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157 lines
4.4 KiB
Plaintext
157 lines
4.4 KiB
Plaintext
/*!
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@page monitor Multi-monitor guide
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@tableofcontents
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@section monitor_objects Monitor objects
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A monitor object represents a currently connected monitor and is represented as
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a pointer to the [opaque](https://en.wikipedia.org/wiki/Opaque_data_type) type
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@ref GLFWmonitor. Monitor objects cannot be created or destroyed by the
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application and retain their addresses until the monitors they represent are
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disconnected or until the library is [terminated](@ref intro_init_terminate).
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Each monitor has a human-readable name, a current video mode, a list of
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supported video modes, a virtual position, an estimated physical size and
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a gamma ramp.
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The virtual position of a monitor is in screen coordinates and, together with
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the current video mode, describes the viewports that the connected monitors
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provide into the virtual desktop that spans them.
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@subsection monitor_monitors Retrieving monitors
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The primary monitor is returned by @ref glfwGetPrimaryMonitor. It is the user's
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preferred monitor and is usually the one with global UI elements like task bar
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or menu bar.
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@code
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GLFWmonitor* primary = glfwGetPrimaryMonitor();
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@endcode
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You can retrieve all currently connected monitors with @ref glfwGetMonitors.
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The primary monitor is always the first monitor in the returned array.
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@code
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int count;
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GLFWmonitor** monitors = glfwGetMonitors(&count);
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@endcode
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@note Monitors other than the primary monitor may be moved to a different index
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in the array if another monitor is disconnected.
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@section monitor_properties Monitor properties
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@subsection monitor_modes Video modes
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Although GLFW generally does a good job at selecting a suitable video
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mode for you when you open a full screen window, it is sometimes useful to
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know exactly which modes are available on a certain system. For example,
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you may want to present the user with a list of video modes to select
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from. To get a list of available video modes, you can use the function
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@ref glfwGetVideoModes.
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@code
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int count;
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GLFWvidmode* modes = glfwGetVideoModes(monitor, &count);
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@endcode
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To get the current video mode of a monitor call @ref glfwGetVideoMode.
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@code
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const GLFWvidmode* mode = glfwGetVideoMode(monitor);
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@endcode
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@subsection monitor_size Physical size
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The physical size in millimetres of a monitor, or an estimation of it, can be
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retrieved with @ref glfwGetMonitorPhysicalSize.
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@code
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int widthMM, heightMM;
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glfwGetMonitorPhysicalSize(monitor, &widthMM, &heightMM);
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@endcode
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This can, for example, be used together with the current video mode to calculate
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the DPI of a monitor.
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@code
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const double dpi = mode->width / (widthMM / 25.4);
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@endcode
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@subsection monitor_pos Virtual position
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The position of the monitor on the virtual desktop, in screen coordinates, can
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be retrieved with @ref glfwGetMonitorPos.
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@code
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int xpos, ypos;
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glfwGetMonitorPos(monitor, &xpos, &ypos);
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@endcode
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@subsection monitor_name Human-readable name
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The human-readable name of a monitor is returned by @ref glfwGetMonitorName.
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It is a regular C string using the UTF-8 encoding.
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@code
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const char* name = glfwGetMonitorName(monitor);
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@endcode
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@note Monitor names are not guaranteed to be unique. Two monitors of the same
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model and make may have the same name. Only the address of a monitor object is
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guaranteed to be unique.
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@subsection monitor_gamma Gamma ramp
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The gamma ramp of a monitor can be set with @ref glfwSetGammaRamp, which accepts
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a monitor handle and a pointer to a @ref GLFWgammaramp structure.
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@code
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GLFWgammaramp ramp;
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unsigned short red[256], green[256], blue[256];
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ramp.size = 256;
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ramp.red = red;
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ramp.green = green;
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ramp.blue = blue;
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for (i = 0; i < ramp.size; i++)
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{
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// Fill out gamma ramp arrays as desired
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}
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glfwSetGammaRamp(monitor, &ramp);
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@endcode
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The gamma ramp data is copied before the function returns, so there is no need
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to keep it around once the ramp has been set.
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@note It is recommended to use gamma ramps of size 256, as that is the size
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supported by virtually all graphics cards on all platforms.
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The current gamma ramp for a monitor is returned by @ref glfwGetGammaRamp. The
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returned structure and its arrays are allocated and freed by GLFW.
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@code
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const GLFWgammaramp* ramp = glfwGetGammaRamp(monitor);
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@endcode
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If you wish to set a regular gamma ramp, you can have GLFW calculate it for you
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from the desired exponent with @ref glfwSetGamma, which in turn calls @ref
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glfwSetGammaRamp with the resulting ramp.
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@code
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glfwSetGamma(monitor, 1.0);
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@endcode
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*/
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