GUI: Add resolution rings

It will refuse to draw the rings if the detector is too far from being
flat (as judged by detgeom_mean_camera_length).  Otherwise, the drawing
is exactly the same as was done by hdfsee.

6 files changed, 115 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index 6110e4f3..de38c04b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -18,6 +18,7 @@ Changes in this development version
 - partialator: Use default event ID when none given in --custom-split
 - Dropped support for pre-2015 stream formats
 - Recognise '.nx5' as HDF5
+- GUI: Optionally show resolution rings
 - GUI: Use sbatch/scancel/scontrol instead of SLURM API
 - GUI: Honour fixed profile radius for single frame indexing (#61)
 - GUI: Better handling of error-filled indexamajig logs
diff --git a/src/crystfel_gui.c b/src/crystfel_gui.c
index 066422a3..1c439b18 100644
--- a/src/crystfel_gui.c
+++ b/src/crystfel_gui.c
@@ -275,6 +275,8 @@ void update_imageview(struct crystfelproject *proj)
 	                                   proj->show_peaks);
 	crystfel_image_view_set_show_centre(CRYSTFEL_IMAGE_VIEW(proj->imageview),
 	                                   proj->show_centre);
+	crystfel_image_view_set_resolution_rings(CRYSTFEL_IMAGE_VIEW(proj->imageview),
+	                                         proj->resolution_rings);
 	crystfel_image_view_set_image(CRYSTFEL_IMAGE_VIEW(proj->imageview),
 	                              proj->cur_image);
 
@@ -670,6 +672,30 @@ static gint show_centre_sig(GtkWidget *w, struct crystfelproject *proj)
 }
 
 
+static gint resolution_rings_sig(GtkWidget *w, struct crystfelproject *proj)
+{
+	int tr = gtk_toggle_action_get_active(GTK_TOGGLE_ACTION(w));
+
+	if ( tr && proj->cur_image == NULL ) {
+		error_box(proj, "Load some images first!\n");
+		return FALSE;
+	}
+
+	if ( tr && isnan(detgeom_mean_camera_length(proj->cur_image->detgeom)) ) {
+		error_box(proj, "Cannot display resolution rings accurately "
+		          "because detector is not flat enough");
+		tr = FALSE;
+		gtk_toggle_action_set_active(GTK_TOGGLE_ACTION(w), FALSE);
+	}
+
+	proj->resolution_rings = tr;
+	crystfel_image_view_set_resolution_rings(CRYSTFEL_IMAGE_VIEW(proj->imageview),
+	                                         tr);
+
+	return FALSE;
+}
+
+
 static gint show_peaks_sig(GtkWidget *w, struct crystfelproject *proj)
 {
 	proj->show_peaks = gtk_toggle_action_get_active(GTK_TOGGLE_ACTION(w));
@@ -711,6 +737,7 @@ static void add_menu_bar(struct crystfelproject *proj, GtkWidget *vbox)
 		"	<menuitem name=\"refls\" action=\"ReflsAction\" />"
 		"	<menuitem name=\"labelrefls\" action=\"LabelReflsAction\" />"
 		"	<menuitem name=\"centre\" action=\"CentreAction\" />"
+		"	<menuitem name=\"resrings\" action=\"ResolutionRingsAction\" />"
 		"       <separator />"
 		"	<menuitem name=\"resetzoom\" action=\"ResetZoomAction\" />"
 		"</menu>"
@@ -757,6 +784,8 @@ static void add_menu_bar(struct crystfelproject *proj, GtkWidget *vbox)
 		  G_CALLBACK(label_refls_sig), FALSE },
 		{ "CentreAction", NULL, "Beam centre", NULL, NULL,
 		  G_CALLBACK(show_centre_sig), FALSE },
+		{ "ResolutionRingsAction", NULL, "Resolution rings", NULL, NULL,
+		  G_CALLBACK(resolution_rings_sig), FALSE },
 		{ "RescanOnChangeAction", NULL, "Rescan streams when changing frame", NULL, NULL,
 		  G_CALLBACK(rescan_on_change_sig), FALSE },
 	};
@@ -1165,6 +1194,10 @@ int main(int argc, char *argv[])
 	gtk_toggle_action_set_active(GTK_TOGGLE_ACTION(act),
 	                             proj.label_refls);
 
