non linear slider for brush tip control

engine/brush.cpp

@@ -164,8 +164,8 @@ ui::StrokeSample ui::Stroke::randomize_sample(const glm::vec2& pos, float pressu
     StrokeSample s;
     s.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 = 100.f * m_brush.m_tip_size * (1.f - rnd_nor() * m_brush.m_jitter_scale);
-    s.flow = m_brush.m_tip_flow * (1.f - rnd_nor() * m_brush.m_jitter_flow) * pressure;
+    s.size = 800.f * glm::pow(m_brush.m_tip_size, 2.f) * (1.f - rnd_nor() * m_brush.m_jitter_scale);
+    s.flow = glm::pow(m_brush.m_tip_flow, 2.f) * (1.f - rnd_nor() * m_brush.m_jitter_flow) * pressure;
     return s;
 }
 std::vector<ui::StrokeSample> ui::Stroke::compute_samples()
@@ -214,7 +214,7 @@ void ui::Stroke::start(const ui::Brush& brush)
 {
     m_last_kp = 0;
     m_dist = 0.f;
-    m_step = glm::max(brush.m_tip_spacing * brush.m_tip_size * 30, 0.1f);
+    m_step = glm::max(brush.m_tip_spacing * 10, 1.f);
     m_brush = brush;
     prng.seed(0);
 }

engine/node_stroke_preview.cpp

@@ -65,8 +65,10 @@ void NodeStrokePreview::draw_stroke()
         glEnable(GL_BLEND);
         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(m_brush);
+        m_stroke.start(b);
         auto samples = m_stroke.compute_samples();
         auto& tex = TextureManager::get(m_brush.m_tex_id);
         tex.bind();

engine/util.cpp

@@ -49,6 +49,19 @@ static const char* gl2str(GLenum err)
     }
 }
 
+double now_seconds()
+{
+    time_t timer;
+    struct tm y2k = { 0 };
+    double seconds;
+
+    y2k.tm_hour = 0;   y2k.tm_min = 0; y2k.tm_sec = 0;
+    y2k.tm_year = 100; y2k.tm_mon = 0; y2k.tm_mday = 1;
+
+    time(&timer);  /* get current time; same as: timer = time(NULL)  */
+    seconds = difftime(timer, mktime(&y2k));
+}
+
 void check_OpenGLError(const char* stmt, const char* fname, int line)
 {
     GLenum err;