Too much changes

shaders/ui_base.vs

@@ -0,0 +1,16 @@
+#version 120
+
+attribute vec2 a_position;
+attribute vec2 a_texcoord;
+attribute vec4 a_color;
+
+varying vec2 v_texcoord;
+varying vec4 v_color;
+
+uniform mat4 u_projectionMatrix;
+
+void main() {
+    v_texcoord = a_texcoord;
+    v_color = a_color;
+    gl_Position = u_projectionMatrix * vec4(a_position.xy,0,1);
+}