Calculation Proof (Default Inputs)

Below is a step-by-step verification using the default values (fontPt = 24 pt; LED width = 31.5 ft; LED height = 17.7 ft; viewerDistance = 150 ft):

1. Point size to inches: 24 pt × (1 in / 72 pt) = 0.333 in tall on the slide.
2. LED wall pixel density:
   Physical height = 17.7 ft × 12 = 212.4 in.
   Vertical resolution = 1080 px → inchPerPx = 212.4 ÷ 1080 ≈ 0.1967 in/px.
3. Text height on LED (px): textPx = 0.333 in ÷ 0.1967 in/px ≈ 1.692 px.
4. Distance scaling: scale = LED_width / viewerDistance = 31.5 ÷ 150 ≈ 0.21.
   - If distance = width, scale = 1 → blue box = 640×360 px, matching PPT preview.
5. Blue box size:
   Width = 640 × 0.21 = 134.4 px;
   Height = 134.4 × (17.7/31.5) ≈ 75.6 px, keeping the real aspect ratio.
6. Slide fit: slideScale = min(134.4/640, 75.6/360) = 0.21
   → slide = 134.4×75.6 px, exactly filling the blue box when distance = width.
7. Visible text size:
   On preview: 1.692 px × 0.21 ≈ 0.355 px;
   On actual wall: 0.355 px × 0.1967 in/px ≈ 0.07 in.

Key validation: At viewerDistance = LED_width, the blue box and PPT preview align 1:1, proving the preview’s real-world accuracy. All dimensions then scale uniformly with distance.