Merge pull request #15 from markuspg/markuspg/gradients

Add new test displaying color gradients

NEWS

@@ -1,5 +1,6 @@
 Version 2.2 (Work in Progress)
 
+* New test: fullscreen color gradients
 * Switch build system from Autotools to Meson
 * Upgrade from GTK+ 2 to 3
 

callbacks.h

@@ -48,6 +48,7 @@ enum test_color {
 
 extern GdkRGBA fgcolors[];
 extern GdkRGBA *fg_color;
+extern GdkRGBA *bg_color;
 extern GdkRGBA grays[];
 
 void set_color_bg(cairo_t *cr);

meson.build

@@ -39,6 +39,7 @@ screentest_srcs = [
   'test_basic.c',
   'test_blink.c',
   'test_bright_pixels.c',
+  'test_gradient.c',
   'test_grid.c',
   'test_horizontal.c',
   'test_lcdalign.c',

screentest.ui

@@ -121,6 +121,16 @@
                 <signal name="activate" handler="on_mode_change"/>
               </object>
             </child>
+            <child>
+              <object class="GtkRadioMenuItem" id="gradient">
+                <property name="visible">True</property>
+                <property name="label" translatable="yes">Gradient</property>
+                <property name="use_underline">True</property>
+                <property name="draw_as_radio">True</property>
+                <property name="group">basic</property>
+                <signal name="activate" handler="on_mode_change"/>
+              </object>
+            </child>
           </object>
         </child>
       </object>

test_gradient.c

@@ -0,0 +1,104 @@
+/*
+ *  Screentest - CRT/LCD monitor testing utility.
+ *  https://tobix.github.io/screentest/
+ *  Copyright (C) 2001 Jan "Yenya" Kasprzak <kas@fi.muni.cz>
+ *  Copyright (C) 2006-2017 Tobias Gruetzmacher <tobias-screentest@23.gs>
+ *  Copyright (C) 2021 Apr Thorsten Kattanek <thorsten.kattanek@gmx.de>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ */
+
+#include "callbacks.h"
+
+enum GRADIENT_ORIENTATION {
+  GO_TOP_LEFT_TO_RIGHT_BOTTOM,
+  GO_TOP_TO_BOTTOM,
+  GO_TOP_RIGHT_TO_LEFT_BOTTOM,
+  GO_RIGHT_TO_LEFT,
+  GO_BOTTOM_RIGHT_TO_TOP_LEFT,
+  GO_BOTTOM_TO_TOP,
+  GO_BOTTOM_LEFT_TO_TOP_RIGHT,
+  GO_LEFT_TO_RIGHT,
+  GO_GRADIENT_ORIENTATIONS_QUANTITY,
+};
+
+static enum GRADIENT_ORIENTATION gradient_orientation;
+
+static void gradient_cycle(G_GNUC_UNUSED GtkWidget *widget) {
+  gradient_orientation =
+      (gradient_orientation + 1) % GO_GRADIENT_ORIENTATIONS_QUANTITY;
+}
+
+static void gradient_draw(GtkWidget *widget, cairo_t *cr) {
+  GdkWindow *win;
+  cairo_pattern_t *pat;
+  gint w, h;
+
+  win = gtk_widget_get_window(widget);
+
+  h = gdk_window_get_height(win);
+  w = gdk_window_get_width(win);
+
+  switch (gradient_orientation) {
+  default:
+  case GO_TOP_LEFT_TO_RIGHT_BOTTOM:
+    pat = cairo_pattern_create_linear(0.0, 0.0, w, h);
+    break;
+  case GO_TOP_TO_BOTTOM:
+    pat = cairo_pattern_create_linear((float)w / 2, 0.0, (float)w / 2, h);
+    break;
+  case GO_TOP_RIGHT_TO_LEFT_BOTTOM:
+    pat = cairo_pattern_create_linear(w, 0.0, 0.0, h);
+    break;
+  case GO_RIGHT_TO_LEFT:
+    pat = cairo_pattern_create_linear(w, (float)h / 2, 0.0, (float)h / 2);
+    break;
+  case GO_BOTTOM_RIGHT_TO_TOP_LEFT:
+    pat = cairo_pattern_create_linear(w, h, 0.0, 0.0);
+    break;
+  case GO_BOTTOM_TO_TOP:
+    pat = cairo_pattern_create_linear((float)w / 2, h, (float)w / 2, 0.0);
+    break;
+  case GO_BOTTOM_LEFT_TO_TOP_RIGHT:
+    pat = cairo_pattern_create_linear(0.0, h, w, 0.0);
+    break;
+  case GO_LEFT_TO_RIGHT:
+    pat = cairo_pattern_create_linear(0.0, (float)h / 2, w, (float)h / 2);
+    break;
+  }
+
+  // Let the gradient start with the foreground color ...
+  cairo_pattern_add_color_stop_rgba(pat, 0.0, fg_color->red, fg_color->green,
+                                    fg_color->blue, fg_color->alpha);
+  // ... and end with the background color
+  cairo_pattern_add_color_stop_rgba(pat, 1.0, bg_color->red, bg_color->green,
+                                    bg_color->blue, bg_color->alpha);
+  cairo_rectangle(cr, 0.0, 0.0, w, h);
+
+  // Draw the gradient
+  cairo_set_source(cr, pat);
+  cairo_fill(cr);
+
+  cairo_pattern_destroy(pat);
+  pat = NULL;
+}
+
+static void gradient_init(G_GNUC_UNUSED GtkWidget *widget) {
+  gradient_orientation = GO_TOP_LEFT_TO_RIGHT_BOTTOM;
+}
+
+G_MODULE_EXPORT struct test_ops gradient_ops = {.init = gradient_init,
+                                                .draw = gradient_draw,
+                                                .cycle = gradient_cycle,
+                                                .close = NULL};