}
static void
-checkerboard_draw (GtkDrawingArea *da,
- cairo_t *cr,
- int width,
- int height,
- gpointer data)
+oval_path (cairo_t *cr,
+ double xc, double yc,
+ double xr, double yr)
{
- gint i, j, xcount, ycount;
+ cairo_save (cr);
+
+ cairo_translate (cr, xc, yc);
+ cairo_scale (cr, 1.0, yr / xr);
+ cairo_move_to (cr, xr, 0.0);
+ cairo_arc (cr,
+ 0, 0,
+ xr,
+ 0, 2 * G_PI);
+ cairo_close_path (cr);
+
+ cairo_restore (cr);
+}
-#define CHECK_SIZE 10
-#define SPACING 2
+/* Fill the given area with checks in the standard style
+ * for showing compositing effects.
+ *
+ * It would make sense to do this as a repeating surface,
+ * but most implementations of RENDER currently have broken
+ * implementations of repeat + transform, even when the
+ * transform is a translation.
+ */
+static void
+fill_checks (cairo_t *cr,
+ int x, int y,
+ int width, int height)
+{
+ int i, j;
- /* At the start of a draw handler, a clip region has been set on
- * the Cairo context, and the contents have been cleared to the
- * widget's background color. The docs for
- * gdk_surface_begin_paint_region() give more details on how this
- * works.
- */
+#define CHECK_SIZE 16
- xcount = 0;
- i = SPACING;
- while (i < width)
+ cairo_rectangle (cr, x, y, width, height);
+ cairo_set_source_rgb (cr, 0.4, 0.4, 0.4);
+ cairo_fill (cr);
+
+ /* Only works for CHECK_SIZE a power of 2 */
+ j = x & (-CHECK_SIZE);
+
+ for (; j < height; j += CHECK_SIZE)
{
- j = SPACING;
- ycount = xcount % 2; /* start with even/odd depending on row */
- while (j < height)
- {
- if (ycount % 2)
- cairo_set_source_rgb (cr, 0.45777, 0, 0.45777);
- else
- cairo_set_source_rgb (cr, 1, 1, 1);
-
- /* If we're outside the clip, this will do nothing.
- */
+ i = y & (-CHECK_SIZE);
+ for (; i < width; i += CHECK_SIZE)
+ if ((i / CHECK_SIZE + j / CHECK_SIZE) % 2 == 0)
cairo_rectangle (cr, i, j, CHECK_SIZE, CHECK_SIZE);
- cairo_fill (cr);
+ }
- j += CHECK_SIZE + SPACING;
- ++ycount;
- }
+ cairo_set_source_rgb (cr, 0.7, 0.7, 0.7);
+ cairo_fill (cr);
- i += CHECK_SIZE + SPACING;
- ++xcount;
- }
+#undef CHECK_SIZE
+}
+
+/* Draw a red, green, and blue circle equally spaced inside
+ * the larger circle of radius r at (xc, yc)
+ */
+static void
+draw_3circles (cairo_t *cr,
+ double xc, double yc,
+ double radius,
+ double alpha)
+{
+ double subradius = radius * (2 / 3. - 0.1);
+
+ cairo_set_source_rgba (cr, 1., 0., 0., alpha);
+ oval_path (cr,
+ xc + radius / 3. * cos (G_PI * (0.5)),
+ yc - radius / 3. * sin (G_PI * (0.5)),
+ subradius, subradius);
+ cairo_fill (cr);
+
+ cairo_set_source_rgba (cr, 0., 1., 0., alpha);
+ oval_path (cr,
+ xc + radius / 3. * cos (G_PI * (0.5 + 2/.3)),
+ yc - radius / 3. * sin (G_PI * (0.5 + 2/.3)),
+ subradius, subradius);
+ cairo_fill (cr);
+
+ cairo_set_source_rgba (cr, 0., 0., 1., alpha);
+ oval_path (cr,
+ xc + radius / 3. * cos (G_PI * (0.5 + 4/.3)),
+ yc - radius / 3. * sin (G_PI * (0.5 + 4/.3)),
+ subradius, subradius);
+ cairo_fill (cr);
+}
+
+static void
+groups_draw (GtkDrawingArea *darea,
+ cairo_t *cr,
+ int width,
+ int height,
+ gpointer data)
+{
+ cairo_surface_t *overlay, *punch, *circles;
+ cairo_t *overlay_cr, *punch_cr, *circles_cr;
+
+ /* Fill the background */
+ double radius = 0.5 * (width < height ? width : height) - 10;
+ double xc = width / 2.;
+ double yc = height / 2.;
+
+ overlay = cairo_surface_create_similar (cairo_get_target (cr),
+ CAIRO_CONTENT_COLOR_ALPHA,
+ width, height);
+
+ punch = cairo_surface_create_similar (cairo_get_target (cr),
+ CAIRO_CONTENT_ALPHA,
+ width, height);
+
+ circles = cairo_surface_create_similar (cairo_get_target (cr),
+ CAIRO_CONTENT_COLOR_ALPHA,
+ width, height);
+
+ fill_checks (cr, 0, 0, width, height);
+
+ /* Draw a black circle on the overlay
+ */
+ overlay_cr = cairo_create (overlay);
+ cairo_set_source_rgb (overlay_cr, 0., 0., 0.);
+ oval_path (overlay_cr, xc, yc, radius, radius);
+ cairo_fill (overlay_cr);
+
+ /* Draw 3 circles to the punch surface, then cut
+ * that out of the main circle in the overlay
+ */
+ punch_cr = cairo_create (punch);
+ draw_3circles (punch_cr, xc, yc, radius, 1.0);
+ cairo_destroy (punch_cr);
+
+ cairo_set_operator (overlay_cr, CAIRO_OPERATOR_DEST_OUT);
+ cairo_set_source_surface (overlay_cr, punch, 0, 0);
+ cairo_paint (overlay_cr);
+
+ /* Now draw the 3 circles in a subgroup again
+ * at half intensity, and use OperatorAdd to join up
+ * without seams.
