@block vert
uniform vec4 rect;
uniform vec2 diffuse_size;
void vert()
{
  pos *= vec3(diffuse_size*rect.zw, 1);
  uv = (uv*rect.zw)+rect.xy;
}
@end

@block frag
uniform vec4 border;
uniform vec2 scale;
uniform vec4 shade;

// border given as [left,down,right,top], in scaled coordinates

vec2 uv9slice(vec2 uv, vec2 s, vec4 b)
{
  vec2 t = clamp((s * uv - b.xy) / (s - b.xy - b.zw), 0., 1.);
  return mix(uv * s, 1. - s * (1. - uv), t);
}

void frag()
{
  vec2 ruv = uv9slice(uv, scale, border);
  color = texture(sampler2D(diffuse,smp), ruv);
  if (color.a < 0.1) discard;
}
@end

#include <base.cg>