viewporter.xml (8232B)
1 <?xml version="1.0" encoding="UTF-8"?> 2 <protocol name="viewporter"> 3 4 <copyright> 5 Copyright © 2013-2016 Collabora, Ltd. 6 7 Permission is hereby granted, free of charge, to any person obtaining a 8 copy of this software and associated documentation files (the "Software"), 9 to deal in the Software without restriction, including without limitation 10 the rights to use, copy, modify, merge, publish, distribute, sublicense, 11 and/or sell copies of the Software, and to permit persons to whom the 12 Software is furnished to do so, subject to the following conditions: 13 14 The above copyright notice and this permission notice (including the next 15 paragraph) shall be included in all copies or substantial portions of the 16 Software. 17 18 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 19 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 20 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 21 THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 22 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 23 FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 24 DEALINGS IN THE SOFTWARE. 25 </copyright> 26 27 <interface name="wp_viewporter" version="1"> 28 <description summary="surface cropping and scaling"> 29 The global interface exposing surface cropping and scaling 30 capabilities is used to instantiate an interface extension for a 31 wl_surface object. This extended interface will then allow 32 cropping and scaling the surface contents, effectively 33 disconnecting the direct relationship between the buffer and the 34 surface size. 35 </description> 36 37 <request name="destroy" type="destructor"> 38 <description summary="unbind from the cropping and scaling interface"> 39 Informs the server that the client will not be using this 40 protocol object anymore. This does not affect any other objects, 41 wp_viewport objects included. 42 </description> 43 </request> 44 45 <enum name="error"> 46 <entry name="viewport_exists" value="0" 47 summary="the surface already has a viewport object associated"/> 48 </enum> 49 50 <request name="get_viewport"> 51 <description summary="extend surface interface for crop and scale"> 52 Instantiate an interface extension for the given wl_surface to 53 crop and scale its content. If the given wl_surface already has 54 a wp_viewport object associated, the viewport_exists 55 protocol error is raised. 56 </description> 57 <arg name="id" type="new_id" interface="wp_viewport" 58 summary="the new viewport interface id"/> 59 <arg name="surface" type="object" interface="wl_surface" 60 summary="the surface"/> 61 </request> 62 </interface> 63 64 <interface name="wp_viewport" version="1"> 65 <description summary="crop and scale interface to a wl_surface"> 66 An additional interface to a wl_surface object, which allows the 67 client to specify the cropping and scaling of the surface 68 contents. 69 70 This interface works with two concepts: the source rectangle (src_x, 71 src_y, src_width, src_height), and the destination size (dst_width, 72 dst_height). The contents of the source rectangle are scaled to the 73 destination size, and content outside the source rectangle is ignored. 74 This state is double-buffered, and is applied on the next 75 wl_surface.commit. 76 77 The two parts of crop and scale state are independent: the source 78 rectangle, and the destination size. Initially both are unset, that 79 is, no scaling is applied. The whole of the current wl_buffer is 80 used as the source, and the surface size is as defined in 81 wl_surface.attach. 82 83 If the destination size is set, it causes the surface size to become 84 dst_width, dst_height. The source (rectangle) is scaled to exactly 85 this size. This overrides whatever the attached wl_buffer size is, 86 unless the wl_buffer is NULL. If the wl_buffer is NULL, the surface 87 has no content and therefore no size. Otherwise, the size is always 88 at least 1x1 in surface local coordinates. 89 90 If the source rectangle is set, it defines what area of the wl_buffer is 91 taken as the source. If the source rectangle is set and the destination 92 size is not set, then src_width and src_height must be integers, and the 93 surface size becomes the source rectangle size. This results in cropping 94 without scaling. If src_width or src_height are not integers and 95 destination size is not set, the bad_size protocol error is raised when 96 the surface state is applied. 97 98 The coordinate transformations from buffer pixel coordinates up to 99 the surface-local coordinates happen in the following order: 100 1. buffer_transform (wl_surface.set_buffer_transform) 101 2. buffer_scale (wl_surface.set_buffer_scale) 102 3. crop and scale (wp_viewport.set*) 103 This means, that the source rectangle coordinates of crop and scale 104 are given in the coordinates after the buffer transform and scale, 105 i.e. in the coordinates that would be the surface-local coordinates 106 if the crop and scale was not applied. 107 108 If src_x or src_y are negative, the bad_value protocol error is raised. 109 Otherwise, if the source rectangle is partially or completely outside of 110 the non-NULL wl_buffer, then the out_of_buffer protocol error is raised 111 when the surface state is applied. A NULL wl_buffer does not raise the 112 out_of_buffer error. 113 114 If the wl_surface associated with the wp_viewport is destroyed, 115 all wp_viewport requests except 'destroy' raise the protocol error 116 no_surface. 117 118 If the wp_viewport object is destroyed, the crop and scale 119 state is removed from the wl_surface. The change will be applied 120 on the next wl_surface.commit. 121 </description> 122 123 <request name="destroy" type="destructor"> 124 <description summary="remove scaling and cropping from the surface"> 125 The associated wl_surface's crop and scale state is removed. 126 The change is applied on the next wl_surface.commit. 127 </description> 128 </request> 129 130 <enum name="error"> 131 <entry name="bad_value" value="0" 132 summary="negative or zero values in width or height"/> 133 <entry name="bad_size" value="1" 134 summary="destination size is not integer"/> 135 <entry name="out_of_buffer" value="2" 136 summary="source rectangle extends outside of the content area"/> 137 <entry name="no_surface" value="3" 138 summary="the wl_surface was destroyed"/> 139 </enum> 140 141 <request name="set_source"> 142 <description summary="set the source rectangle for cropping"> 143 Set the source rectangle of the associated wl_surface. See 144 wp_viewport for the description, and relation to the wl_buffer 145 size. 146 147 If all of x, y, width and height are -1.0, the source rectangle is 148 unset instead. Any other set of values where width or height are zero 149 or negative, or x or y are negative, raise the bad_value protocol 150 error. 151 152 The crop and scale state is double-buffered state, and will be 153 applied on the next wl_surface.commit. 154 </description> 155 <arg name="x" type="fixed" summary="source rectangle x"/> 156 <arg name="y" type="fixed" summary="source rectangle y"/> 157 <arg name="width" type="fixed" summary="source rectangle width"/> 158 <arg name="height" type="fixed" summary="source rectangle height"/> 159 </request> 160 161 <request name="set_destination"> 162 <description summary="set the surface size for scaling"> 163 Set the destination size of the associated wl_surface. See 164 wp_viewport for the description, and relation to the wl_buffer 165 size. 166 167 If width is -1 and height is -1, the destination size is unset 168 instead. Any other pair of values for width and height that 169 contains zero or negative values raises the bad_value protocol 170 error. 171 172 The crop and scale state is double-buffered state, and will be 173 applied on the next wl_surface.commit. 174 </description> 175 <arg name="width" type="int" summary="surface width"/> 176 <arg name="height" type="int" summary="surface height"/> 177 </request> 178 </interface> 179 180 </protocol>