uniform sampler2D normal;
uniform vec2 mouse;
uniform float Za;
vec4 effect(vec4 color,sampler2D tex,vec2 tc,vec2 pc)
{
vec4 img_color = texture2D( tex, tc );
vec4 normalColor = texture2D( normal, tc );
float X = (mouse.x - pc.x);
float Y = (mouse.y - pc.y);
float Z = Za;
float dotProduct = X * normalColor.r + Y * normalColor.g + Z * normalColor.b;
dotProduct /= sqrt(X * X + Y * Y + Z * Z) * sqrt(normalColor.r * normalColor.r + normalColor.g * normalColor.g + normalColor.b * normalColor.b);
float factor = dotProduct;
img_color.r = img_color.r + factor;
img_color.g = img_color.g + factor;
img_color.b = img_color.b + factor;
return img_color;
}