ppapi: Add support for touch events.

ppapi/c/pp_touch_point.h

+/* Copyright (c) 2012 The Chromium Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+/* From pp_touch_point.idl modified Thu Jun 21 16:46:17 2012. */
+
+#ifndef PPAPI_C_PP_TOUCH_POINT_H_
+#define PPAPI_C_PP_TOUCH_POINT_H_
+
+#include "ppapi/c/pp_macros.h"
+#include "ppapi/c/pp_point.h"
+#include "ppapi/c/pp_stdint.h"
+
+/**
+ * @file
+ * This file defines the API to create a touch-point.
+ */
+
+
+/**
+ * @addtogroup Structs
+ * @{
+ */
+/**
+ * The <code>PP_TouchPoint</code> represents all information about a single
+ * touch point, such ase position, id, rotation angle, and pressure.
+ */
+struct PP_TouchPoint {
+  /**
+   * The identifier for this TouchPoint. This corresponds to the order
+   * in which the points were pressed. For example, the first point to be
+   * pressed has an id of 0, the second has an id of 1, and so on. An id can be
+   * reused when a touch point is released.  For example, if two fingers are
+   * down, with id 0 and 1, and finger 0 releases, the next finger to be
+   * pressed can be assigned to id 0.
+   */
+  uint32_t id;
+  /**
+   * The x-y pixel position of this TouchPoint, relative to the upper-left of
+   * the instance receiving the event.
+   */
+  struct PP_FloatPoint position;
+  /**
+   * The elliptical radii, in screen pixels, in the x and y direction of this
+   * TouchPoint.
+   */
+  struct PP_FloatPoint radius;
+  /**
+   * The angle of rotation in degrees of the elliptical model of this TouchPoint
+   * clockwise from "up."
+   */
+  float rotation_angle;
+  /**
+   * The pressure applied to this TouchPoint.  This is typically a
+   * value between 0 and 1, with 0 indicating no pressure and 1 indicating
+   * some maximum pressure, but scaling differs depending on the hardware and
+   * the value is not guaranteed to stay within that range.
+   */
+  float pressure;
+};
+PP_COMPILE_ASSERT_STRUCT_SIZE_IN_BYTES(PP_TouchPoint, 28);
+/**
+ * @}
+ */
+
+/**
+ * @addtogroup Functions
+ * @{
+ */
+
+/**
+ * PP_MakeTouchPoint() creates a <code>PP_TouchPoint</code>.
+ *
+ * @return A <code>PP_TouchPoint</code> structure.
+ */
+PP_INLINE struct PP_TouchPoint PP_MakeTouchPoint() {
+  struct PP_TouchPoint result = { 0, {0, 0}, {0, 0}, 0, 0 };
+  return result;
+}
+/**
+ * @}
+ */
+
+#endif  /* PPAPI_C_PP_TOUCH_POINT_H_ */
+