GUI: Draw histograms and response function, ...

...handle errors and change layout.

haader_gui.cpp

@@ -15,6 +15,8 @@ struct Gui {
     haader::HdrImage hdr_image;
     haader::ResponseFunction response_function;
     haader::Image ldr_image;
+    haader::Histogram hdr_histogram;
+    haader::LdrHistogram ldr_histogram;
     cairo_surface_t *surface;
     double exposure_time;
     double compression;
@@ -46,6 +48,7 @@ static cairo_surface_t* image_to_cairo_surface(const haader::Image &image) {
 
 static void expose(Gui &gui) {
     gui.ldr_image = gui.hdr_image.expose(gui.exposure_time, gui.response_function, gui.compression);
+    gui.ldr_histogram = gui.ldr_image.histogram();
     if (gui.surface) {
         cairo_surface_destroy(gui.surface);
         gui.surface = NULL;
@@ -59,11 +62,72 @@ static gboolean canvas_draw(GtkWidget *widget, cairo_t *cr, gpointer user_data)
     cairo_paint(cr);
 
     Gui *gui = (Gui*) user_data;
-    if (gui->surface) {
-        cairo_set_source_surface(cr, gui->surface, 0, 0);
-        cairo_paint(cr);
+    if (!gui->surface) {
+        return false;
     }
 
+    if (gui->hdr_histogram.m_bins.size() != 256) {
+        return false;
+    }
+
+    if (gui->ldr_histogram.m_bins.size() != 256) {
+        return false;
+    }
+
+    cairo_set_source_surface(cr, gui->surface, 5, 5);
+    cairo_paint(cr);
+
+    // canvas rect
+    double cx = gui->ldr_image.get_width() + 10.0;
+    double cy = 5.0;
+    double cw = 256;
+    double ch = 256;
+
+    cairo_set_source_rgb(cr, 0.0, 0.0, 0.0);
+    cairo_rectangle(cr, cx, cy, cw, ch);
+    cairo_fill(cr);
+
+    {
+        double hist_scale = (256.0 / (double)(gui->hdr_histogram.m_max_freq));
+        for (unsigned int i = 0; i < 256; i++) {
+            double y = gui->hdr_histogram.m_bins[i] * hist_scale;
+            cairo_rectangle(cr, cx + i, cy + ch - y, 1, y);
+        }
+        cairo_set_source_rgba(cr, 1.0, 0.0, 0.2, 0.4);
+        cairo_fill(cr);
+    }
+
+    {
+        double hist_scale = (256.0 / (double)(gui->ldr_histogram.m_max_freq));
+        for (unsigned int i = 0; i < 256; i++) {
+            double y = gui->ldr_histogram.m_bins[i] * hist_scale;
+            cairo_rectangle(cr, cx + i, cy + ch - y, 1, y);
+        }
+        cairo_set_source_rgba(cr, 1.0, 0.0, 0.2, 0.9);
+        cairo_fill(cr);
+    }
+
+
+    double minl = gui->hdr_histogram.m_min_value;
+    double maxl = gui->hdr_histogram.m_max_value;
+    double log_exp = log(gui->exposure_time);
+    double scale = (maxl - minl) / 256.0;
+
+    for (int i = 0; i < 256; i++) {
+        double lum = minl + i * scale;
+        int ly = gui->response_function.lookup((lum + log_exp) * gui->compression);
+        cairo_line_to(cr, cx + i, cy + ch - ly);
+    }
+    cairo_set_source_rgba(cr, 1.0, 1.0, 1.0, 0.8);
+    cairo_set_line_width(cr, 1.0);
+    cairo_stroke_preserve(cr);
+
+    cairo_line_to(cr, cx + cw, cy + ch);
+    cairo_line_to(cr, cx, cy + ch);
+    cairo_close_path(cr);
+    cairo_set_source_rgba(cr, 0.0, 0.5, 1.0, 0.2);
+    cairo_fill(cr);
+
     return FALSE;
 }
 
@@ -102,36 +166,42 @@ void file_select_clicked(GtkButton *button, gpointer user_data) {
 
     gtk_file_chooser_set_select_multiple (GTK_FILE_CHOOSER(dialog), true);
 
-    int res = gtk_dialog_run(GTK_DIALOG(dialog));
-    if (res == GTK_RESPONSE_ACCEPT) {
+    bool ok = true;
+    if (gtk_dialog_run(GTK_DIALOG(dialog)) == GTK_RESPONSE_ACCEPT) {
         GSList *list = gtk_file_chooser_get_filenames(GTK_FILE_CHOOSER(dialog));
         vector<string> new_list;
 
