From 7ce94597152bf8e681b6920e95837aa0db62dfef Mon Sep 17 00:00:00 2001 From: Alexander Orzechowski Date: Wed, 14 Jun 2023 10:33:57 -0400 Subject: output: add documentation for wlr_output_state --- include/wlr/types/wlr_output.h | 114 +++++++++++++++++++++++++++++++++++++++-- 1 file changed, 111 insertions(+), 3 deletions(-) diff --git a/include/wlr/types/wlr_output.h b/include/wlr/types/wlr_output.h index a38a431a..5ed29208 100644 --- a/include/wlr/types/wlr_output.h +++ b/include/wlr/types/wlr_output.h @@ -462,8 +462,23 @@ bool wlr_output_commit(struct wlr_output *output); * Discard the pending output state. */ void wlr_output_rollback(struct wlr_output *output); + +/** + * Test whether this output state would be accepted by the backend. If this + * function returns true, wlr_output_commit_state() will only fail due to a + * runtime error. This function does not change the current state of the + * output. + */ bool wlr_output_test_state(struct wlr_output *output, const struct wlr_output_state *state); +/** + * Attempts to apply the state to this output. This function may fail for any + * reason and return false. If failed, none of the state would have been applied, + * this function is atomic. If the commit succeeded, true is returned. + * + * Note: wlr_output_state_finish() would typically be called after the state + * has been committed. + */ bool wlr_output_commit_state(struct wlr_output *output, const struct wlr_output_state *state); /** @@ -552,38 +567,131 @@ bool wlr_output_cursor_move(struct wlr_output_cursor *cursor, double x, double y); void wlr_output_cursor_destroy(struct wlr_output_cursor *cursor); - +/** + * Releases all resources associated with an output state. + */ void wlr_output_state_finish(struct wlr_output_state *state); +/** + * Enables or disables an output. A disabled output is turned off and doesn't + * emit `frame` events. + * + * This state will be applied once wlr_output_commit_state() is called. + */ void wlr_output_state_set_enabled(struct wlr_output_state *state, bool enabled); +/** + * Sets the output mode of an output. An output mode will specify the resolution + * and refresh rate, among other things. + * + * This state will be applied once wlr_output_commit_state() is called. + */ void wlr_output_state_set_mode(struct wlr_output_state *state, struct wlr_output_mode *mode); +/** + * Sets a custom output mode for an output. See wlr_output_state_set_mode() + * for details. + * + * When the output advertises fixed modes, custom modes are not guaranteed to + * work correctly, they may result in visual artifacts. If a suitable fixed mode + * is available, compositors should prefer it and use wlr_output_state_set_mode() + * instead of custom modes. + * + * Setting `refresh` to zero lets the backend pick a preferred value. The + * output needs to be enabled. + * + * This state will be applied once wlr_output_commit_state() is called. + */ void wlr_output_state_set_custom_mode(struct wlr_output_state *state, int32_t width, int32_t height, int32_t refresh); +/** + * Sets the scale of an output. The scale is used to increase the size of UI + * elements to aid users who use high DPI outputs. + * + * This state will be applied once wlr_output_commit_state() is called. + */ void wlr_output_state_set_scale(struct wlr_output_state *state, float scale); +/** + * Sets the transform of an output. The transform is used to rotate or flip + * the contents of the screen. + * + * This state will be applied once wlr_output_commit_state() is called. + */ void wlr_output_state_set_transform(struct wlr_output_state *state, enum wl_output_transform transform); +/** + * Enables or disable adaptive sync for an output (ie. variable refresh rate). + * Compositors can inspect `wlr_output.adaptive_sync_status` to query the + * effective status. Backends that don't support adaptive sync will reject the + * output commit. + * + * This state will be applied once wlr_output_commit_state() is called. + */ void wlr_output_state_set_adaptive_sync_enabled(struct wlr_output_state *state, bool enabled); +/** + * Sets the render format for an output. + * + * The default value is DRM_FORMAT_XRGB8888. + * + * While high bit depth render formats are necessary for a monitor to receive + * useful high bit data, they do not guarantee it; a DRM_FORMAT_XBGR2101010 + * buffer will only lead to sending 10-bpc image data to the monitor if + * hardware and software permit this. + * + * This only affects the format of the output buffer used when rendering using + * the output's own swapchain as with wlr_output_begin_render_pass(). It has no + * impact on the cursor buffer format, or on the formats supported for direct + * scan-out (see also wlr_output_state_set_buffer()). + * + * This state will be applied once wlr_output_commit_state() is called. + */ void wlr_output_state_set_render_format(struct wlr_output_state *state, uint32_t format); +/** + * Sets the subpixel layout hint for an output. Note that this is only a hint + * and may be ignored. The default value depends on the backend. + * + * This state will be applied once wlr_output_commit_state() is called. + */ void wlr_output_state_set_subpixel(struct wlr_output_state *state, enum wl_output_subpixel subpixel); +/** + * Sets the buffer for an output. The buffer contains the contents of the + * screen. If the compositor wishes to present a new frame, they must commit + * with a buffer. + * + * This state will be applied once wlr_output_commit_state() is called. + */ void wlr_output_state_set_buffer(struct wlr_output_state *state, struct wlr_buffer *buffer); +/** + * Sets the gamma table for an output. `r`, `g` and `b` are gamma ramps for + * red, green and blue. `size` is the length of the ramps and must not exceed + * the value returned by wlr_output_get_gamma_size(). + * + * Providing zero-sized ramps resets the gamma table. + * + * This state will be applied once wlr_output_commit_state() is called. + */ bool wlr_output_state_set_gamma_lut(struct wlr_output_state *state, size_t ramp_size, const uint16_t *r, const uint16_t *g, const uint16_t *b); /** - * Sets the state's damage region. + * Sets the damage region for an output. This is used as a hint to the backend + * and can be used to reduce power consumption or increase performance on some + * devices. * * This should be called in along with wlr_output_state_set_buffer(). + * This state will be applied once wlr_output_commit_state() is called. */ void wlr_output_state_set_damage(struct wlr_output_state *state, const pixman_region32_t *damage); /** - * Set the state's layers. + * Set the output layers for an output. Output layers are used to try and take + * advantage of backend features that may reduce the amount of things that + * need to be composited. * * The array must be kept valid by the caller until wlr_output_state_finish(). + * This state will be applied once wlr_output_commit_state() is called. */ void wlr_output_state_set_layers(struct wlr_output_state *state, struct wlr_output_layer_state *layers, size_t layers_len); -- cgit v1.2.3