When leveling, the center circle is now shown when the pointer approaches it.

- solidify/Makefile: added util.o
- solidify/util.h, solidify/util.c (draw_circle): wrapper for gdk_draw_arc
- solidify/Makefile: added style.o
- solidify/style.h, solidify/style.c, solidify/solidify.c (main): GUI style
  parameters and items
- solidify/level.c (scroll_z. scroll_xy, scroll_event, level),
  solidify/overlap.c (scroll_event, overlap): renamed "da" to "darea", to
  avoid confusion with "da" for GdkDrawable in style.c
- solidify/level.c (r_center, scroll_event): moved center radius
  calculation to separate function
- solidify/level.c (draw_image): renamed to draw_map
- solidify/level.c (draw_image): draw an on-screen display (OSD)
- solidify/level.c (scroll_z, scroll_xy, expose_event, level): propagate
  OSD on/off switch
- solidify/level.c (scroll_event, motion_notify_event, level): enable OSD
  when approaching the center circle

solidify/Makefile

@@ -12,7 +12,7 @@
 
 SHELL = /bin/bash
 
-OBJS = array.o face.o histo.o level.o overlap.o solidify.o
+OBJS = array.o face.o histo.o level.o overlap.o solidify.o style.o util.o
 
 CFLAGS_WARN = -Wall -Wshadow -Wmissing-prototypes \
 	      -Wmissing-declarations -Wno-format-zero-length

solidify/level.c

@@ -16,15 +16,26 @@
 #include <math.h>
 #include <gtk/gtk.h>
 
+#include "util.h"
 #include "array.h"
 #include "face.h"
+#include "style.h"
 #include "level.h"
 
 
 #define	NEAR	1
 
 
-static void draw_image(GtkWidget *widget, struct face *f)
+static int has_osd;
+
+
+static double r_center(const struct face *f)
+{
+	return hypot(f->sx, f->sy)/LEVEL_CENTER_DIV;
+}
+
+
+static void draw_map(GtkWidget *widget, struct face *f)
 {
 	int x, y, z;
 	double z0;
@@ -70,7 +81,17 @@ static void draw_image(GtkWidget *widget, struct face *f)
 }
 
 
-static void scroll_z(GtkWidget *da, struct face *f, int up)
+static void draw_image(GtkWidget *widget, struct face *f, int osd)
+{
+	draw_map(widget, f);
+	has_osd = osd;
+	if (osd)
+		draw_circle(widget->window, gc_osd,
+		    f->sx/2, f->sy/2, r_center(f));
+}
+
+
+static void scroll_z(GtkWidget *darea, struct face *f, int up, int osd)
 {
 	if (up) {
 		if (f->z_ref < f->a->max_z)
@@ -79,42 +100,46 @@ static void scroll_z(GtkWidget *da, struct face *f, int up)
 		if (f->z_ref > f->a->min_z)
 			f->z_ref--;
 	}
-	draw_image(da, f);
+	draw_image(darea, f, osd);
 }
 
 
-static void scroll_xy(GtkWidget *da, struct face *f, int dx, int dy, int up)
+static void scroll_xy(GtkWidget *darea, struct face *f, int dx, int dy, int up,
+    int osd)
 {
 	double d;
 
 	d = (double) (up ? 1 : -1)/(dx*dx+dy*dy)/2.0;
 	f->fx += d*dx;
 	f->fy += d*dy;
-	draw_image(da, f);
+	draw_image(darea, f, osd);
 }
 
 
 static gboolean scroll_event(GtkWidget *widget, GdkEventScroll *event,
     gpointer data)
 {
-	GtkWidget *da = gtk_bin_get_child(GTK_BIN(widget));
+	GtkWidget *darea = gtk_bin_get_child(GTK_BIN(widget));
 	struct face *f = data;
 	int dx = event->x-f->sx/2;
 	int dy = event->y-f->sy/2;
-	int center = hypot(dx, dy)/hypot(f->sx, f->sy) < 0.25;
+	double r = hypot(dx, dy);
+	double rc = r_center(f);
+	int center = r < rc;
+	int osd = fabs(r-rc) < OSD_PROXIMITY;
 
