change brush size based on camera fov / zoom, refactor brush value curves

engine/brush.cpp

@@ -1,6 +1,7 @@
 #include "pch.h"
 #include "log.h"
 #include "brush.h"
+#include "canvas.h"
 
 void ui::BrushMesh::draw(const std::vector<StrokeSample>& samples, const glm::mat4& proj)
 {
@@ -168,8 +169,8 @@ ui::StrokeSample ui::Stroke::randomize_sample(const glm::vec2& pos, float pressu
     s.origin = pos;
     s.angle = -curve_angle + (m_brush.m_tip_angle + rnd_nor() * m_brush.m_jitter_angle) * (float)(M_PI * 2.0);
     s.pos = pos + (rnd_vec() * m_brush.m_jitter_spread * 100.f);
-    s.size = 800.f * glm::pow(m_brush.m_tip_size, 3.f) * (1.f - rnd_nor() * m_brush.m_jitter_scale) * size_dyn;
+    s.size = 800.f * m_brush.m_tip_size * (1.f - rnd_nor() * m_brush.m_jitter_scale) * size_dyn;
-    s.flow = glm::pow(m_brush.m_tip_flow, 2.f) * (1.f - rnd_nor() * m_brush.m_jitter_flow) * flow_dyn;
+    s.flow = m_brush.m_tip_flow * (1.f - rnd_nor() * m_brush.m_jitter_flow) * flow_dyn;
     return s;
 }
 std::vector<ui::StrokeSample> ui::Stroke::compute_samples()
@@ -226,7 +227,7 @@ void ui::Stroke::add_point(glm::vec2 pos, float pressure)
     pressure = pressure * glm::pow(m_curve, 2.f);
     
     if (m_brush.m_tip_size_pressure)
-        m_step = glm::max(glm::pow(m_brush.m_tip_spacing * 4.f, 2.f) * glm::pow(m_brush.m_tip_size, 3.f) * 800.f * pressure, 1.f);
+        m_step = glm::max(m_brush.m_tip_spacing * m_brush.m_tip_size * pressure * 800.f, 1.f);
 
     float dist = m_keypoints.empty() ? 0.f :
         m_keypoints.back().dist + glm::distance(m_keypoints.back().pos, pos);
@@ -245,6 +246,7 @@ void ui::Stroke::start(const ui::Brush& brush)
     m_last_kp = 0;
     m_dist = 0.f;
     m_brush = brush;
-    m_step = glm::max(glm::pow(m_brush.m_tip_spacing * 4.f, 2.f) * glm::pow(m_brush.m_tip_size, 3.f) * 800.f, 1.f);
+    m_brush.m_tip_size *= 1.f / glm::tan(glm::radians(Canvas::I->m_cam_fov * 0.5f));
+    m_step = glm::max(m_brush.m_tip_spacing * m_brush.m_tip_size * 800.f, 1.f);
     prng.seed(0);
 }

engine/canvas_modes.cpp

@@ -36,6 +36,7 @@ void CanvasModeBasicCamera::on_MouseEvent(MouseEvent* me, glm::vec2& loc)
         case kEventType::MouseScroll:
             m_zoom_canvas += me->m_scroll_delta * 0.1f;
             canvas->m_cam_fov -= me->m_scroll_delta * 20.1f;
+            App::I.brush_update();
             break;
         case kEventType::MouseCancel:
             m_draggingR = false;
@@ -59,6 +60,7 @@ void CanvasModeBasicCamera::on_GestureEvent(GestureEvent* ge)
             canvas->m_pan = m_pan_start + ge->m_pos_delta * glm::vec2(-1, -1) * 0.3f * (canvas->m_cam_fov / 85.f);
             canvas->m_cam_fov = m_camera_fov - ge->m_distance_delta * .05f;
             canvas->m_cam_rot = canvas->m_pan * 0.003f;
+            App::I.brush_update();
             break;
         default:
             break;

engine/node_panel_stroke.cpp

@@ -21,9 +21,9 @@ void NodePanelStroke::init()
 
 void NodePanelStroke::set_params(const ui::Brush &b)
 {
-    m_tip_size->m_value.x = b.m_tip_size;
+    m_tip_size->m_value.x = glm::pow(b.m_tip_size, 1.f/3.f);
-    m_tip_spacing->m_value.x = b.m_tip_spacing;
+    m_tip_spacing->m_value.x = glm::pow(b.m_tip_spacing, 1.f/2.f) / 4.f;
-    m_tip_flow->m_value.x = b.m_tip_flow;
+    m_tip_flow->m_value.x = glm::pow(b.m_tip_flow, 1.f/2.f);
     m_tip_opacity->m_value.x = b.m_tip_opacity;
     m_tip_angle->m_value.x = b.m_tip_angle;
     m_jitter_scale->m_value.x = b.m_jitter_scale;
@@ -50,6 +50,9 @@ void NodePanelStroke::init_controls()
     init_slider(m_jitter_angle, "jitter-angle", &ui::Brush::m_jitter_angle);
     init_slider(m_jitter_spread, "jitter-spread", &ui::Brush::m_jitter_spread);
     init_slider(m_jitter_flow, "jitter-flow", &ui::Brush::m_jitter_flow);
+    m_curves[m_tip_size] = [](float v){ return glm::pow(v, 3.f); };
+    m_curves[m_tip_spacing] = [](float v){ return glm::pow(v * 4.f, 2.f); };
+    m_curves[m_tip_flow] = [](float v){ return glm::pow(v, 2.f); };
 
     init_checkbox(m_tip_angle_follow, "tip-angle-follow", &ui::Brush::m_tip_angle_follow);
     init_checkbox(m_tip_flow_pressure, "tip-flow-pressure", &ui::Brush::m_tip_flow_pressure);
@@ -68,7 +71,8 @@ void NodePanelStroke::init_slider(NodeSliderH*& target, const char* id, float ui
 
 void NodePanelStroke::handle_slide(float ui::Brush::* prop, Node* target, float value)
 {
-    m_canvas->m_brush.*prop = value;
+    auto curve = m_curves.find((NodeSliderH*)target);
+    m_canvas->m_brush.*prop = curve != m_curves.end() ? curve->second(value) : value;
     m_canvas->draw_stroke();
     if (on_stroke_change)
         on_stroke_change(this);

engine/node_panel_stroke.h

@@ -22,12 +22,14 @@ public:
     NodeCheckBox* m_tip_flow_pressure;
     NodeCheckBox* m_tip_size_pressure;
     std::function<void(Node* target)> on_stroke_change;
+    std::map<NodeSliderH*, std::function<float(float)>> m_curves;
+    
     virtual Node* clone_instantiate() const override;
     virtual void clone_finalize(Node* dest) const override;
     virtual void init() override;
     void init_controls();
     void set_params(const ui::Brush& b);
-
+    
     void init_slider(NodeSliderH*& slider, const char* id, float ui::Brush::* prop);
     void handle_slide(float ui::Brush::* prop, Node* target, float value);
 

engine/node_stroke_preview.cpp

@@ -67,7 +67,6 @@ void NodeStrokePreview::draw_stroke()
         glm::mat4 proj = glm::ortho<float>(0, (float)m_rtt.getWidth(), 0, (float)m_rtt.getHeight(), -1, 1);
 
         auto b = m_brush;
-        //b.m_tip_size *= .7f; // reduce the size in the preview
         m_stroke.reset();
         m_stroke.start(b);
         if (!m_stroke.m_keypoints.empty())