.TH "wayland::viewport_t" 3 "Wed May 3 2023" "Version 1.0.0" "Wayland++" \" -*- nroff -*- .ad l .nh .SH NAME wayland::viewport_t \- crop and scale interface to a wl_surface .SH SYNOPSIS .br .PP .PP \fC#include \fP .PP Inherits \fBwayland::proxy_t\fP\&. .SS "Public Types" .in +1c .ti -1c .RI "enum class \fBwrapper_type\fP { \fBstandard\fP, \fBdisplay\fP, \fBforeign\fP, \fBproxy_wrapper\fP }" .br .in -1c .SS "Public Member Functions" .in +1c .ti -1c .RI "void \fBset_source\fP (double x, double y, double width, double height)" .br .RI "set the source rectangle for cropping " .ti -1c .RI "void \fBset_destination\fP (int32_t width, int32_t height)" .br .RI "set the surface size for scaling " .ti -1c .RI "uint32_t \fBget_id\fP () const" .br .RI "Get the id of a proxy object\&. " .ti -1c .RI "std::string \fBget_class\fP () const" .br .RI "Get the interface name (class) of a proxy object\&. " .ti -1c .RI "uint32_t \fBget_version\fP () const" .br .RI "Get the protocol object version of a proxy object\&. " .ti -1c .RI "\fBwrapper_type\fP \fBget_wrapper_type\fP () const" .br .RI "Get the type of a proxy object\&. " .ti -1c .RI "void \fBset_queue\fP (\fBevent_queue_t\fP queue)" .br .RI "Assign a proxy to an event queue\&. " .ti -1c .RI "wl_proxy * \fBc_ptr\fP () const" .br .RI "Get a pointer to the underlying C struct\&. " .ti -1c .RI "bool \fBproxy_has_object\fP () const" .br .RI "Check whether this wrapper actually wraps an object\&. " .ti -1c .RI "\fBoperator bool\fP () const" .br .RI "Check whether this wrapper actually wraps an object\&. " .ti -1c .RI "bool \fBoperator==\fP (const \fBproxy_t\fP &right) const" .br .RI "Check whether two wrappers refer to the same object\&. " .ti -1c .RI "bool \fBoperator!=\fP (const \fBproxy_t\fP &right) const" .br .RI "Check whether two wrappers refer to different objects\&. " .ti -1c .RI "void \fBproxy_release\fP ()" .br .RI "Release the wrapped object (if any), making this an empty wrapper\&. " .in -1c .SS "Static Public Attributes" .in +1c .ti -1c .RI "static constexpr std::uint32_t \fBset_source_since_version\fP = 1" .br .RI "Minimum protocol version required for the \fBset_source\fP function\&. " .ti -1c .RI "static constexpr std::uint32_t \fBset_destination_since_version\fP = 1" .br .RI "Minimum protocol version required for the \fBset_destination\fP function\&. " .in -1c .SH "Detailed Description" .PP crop and scale interface to a wl_surface An additional interface to a wl_surface object, which allows the client to specify the cropping and scaling of the surface contents\&. .PP This interface works with two concepts: the source rectangle (src_x, src_y, src_width, src_height), and the destination size (dst_width, dst_height)\&. The contents of the source rectangle are scaled to the destination size, and content outside the source rectangle is ignored\&. This state is double-buffered, and is applied on the next wl_surface\&.commit\&. .PP The two parts of crop and scale state are independent: the source rectangle, and the destination size\&. Initially both are unset, that is, no scaling is applied\&. The whole of the current wl_buffer is used as the source, and the surface size is as defined in wl_surface\&.attach\&. .PP If the destination size is set, it causes the surface size to become dst_width, dst_height\&. The source (rectangle) is scaled to exactly this size\&. This overrides whatever the attached wl_buffer size is, unless the wl_buffer is NULL\&. If the wl_buffer is NULL, the surface has no content and therefore no size\&. Otherwise, the size is always at least 1x1 in surface local coordinates\&. .PP If the source rectangle is set, it defines what area of the wl_buffer is taken as the source\&. If the source rectangle is set and the destination size is not set, then src_width and src_height must be integers, and the surface size becomes the source rectangle size\&. This results in cropping without scaling\&. If src_width or src_height are not integers and destination size is not set, the bad_size protocol error is raised when the surface state is applied\&. .PP The coordinate transformations from buffer pixel coordinates up to the surface-local coordinates happen in the following order: .IP "1." 