2 commits

Author	SHA1	Message	Date
Cameron	7989cb2650	Add global time scaling (#5752) ... # Objective - Make `Time` API more consistent. - Support time accel/decel/pause. ## Solution This is just the `Time` half of #3002. I was told that part isn't controversial. - Give the "delta time" and "total elapsed time" methods `f32`, `f64`, and `Duration` variants with consistent naming. - Implement accelerating / decelerating the passage of time. - Implement stopping time. --- ## Changelog - Changed `time_since_startup` to `elapsed` because `time.time_*` is just silly. - Added `relative_speed` and `set_relative_speed` methods. - Added `is_paused`, `pause`, `unpause` , and methods. (I'd prefer `resume`, but `unpause` matches `Timer` API.) - Added `raw_*` variants of the "delta time" and "total elapsed time" methods. - Added `first_update` method because there's a non-zero duration between startup and the first update. ## Migration Guide - `time.time_since_startup()` -> `time.elapsed()` - `time.seconds_since_startup()` -> `time.elapsed_seconds_f64()` - `time.seconds_since_startup_wrapped_f32()` -> `time.elapsed_seconds_wrapped()` If you aren't sure which to use, most systems should continue to use "scaled" time (e.g. `time.delta_seconds()`). The realtime "unscaled" time measurements (e.g. `time.raw_delta_seconds()`) are mostly for debugging and profiling.	2022-10-22 18:52:29 +00:00
Charles	8073362039	add globals to mesh view bind group (#5409) ... # Objective - It's often really useful to have access to the time when writing shaders. ## Solution - Add a UnifformBuffer in the mesh view bind group - This buffer contains the time, delta time and a wrapping frame count https://user-images.githubusercontent.com/8348954/180130314-97948c2a-2d11-423d-a9c4-fb5c9d1892c7.mp4 --- ## Changelog - Added a `GlobalsUniform` at position 9 of the mesh view bind group ## Notes The implementation is currently split between bevy_render and bevy_pbr because I was basing my implementation on the `ViewPlugin`. I'm not sure if that's the right way to structure it. I named this `globals` instead of just time because we could potentially add more things to it. ## References in other engines - Godot: <https://docs.godotengine.org/en/stable/tutorials/shaders/shader_reference/canvas_item_shader.html#global-built-ins> - Global time since startup, in seconds, by default resets to 0 after 3600 seconds - Doesn't seem to have anything else - Unreal: <https://docs.unrealengine.com/4.26/en-US/RenderingAndGraphics/Materials/ExpressionReference/Constant/> - Generic time value that updates every frame. Can be paused or scaled. - Frame count node, doesn't seem to be an equivalent for shaders: <https://docs.unrealengine.com/4.26/en-US/BlueprintAPI/Utilities/GetFrameCount/> - Unity: <https://docs.unity3d.com/Manual/SL-UnityShaderVariables.html> - time since startup in seconds. No mention of time wrapping. Stored as a `vec4(t/20, t, t*2, t*3)` where `t` is the value in seconds - Also has delta time, sin time and cos time - ShaderToy: <https://www.shadertoy.com/howto> - iTime is the time since startup in seconds. - iFrameRate - iTimeDelta - iFrame frame counter Co-authored-by: Charles <IceSentry@users.noreply.github.com>	2022-09-28 04:20:27 +00:00