discard Poi transparent fragment,#12

Author: iSpring

src/world/graphics/Poi.ts

@@ -22,23 +22,29 @@ void main(void) {
 
 //http://stackoverflow.com/questions/3497068/textured-points-in-opengl-es-2-0
 //gl_FragColor = texture2D(uSampler, vec2(gl_PointCoord.x, 1.0 - gl_PointCoord.y));
+
+//https://www.opengl.org/sdk/docs/tutorials/ClockworkCoders/discard.php
 const fs =
     `
 precision mediump float;
 uniform sampler2D uSampler;
 
 void main()
 {
-	gl_FragColor = texture2D(uSampler, vec2(gl_PointCoord.x, gl_PointCoord.y));
+	vec4 color = texture2D(uSampler, vec2(gl_PointCoord.x, gl_PointCoord.y));
+    if(color.a == 0.0){
+        discard;
+    }
+    gl_FragColor = color;
 }
 `;
 
 class Poi extends Graphic {
     private constructor(
-        public geometry: Marker, 
-        public material: PoiMaterial, 
-        public uuid: string,        
-        public name: string, 
+        public geometry: Marker,
+        public material: PoiMaterial,
+        public uuid: string,
+        public name: string,
         public address: string,
         public phone: string) {
         super(geometry, material);