From bb3067ebfbe17eaa819d21b836d7410836e19c86 Mon Sep 17 00:00:00 2001
From: Recep Aslantas <info@recp.me>
Date: Sun, 16 Oct 2016 20:44:13 +0300
Subject: [PATCH] mat4 swap rows/columns

---
 include/cglm-mat.h | 43 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)

diff --git a/include/cglm-mat.h b/include/cglm-mat.h
index 1f32c06..565d701 100644
--- a/include/cglm-mat.h
+++ b/include/cglm-mat.h
@@ -443,5 +443,48 @@ glm_mat4_inv_precise(mat4 mat, mat4 dest) {
 #endif
 }
 
+/*!
+ * @brief swap two matrix columns
+ *
+ * @param[in,out] mat  matrix
+ * @param[in]     col1 col1
+ * @param[in]     col2 col2
+ */
+CGLM_INLINE
+void
+glm_mat4_swap_col(mat4 mat, int col1, int col2) {
+  vec4 tmp;
+  glm_vec4_dup(mat[col1], tmp);
+  glm_vec4_dup(mat[col2], mat[col1]);
+  glm_vec4_dup(tmp, mat[col2]);
+}
+
+/*!
+ * @brief swap two matrix rows
+ *
+ * @param[in,out] mat  matrix
+ * @param[in]     col1 col1
+ * @param[in]     col2 col2
+ */
+CGLM_INLINE
+void
+glm_mat4_swap_row(mat4 mat, int row1, int row2) {
+  vec4 tmp;
+  tmp[0] = mat[0][row1];
+  tmp[1] = mat[1][row1];
+  tmp[2] = mat[2][row1];
+  tmp[3] = mat[3][row1];
+
+  mat[0][row1] = mat[0][row2];
+  mat[1][row1] = mat[1][row2];
+  mat[2][row1] = mat[2][row2];
+  mat[3][row1] = mat[3][row2];
+
+  mat[0][row2] = tmp[0];
+  mat[1][row2] = tmp[1];
+  mat[2][row2] = tmp[2];;
+  mat[3][row2] = tmp[3];
+}
+
 #else
 #endif /* cglm_mat_h */