minor dynamic resolution changes

[uwes-ufo]

Description

Fixes # (issue) avoid initial delay and improve the comprehensibility of the implementation

Screenshots (if appropriate):

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• This change requires a documentation update
• Housekeeping

How Has This Been Tested?

Test Configuration:

• Operating system: <Name, version number>
• Graphics Card: <Manufacturer (likely Intel, NVidia, AMD?), Model (HD, Geforce, Radeon..., with model number), driver version?>

Checklist:

• My code follows the code style of this project.
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation (header file)
• I have updated the respective chapter in the Stellarium User Guide
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

[github-actions]

Great PR! Please pay attention to the following items before merging:

Files matching src/**/*.cpp:

• Are possibly unused includes removed?

This is an automatically generated QA checklist based on modified files.

[alex-w]

I see no visual difference

@10110111 please check this pull request

[10110111]

What role does dynResTimer play after this patch? It doesn't seem to affect anything in the remaining logic.

[uwes-ufo]

// if we don't have a timeout or too much change, we skip the frame
return true;

void AtmosphereShowMySky::computeColor
...

if (dynamicResolution(prj, sunPos, width, height))
			return;

we leave void AtmosphereShowMySky::computeColor before anything happens... (skip)
reduces cpu load (without that, my little laptop would burn down)

dynResTimer=changed?5:17;

If the scene is rendered in real time and is practically static, Stellarium generates approximately 18 frames per second. We draw about one atmosphere per second at full resolution. For faster-moving scenes, Stellarium increases the frame rate to the maximum, perhaps 50 frames per second depending on the hardware's capabilities. We draw about 10 atmospheres per second in reduced resolution.

dynResTimer is like a clock divider.

[10110111]

Honestly, the previous comment was a bit more understandable. I think the following would be better:

If the change is too big, the scene is considered dynamic and needs a higher frame rate, so it's rendered in lower resolution. Otherwise there's been a timeout, so the scene is updated in full resolution.

[uwes-ufo]

#4672 (comment)

[10110111]

Aside from my comments on comments, this LGTM.

[uwes-ufo]

I am completely flexible regarding the comments.

This line deals exclusively with the resolution.

// if the change is too big, we draw with reduced resolution, otherwise with full resolution
atmoRes=changed?reducedResolution:1;

This line deals exclusively with the frame rate.

// At reduced resolution, we hurry to redraw - at full resolution, we have time.
dynResTimer=changed?5:17;                                       // dynResTimer is like a clock divider.

The interplay of both factors is illustrated here.

// If the scene is rendered in real time and is practically static,
// Stellarium generates approximately 18 frames per second.
// We draw about one atmosphere per second at full resolution.
// For faster-moving scenes, Stellarium increases the frame rate to the maximum,
// perhaps 50 frames per second depending on the hardware's capabilities.
// We draw about 10 atmospheres per second in reduced resolution.

[github-actions]

Hello @uwes-ufo!

Please check the fresh version (development snapshot) of Stellarium:
https://github.com/Stellarium/stellarium-data/releases/tag/weekly-snapshot

[github-actions]

Hello @uwes-ufo!

Please check the latest stable version of Stellarium:
https://github.com/Stellarium/stellarium/releases/latest