         GSList *element = list;
         while (element != NULL) {
-            //TODO handle errors
-            gui->stack.add_from_file_path((const char*)(element->data));
+            ok = ok && gui->stack.add_from_file_path((const char*)(element->data));
             g_free(element->data);
             element = g_slist_next(element);
+            if (!ok) {
+                break;
+            }
         }
 
         g_slist_free(list);
     }
 
-    // create HDR-image
-    haader::InverseResponseFunction irf;
-    if (gui->stack.get_inverse_response_function(irf, 4096)) {
-        gui->hdr_image = gui->stack.get_hdr_image(irf);
-        gui->ldr_image = gui->hdr_image.get_log_image();
-        if (gui->surface) {
-            cairo_surface_destroy(gui->surface);
-            gui->surface = NULL;
+    if (ok) {
+        // create HDR-image
+        haader::InverseResponseFunction irf;
+        if (gui->stack.get_inverse_response_function(irf, 4096)) {
+            gui->hdr_image = gui->stack.get_hdr_image(irf);
+            gui->ldr_image = gui->hdr_image.get_log_image();
+            gui->hdr_histogram = gui->hdr_image.histogram(256);
+            gui->ldr_histogram = gui->ldr_image.histogram();
+            if (gui->surface) {
+                cairo_surface_destroy(gui->surface);
+                gui->surface = NULL;
+            }
+            gui->surface = image_to_cairo_surface(gui->ldr_image);
+            gui->response_function = irf.to_response_function(1024);
         }
-        gui->surface = image_to_cairo_surface(gui->ldr_image);
-        gui->response_function = irf.to_response_function(1024);
-    }
 
-    gtk_widget_queue_draw(gui->canvas);
+        gtk_widget_queue_draw(gui->canvas);
+    }
 
     gtk_widget_destroy (dialog);
 }
@@ -152,15 +222,33 @@ int main(int argc, char *argv[])
     GtkWidget *file_button = gtk_button_new_with_label("Select files");
     gui.canvas = gtk_drawing_area_new();
     GtkWidget *scale_exposure = gtk_scale_new_with_range(GTK_ORIENTATION_HORIZONTAL, -20.0, 4.0, 0.001);
+    gtk_range_set_value(GTK_RANGE(scale_exposure), log(gui.exposure_time) / log(2));
+
     GtkWidget *scale_compression = gtk_scale_new_with_range(GTK_ORIENTATION_HORIZONTAL, -4, 4.0, 0.001);
+    gtk_range_set_value(GTK_RANGE(scale_compression), log(gui.compression) / log(2));
 
     GtkWidget *vbox = gtk_box_new(GTK_ORIENTATION_VERTICAL, 5);
 
     gtk_container_add(GTK_CONTAINER(gui.window), vbox);
     gtk_box_pack_start(GTK_BOX(vbox), file_button, false, false, 0);
     gtk_box_pack_start(GTK_BOX(vbox), gui.canvas, true, true, 0);
-    gtk_box_pack_start(GTK_BOX(vbox), scale_exposure, false, false, 0);
-    gtk_box_pack_start(GTK_BOX(vbox), scale_compression, false, false, 0);
+
+    GtkWidget *grid = gtk_grid_new();
+    gtk_box_pack_start(GTK_BOX(vbox), grid, false, false, 0);
+
+    {
+        GtkWidget *label = gtk_label_new("Exposure");
+        gtk_grid_attach(GTK_GRID(grid), label, 0, 0, 1, 1);
+        gtk_widget_set_size_request(scale_exposure, 600, -1);
+        gtk_grid_attach(GTK_GRID(grid), scale_exposure, 1, 0, 1, 1);
+    }
+
+    {
+        GtkWidget *label = gtk_label_new("Compression");
+        gtk_grid_attach(GTK_GRID(grid), label, 0, 1, 1, 1);
+        gtk_widget_set_size_request(scale_compression, 600, -1);
+        gtk_grid_attach(GTK_GRID(grid), scale_compression, 1, 1, 1, 1);
+    }
 
     g_signal_connect(gui.window, "destroy", G_CALLBACK(gtk_main_quit), NULL);
     g_signal_connect(gui.canvas, "draw", G_CALLBACK(canvas_draw), &gui);