added alpha blending for image and text, nodes position are clamped to be integer

engine/app.cpp

@@ -89,7 +89,8 @@ void App::init()
         "in vec2 uv;"
         "out vec4 frag;"
         "void main(){"
-        "   frag = vec4(texture(tex, uv).r * col.rgb, col.a);"
+        "   float a = texture(tex, uv).r;"
+        "   frag = vec4(col.rgb, a);"
         "}";
 
 #ifdef _WIN32
@@ -141,7 +142,10 @@ void App::init()
     glDisable(GL_DEPTH_TEST);
     glPointSize(5);
     glLineWidth(2);
-    
+
+    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+    glBlendEquation(GL_FUNC_ADD);
+
     //int n;
     //glGetIntegerv(GL_NUM_EXTENSIONS, &n);
     //for (int i = 0; i < n; i++)