[orx-fcurve] Add fcurve subproject

2024-03-14 13:48:00 +01:00
parent 82cf4e0a89
commit e70aaf34c8
10 changed files with 987 additions and 0 deletions
--- a/orx-fcurve/src/commonMain/kotlin/EFCurve.kt
+++ b/orx-fcurve/src/commonMain/kotlin/EFCurve.kt
@@ -0,0 +1,89 @@
+package org.openrndr.extra.fcurve
+
+import org.openrndr.extra.expressions.evaluateExpression
+
+/**
+ * expand efcurve to fcurve
+ * @param ef an efcurve string
+ * @param constants a map of constants that is passed to [evaluateExpression]
+ */
+fun efcurve(ef: String, constants: Map<String, Double> = emptyMap()): String {
+    val expression = Regex("_([^_]+)_")
+    val repetition = Regex("\\|([^|]+)\\|\\[([^\\[\\]]+)]")
+    val list = Regex("\\|([^|]+)\\|\\{([^\\[\\]]+)}")
+
+    /**
+     * perform comment substitution
+     * (?m) enables multiline mode
+     */
+    var curve = Regex("(?m)(#.*)$").replace(ef, "")
+
+    /**
+     * Allow for nested repetitions and lists
+     */
+    do {
+        val referenceCurve = curve
+
+        /**
+         * perform list expansion |text|{items}
+         */
+        curve = list.replace(curve) { occ ->
+            val listText = expression.replace(occ.groupValues[2]) { exp ->
+                val expressionText = exp.groupValues[1]
+                evaluateExpression(expressionText, constants)?.toString()
+                    ?: error("parse error in repetition count expression '$expressionText'")
+            }
+            val listTokens = listText.split(Regex("[,;][\t\n ]*|[\t\n ]+"))
+            val listItems = listTokens.filter { it.isNotEmpty() }
+                .map { it.trim().toDoubleOrNull() ?: error("'$it' is not a number in $listTokens") }
+
+            listItems.mapIndexed { index, value ->
+                expression.replace(occ.groupValues[1]) { exp ->
+                    val expressionText = exp.groupValues[1]
+                    evaluateExpression(
+                        exp.groupValues[1],
+                        constants + mapOf("index" to index.toDouble(), "it" to value)
+                    )?.toString() ?: error("parse error in repeated expression '$expressionText'")
+                }
+            }.joinToString(" ")
+        }
+
+        /**
+         * perform repetition expansion |text|[repeat-count]
+         */
+        curve = repetition.replace(curve) { occ ->
+            val repetitions = expression.replace(occ.groupValues[2]) { exp ->
+                val expressionText = exp.groupValues[1]
+                evaluateExpression(expressionText, constants)?.toInt()?.toString()
+                    ?: error("parse error in repetition count expression '$expressionText'")
+            }.toInt()
+            List(repetitions) { repetition ->
+                expression.replace(occ.groupValues[1]) { exp ->
+                    val expressionText = exp.groupValues[1]
+                    evaluateExpression(exp.groupValues[1], constants + mapOf("it" to repetition.toDouble()))?.toString()
+                        ?: error("parse error in repeated expression '$expressionText'")
+                }
+            }.joinToString(" ")
+        }
+    } while (curve != referenceCurve)
+
+    /**
+     * evaluate expression in expansion
+     */
+    return (expression.replace(curve) { ef ->
+        evaluateExpression(ef.groupValues[1], constants)?.toString() ?: error("parse error in '$curve")
+    })
+}
+
+fun main() {
+    efcurve("""M1 |h5 m3|{
+        |10.3 # toch wel handig zo'n comment
+        |11.2
+        |14.5
+        |}
+    """.trimMargin())
+
+    println(efcurve("|M0 |h4 m3|[2]|[5]"))
+
+    println(efcurve("""M0|h4 m_it_|{|_cos(it * PI * 0.5)_ |[4]}"""))
+}