match jitter to PS, preset change also size

src/brush.cpp

@@ -158,7 +158,7 @@ StrokeSample Stroke::randomize_sample(const glm::vec3& pos, float pressure, floa
     s.scale = m_brush->m_tip_scale * randflipx * (m_brush->m_tip_flipx ? -1.f : 1.f) * aspect_scale;
     s.angle = (m_brush->m_tip_angle + rnd_neg() * m_brush->m_jitter_angle) * (float)(M_PI * 2.0);
     s.size = size * (1.f - rnd_nor() * m_brush->m_jitter_scale) * size_dyn;
-    s.pos = pos + (scatter_scale * rnd_vec() * m_brush->m_jitter_scatter * s.size);
+    s.pos = pos + (scatter_scale * rnd_vec() * m_brush->m_jitter_scatter * s.size * 0.5f); // 0.5 because PS scatters by half size
     s.flow = m_brush->m_tip_flow * (1.f - rnd_nor() * m_brush->m_jitter_flow) * flow_dyn;
     s.opacity = m_brush->m_tip_opacity * (1.f - rnd_nor() * m_brush->m_jitter_opacity) * opacity_dyn;
     auto hsv = convert_rgb2hsv(m_brush->m_tip_color);

src/brush.h

@@ -72,7 +72,7 @@ public:
     bool  m_tip_randflipx = false;
     bool  m_tip_randflipy = false;
     float m_tip_aspect = 0.5f;
-    float m_dual_flow = .75f;
+    float m_dual_flow = 1.f;
     float m_dual_opacity = 1.f;
     float m_dual_rotate = .25f;
     float m_dual_angle = 0;

src/node_panel_stroke.cpp

@@ -299,9 +299,10 @@ void NodePanelStroke::init_controls()
 
         m_presets_popup->on_brush_changed = [this](Node* target, std::shared_ptr<Brush>& b) {
             // don't change some params
-            b->m_tip_size = Canvas::I->m_current_brush->m_tip_size;
-            b->m_tip_color = Canvas::I->m_current_brush->m_tip_color;
+            //b->m_tip_size = Canvas::I->m_current_brush->m_tip_size;
+            auto old_color = Canvas::I->m_current_brush->m_tip_color;
             *Canvas::I->m_current_brush = *b;
+            Canvas::I->m_current_brush->m_tip_color = old_color;
             m_preview->draw_stroke();
             m_brush_thumb->set_image(b->m_brush_thumb_path);
             m_dual_brush_thumb->set_image(b->m_dual_thumb_path);