 	switch (event->direction) {
 	case GDK_SCROLL_UP:
 		if (center)
-			scroll_z(da, f, 0);
+			scroll_z(darea, f, 0, osd);
 		else
-			scroll_xy(da, f, dx, dy, 1);
+			scroll_xy(darea, f, dx, dy, 1, osd);
 		break;
 	case GDK_SCROLL_DOWN:
 		if (center)
-			scroll_z(da, f, 1);
+			scroll_z(darea, f, 1, osd);
 		else
-			scroll_xy(da, f, dx, dy, 0);
+			scroll_xy(darea, f, dx, dy, 0, osd);
 		break;
 	default:
 		/* ignore */;
@@ -126,25 +151,50 @@ static gboolean scroll_event(GtkWidget *widget, GdkEventScroll *event,
 static gboolean expose_event(GtkWidget *widget, GdkEventExpose *event,
     gpointer user_data)
 {
-	draw_image(widget, user_data);
+	draw_image(widget, user_data, has_osd);
 	return TRUE;
 }
 
 
+static gboolean motion_notify_event(GtkWidget *widget, GdkEventMotion *event,
+    gpointer data)
+{
+	struct face *f = data;
+	int dx = event->x-f->sx/2;
+	int dy = event->y-f->sy/2;
+	double r = hypot(dx, dy);
+	double rc = r_center(f);
+	int osd = fabs(r-rc) < OSD_PROXIMITY;
+
+	if (osd != has_osd)
+		draw_image(widget, f, osd);
+	return FALSE;
+}
+
+
 void level(GtkWidget *canvas, struct face *f)
 {
-	GtkWidget *evbox, *da;
+	GtkWidget *evbox, *darea;
 
 	evbox = gtk_event_box_new();
-	da = gtk_drawing_area_new();
-	gtk_widget_set_size_request(da, f->sx, f->sy);
-	gtk_container_add(GTK_CONTAINER(canvas), evbox);
-	gtk_container_add(GTK_CONTAINER(evbox), da);
+	darea = gtk_drawing_area_new();
 
-	draw_image(da, f);
+	gtk_widget_set_events(darea,
+	    GDK_EXPOSE | GDK_KEY_PRESS_MASK |
+	    GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK |
+	    GDK_SCROLL |
+	    GDK_POINTER_MOTION_MASK);
+
+	gtk_widget_set_size_request(darea, f->sx, f->sy);
+	gtk_container_add(GTK_CONTAINER(canvas), evbox);
+	gtk_container_add(GTK_CONTAINER(evbox), darea);
+
+	draw_image(darea, f, 0);
 
 	g_signal_connect(G_OBJECT(evbox), "scroll-event",
 	    G_CALLBACK(scroll_event), f);
-	g_signal_connect(G_OBJECT(da), "expose-event",
+	g_signal_connect(G_OBJECT(darea), "expose-event",
 	    G_CALLBACK(expose_event), f);
+	g_signal_connect(G_OBJECT(darea), "motion-notify-event",
+	    G_CALLBACK(motion_notify_event), f);
 }

solidify/overlap.c

@@ -203,7 +203,7 @@ static void shift(struct matrix *m, int dx, int dy, int dir)
 static gboolean scroll_event(GtkWidget *widget, GdkEventScroll *event,
     gpointer data)
 {
-	GtkWidget *da = gtk_bin_get_child(GTK_BIN(widget));
+	GtkWidget *darea = gtk_bin_get_child(GTK_BIN(widget));
 	struct solid *s = data;
 	int dx = event->x-sx(s)/2;
 	int dy = event->y-sy(s)/2;
@@ -218,14 +218,14 @@ static gboolean scroll_event(GtkWidget *widget, GdkEventScroll *event,
 			shift(&s->a->m, dx, dy, 1);
 		else
 			rotate(&s->a->m, r);
-		draw_image(da, s);
+		draw_image(darea, s);
 		break;
 	case GDK_SCROLL_DOWN:
 		if (center)
 			shift(&s->a->m, dx, dy, -1);
 		else
 			rotate(&s->a->m, -r);
-		draw_image(da, s);
+		draw_image(darea, s);
 		break;
 	default:
 		/* ignore */;
@@ -245,18 +245,18 @@ static gboolean expose_event(GtkWidget *widget, GdkEventExpose *event,
 
