New method mrpt::opengl::CPointCloudColoured::setAllPointsAlpha()

Author: jlblancoc

doc/source/doxygen-docs/changelog.md

@@ -1,5 +1,10 @@
 \page changelog Change Log
 
+# Version 2.14.12: UNRELEASED
+- Changes in libraries:
+  - \ref mrpt_opengl_grp
+    - New method mrpt::opengl::CPointCloudColoured::setAllPointsAlpha().
+
 # Version 2.14.11: Released May 31rd, 2025
 - BUG FIXES:
   - Fix build against all tf2 versions in all active ROS 2 distributions.

libs/opengl/include/mrpt/opengl/CPointCloudColoured.h

@@ -17,15 +17,10 @@
 
 namespace mrpt::opengl
 {
-/** A cloud of points, each one with an individual colour (R,G,B). The alpha
- * component is shared by all the points and is stored in the base member
- * m_color_A.
+/** A cloud of points, each one with an individual color (R,G,B,A).
  *
  * To load from a points-map, CPointCloudColoured::loadFromPointsMap().
  *
- * This class uses smart optimizations while rendering to efficiently draw
- * clouds of millions of points, using octrees.
- *
  * ![mrpt::opengl::CPointCloudColoured](preview_CPointCloudColoured.png)
  *
  * \sa opengl::Scene, opengl::CPointCloud
@@ -143,6 +138,15 @@ class CPointCloudColoured :
     m_point_colors[index].B = b;
     m_point_colors[index].A = a;
   }
+  /** Overwrites the alpha (transparency) channel for all existing points */
+  void setAllPointsAlpha(uint8_t alpha_channel)
+  {
+    std::unique_lock<std::shared_mutex> wfWriteLock(CRenderizableShaderPoints::m_pointsMtx.data);
+    for (auto& pt : m_point_colors)
+    {
+      pt.A = alpha_channel;
+    }
+  }
   /** Like \c getPointColor but without checking for out-of-index errors */
   void getPointColor_fast(size_t index, float& R, float& G, float& B) const
   {