Icons and library entries for new pathsim discrete and Polynomial blocks

scripts/config/pathsim/blocks.json

@@ -49,6 +49,7 @@
       "Divider",
       "Amplifier",
       "Function",
+      "Polynomial",
       "Sin",
       "Cos",
       "Tan",
@@ -78,9 +79,15 @@
       "LogicNot"
     ],
 
-    "Mixed": [
+    "Discrete": [
       "SampleHold",
+      "FirstOrderHold",
       "FIR",
+      "DiscreteIntegrator",
+      "DiscreteDerivative",
+      "DiscreteStateSpace",
+      "DiscreteTransferFunction",
+      "TappedDelay",
       "ADC",
       "DAC",
       "Counter",

src/lib/components/icons/blocks/curves.ts

@@ -647,6 +647,17 @@ export function sampleHoldSamples(n = 6): Sample[] {
 	return out;
 }
 
+/** First-order hold — piecewise-linear interpolation through sample points.
+ *  Same sample values as SampleHold so the two icons read as a pair. */
+export function firstOrderHoldSamples(n = 6): Sample[] {
+	const samplesY = [0.1, 0.3, 0.55, 0.75, 0.55, 0.85];
+	const out: Sample[] = [];
+	for (let i = 0; i < n; i++) {
+		out.push([i / (n - 1), samplesY[i]]);
+	}
+	return out;
+}
+
 export function backlashSamples(): Sample[] {
 	return [
 		[-1, -0.7],

src/lib/components/icons/blocks/registry.ts

@@ -108,6 +108,15 @@ export const iconRegistry: Record<string, IconDef> = {
 	DynamicalSystem: { kind: 'math', latex: '\\begin{aligned}\\dot{x} &= f(x, u, t)\\\\ y &= g(x, u, t)\\end{aligned}' },
 	DynamicalFunction: { kind: 'math', latex: 'f(u, t)' },
 	Function: { kind: 'math', latex: 'f(u)' },
+	Polynomial: { kind: 'math', latex: 'y = \\sum_{k=0}^{n} c_k\\,u^{n-k}' },
+
+	/* --- Discrete-time blocks --- */
+	FirstOrderHold: { kind: 'plot', samples: () => C.firstOrderHoldSamples() },
+	DiscreteIntegrator: { kind: 'math', latex: '\\dfrac{T}{z-1}' },
+	DiscreteDerivative: { kind: 'math', latex: '\\dfrac{z-1}{T\\,z}' },
+	DiscreteStateSpace: { kind: 'math', latex: '\\begin{aligned}x[k{+}1] &= Ax[k]{+}Bu[k]\\\\ y[k] &= Cx[k]{+}Du[k]\\end{aligned}' },
+	DiscreteTransferFunction: { kind: 'math', latex: 'H(z) = \\dfrac{B(z)}{A(z)}' },
+	TappedDelay: { kind: 'svg', name: 'TappedDelay' },
 
 	/* --- Geometric SVGs (kept as files) --- */
 	Adder: { kind: 'svg', name: 'Adder' },

src/lib/constants/python.ts

@@ -29,7 +29,7 @@ export const BLOCK_CATEGORY_ORDER: string[] = [
 	'Dynamic',
 	'Algebraic',
 	'Logic',
-	'Mixed',
+	'Discrete',
 	'Recording',
 	'Subsystem'
 ];

src/lib/nodes/shapes/registry.ts

@@ -88,7 +88,7 @@ const categoryShapeMap: Record<string, string> = {
 	Dynamic: 'rect',
 	Algebraic: 'rect',
 	Logic: 'rect',
-	Mixed: 'mixed',
+	Discrete: 'mixed',
 	Recording: 'pill',
 	Subsystem: 'rect',
 	Chemical: 'rect'

src/lib/nodes/uiConfig.ts

@@ -78,12 +78,16 @@ export const syncPortBlocks = new Set([
 	'Mod',
 	'Clip',
 	'Pow',
+	'Polynomial',
 	'Rescale',
 	'Alias',
 
 	// Logic blocks (element-wise)
 	'LogicNot',
 
-	// Mixed blocks (parallel sampling)
-	'SampleHold'
+	// Discrete blocks (parallel sampling / discrete dynamics)
+	'SampleHold',
+	'FirstOrderHold',
+	'DiscreteIntegrator',
+	'DiscreteDerivative'
 ]);