4 buffer_transform (wl_surface\&.set_buffer_transform) .IP "2." 4 buffer_scale (wl_surface\&.set_buffer_scale) .IP "3." 4 crop and scale (wp_viewport\&.set*) This means, that the source rectangle coordinates of crop and scale are given in the coordinates after the buffer transform and scale, i\&.e\&. in the coordinates that would be the surface-local coordinates if the crop and scale was not applied\&. .PP .PP If src_x or src_y are negative, the bad_value protocol error is raised\&. Otherwise, if the source rectangle is partially or completely outside of the non-NULL wl_buffer, then the out_of_buffer protocol error is raised when the surface state is applied\&. A NULL wl_buffer does not raise the out_of_buffer error\&. .PP The x, y arguments of wl_surface\&.attach are applied as normal to the surface\&. They indicate how many pixels to remove from the surface size from the left and the top\&. In other words, they are still in the surface-local coordinate system, just like dst_width and dst_height are\&. .PP If the wl_surface associated with the wp_viewport is destroyed, all wp_viewport requests except 'destroy' raise the protocol error no_surface\&. .PP If the wp_viewport object is destroyed, the crop and scale state is removed from the wl_surface\&. The change will be applied on the next wl_surface\&.commit\&. .PP Definition at line \fB436\fP of file \fBwayland\-client\-protocol\-extra\&.hpp\fP\&. .SH "Member Enumeration Documentation" .PP .SS "enum class \fBwayland::proxy_t::wrapper_type\fP\fC [strong]\fP, \fC [inherited]\fP" Underlying wl_proxy type and properties of a \fBproxy_t\fP that affect construction, destruction, and event handling .PP \fBEnumerator\fP .in +1c .TP \fB\fIstandard \fP\fP C pointer is a standard type compatible with wl_proxy*\&. Events are dispatched and it is destructed when the \fBproxy_t\fP is destructed\&. User data is set\&. .TP \fB\fIdisplay \fP\fP C pointer is a wl_display*\&. No events are dispatched, wl_display_disconnect is called when the \fBproxy_t\fP is destructed\&. User data is set\&. .TP \fB\fIforeign \fP\fP C pointer is a standard type compatible with wl_proxy*, but another library owns it and it should not be touched in a way that could affect the operation of the other library\&. No events are dispatched, wl_proxy_destroy is not called when the \fBproxy_t\fP is destructed, user data is not touched\&. Consequently, there is no reference counting for the \fBproxy_t\fP\&. Lifetime of such wrappers should preferably be short to minimize the chance that the owning library decides to destroy the wl_proxy\&. .TP \fB\fIproxy_wrapper \fP\fP C pointer is a wl_proxy* that was constructed with wl_proxy_create_wrapper\&. No events are dispatched, wl_proxy_wrapper_destroy is called when the \fBproxy_t\fP is destroyed\&. Reference counting is active\&. A reference to the \fBproxy_t\fP creating this proxy wrapper is held to extend its lifetime until after the proxy wrapper is destroyed\&. .PP Definition at line \fB115\fP of file \fBwayland\-client\&.hpp\fP\&. .SH "Member Function Documentation" .PP .SS "wl_proxy * wayland::proxy_t::c_ptr () const\fC [inherited]\fP" .PP Get a pointer to the underlying C struct\&. .PP \fBReturns\fP .RS 4 The underlying wl_proxy wrapped by this \fBproxy_t\fP if it exists, otherwise an exception is thrown .RE .PP .SS "std::string wayland::proxy_t::get_class () const\fC [inherited]\fP" .PP Get the interface name (class) of a proxy object\&. .PP \fBReturns\fP .RS 4 The interface name of the object associated with the proxy .RE .PP .SS "uint32_t wayland::proxy_t::get_id () const\fC [inherited]\fP" .PP Get the id of a proxy object\&. .PP \fBReturns\fP .RS 4 The id the object associated with the proxy .RE .PP .SS "uint32_t wayland::proxy_t::get_version () const\fC [inherited]\fP" .PP Get the protocol object version of a proxy object\&. Gets the protocol object version of a proxy object, or 0 if the proxy was created with unversioned API\&. .PP A returned value of 0 means that no version information is available, so the caller must make safe assumptions about the