//
// This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; version 2 of the License.
//
// This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty
// of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. 
//


/*[configuration]

[OptionRangeFloat]
GUIName = Aspect ratio correction
OptionName = ASPECT
MinValue = 0
MaxValue = 2
StepAmount = 0.0025
DefaultValue = 0.75

[OptionRangeFloat]
GUIName = Overall zoom
OptionName = ZOOM
MinValue = 0
MaxValue = 2
StepAmount = 0.0025
DefaultValue = 0.97

[OptionRangeFloat]
GUIName = Vertical offset
OptionName = OFFSET
MinValue = 0
MaxValue = 0.2
StepAmount = 0.00025
DefaultValue = 0.11

[/configuration]*/


void main()
{
  float2 coord = float2(0.5,1-GetOption(OFFSET)) + (GetCoordinates()-float2(0.5,1)) * float2(1,GetOption(ASPECT)) / GetOption(ZOOM);
  SetOutput(clamp(coord,0,1)==coord ? SampleLocation(coord) : float4(0));
}