Anti-aliasing fails with fill-image

[peterqliu]

Vis-a-vis solid-color polygons. Most apparent at coastlines.

[jfirebaugh]

@peterqliu Can you supply a test case style please?

[peterqliu]

check out the jaggies

[mourner]

Hmm, it throws Uncaught SyntaxError: Unexpected token ] in mapbox-gl.js for me — @jfirebaugh any idea why?

[jfirebaugh]

The style is invalid JSON. @peterqliu looks like it was broken in the last commit.

[mourner]

Hmm, why does it report mapbox-gl.js error? We probably should have a better error thrown when Mapbox GL fails to parse the JSON.

[peterqliu]

@jfirebaugh @mourner my bad, now fixed

[ansis]

We need a new patterned outline shader to fix this. The shader would be similar to the outline shader but would read the correct color value from a texture just like the pattern shader.

[peterqliu]

Updated example at https://api.mapbox.com/styles/v1/peterqliu/cimdq8c4j00gk9lm1aeon9bay.html?title=true&access_token=pk.eyJ1IjoicGV0ZXJxbGl1IiwiYSI6ImpvZmV0UEEifQ._D4bRmVcGfJvo1wjuOpA1g#14.95732842875686/31.394041930859558/-81.27884342612008/0

[ansis]

osx has a useful feature that lets you zoom in and magnify pixels that could be useful for this.

• open the Accessibility system preferences
• check Use scroll gesture with modifier keys to zoom
• uncheck Smooth images

You should now be able to use control + scrolling to zoom in on pixels.

[ansis]

@mollymerp It's sounds like you already have a good idea about how to approach this. In case it helps, this is how I'd break it down:

• I'd duplicate the outline shader shaders/outline.*.glsl and set it up in js/render/painter/use_program.js
• modify js/render/draw_fill.js so that it uses the new pattern outline program to render a solid red outline for all fill patterns. much of this and drawStroke might need to be duplicated
• the red outline should now show up when you render your test case
• switch the test case to a pattern with a lot of sharp color variation
• copy the relevant parts of the pattern shader to the pattern outline shader, update js/render/painter/use_program.js, and then set it up in /js/render/draw_fill.js.

[mollymerp]

working on this in #2372

[ansis]

merged in #2372