+ */
+ circles_cr = cairo_create (circles);
+
+ cairo_set_operator (circles_cr, CAIRO_OPERATOR_OVER);
+ draw_3circles (circles_cr, xc, yc, radius, 0.5);
+ cairo_destroy (circles_cr);
+
+ cairo_set_operator (overlay_cr, CAIRO_OPERATOR_ADD);
+ cairo_set_source_surface (overlay_cr, circles, 0, 0);
+ cairo_paint (overlay_cr);
+
+ cairo_destroy (overlay_cr);
+
+ cairo_set_source_surface (cr, overlay, 0, 0);
+ cairo_paint (cr);
+
+ cairo_surface_destroy (overlay);
+ cairo_surface_destroy (punch);
+ cairo_surface_destroy (circles);
}
static void
gtk_window_set_child (GTK_WINDOW (window), vbox);
/*
- * Create the checkerboard area
+ * Create the groups area
*/
-
label = gtk_label_new (NULL);
gtk_label_set_markup (GTK_LABEL (label),
- "<u>Checkerboard pattern</u>");
+ "<u>Knockout groups</u>");
gtk_box_append (GTK_BOX (vbox), label);
frame = gtk_frame_new (NULL);
da = gtk_drawing_area_new ();
gtk_drawing_area_set_content_width (GTK_DRAWING_AREA (da), 100);
gtk_drawing_area_set_content_height (GTK_DRAWING_AREA (da), 100);
- gtk_drawing_area_set_draw_func (GTK_DRAWING_AREA (da), checkerboard_draw, NULL, NULL);
+ gtk_drawing_area_set_draw_func (GTK_DRAWING_AREA (da), groups_draw, NULL, NULL);
gtk_frame_set_child (GTK_FRAME (frame), da);
/*
+++ /dev/null
-/* testimage.c
- * Copyright (C) 2005 Red Hat, Inc.
- * Based on cairo-demo/X11/cairo-knockout.c
- *
- * Author: Owen Taylor
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Library General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
- *
- * This library 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
- * Library General Public License for more details.
- *
- * You should have received a copy of the GNU Library General Public
- * License along with this library. If not, see <http://www.gnu.org/licenses/>.
- */
-
-#include <math.h>
-
-#include <gtk/gtk.h>
-
-static void
-oval_path (cairo_t *cr,
- double xc, double yc,
- double xr, double yr)
-{
- cairo_save (cr);
-
- cairo_translate (cr, xc, yc);
- cairo_scale (cr, 1.0, yr / xr);
- cairo_move_to (cr, xr, 0.0);
- cairo_arc (cr,
- 0, 0,
- xr,
- 0, 2 * G_PI);
- cairo_close_path (cr);
-
- cairo_restore (cr);
-}
-
-/* Create a path that is a circular oval with radii xr, yr at xc,
- * yc.
- */
-/* Fill the given area with checks in the standard style
- * for showing compositing effects.
- *
- * It would make sense to do this as a repeating surface,
- * but most implementations of RENDER currently have broken
- * implementations of repeat + transform, even when the
- * transform is a translation.