object's real version\&. .PP \fBdisplay_t\fP will always return version 0\&. .PP \fBReturns\fP .RS 4 The protocol object version of the proxy or 0 .RE .PP .SS "\fBwrapper_type\fP wayland::proxy_t::get_wrapper_type () const\fC [inline]\fP, \fC [inherited]\fP" .PP Get the type of a proxy object\&. .PP Definition at line \fB301\fP of file \fBwayland\-client\&.hpp\fP\&. .SS "wayland::proxy_t::operator bool () const\fC [inherited]\fP" .PP Check whether this wrapper actually wraps an object\&. .PP \fBReturns\fP .RS 4 true if there is an underlying object, false if this wrapper is empty .RE .PP .SS "bool wayland::proxy_t::operator!= (const \fBproxy_t\fP & right) const\fC [inherited]\fP" .PP Check whether two wrappers refer to different objects\&. .SS "bool wayland::proxy_t::operator== (const \fBproxy_t\fP & right) const\fC [inherited]\fP" .PP Check whether two wrappers refer to the same object\&. .SS "bool wayland::proxy_t::proxy_has_object () const\fC [inherited]\fP" .PP Check whether this wrapper actually wraps an object\&. .PP \fBReturns\fP .RS 4 true if there is an underlying object, false if this wrapper is empty .RE .PP .SS "void wayland::proxy_t::proxy_release ()\fC [inherited]\fP" .PP Release the wrapped object (if any), making this an empty wrapper\&. Note that \fBdisplay_t\fP instances cannot be released this way\&. Attempts to do so are ignored\&. .PP \fBExamples\fP .in +1c \fBforeign_display\&.cpp\fP\&. .SS "void viewport_t::set_destination (int32_t width, int32_t height)" .PP set the surface size for scaling .PP \fBParameters\fP .RS 4 \fIwidth\fP surface width .br \fIheight\fP surface height .RE .PP Set the destination size of the associated wl_surface\&. See wp_viewport for the description, and relation to the wl_buffer size\&. .PP If width is -1 and height is -1, the destination size is unset instead\&. Any other pair of values for width and height that contains zero or negative values raises the bad_value protocol error\&. .PP The crop and scale state is double-buffered state, and will be applied on the next wl_surface\&.commit\&. .PP Definition at line \fB953\fP of file \fBwayland\-client\-protocol\-extra\&.cpp\fP\&. .SS "void wayland::proxy_t::set_queue (\fBevent_queue_t\fP queue)\fC [inherited]\fP" .PP Assign a proxy to an event queue\&. .PP \fBParameters\fP .RS 4 \fIqueue\fP The event queue that will handle this proxy .RE .PP Assign proxy to event queue\&. Events coming from proxy will be queued in queue instead of the display's main queue\&. .PP See also: \fBdisplay_t::dispatch_queue()\fP\&. .PP \fBExamples\fP .in +1c \fBproxy_wrapper\&.cpp\fP\&. .SS "void viewport_t::set_source (double x, double y, double width, double height)" .PP set the source rectangle for cropping .PP \fBParameters\fP .RS 4 \fIx\fP source rectangle x .br \fIy\fP source rectangle y .br \fIwidth\fP source rectangle width .br \fIheight\fP source rectangle height .RE .PP Set the source rectangle of the associated wl_surface\&. See wp_viewport for the description, and relation to the wl_buffer size\&. .PP If all of x, y, width and height are -1\&.0, the source rectangle is unset instead\&. Any other set of values where width or height are zero or negative, or x or y are negative, raise the bad_value protocol error\&. .PP The crop and scale state is double-buffered state, and will be applied on the next wl_surface\&.commit\&. .PP Definition at line \fB947\fP of file \fBwayland\-client\-protocol\-extra\&.cpp\fP\&. .SH "Member Data Documentation" .PP .SS "constexpr std::uint32_t wayland::viewport_t::set_destination_since_version = 1\fC [static]\fP, \fC [constexpr]\fP" .PP Minimum protocol version required for the \fBset_destination\fP function\&. .PP Definition at line \fB504\fP of file \fBwayland\-client\-protocol\-extra\&.hpp\fP\&. .SS "constexpr std::uint32_t wayland::viewport_t::set_source_since_version = 1\fC [static]\fP, \fC [constexpr]\fP" .PP Minimum protocol version required for the \fBset_source\fP function\&. .PP Definition at line \fB481\fP of file \fBwayland\-client\-protocol\-extra\&.hpp\fP\&. .SH "Author" .PP Generated automatically by Doxygen for Wayland++ from the source code\&.