Function GetPostEffectType( c_num )

Returns the type of post effect set on the given canvas.

Possible Effect Types

• POST_EFFECT_TYPE_BLOOM
• POST_EFFECT_TYPE_BLUR
• POST_EFFECT_TYPE_MOTION_BLUR
• POST_EFFECT_TYPE_RADIAL_BLUR
• POST_EFFECT_TYPE_COLORIZE
• POST_EFFECT_TYPE_INVERT
• POST_EFFECT_TYPE_MINERAL