Add spring-tool, a small utility to plot spring behavior
The weston_spring is a very flexible and powerful mecanhism for driving
animations. However, it can be a little difficult to tame, but this
little helper can plot the response of the spring to a set of initial
parameters and makes it easy to tune and tweak the spring behavior.
diff --git a/src/spring-tool.c b/src/spring-tool.c
new file mode 100644
index 0000000..f2be784
--- /dev/null
+++ b/src/spring-tool.c
@@ -0,0 +1,64 @@
+/*
+ * Copyright © 2011 Intel Corporation
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and
+ * its documentation for any purpose is hereby granted without fee, provided
+ * that the above copyright notice appear in all copies and that both that
+ * copyright notice and this permission notice appear in supporting
+ * documentation, and that the name of the copyright holders not be used in
+ * advertising or publicity pertaining to distribution of the software
+ * without specific, written prior permission. The copyright holders make
+ * no representations about the suitability of this software for any
+ * purpose. It is provided "as is" without express or implied warranty.
+ *
+ * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS
+ * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS, IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+ * RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
+ * CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include "compositor.h"
+
+WL_EXPORT void
+weston_surface_geometry_dirty(struct weston_surface *surface)
+{
+}
+
+WL_EXPORT int
+weston_log(const char *fmt, ...)
+{
+ return 0;
+}
+
+WL_EXPORT void
+weston_compositor_schedule_repaint(struct weston_compositor *compositor)
+{
+}
+
+int
+main(int argc, char *argv[])
+{
+ const double k = 300.0;
+ const double current = 0.0;
+ const double target = 1.0;
+ const double friction = 1400;
+
+ struct weston_spring spring;
+ uint32_t time = 0;
+
+ weston_spring_init(&spring, k, current, target);
+ spring.friction = friction;
+ spring.previous = -0.03;
+ spring.timestamp = 0;
+
+ while (!weston_spring_done(&spring)) {
+ printf("\t%d\t%f\n", time, spring.current);
+ weston_spring_update(&spring, time);
+ time += 16;
+ }
+
+ return 0;
+}