h"
 #include "overlap.h"
 
 
 #define	UNDEF_F	HUGE_VAL
+#define BORDER 10	/* pixels around the minimum drawing area */
+
+
+static int sx(const struct solid *s)
+{
+	return (s->a->sx > s->b->sx ? s->a->sx : s->b->sx)+2*BORDER;
+}
+
+
+static int sy(const struct solid *s)
+{
+	return (s->a->sy > s->b->sy ? s->a->sy : s->b->sy)+2*BORDER;
+}
 
 
 static double ramp(int z0, double w0, int z1, double w1)
@@ -59,19 +73,20 @@ static double zmix(struct face *f, double x, double y)
 }
 
 
-static void draw_image(GtkWidget *widget, struct face *f)
+static void draw_image(GtkWidget *widget, struct solid *s)
 {
 	guchar *rgbbuf, *p;
 	int x, y;
 	double z;
+	struct face *f = s->a;
 
-	rgbbuf = p = calloc(f->sx*f->sy, 3);
+	rgbbuf = p = calloc(sx(s)*sy(s), 3);
 	if (!rgbbuf) {
 		perror("calloc");
 		exit(1);
 	}
-	for (y = f->sy-1; y >= 0; y--)
-		for (x = 0; x != f->sx ; x++) {
+	for (y = sy(s)-1; y >= 0; y--)
+		for (x = 0; x != sx(s) ; x++) {
 			int xa = x+f->a->min_x;
 			int ya = y+f->a->min_y;
 
@@ -93,7 +108,7 @@ static void draw_image(GtkWidget *widget, struct face *f)
 		}
 	gdk_draw_rgb_image(widget->window,
 	    widget->style->fg_gc[GTK_STATE_NORMAL],
-	    0, 0, f->sx, f->sy, GDK_RGB_DITHER_MAX, rgbbuf, f->sx*3);
+	    0, 0, sx(s), sy(s), GDK_RGB_DITHER_MAX, rgbbuf, sx(s)*3);
 	free(rgbbuf);
 }
 
@@ -124,7 +139,8 @@ static gboolean scroll_event(GtkWidget *widget, GdkEventScroll *event,
     gpointer data)
 {
 	GtkWidget *da = gtk_bin_get_child(GTK_BIN(widget));
-	struct face *f = data;
+	struct solid *s = data;
+	struct face *f = s->a;
 	int dx = event->x-f->sx/2;
 	int dy = event->y-f->sy/2;
 	double r = hypot(dx, dy);
@@ -134,11 +150,11 @@ static gboolean scroll_event(GtkWidget *widget, GdkEventScroll *event,
 	switch (event->direction) {
 	case GDK_SCROLL_UP:
 		rotate(&f->m, r);
-		draw_image(da, f);
+		draw_image(da, s);
 		break;
 	case GDK_SCROLL_DOWN:
 		rotate(&f->m, -r);
-		draw_image(da, f);
+		draw_image(da, s);
 		break;
 	default:
 		/* ignore */;
@@ -156,22 +172,20 @@ static gboolean expose_event(GtkWidget *widget, GdkEventExpose *event,
 
 
 
-void overlap(GtkWidget *canvas, struct face *f)
+void overlap(GtkWidget *canvas, struct solid *s)
 {
 	GtkWidget *evbox, *da;
 
 	evbox = gtk_event_box_new();
 	da = gtk_drawing_area_new();
-	gtk_widget_set_size_request(da, f->sx, f->sy);
+	gtk_widget_set_size_request(da, sx(s), sy(s));
 	gtk_container_add(GTK_CONTAINER(canvas), evbox);
 	gtk_container_add(GTK_CONTAINER(evbox), da);
 
-	draw_image(da, f);
+	draw_image(da, s);
 
 	g_signal_connect(G_OBJECT(evbox), "scroll-event",
-	    G_CALLBACK(scroll_event), f);
+	    G_CALLBACK(scroll_event), s);
 	g_signal_connect(G_OBJECT(da), "expose-event",
-	    G_CALLBACK(expose_event), f);
-
-	return evbox;
+	    G_CALLBACK(expose_event), s);
 }

solidify/overlap.h

@@ -15,7 +15,9 @@
 
 #include <gtk/gtk.h>
 
+#include "solid.h"
 
-void overlap(GtkWidget *canvas, struct face *face);
+
+void overlap(GtkWidget *canvas, struct solid *solid);
 
 #endif /* !OVERLAP_H */

solidify/solid.h

@@ -0,0 +1,21 @@
+/*
+ * solid.h - 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.
+ */
+
+#ifndef SOLID_H
+#define SOLID_H
+
+struct solid {
+	struct face *a, *b;
+	double dist;
+};
+
+#endif /* SOLID_H */

solidify/solidify.c

@@ -17,11 +17,12 @@
 #include <gtk/gtk.h>
 
 #include "face.h"
+#include "solid.h"
 #include "level.h"
 #include "overlap.h"
 
 
-static struct face *face_a, *face_b;
+static struct solid solid;
 static const struct face *active;
 static GtkWidget *canvas;
 
@@ -38,7 +39,7 @@ static void clicked(GtkButton *button, gpointer user_data)
 	if (face)
 		level(canvas, face);
 	else
-		overlap(canvas, face_a);
+		overlap(canvas, &solid);
 	active = face;
 
 	gtk_widget_show_all(canvas);
@@ -54,12 +55,12 @@ static GtkWidget *gui_buttons(void)
 	but = gtk_button_new_with_label("A");
 	gtk_box_pack_start(GTK_BOX(vbox), but, FALSE, FALSE, 0);
 	g_signal_connect(G_OBJECT(but), "clicked",
-	    G_CALLBACK(clicked), face_a);
+	    G_CALLBACK(clicked), solid.a);
 
 	but = gtk_button_new_with_label("B");
 	gtk_box_pack_start(GTK_BOX(vbox), but, FALSE, FALSE, 0);
 	g_signal_connect(G_OBJECT(but), "clicked",
-	    G_CALLBACK(clicked), face_b);
+	    G_CALLBACK(clicked), solid.b);
 
 	but = gtk_button_new_with_label("A+B");
 	gtk_box_pack_start(GTK_BOX(vbox), but, FALSE, FALSE, 0);
@@ -98,8 +99,8 @@ static void gui(void)
 	buttons = gui_buttons();
 	gtk_box_pack_start(GTK_BOX(hbox), buttons, FALSE, FALSE, 0);
 
-	level(canvas, face_a);
-	active = face_a;
+	level(canvas, solid.a);
+	active = solid.a;
 
 	gtk_widget_show_all(root);
 
@@ -129,8 +130,8 @@ int main(int argc, char **argv)
 		usage(*argv);
 	}
 	setlocale(LC_ALL, "C"); /* damage control */
-	face_a = read_face(argv[1]);
-	face_b = face_a;
+	solid.a = read_face(argv[1]);
+	solid.b = solid.a;
 	gui();
 
 	return 0;