2e1c4e51b3
Previously everytime we receive a vblank event, we always request a new one. This made the logic somewhat simpler. But this generated many useless vblank events, and wasted power. We only need vblank events for two things: 1. after we rendered a frame, we need to know when it has been displayed on the screen. 2. estimating the refresh rate. This commit makes sure we only request vblank events when it's actually needed. Fixes #1079 Signed-off-by: Yuxuan Shui <yshuiv7@gmail.com>
36 lines
1.4 KiB
C
36 lines
1.4 KiB
C
#pragma once
|
|
|
|
#include "utils.h"
|
|
|
|
#define NTIERS (3)
|
|
|
|
struct render_statistics {
|
|
/// Rolling window of rendering times (in us) and the tiers they belong to.
|
|
/// We keep track of the tiers because the vblank time estimate can change over
|
|
/// time.
|
|
struct rolling_window render_times;
|
|
/// Estimate the 95-th percentile of rendering times
|
|
struct rolling_quantile render_time_quantile;
|
|
/// Time between each vblanks
|
|
struct cumulative_mean_and_var vblank_time_us;
|
|
};
|
|
|
|
void render_statistics_init(struct render_statistics *rs, int window_size);
|
|
void render_statistics_reset(struct render_statistics *rs);
|
|
void render_statistics_destroy(struct render_statistics *rs);
|
|
|
|
void render_statistics_add_vblank_time_sample(struct render_statistics *rs, int time_us);
|
|
void render_statistics_add_render_time_sample(struct render_statistics *rs, int time_us);
|
|
|
|
/// How much time budget we should give to the backend for rendering, in microseconds.
|
|
///
|
|
/// A `divisor` is also returned, indicating the target framerate. The divisor is
|
|
/// the number of vblanks we should wait between each frame. A divisor of 1 means
|
|
/// full framerate, 2 means half framerate, etc.
|
|
unsigned int
|
|
render_statistics_get_budget(struct render_statistics *rs, unsigned int *divisor);
|
|
|
|
/// Return the measured vblank interval in microseconds. Returns 0 if not enough
|
|
/// samples have been collected yet.
|
|
unsigned int render_statistics_get_vblank_time(struct render_statistics *rs);
|