+	act = gtk_ui_manager_get_action(proj.ui, "/mainwindow/view/resrings");
+	gtk_toggle_action_set_active(GTK_TOGGLE_ACTION(act),
+	                             proj.resolution_rings);
+
 	act = gtk_ui_manager_get_action(proj.ui, "/mainwindow/tools/rescanonchange");
 	gtk_toggle_action_set_active(GTK_TOGGLE_ACTION(act),
 	                             proj.rescan_on_change);
diff --git a/src/crystfelimageview.c b/src/crystfelimageview.c
index 74d8cca5..88cfb149 100644
--- a/src/crystfelimageview.c
+++ b/src/crystfelimageview.c
@@ -603,6 +603,48 @@ static void draw_refls(cairo_t *cr,
 }
 
 
+static double ring_radius(double d, double wl, double z)
+{
+	double theta = asin(wl / (2.0*d));
+	return z * tan(2.0*theta);
+}
+
+
+static void show_ring(cairo_t *cr, double wl, double mean_z,
+                      double d, const char *label,
+                      double r, double g, double b)
+{
+	cairo_text_extents_t size;
+	double bs, lw;
+	double radius = ring_radius(d, wl, mean_z);
+
+	if ( isnan(radius) ) return;
+
+	bs = 17.0;
+	lw = 1.0;
+	cairo_device_to_user_distance(cr, &bs, &lw);
+	bs = fabs(bs);
+	lw = fabs(lw);
+
+	cairo_save(cr);
+
+	cairo_arc(cr, 0.0, 0.0, radius, 0.0, 2.0*M_PI);
+	cairo_set_source_rgb(cr, r, g, b);
+	cairo_set_line_width(cr, lw);
+	cairo_stroke(cr);
+
+	cairo_rotate(cr, -M_PI/4.0);
+	cairo_scale(cr, 1.0, -1.0);
+	cairo_set_font_size(cr, bs);
+	cairo_text_extents(cr, label, &size);
+	cairo_translate(cr, -size.width/2.0, radius-5.0*lw);
+	cairo_show_text(cr, label);
+	cairo_fill(cr);
+
+	cairo_restore(cr);
+}
+
+
 static double crystal_cols[][3] =
 {
 	{0.0, 1.0, 0.0},   /* bright green */
@@ -673,6 +715,24 @@ static gint draw_sig(GtkWidget *window, cairo_t *cr, CrystFELImageView *iv)
 		}
 	}
 
+	if ( iv->resolution_rings ) {
+		double wl = iv->image->lambda;
+		double mean_z = detgeom_mean_camera_length(iv->image->detgeom);
+		if ( !isnan(mean_z) ) {
+			show_ring(cr, wl, mean_z, 10.0e-10, "10A",   1.0, 0.0, 0.0);
+			show_ring(cr, wl, mean_z, 9.0e-10,   "9A",   1.0, 0.0, 0.0);
+			show_ring(cr, wl, mean_z, 8.0e-10,   "8A",   1.0, 0.0, 0.0);
+			show_ring(cr, wl, mean_z, 7.0e-10,   "7A",   1.0, 0.5, 0.0);
+			show_ring(cr, wl, mean_z, 6.0e-10,   "6A",   1.0, 1.0, 0.0);
+			show_ring(cr, wl, mean_z, 5.0e-10,   "5A",   0.0, 1.0, 0.0);
+			show_ring(cr, wl, mean_z, 4.0e-10,   "4A",   0.2, 1.0, 0.2);
+			show_ring(cr, wl, mean_z, 3.0e-10,   "3A",   0.4, 1.0, 0.4);
+			show_ring(cr, wl, mean_z, 2.0e-10,   "2A",   0.6, 1.0, 0.6);
+			show_ring(cr, wl, mean_z, 1.0e-10,   "1A",   0.8, 1.0, 0.8);
+			show_ring(cr, wl, mean_z, 0.5e-10, "0.5A",   1.0, 1.0, 1.0);
+		}
+	}
+
 	cairo_restore(cr);
 
