fix: chrome shader varying-pack compatibility#20
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Drops the v_edgeWidth and v_borderZero varyings from Border, RoundedWithBorder, and RoundedWithBorderAndShadow shaders and recomputes them as locals in the fragment shader. Older ANGLE/GLSL packers (e.g. Chrome 35 on TVs) reject these shaders with "Could not pack varying _v_borderZero/_v_edgeWidth" even though they nominally fit within MAX_VARYING_VECTORS=8. Also surfaces real link errors from createProgram instead of silently returning undefined. Ports lightning-js/renderer#758 with the local border-gap/border-align shader variants preserved, and additionally applies the same v_edgeWidth removal to Border.ts for consistency. Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
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Summary
v_edgeWidthandv_borderZerovaryings fromBorder,RoundedWithBorder, andRoundedWithBorderAndShadowshaders and recomputes them as locals in the fragment shader.createPrograminstead of silently returningundefined.Why
Older ANGLE/GLSL packers (Chrome 35-era TV browsers) reject these shader programs with
Could not pack varying _v_borderZero/Could not pack varying _v_edgeWidtheven though they nominally fit withinMAX_VARYING_VECTORS=8. The strayfloatvaryings refused to coalesce into the leftover scalar slot of a vec2-packed row. Moving them to fragment locals removes the packer ambiguity entirely — same render result, fewer slots needed.Ports lightning-js/renderer#758 and adapts it to the local
border-gap/border-align/border-fillshader variants that this fork carries. The upstream PR only touchedRoundedWithBorderandRoundedWithBorderAndShadow; this PR additionally cleans upBorder.tsfor consistency since the same trivially-computable varying lived there.Test plan
pnpm build— cleanpnpm test— 148/148 passpnpm test:visualand verifyshader-border*,shader-rounded*, andshader-shadow*snapshots are unchangedpnpm start:prod) — shader programs link without warnings🤖 Generated with Claude Code