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 The x, y arguments of wl_surface.attach are applied as normal to 115 the surface. They indicate how many pixels to remove from the 116 surface size from the left and the top. In other words, they are 117 still in the surface-local coordinate system, just like dst_width 118 and dst_height are. 119 120 If the wl_surface associated with the wp_viewport is destroyed, 121 all wp_viewport requests except 'destroy' raise the protocol error 122 no_surface. 123 124 If the wp_viewport object is destroyed, the crop and scale 125 state is removed from the wl_surface. The change will be applied 126 on the next wl_surface.commit. 127 </description> 128 129 <request name="destroy" type="destructor"> 130 <description summary="remove scaling and cropping from the surface"> 131 The associated wl_surface's crop and scale state is removed. 132 The change is applied on the next wl_surface.commit. 133 </description> 134 </request> 135 136 <enum name="error"> 137 <entry name="bad_value" value="0" 138 summary="negative or zero values in width or height"/> 139 <entry name="bad_size" value="1" 140 summary="destination size is not integer"/> 141 <entry name="out_of_buffer" value="2" 142 summary="source rectangle extends outside of the content area"/> 143 <entry name="no_surface" value="3" 144 summary="the wl_surface was destroyed"/> 145 </enum> 146 147 <request name="set_source"> 148 <description summary="set the source rectangle for cropping"> 149 Set the source rectangle of the associated wl_surface. See 150 wp_viewport for the description, and relation to the wl_buffer 151 size. 152 153 If all of x, y, width and height are -1.0, the source rectangle is 154 unset instead. Any other set of values where width or height are zero 155 or negative, or x or y are negative, raise the bad_value protocol 156 error. 157 158 The crop and scale state is double-buffered state, and will be 159 applied on the next wl_surface.commit. 160 </description> 161 <arg name="x" type="fixed" summary="source rectangle x"/> 162 <arg name="y" type="fixed" summary="source rectangle y"/> 163 <arg name="width" type="fixed" summary="source rectangle width"/> 164 <arg name="height" type="fixed" summary="source rectangle height"/> 165 </request> 166 167 <request name="set_destination"> 168 <description summary="set the surface size for scaling"> 169 Set the destination size of the associated wl_surface. See 170 wp_viewport for the description, and relation to the wl_buffer 171 size. 172 173 If width is -1 and height is -1, the destination size is unset 174 instead. Any other pair of values for width and height that 175 contains zero or negative values raises the bad_value protocol 176 error. 177 178 The crop and scale state is double-buffered state, and will be 179 applied on the next wl_surface.commit. 180 </description> 181 <arg name="width" type="int" summary="surface width"/> 182 <arg name="height" type="int" summary="surface height"/> 183 </request> 184 </interface> 185 186 </protocol> 187
