From ab08fa6065b5b08627b51203eb92ef65ed7b5ea2 Mon Sep 17 00:00:00 2001
From: hachem <im@hachem.wtf>
Date: Sun, 6 Sep 2026 18:53:29 +0200
Subject: c: quantum gate and state foundations

---
 src/core/quantum_components.c | 51 +++++++++++++++++++++++++++++++++++++++++++
 src/maths/matrix.c            |  9 ++++++++
 2 files changed, 60 insertions(+)
 create mode 100644 src/core/quantum_components.c

(limited to 'src')

diff --git a/src/core/quantum_components.c b/src/core/quantum_components.c
new file mode 100644
index 0000000..3b9eef5
--- /dev/null
+++ b/src/core/quantum_components.c
@@ -0,0 +1,51 @@
+#include "core/quantum_components.h"
+
+#include <assert.h>
+
+struct PsiVector psi_new_state_0(void)
+{
+	return psi_column_vector(psi_new_complex(1.0, 0.0), psi_new_complex(0.0, 0.0));
+}
+
+struct PsiVector psi_new_state_1(void)
+{
+	return psi_column_vector(psi_new_complex(0.0, 0.0), psi_new_complex(1.0, 0.0));
+}
+
+struct PsiQuantumGate psi_new_quantum_gate(const char *name, struct PsiMatrix matrix, size_t num_qubits)
+{
+	size_t expected_dim = (size_t)1 << num_qubits;
+	assert(matrix.rows == expected_dim);
+	assert(matrix.cols == expected_dim);
+
+	return (struct PsiQuantumGate)
+	{
+		name,
+		matrix,
+		num_qubits,
+	};
+}
+
+struct PsiQuantumGate psi_new_quantum_gate_from_matrix(const char *name, struct PsiMatrix matrix)
+{
+	assert(matrix.rows == matrix.cols);
+
+	size_t dim = matrix.rows;
+	assert(dim > 0 && (dim & (dim - 1)) == 0);
+
+	size_t num_qubits = 0;
+	while (((size_t)1 << num_qubits) < dim)
+		num_qubits++;
+
+	return (struct PsiQuantumGate)
+	{
+		name,
+		matrix,
+		num_qubits,
+	};
+}
+
+void psi_free_quantum_gate(struct PsiQuantumGate *gate)
+{
+	psi_free_matrix(&gate->matrix);
+}
diff --git a/src/maths/matrix.c b/src/maths/matrix.c
index 400c2a7..44b953c 100644
--- a/src/maths/matrix.c
+++ b/src/maths/matrix.c
@@ -30,6 +30,15 @@ struct PsiMatrix psi_clone_matrix(struct PsiMatrix m)
 	return psi_new_matrix_from(m.data, m.rows, m.cols);
 }
 
+struct PsiMatrix psi_identity_matrix(size_t size)
+{
+	struct PsiMatrix m = psi_new_matrix(size, size);
+	for (size_t i = 0; i < size; i++)
+		m.data[i * size + i] = psi_new_complex(1.0, 0.0);
+
+	return m;
+}
+
 void psi_free_matrix(struct PsiMatrix *m)
 {
 	free(m->data);
-- 
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