 void overlap(GtkWidget *canvas, struct solid *s)
 {
-	GtkWidget *evbox, *da;
+	GtkWidget *evbox, *darea;
 
 	evbox = gtk_event_box_new();
-	da = gtk_drawing_area_new();
-	gtk_widget_set_size_request(da, sx(s), sy(s));
+	darea = gtk_drawing_area_new();
+	gtk_widget_set_size_request(darea, sx(s), sy(s));
 	gtk_container_add(GTK_CONTAINER(canvas), evbox);
-	gtk_container_add(GTK_CONTAINER(evbox), da);
+	gtk_container_add(GTK_CONTAINER(evbox), darea);
 
-	draw_image(da, s);
+	draw_image(darea, s);
 
 	g_signal_connect(G_OBJECT(evbox), "scroll-event",
 	    G_CALLBACK(scroll_event), s);
-	g_signal_connect(G_OBJECT(da), "expose-event",
+	g_signal_connect(G_OBJECT(darea), "expose-event",
 	    G_CALLBACK(expose_event), s);
 }

solidify/solidify.c

@@ -18,6 +18,7 @@
 
 #include "face.h"
 #include "solid.h"
+#include "style.h"
 #include "level.h"
 #include "overlap.h"
 
@@ -102,6 +103,8 @@ static void gui(void)
 	level(canvas, solid.a);
 	active = solid.a;
 
+	init_style(root->window);
+
 	gtk_widget_show_all(root);
 
 	g_signal_connect(G_OBJECT(root), "key-press-event",

solidify/style.c

@@ -0,0 +1,53 @@
+/*
+ * style.c - GUI style parameters and items
+ *
+ * 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 <stdlib.h>
+#include <gtk/gtk.h>
+
+#include "style.h"
+
+
+GdkGC *gc_osd;
+
+
+static GdkColor get_color(GdkDrawable *da, const char *spec)
+{
+	GdkColormap *cmap;
+	GdkColor color;
+
+	cmap = gdk_drawable_get_colormap(da);
+	if (!gdk_color_parse(spec, &color))
+		abort();
+	if (!gdk_colormap_alloc_color(cmap, &color, FALSE, TRUE))
+		abort();
+	return color;
+}
+
+
+static GdkGC *gc(GdkDrawable *da, const char *spec, int width)
+{
+	GdkGCValues gc_values = {
+		.background = get_color(da, "black"),
+		.foreground = get_color(da, spec),
+		.line_width = width,
+	};
+
+	return gdk_gc_new_with_values(da, &gc_values,
+	    GDK_GC_FOREGROUND | GDK_GC_BACKGROUND | GDK_GC_LINE_WIDTH);
+}
+
+
+void init_style(GdkDrawable *da)
+{
+	gc_osd = gc(da, "#ffff00", 4);
+}

solidify/style.h

@@ -0,0 +1,28 @@
+/*
+ * style.h - GUI style parameters and items
+ *
+ * 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 STYLE_H
+#define STYLE_H
+
+#include <gtk/gtk.h>
+
+
+extern GdkGC *gc_osd;
+
+
+#define	OSD_PROXIMITY		20
+#define	LEVEL_CENTER_DIV	5
+
+
+void init_style(GdkDrawable *da);
+
+#endif /* !STYLE_H */

solidify/util.c

@@ -0,0 +1,22 @@
+/*
+ * util.c - Common utility functions
+ *
+ * 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 <gtk/gtk.h>
+
+#include "util.h"
+
+
+void draw_circle(GdkDrawable *da, GdkGC *gc, int x, int y, int r)
+{
+	gdk_draw_arc(da, gc, FALSE, x-r, y-r, 2*r, 2*r, 0, 360*64);
+}

solidify/util.h

@@ -14,6 +14,7 @@
 #define UTIL_H
 
 #include <stdlib.h>
+#include <gtk/gtk.h>
 
 
 #define alloc_size(s)				\
@@ -24,4 +25,7 @@
 
 #define alloc_type(t) ((t *) alloc_size(sizeof(t)))
 
+
+void draw_circle(GdkDrawable *da, GdkGC *gc, int x, int y, int r);
+
 #endif /* UTIL_H */