From ea09b4edb7d2c5149a23fa8709b6eea512ec715c Mon Sep 17 00:00:00 2001
From: omigamedev <omarator@gmail.com>
Date: Fri, 24 Aug 2018 15:53:05 +0200
Subject: [PATCH] fix black sample

---
 engine/brush.cpp | 4 ++++
 engine/brush.h   | 8 ++++++++
 2 files changed, 12 insertions(+)

diff --git a/engine/brush.cpp b/engine/brush.cpp
index 5119d71..4f3f6ec 100644
--- a/engine/brush.cpp
+++ b/engine/brush.cpp
@@ -183,6 +183,8 @@ std::vector<ui::StrokeSample> ui::Stroke::compute_samples()
             s.angle += curve_angle;
         }
         m_prev_sample = s;
+        if (!s.valid())
+            LOG("Invalid sample");
         samples.push_back(s);
     }
     return std::move(samples);
@@ -215,6 +217,8 @@ void ui::Stroke::add_point(glm::vec2 pos, float pressure)
         m_keypoints.back().dist + glm::distance(m_keypoints.back().pos, pos);
     if (m_keypoints.empty())
         m_prev_sample.origin = pos;
+    else if (m_keypoints.back().pos == pos)
+        return; // skip same point, leading to black samples (NaN values)
     Keypoint kp;
     kp.pos = pos;
     kp.pressure = pressure;
diff --git a/engine/brush.h b/engine/brush.h
index d849d4e..d1bb393 100644
--- a/engine/brush.h
+++ b/engine/brush.h
@@ -47,6 +47,14 @@ struct StrokeSample
     float size = 0;
     float flow = 0;
     float angle = 0;
+    bool valid() const
+    {
+        return !(
+            glm::any(glm::isnan(col)) ||
+            glm::any(glm::isnan(pos)) ||
+            glm::any(glm::isnan(origin))
+        );
+    }
 };
 
 class BrushMesh