1.add DrawRect2D.vert/.geom shaders

2.add AlphaMask.frag shader

shader/AlphaMask.frag

@@ -0,0 +1,16 @@
+#version 450 core
+
+layout(binding = 2) uniform sampler2D tex;
+
+layout(location = 0) in vec2 FragmentTexCoord;
+layout(location = 0) out vec4 FragColor;
+
+void main()
+{
+    vec4 color=texture(tex,FragmentTexCoord);
+
+    if(color.a<0.3)
+        discard;
+
+    FragColor=vec4(color.rgb,1);
+}

shader/DrawRect2D.geom

@@ -0,0 +1,17 @@
+#version 450 core
+
+layout (points) in;
+layout (triangle_strip,max_vertices=4) out;
+
+void main()
+{
+    vec2 lt=gl_in[0].gl_Position.xy;
+    vec2 rb=gl_in[0].gl_Position.zw;
+
+    gl_Position=vec4(lt, vec2(0,1));EmitVertex();
+    gl_Position=vec4(lt.x,rb.y, vec2(0,1));EmitVertex();
+    gl_Position=vec4(rb.x,lt.y, vec2(0,1));EmitVertex();
+    gl_Position=vec4(rb, vec2(0,1));EmitVertex();
+
+    EndPrimitive();
+}

shader/DrawRect2D.vert

@@ -0,0 +1,32 @@
+#version 450 core
+
+layout(location = 0) in vec4 Vertex;
+
+layout(binding=0) uniform WorldMatrix     // hgl/math/Math.h
+{
+    mat4 ortho;
+
+    mat4 projection;
+    mat4 inverse_projection;
+
+    mat4 modelview;
+    mat4 inverse_modelview;
+
+    mat4 mvp;
+    mat4 inverse_mvp;
+
+    vec4 view_pos;
+    vec2 canvas_resolution;
+    vec2 viewport_resolution;
+}world;
+
+void main()
+{
+    vec4 lt=vec4(Vertex.xy,vec2(0,1));
+    vec4 rb=vec4(Vertex.zw,vec2(0,1));
+
+    vec4 lt_fin=lt*world.ortho;
+    vec4 rb_fin=rb*world.ortho;
+
+    gl_Position=vec4(lt_fin.xy,rb_fin.xy);
+}