# Adjustments An adjustment is specified by a **mode**, a **direction** and a **delta**. For each reference point and corresponding shift vector, the adjustment is computed and applied. The resulting shift vector is again cached in the warping library. This way of implementation allows incremental adjustments. **Mode** defines the way of the distortion. Following modes are available:
- Parallelogram - Trapezoid - Pin balance - Pincushion - Shift - Size - Rotation (around bitmap image center point)
**Direction** specifies the direction in which the distortion is applied. Following directions are available:
- Up - Down - Left - Right
**Delta** specifies the amount of distortion that is applied. Delta is an unsigned integer value in range 0..255 (1 byte). The delta is added to the existing offset of the corresponding reference points. #### Predefined Adjustments Based on mode and direction, the following transformations are possible:
**Mode** **Direction****Trapezoid****Parallelogram****Pincushion****Pin balance**
Up
Down
Left
Right
**Mode** **Direction****Size****Rotation****Shift**
Up
Down
Left
Right
#### Formulas for adjustments The following formulas describe the mathematically necessary adjustments of the reference points. If the requested adjustment exceeds the limit, no calculation shall be done and the previous status will be kept. ##### Trapezoid mode
##### Parallelogram mode
##### Pinbalance mode
##### Pincushion mode
##### Size mode
##### Rotation mode
##### Shift mode

NumOfRefPointsX - number of reference points in horizontal direction NumOfRefPointsY - number of reference points in vertical direction x\[i\]\[j\] - x-coordinate of reference point, a 2-dimensional array of floating point variables y\[i\]\[j\] - y-coordinate of reference point, a 2-dimensional array of floating point variables

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