Support for older devices

Cocos Creator
1

Now our small team is looking for a local alternative to the Playcanvas online engine on which we have been developing games for some time. The main requirement that forced us to develop there is support for old devices, namely TVs (Samsung Tizen OS and LG WebOS). They have an old version of the web engine (Chromium ~53), and also, according to old technologies, old/weak hardware.

Regarding Cocos Creator - I see the possibility of setting a browser target from the editor (browserslist query string - “defaults, chrome >37”), which gives hope. But when I try to test the build of an empty project - I get shader errors at startup on TV. Switching the render pipeline did not help. Am I missing something?

Error 16323, please go to https://github.com/cocos/cocos-engine/blob/3.8.8/EngineErrorMap.md#16323 to see details. Arguments: FragmentShader, builtin-standard|standard-vs|standard-fs|CC_USE_FOG4|CC_SUPPORT_CASCADED_SHADOW_MAP1|CC_TONE_MAPPING_TYPE1|CC_SHADOWMAP_FORMAT1|CC_SHADOWMAP_USE_LINEAR_DEPTH1
Error 16324, please go to https://github.com/cocos/cocos-engine/blob/3.8.8/EngineErrorMap.md#16324 to see details. Arguments
//large shader code here
ERROR: 0:80: 'highp' : precision is not supported in fragment shader 
WARNING: 0:3648: '' : unexpected end of file found in directive

(256 warnings) WebGL: INVALID_OPERATION: drawElements: no valid shader program in use
(warning) WebGL: too many errors, no more errors will be reported to the console for this context.

shader errors
shader errors1541×895 66.6 KB

Is there any way to fix this?

2

Additional WebGL info from TV - webglreport .com

webgl info
webgl info3993×2984 812 KB

3

It seems that the problem can be solved by creating a custom shader and material.

I will try to research more in this direction.

4

Copied the standard material and added wrapping around precision highp float;

#ifdef GL_FRAGMENT_PRECISION_HIGH
  precision highp float;
#else
  precision mediump float;
#endif

It seems like this is only required for fragment shaders, but since vertex and fragment have linked parameters, I applied it to all of them.

Perhaps this approach could be used to update the standard shaders in the editor repository for better compatibility?