From c259ae4ceee403460bc342cf92fb582150e4aaac Mon Sep 17 00:00:00 2001
From: Josh Holtrop <jholtrop@gmail.com>
Date: Wed, 23 Mar 2022 22:12:38 -0400
Subject: [PATCH] Add Framebuffer.copy_rows_up()

---
 src/hulk/framebuffer.d | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/src/hulk/framebuffer.d b/src/hulk/framebuffer.d
index 5ba3d0f..8398901 100644
--- a/src/hulk/framebuffer.d
+++ b/src/hulk/framebuffer.d
@@ -168,6 +168,20 @@ struct Framebuffer
         blend_alpha_bitmap(x, y, alpha_bitmap.ptr, width, height, color);
     }
 
+    /**
+     * Copy framebuffer rows up in the framebuffer.
+     *
+     * @param y Y coordinate of bottom side of region to copy up.
+     * @param height Height of region to copy up.
+     * @param offset Number of rows to copy region up by.
+     */
+    void copy_rows_up(size_t y, size_t height, size_t offset)
+    {
+        memcpy32(&m_buffer[buffer_index(0u, y + height + offset - 1u)],
+                 &m_buffer[buffer_index(0u, y + height - 1u)],
+                 (m_stride * height));
+    }
+
     /**
      * Scale a color value by an alpha amount.
      *