nx_css_dimension_to_px.nx

nx_css_dimension_to_px.nx -- convert a CSS dimension (NUMBER body + UNIT body) into absolute integer pixels. Phase 2.5 bridge primitive completing the value-decoder layer between Phase 2 (CSS apply emits VAL_DIMENSION as byte ranges) and Phase 3 layout. Supports the 4 most-common CSS length units (per W3C CSS Values Module Level 4 table of distance units): px absolute device pixels (direct) em relative to parent font-size in px rem relative to root font-size in px % percentage of parent dimension (caller-supplied) Math is integer-only Q3 (thousandths) per the nx_css_number_parse contract; this primitive ROUNDS toward zero to get whole pixels for the layout pipeline (sub-pixel positioning is Phase 4b queued). What it does NOT handle (Phase 2b improvements): - pt / pc / in / cm / mm / Q absolute length units - vw / vh / vmin / vmax viewport-relative units - ex / ch font-relative units (require font metrics from nx_text_render) - fr fractional flex units (require flexbox; Phase 3b) - calc() / clamp() / min() / max() functional values - negative dimensions (margin: -10px) -- caller computes sign Per cardinal feedback-honest-perf-verdict-no-aspirational-claims: gap list is EXACT. genealogy_id: w3c_css_values_module_level_4_distance_units lineage_id: nishi_browser_css_dimension_to_px_v1 nx_safety_envelope: intended_use: "CSS dimension -> integer px -- layout input" sil_target: SIL1 evidence: [W3C_CSS_Values_canonical_basis, bounded_4_supported_units, integer_Q3_arithmetic_no_FP] verdict: NOT_YET_EVALUATED