Invert.glsl

#include "Uniforms.glsl"
#include "Samplers.glsl"
#include "Transform.glsl"
#include "ScreenPos.glsl"

varying vec2 vScreenPos;

#ifdef GL_ES
  precision mediump float;
#endif

void VS()
{
  mat4 modelMatrix = iModelMatrix;
  vec3 worldPos = GetWorldPos(modelMatrix);
  gl_Position = GetClipPos(worldPos);
  vScreenPos = GetScreenPosPreDiv(gl_Position);
}

void PS()
{
  vec4 color = texture2D(sDiffMap, vScreenPos);
  gl_FragColor = vec4(vec3(1.0, 1.0, 1.0) - color.rgb, color.a);
}