fix debug build with vs2017

engine/brush.h

@@ -31,11 +31,11 @@ public:
 
 struct StrokeSample
 {
-    glm::vec2 pos;
-    glm::vec2 origin;
-    float size;
-    float flow;
-    float angle;
+    glm::vec2 pos = { 0, 0 };
+    glm::vec2 origin = { 0,0 };
+    float size = 0;
+    float flow = 0;
+    float angle = 0;
 };
 
 class BrushMesh
@@ -45,8 +45,8 @@ public:
     GLuint vao{ 0 };
     struct vertex_t { glm::vec4 pos; glm::vec2 uvs; };
     struct instance_t { glm::mat4 mvp; float flow; };
-    int loc_flow;
-    int loc_mvp;
+    int loc_flow = 0;
+    int loc_mvp = 0;
     
     bool create();
     void draw(const std::vector<StrokeSample>& samples, const glm::mat4& proj);
@@ -57,19 +57,19 @@ class Stroke
 public:
     struct Keypoint
     {
-        glm::vec2 pos;
-        float pressure;
-        float dist;
+        glm::vec2 pos = { 0, 0 };
+        float pressure = 0;
+        float dist = 0;
     };
     struct Camera
     {
-        glm::vec2 rot;
-        float fov;
+        glm::vec2 rot = { 0, 0 };
+        float fov = 0;
     };
-    int m_layer;
-    float m_curve;
-    float m_dist;
-    float m_step;
+    int m_layer = 0;
+    float m_curve = 0;
+    float m_dist = 0;
+    float m_step = 0;
     Camera m_camera;
     ui::Brush m_brush;
     cbuffer<float, 3> m_curve_angles;