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 */ 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
