1 /* Copyright (c) 2012 The Chromium Authors. All rights reserved.
2 * Use of this source code is governed by a BSD-style license that can be
3 * found in the LICENSE file.
4 */
5
6 /* From pp_touch_point.idl modified Thu Mar 28 10:13:07 2013. */
7
8 #ifndef PPAPI_C_PP_TOUCH_POINT_H_
9 #define PPAPI_C_PP_TOUCH_POINT_H_
10
11 #include "ppapi/c/pp_macros.h"
12 #include "ppapi/c/pp_point.h"
13 #include "ppapi/c/pp_stdint.h"
14
15 /**
16 * @file
17 * This file defines the API to create a touch point or position where fingers
18 * makes contact with touch screen device.
19 */
20
21
22 /**
23 * @addtogroup Structs
24 * @{
25 */
26 /**
27 * The <code>PP_TouchPoint</code> struct represents all information about a
28 * single touch point, such as position, id, rotation angle, and pressure.
29 */
30 struct PP_TouchPoint {
31 /**
32 * This value represents the identifier for this TouchPoint. The id
33 * corresponds to the order in which the points were pressed. For example,
34 * the first point to be pressed has an id of 0, the second has an id of 1,
35 * and so on. An id can be reused when a touch point is released. For
36 * example, if two fingers are down, with id 0 and 1, and finger 0 releases,
37 * the next finger to be pressed can be assigned to id 0.
38 */
39 uint32_t id;
40 /**
41 * This value represents the x and y pixel position of this TouchPoint
42 * relative to the upper-left of the module instance receiving the event.
43 */
44 struct PP_FloatPoint position;
45 /**
46 * This value represents the elliptical radii, in screen pixels, in the x
47 * and y direction of this TouchPoint.
48 */
49 struct PP_FloatPoint radius;
50 /**
51 * This value represents the angle of rotation in degrees of the elliptical
52 * model of this TouchPoint clockwise from "up."
53 */
54 float rotation_angle;
55 /**
56 * This value represents the pressure applied to this TouchPoint. This value
57 * is typically between 0 and 1, with 0 indicating no pressure and 1
58 * indicating some maximum pressure. Scaling differs depending on the
59 * hardware and the value is not guaranteed to stay within that range.
60 */
61 float pressure;
62 };
63 PP_COMPILE_ASSERT_STRUCT_SIZE_IN_BYTES(PP_TouchPoint, 28);
64 /**
65 * @}
66 */
67
68 /**
69 * @addtogroup Functions
70 * @{
71 */
72
73 /**
74 * PP_MakeTouchPoint() creates a <code>PP_TouchPoint</code>.
75 *
76 * @return A <code>PP_TouchPoint</code> structure.
77 */
PP_MakeTouchPoint(void)78 PP_INLINE struct PP_TouchPoint PP_MakeTouchPoint(void) {
79 struct PP_TouchPoint result = { 0, {0, 0}, {0, 0}, 0, 0 };
80 return result;
81 }
82 /**
83 * @}
84 */
85
86 #endif /* PPAPI_C_PP_TOUCH_POINT_H_ */
87
88