refactoring (broken right now)

Scenarios/Scenario.cs

@@ -1,23 +1,121 @@
-using SFML.Graphics;
+using System;
+using SFML.Graphics;
+using SFML.System;
+using FluidSim.Components;
 
-namespace FluidSim.Core
+namespace FluidSim.Tests
 {
     public abstract class Scenario
     {
-        /// <summary>
-        /// Initialize the scenario with a given audio sample rate.
-        /// </summary>
+        /// <summary>Initialize the scenario with a given audio sample rate.</summary>
         public abstract void Initialize(int sampleRate);
 
-        /// <summary>
-        /// Advance one simulation step and return an audio sample.
-        /// The step size is 1 / sampleRate seconds.
-        /// </summary>
+        /// <summary>Advance one simulation step and return an audio sample.</summary>
         public abstract float Process();
 
-        /// <summary>
-        /// Draw the current simulation state onto the given SFML render target.
-        /// </summary>
+        /// <summary>Draw the current simulation state onto the given SFML render target.</summary>
         public abstract void Draw(RenderWindow target);
+
+        // ---------- Shared drawing helpers ----------
+
+        protected const double AmbientPressure = 101325.0;
+
+        /// <summary>Blue (low) → Green (ambient) → Red (high).</summary>
+        protected Color PressureColor(double pressure)
+        {
+            double range = AmbientPressure * 0.05;   // ±5% gives full colour swing
+            double t = (pressure - AmbientPressure) / range;
+            t = Math.Clamp(t, -1.0, 1.0);
+
+            byte r, g, b;
+            if (t < 0)
+            {
+                double factor = -t;
+                r = 0;
+                g = (byte)(255 * (1 - factor));
+                b = (byte)(255 * factor);
+            }
+            else
+            {
+                double factor = t;
+                r = (byte)(255 * factor);
+                g = (byte)(255 * (1 - factor));
+                b = 0;
+            }
+            return new Color(r, g, b);
+        }
+
+        /// <summary>
+        /// Draws the pipe as a smooth triangle‑strip whose radius varies with cell pressure.
+        /// </summary>
+        protected void DrawPipe(RenderWindow target, Pipe1D pipe, float pipeCenterY, float pipeStartX, float pipeEndX)
+        {
+            int n = pipe.CellCount;
+            if (n < 2) return;
+
+            float pipeLengthPx = pipeEndX - pipeStartX;
+            float dx = pipeLengthPx / (n - 1);   // spacing between cell centres
+
+            float baseRadius = 25f;
+            float rangeFactor = 1f;
+            float scaleFactor = 5f;
+
+            // ----- smoothstep helper -----
+            static float SmoothStep(float edge0, float edge1, float x)
+            {
+                float t = Math.Clamp((x - edge0) / (edge1 - edge0), 0f, 1f);
+                return t * t * (3f - 2f * t);
+            }
+
+            // ----- Pre‑compute cell positions and radii -----
+            var centers = new float[n];
+            var radii = new float[n];
+            for (int i = 0; i < n; i++)
+            {
+                double p = pipe.GetCellPressure(i);
+                float deviation = (float)Math.Tanh((p - AmbientPressure) / AmbientPressure / rangeFactor);
+                radii[i] = baseRadius * (1f + deviation * scaleFactor);
+                if (radii[i] < 2f) radii[i] = 2f;
+                centers[i] = pipeStartX + i * dx;
+            }
+
+            // ----- Build triangle‑strip vertices -----
+            int segmentsPerCell = 8;
+            int totalPoints = n + (n - 1) * segmentsPerCell;
+            Vertex[] stripVertices = new Vertex[totalPoints * 2];
+            int idx = 0;
+
+            for (int i = 0; i < n; i++)
+            {
+                float x = centers[i];
+                float r = radii[i];
+                double p = pipe.GetCellPressure(i);
+                Color col = PressureColor(p);
+
+                stripVertices[idx++] = new Vertex(new Vector2f(x, pipeCenterY - r), col);
+                stripVertices[idx++] = new Vertex(new Vector2f(x, pipeCenterY + r), col);
+
+                if (i < n - 1)
+                {
+                    for (int s = 1; s <= segmentsPerCell; s++)
+                    {
+                        float t = s / (float)segmentsPerCell;
+                        float st = SmoothStep(0f, 1f, t);
+                        float xi = centers[i] + (centers[i + 1] - centers[i]) * t;
+                        float ri = radii[i] + (radii[i + 1] - radii[i]) * st;
+                        double pi = pipe.GetCellPressure(i) * (1 - t) + pipe.GetCellPressure(i + 1) * t;
+                        Color coli = PressureColor(pi);
+
+                        stripVertices[idx++] = new Vertex(new Vector2f(xi, pipeCenterY - ri), coli);
+                        stripVertices[idx++] = new Vertex(new Vector2f(xi, pipeCenterY + ri), coli);
+                    }
+                }
+            }
+
+            var pipeMesh = new VertexArray(PrimitiveType.TriangleStrip, (uint)stripVertices.Length);
+            for (int i = 0; i < stripVertices.Length; i++)
+                pipeMesh[(uint)i] = stripVertices[i];
+            target.Draw(pipeMesh);
+        }
     }
 }