 	return FALSE;
@@ -847,6 +907,7 @@ GtkWidget *crystfel_image_view_new()
 	iv->label_refls = 1;
 	iv->need_rerender = 0;
 	iv->need_recentre = 1;
+	iv->resolution_rings = 0;
 
 	g_signal_connect(G_OBJECT(iv), "destroy",
 	                 G_CALLBACK(destroy_sig), iv);
@@ -1165,3 +1226,12 @@ void crystfel_image_view_set_refl_box_size(CrystFELImageView *iv,
 	iv->need_rerender = 1;
 	redraw(iv);
 }
+
+
+void crystfel_image_view_set_resolution_rings(CrystFELImageView *iv,
+                                              int rings)
+{
+	iv->resolution_rings = rings;
+	iv->need_rerender = 1;
+	redraw(iv);
+}
diff --git a/src/crystfelimageview.h b/src/crystfelimageview.h
index c53e4980..aa7d61d2 100644
--- a/src/crystfelimageview.h
+++ b/src/crystfelimageview.h
@@ -94,6 +94,7 @@ struct _crystfelimageview
 	int                  label_refls;
 	float                peak_box_size;
 	float                refl_box_size;
+	int                  resolution_rings;
 };
 
 struct _crystfelimageviewclass
@@ -133,4 +134,7 @@ extern void crystfel_image_view_set_peak_box_size(CrystFELImageView *iv,
 extern void crystfel_image_view_set_refl_box_size(CrystFELImageView *iv,
                                                   float box_size);
 
+extern void crystfel_image_view_set_resolution_rings(CrystFELImageView *iv,
+                                                     int rings);
+
 #endif	/* CRYSTFELIMAGEVIEW_H */
diff --git a/src/gui_project.c b/src/gui_project.c
index 7ab4e367..00a217af 100644
--- a/src/gui_project.c
+++ b/src/gui_project.c
@@ -534,6 +534,10 @@ static void handle_var(const char *key, const char *val,
 		proj->show_centre = parse_int(val);
 	}
 
+	if ( strcmp(key, "resolution_rings") == 0 ) {
+		proj->resolution_rings = parse_int(val);
+	}
+
 	if ( strcmp(key, "rescan_on_change") == 0 ) {
 		proj->rescan_on_change = parse_int(val);
 	}
@@ -1136,6 +1140,7 @@ int save_project(struct crystfelproject *proj)
 	}
 
 	fprintf(fh, "show_centre %i\n", proj->show_centre);
+	fprintf(fh, "resolution_rings %i\n", proj->resolution_rings);
 	fprintf(fh, "show_peaks %i\n", proj->show_peaks);
 	fprintf(fh, "show_refls %i\n", proj->show_refls);
 	fprintf(fh, "label_refls %i\n", proj->label_refls);
@@ -1229,6 +1234,7 @@ int default_project(struct crystfelproject *proj)
 
 	/* Default parameter values */
 	proj->show_centre = 1;
+	proj->resolution_rings = 0;
 	proj->show_peaks = 1;
 	proj->show_refls = 1;
 	proj->label_refls = 1;
diff --git a/src/gui_project.h b/src/gui_project.h
index 8ec81ee2..546bae9a 100644
--- a/src/gui_project.h
+++ b/src/gui_project.h
@@ -302,6 +302,7 @@ struct crystfelproject {
 	char **filenames;
 	char **events;
 	int show_centre;
+	int resolution_rings;
 	int rescan_on_change;
 
 	int show_peaks;