add initial text shaders

runtime/shaders/text.f.glsl

@@ -0,0 +1,9 @@
+varying vec2 texture_coord_v;
+
+uniform sampler2D texture;
+uniform vec4 color;
+
+void main(void)
+{
+    gl_FragColor = vec4(1, 1, 1, texture2D(texture, texture_coord_v).a) * color;
+}

runtime/shaders/text.v.glsl

@@ -0,0 +1,9 @@
+attribute vec4 coords;
+
+varying vec2 texture_coord_v;
+
+void main(void)
+{
+    gl_Position = vec4(coords.xy, 0, 1);
+    texture_coord_v = coords.zw;
+}