Carter Anderson 5e2cfb2f19 Camera Driven Viewports (#4898) ... # Objective Users should be able to render cameras to specific areas of a render target, which enables scenarios like split screen, minimaps, etc. Builds on the new Camera Driven Rendering added here: #4745 Fixes: #202 Alternative to #1389 and #3626 (which are incompatible with the new Camera Driven Rendering) ## Solution  Cameras can now configure an optional "viewport", which defines a rectangle within their render target to draw to. If a `Viewport` is defined, the camera's `CameraProjection`, `View`, and visibility calculations will use the viewport configuration instead of the full render target. ```rust // This camera will render to the first half of the primary window (on the left side). commands.spawn_bundle(Camera3dBundle { camera: Camera { viewport: Some(Viewport { physical_position: UVec2::new(0, 0), physical_size: UVec2::new(window.physical_width() / 2, window.physical_height()), depth: 0.0..1.0, }), ..default() }, ..default() }); ``` To account for this, the `Camera` component has received a few adjustments: * `Camera` now has some new getter functions: * `logical_viewport_size`, `physical_viewport_size`, `logical_target_size`, `physical_target_size`, `projection_matrix` * All computed camera values are now private and live on the `ComputedCameraValues` field (logical/physical width/height, the projection matrix). They are now exposed on `Camera` via getters/setters This wasn't _needed_ for viewports, but it was long overdue. --- ## Changelog ### Added * `Camera` components now have a `viewport` field, which can be set to draw to a portion of a render target instead of the full target. * `Camera` component has some new functions: `logical_viewport_size`, `physical_viewport_size`, `logical_target_size`, `physical_target_size`, and `projection_matrix` * Added a new split_screen example illustrating how to render two cameras to the same scene ## Migration Guide `Camera::projection_matrix` is no longer a public field. Use the new `Camera::projection_matrix()` method instead: ```rust // Bevy 0.7 let projection = camera.projection_matrix; // Bevy 0.8 let projection = camera.projection_matrix(); ```		2022-06-05 00:27:49 +00:00
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src	Camera Driven Viewports (#4898)	2022-06-05 00:27:49 +00:00
Cargo.toml	Camera Driven Rendering (#4745)	2022-06-02 00:12:17 +00:00