add no_tex and unlit shader

source/shaders/unlit.sglsl

@@ -0,0 +1,31 @@
+@vs vs
+in vec3 a_pos;
+in vec2 a_tex_coords;
+
+out vec2 tex_coords;
+
+uniform vs_p {
+uniform mat4 vp;
+uniform mat4 model;
+uniform mat4 proj;
+};
+
+void main() {
+  gl_Position = proj * vp * vec4(vec3(model * vec4(a_pos,1.0)), 1.0);  
+  tex_coords = a_tex_coords;
+}
+@end
+
+@fs fs
+in vec2 tex_coords;
+out vec4 color;
+
+uniform texture2D diffuse;
+uniform sampler smp;
+
+void main() {
+  color = texture(sampler2D(diffuse,smp),tex_coords);
+}
+@end
+
+@program unlit vs fs