// (Optional) When using multiple viewports: set io.MouseHoveredViewport to the viewport the OS mouse cursor is hovering.
// Important: this information is not easy to provide and many high-level windowing library won't be able to provide it correctly, because
// - This is _ignoring_ viewports with the ImGuiViewportFlags_NoInputs flag (pass-through windows).
// - This is _regardless_ of whether another viewport is focused or being dragged from.
// If ImGuiBackendFlags_HasMouseHoveredViewport is not set by the backend, imgui will ignore this field and infer the information by relying on the
// rectangles and last focused time of every viewports it knows about. It will be unaware of other windows that may be sitting between or over your windows.
// [GLFW] FIXME: This is currently only correct on Win32. See what we do below with the WM_NCHITTEST, missing an equivalent for other systems.
// If ImGuiBackendFlags_HasMouseHoveredViewport is not set by the backend, Dear imGui will ignore this field and infer the information using its flawed heuristic.
// - [X] GLFW >= 3.3 backend ON WINDOWS ONLY does correctly ignore viewports with the _NoInputs flag.
// - [!] GLFW <= 3.2 backend CANNOT correctly ignore viewports with the _NoInputs flag, and CANNOT reported Hovered Viewport because of mouse capture.
// Some backend are not able to handle that correctly. If a backend report an hovered viewport that has the _NoInputs flag (e.g. when dragging a window
// for docking, the viewport has the _NoInputs flag in order to allow us to find the viewport under), then Dear ImGui is forced to ignore the value reported
// by the backend, and use its flawed heuristic to guess the viewport behind.
// - [X] GLFW backend correctly reports this regardless of another viewport behind focused and dragged from (we need this to find a useful drag and drop target).
// FIXME: This is currently only correct on Win32. See what we do below with the WM_NCHITTEST, missing an equivalent for other systems.
// See https://github.com/glfw/glfw/issues/1236 if you want to help in making this a GLFW feature.
// We don't support ImGuiBackendFlags_HasMouseHoveredViewport
// (Optional) When using multiple viewports: set io.MouseHoveredViewport to the viewport the OS mouse cursor is hovering.
// If ImGuiBackendFlags_HasMouseHoveredViewport is not set by the backend, Dear imGui will ignore this field and infer the information using its flawed heuristic.
// - [!] SDL backend does NOT correctly ignore viewports with the _NoInputs flag.
// Some backend are not able to handle that correctly. If a backend report an hovered viewport that has the _NoInputs flag (e.g. when dragging a window
// for docking, the viewport has the _NoInputs flag in order to allow us to find the viewport under), then Dear ImGui is forced to ignore the value reported
// by the backend, and use its flawed heuristic to guess the viewport behind.
// - [X] SDL backend correctly reports this regardless of another viewport behind focused and dragged from (we need this to find a useful drag and drop target).
// (Optional) When using multiple viewports: set io.MouseHoveredViewport to the viewport the OS mouse cursor is hovering.
// Important: this information is not easy to provide and many high-level windowing library won't be able to provide it correctly, because
// - This is _ignoring_ viewports with the ImGuiViewportFlags_NoInputs flag (pass-through windows).
// - This is _regardless_ of whether another viewport is focused or being dragged from.
// If ImGuiBackendFlags_HasMouseHoveredViewport is not set by the backend, imgui will ignore this field and infer the information by relying on the
// rectangles and last focused time of every viewports it knows about. It will be unaware of foreign windows that may be sitting between or over your windows.
// If ImGuiBackendFlags_HasMouseHoveredViewport is not set by the backend, Dear imGui will ignore this field and infer the information using its flawed heuristic.
// - [X] Win32 backend correctly ignore viewports with the _NoInputs flag (here using ::WindowFromPoint with WM_NCHITTEST + HTTRANSPARENT in WndProc does that)
// Some backend are not able to handle that correctly. If a backend report an hovered viewport that has the _NoInputs flag (e.g. when dragging a window
// for docking, the viewport has the _NoInputs flag in order to allow us to find the viewport under), then Dear ImGui is forced to ignore the value reported
// by the backend, and use its flawed heuristic to guess the viewport behind.
// - [X] Win32 backend correctly reports this regardless of another viewport behind focused and dragged from (we need this to find a useful drag and drop target).
viewport_hovered=FindHoveredViewportFromPlatformWindowStack(g.IO.MousePos);// Backend failed to handle _NoInputs viewport: revert to our fallback.
}
else
{
// If the backend doesn't know how to honor ImGuiViewportFlags_NoInputs, we do a search ourselves. Note that this search:
// A) won't take account of the possibility that non-imgui windows may be in-between our dragged window and our target window.
// B) uses LastFrameAsRefViewport as a flawed replacement for the last time a window was focused (we could/should fix that by introducing Focus functions in PlatformIO)
// B) won't take account of how the backend apply parent<>child relationship to secondary viewports, which affects their Z order.
// C) uses LastFrameAsRefViewport as a flawed replacement for the last time a window was focused (we could/should fix that by introducing Focus functions in PlatformIO)
ImGuiBackendFlags_HasMouseHoveredViewport=1<<11,// Backend Platform supports setting io.MouseHoveredViewport to the viewport directly under the mouse _IGNORING_ viewports with the ImGuiViewportFlags_NoInputs flag and _REGARDLESS_ of whether another viewport is focused and may be capturing the mouse. This information is _NOT EASY_ to provide correctly with most high-level engines! Don't set this without studying _carefully_ how the backends handle ImGuiViewportFlags_NoInputs!
ImGuiBackendFlags_HasMouseHoveredViewport=1<<11,// Backend Platform supports setting io.MouseHoveredViewport to the viewport directly under the mouse. IF POSSIBLE, ignore viewports with the ImGuiViewportFlags_NoInputs flag (Win32 backend, GLFW 3.30+ backend can do this, SDL backend cannot). If this cannot be done, Dear ImGui needs to use a flawed heuristic to find the viewport under.
boolMouseDown[5];// Mouse buttons: 0=left, 1=right, 2=middle + extras (ImGuiMouseButton_COUNT == 5). Dear ImGui mostly uses left and right buttons. Others buttons allows us to track if the mouse is being used by your application + available to user as a convenience via IsMouse** API.
floatMouseWheel;// Mouse wheel Vertical: 1 unit scrolls about 5 lines text.
floatMouseWheelH;// Mouse wheel Horizontal. Most users don't have a mouse with an horizontal wheel, may not be filled by all backends.
ImGuiIDMouseHoveredViewport;// (Optional) When using multiple viewports: viewport the OS mouse cursor is hovering _IGNORING_ viewports with the ImGuiViewportFlags_NoInputs flag, and _REGARDLESS_ of whether another viewport is focused. Set io.BackendFlags |= ImGuiBackendFlags_HasMouseHoveredViewport if you can provide this info. If you don't imgui will infer the value using the rectangles and last focused time of the viewports it knows about (ignoring other OS windows).
ImGuiIDMouseHoveredViewport;// (Optional) With multi-viewports: viewport the OS mouse is hovering. If possible _IGNORING_ viewports with the ImGuiViewportFlags_NoInputs flag is much better (few backends can handle that). Set io.BackendFlags |= ImGuiBackendFlags_HasMouseHoveredViewport if you can provide this info. If you don't imgui will infer the value using the rectangles and last focused time of the viewports it knows about (ignoring other OS windows).
ocornut
3 years ago