[WIP] Billboard(the 2d way)

Two Modes:

1.fixed billboard size,the size in UBO
2.dynamic billboard size,the size in VAB

two modes to use GeometryShader, convert point/line data to quad data.

ShaderLibrary/Std3D/Billboard/2DWay.mtl

@@ -0,0 +1,43 @@
+#Material
+Name Billboard2DWay
+Base Std3D/Billboard
+
+#VertexInput
+vec2 TexCoord
+
+#Vertex
+Output
+{
+    vec2 TexCoord
+}
+
+Code
+{
+    void main()
+    {
+        Output.TexCoord=TexCoord;
+
+        vec4 pos=GetPosition3D()
+                +camera.camera_right*TexCoord.x*Billboard.Size.x
+                +camera.camera_up   *TexCoord.y*Billboard.Size.y;
+
+        gl_Position=GetPosition3D();
+    }
+}
+
+#Fragment
+
+sampler2D TextureBaseColor
+
+Output
+{
+    vec4 FragColor;
+}
+
+Code
+{
+    void main()
+    {
+        FragColor=texture(TextureBaseColor,Input.TexCoord);
+    }
+}