- */
-static void
-fill_checks (cairo_t *cr,
- int x, int y,
- int width, int height)
-{
- int i, j;
-
-#define CHECK_SIZE 32
-
- cairo_rectangle (cr, x, y, width, height);
- cairo_set_source_rgb (cr, 0.4, 0.4, 0.4);
- cairo_fill (cr);
-
- /* Only works for CHECK_SIZE a power of 2 */
- j = x & (-CHECK_SIZE);
-
- for (; j < height; j += CHECK_SIZE)
- {
- i = y & (-CHECK_SIZE);
- for (; i < width; i += CHECK_SIZE)
- if ((i / CHECK_SIZE + j / CHECK_SIZE) % 2 == 0)
- cairo_rectangle (cr, i, j, CHECK_SIZE, CHECK_SIZE);
- }
-
- cairo_set_source_rgb (cr, 0.7, 0.7, 0.7);
- cairo_fill (cr);
-}
-
-/* Draw a red, green, and blue circle equally spaced inside
- * the larger circle of radius r at (xc, yc)
- */
-static void
-draw_3circles (cairo_t *cr,
- double xc, double yc,
- double radius,
- double alpha)
-{
- double subradius = radius * (2 / 3. - 0.1);
-
- cairo_set_source_rgba (cr, 1., 0., 0., alpha);
- oval_path (cr,
- xc + radius / 3. * cos (G_PI * (0.5)),
- yc - radius / 3. * sin (G_PI * (0.5)),
- subradius, subradius);
- cairo_fill (cr);
-
- cairo_set_source_rgba (cr, 0., 1., 0., alpha);
- oval_path (cr,
- xc + radius / 3. * cos (G_PI * (0.5 + 2/.3)),
- yc - radius / 3. * sin (G_PI * (0.5 + 2/.3)),
- subradius, subradius);
- cairo_fill (cr);
-
- cairo_set_source_rgba (cr, 0., 0., 1., alpha);
- oval_path (cr,
- xc + radius / 3. * cos (G_PI * (0.5 + 4/.3)),
- yc - radius / 3. * sin (G_PI * (0.5 + 4/.3)),
- subradius, subradius);
- cairo_fill (cr);
-}
-
-static void
-on_draw (GtkDrawingArea *darea,
- cairo_t *cr,
- int width,
- int height,
- gpointer data)
-{
- cairo_surface_t *overlay, *punch, *circles;
- cairo_t *overlay_cr, *punch_cr, *circles_cr;
-
- /* Fill the background */
- double radius = 0.5 * (width < height ? width : height) - 10;
- double xc = width / 2.;
- double yc = height / 2.;
-
- overlay = cairo_surface_create_similar (cairo_get_target (cr),
- CAIRO_CONTENT_COLOR_ALPHA,
- width, height);
-
- punch = cairo_surface_create_similar (cairo_get_target (cr),
- CAIRO_CONTENT_ALPHA,
- width, height);
-
- circles = cairo_surface_create_similar (cairo_get_target (cr),
- CAIRO_CONTENT_COLOR_ALPHA,
- width, height);
-
- fill_checks (cr, 0, 0, width, height);
-
- /* Draw a black circle on the overlay
- */
- overlay_cr = cairo_create (overlay);
- cairo_set_source_rgb (overlay_cr, 0., 0., 0.);
- oval_path (overlay_cr, xc, yc, radius, radius);
- cairo_fill (overlay_cr);
-
- /* Draw 3 circles to the punch surface, then cut
- * that out of the main circle in the overlay
- */
- punch_cr = cairo_create (punch);
- draw_3circles (punch_cr, xc, yc, radius, 1.0);
- cairo_destroy (punch_cr);
-
- cairo_set_operator (overlay_cr, CAIRO_OPERATOR_DEST_OUT);
- cairo_set_source_surface (overlay_cr, punch, 0, 0);
- cairo_paint (overlay_cr);
-
- /* Now draw the 3 circles in a subgroup again
- * at half intensity, and use OperatorAdd to join up
- * without seams.
- */
- circles_cr = cairo_create (circles);
-
- cairo_set_operator (circles_cr, CAIRO_OPERATOR_OVER);
- draw_3circles (circles_cr, xc, yc, radius, 0.5);
- cairo_destroy (circles_cr);
-
- cairo_set_operator (overlay_cr, CAIRO_OPERATOR_ADD);
- cairo_set_source_surface (overlay_cr, circles, 0, 0);
- cairo_paint (overlay_cr);
-
- cairo_destroy (overlay_cr);
-
- cairo_set_source_surface (cr, overlay, 0, 0);
- cairo_paint (cr);
-
- cairo_surface_destroy (overlay);
- cairo_surface_destroy (punch);
- cairo_surface_destroy (circles);
-}
-
-static void
-quit_cb (GtkWidget *widget,
- gpointer data)
-{
- gboolean *done = data;
-
- *done = TRUE;
-
- g_main_context_wakeup (NULL);
-}
-
-int
-main (int argc, char **argv)
-{
- GtkWidget *window, *darea;
- gboolean done = FALSE;
-
- gtk_init ();
-
- window = gtk_window_new ();
-
- gtk_window_set_default_size (GTK_WINDOW (window), 400, 400);
- gtk_window_set_title (GTK_WINDOW (window), "cairo: Knockout Groups");
-
- darea = gtk_drawing_area_new ();
- gtk_window_set_child (GTK_WINDOW (window), darea);
-
- gtk_drawing_area_set_draw_func (GTK_DRAWING_AREA (darea), on_draw, NULL, NULL);
- g_signal_connect (window, "destroy", G_CALLBACK (quit_cb), &done);
-
- gtk_widget_show (window);
-
- while (!done)
- g_main_context_iteration (NULL, TRUE);
-
- return 0;
-}
projects / gtk4.git / commitdiff