MPO4 Lines – Modal Engine

█ OVERVIEW
MPO4 Lines – Modal Engine is an advanced multi-line modal oscillator for TradingView, designed to detect momentum shifts, trend strength, and reversal points through candle-based pressure analysis with multiple fast lines and a reference slow line. It features divergence detection on Fast Line A, overbought/oversold return signals, dynamic coloring modes, and layered gradient visualizations for enhanced clarity and decision-making.

█ CONCEPT
The indicator is built upon the Market Pressure Oscillator (MPO) and serves as its expanded evolution, aimed at enabling broader market analysis through multiple lines with varying parameters. It calculates modal pressure using candle body size and direction, weighted against average body size over a lookback period, then normalized and smoothed via EMA. It generates four distinct oscillator lines: a heavily smoothed Slow Line (trend reference), two Fast Lines (A & B) for momentum and support/resistance, and an optional Line 4 for additional confirmation. Divergence is calculated solely on Fast Line A, with visual gradients between lines and bands for intuitive interpretation.

█ WHY USE IT?
- Multi-Layer Momentum: Combines slow trend reference with dual fast lines for precise entry/exit timing.
- Divergence Precision: Bullish/bearish divergences on Fast Line A with labeled confirmation.
- OB/OS Return Signals: Clear buy/sell markers when Fast Line A exits oversold/overbought zones.
- Dynamic Visuals: Gradient fills, line-to-line shading, and band gradients for instant market state recognition.
- Flexible Coloring: Slow Line color by direction or zero-position; fast lines by sign.
- Full Customization: Independent lengths, smoothing, visibility, and transparency — by adjusting the lengths of different lines, you can tailor results for various strategies; for example, enabling Line 4 and tuning its length allows trading based on crossovers between different lines.

█ HOW IT WORKS?
- Candle Pressure Calculation: Body = math.abs(close - open); avgBody = ta.sma(body, len). Direction = +1 (bull), –1 (bear), 0 (neutral). Weight = body / avgBody. Contribution = direction × weight.
- Rolling Sum & Normalization: Sums contributions over lookback, normalizes to ±100 scale (÷ (len × 2) × 100).

Smoothing: Applies primary EMA (smoothLen), with extra EMA on Slow Line for stability.
Line Structure:
- Slow Line = calcCPO(len1=20, smoothLen1=5) → extra EMA (5)
- Fast Line A = calcCPO(len2=6, smoothLen2=7)
- Fast Line B = calcCPO(len3=6, smoothLen3=10)
- Line 4 = calcCPO(len4=14, smoothLen4=1)

Divergence Detection: Uses ta.pivothigh/low on price and Fast Line A (pivotLength left/right). Bullish: lower price low + higher osc low. Bearish: higher price high + lower osc high. Valid within 5–60 bar window.

Signals:
- Buy: Fast Line A crosses above oversold (–30)
- Sell: Fast Line A crosses below overbought (+30)
- Slow Line color flip (direction or zero-cross)
- Divergence labels ("Bull" / "Bear")
- Band Coloring as Momentum Signal:
When Fast Line A ≤ Fast Line B → Overbought band turns red (bearish pressure building)
When Fast Line A > Fast Line B → Oversold band turns green (bullish pressure building) This dynamic coloring serves as visual confirmation of momentum shift following fast line crossovers

Visualization:
- Gradients: Fast B → Zero (multi-layer fade), Fast A ↔ B fill, OB/OS bands
- Dynamic colors: Green/red based on sign or trend
- Zero line + dashed OB/OS thresholds

Alerts: Trigger on OB/OS returns, Slow Line changes, and divergences.

█ SETTINGS AND CUSTOMIZATION
- Line Visibility: Toggle Slow, Fast A, Fast B, Line 4 independently.

Line Lengths:
- Slow Line: Base (20), Primary EMA (5), Extra EMA (5)
- Fast A: Lookback (6), EMA (7)
- Fast B: Lookback (6), EMA (10)
- Line 4: Lookback (14), EMA (1)

- Slow Line Coloring Mode: “Direction” (trend-based) or “Position vs Zero”.
- Bands & Thresholds: Overbought (+30), Oversold (–30), step 0.1.
- Signals: Enable Fast A OB/OS return markers (default: on).
- Divergence: Enable/disable, Pivot Length (default: 2, min 1).
- Colors & Appearance: Full control over bullish/bearish hues for all lines, zero, bands, divergence, and text.

Gradients & Transparency:
- Fast B → Zero: 75 (default)
- Fast A ↔ B fill: 50
- Band gradients: 40
- Toggle each gradient independently

█ USAGE EXAMPLES
The indicator allows users to configure various strategies manually, though no built-in alerts exist for them. Entry signals can include color of fast lines, crossovers between different lines, alignment of colors across lines, or consistency in direction.
- Trend Confirmation: Slow Line above zero + green = bullish bias; below + red = bearish.
- Entry Timing: Buy on Fast A crossing above –30 (circle marker), especially if Slow Line is rising or near zero.
- Reversal Setup: Bullish divergence (“Bull” label) + Fast A in oversold + green gradient band = high-probability long.
- Scalping: Fast A vs Fast B crossover in direction of Slow Line trend.
- Noise Reduction: Increase extraSmoothLen on Slow Line

█ USER NOTES
- Best combined with volume, support/resistance, or trend channels.
- Adjust lookback and smoothing to asset volatility.
- Divergence delay = pivotLength; plan entries accordingly.