Extension causes high cpu load when running preview with code that contains multiline comments

[SteScheller]

Hi,

I encountered an issue when running the Shader Toy: Show GLSL Preview command with code that contains c-style multiline comments. Upon running the command, the editor becomes unresponsive to keyboard input in combination with the plugin vscodevim.

Here are the generated descriptions of the issue:

• Issue Type: Performance
• Extension Name: shader-toy
• Extension Version: 0.10.8
• OS Version: Linux x64 5.6.14-arch1-1
• VSCode version: 1.45.1

stevensona.shader-toy-unresponsive.cpuprofile.txt

code to reproduce the issue:

/******************************************************************************
*   Multiline Comment
******************************************************************************/
void mainImage( out vec4 fragColor, in vec2 fragCoord )
{
    // Normalized pixel coordinates (from 0 to 1)
    vec2 uv = fragCoord/iResolution.xy;

    // Time varying pixel color
    vec3 col = 0.5 + 0.5*cos(iTime+uv.xyx+vec3(0,2,4));

    // Output to screen
    fragColor = vec4(col,1.0);
}

[Malacath-92]

Huh, I thought I got all comment parsing problems last time. Will check this out later today.
Thanks for bringing it to our attention :)

[Malacath-92]

As you suggested, this was a bug in parsing multi-line comments. You freaked out our naive strategy by putting a lot of asterisks in your comment *shakes fist*
The new strategy should cover all cases (as per the language definition):

When encountering the token sequence /* ignore everything until finding the token / and stop if the previous token is a *, if not continue ignoring.

So this doesn't handle nested multi-line comments, but neither does the GLSL spec, so there's no harm done by us at lest.

Edit: This fix will probably be published in the coming days.

[SteScheller]

Thank you very much for taking care of it so quickly! I will look for the update and rethink my code comment behavior :)

[SteScheller]

Just tested it with the updated plugin and it worked fine now. Thank you!