How to use OutdoorPlugIn_ReadPredictionArea in Winprop API

Please use the following code which should work:

    int NumberCorners;
    int DatabaseFileType = DATABASE_TYPE_WINPROP_ODB;
    struct COORDPOINT* Polygon;
    double* Resolution = &GeneralParameters.Resolution;
    int NumberHeights = 0;
    int PolygonUsed = 0;

    OutdoorPlugIn_ReadPredictionArea(my_odb_database, &NumberCorners, &Polygon, DatabaseFileType, Resolution, &NumberHeights, nullptr, &PolygonUsed);

Please use the following code which should work:

    int NumberCorners;
    int DatabaseFileType = DATABASE_TYPE_WINPROP_ODB;
    struct COORDPOINT* Polygon;
    double* Resolution = &GeneralParameters.Resolution;
    int NumberHeights = 0;
    int PolygonUsed = 0;

    OutdoorPlugIn_ReadPredictionArea(my_odb_database, &NumberCorners, &Polygon, DatabaseFileType, Resolution, &NumberHeights, nullptr, &PolygonUsed);

Hi Reinerh,

Thank you for your assistance. Sorry that I'm not often working with C++, so I'm not very familiar with writing this code. I still have some confusion regarding the initialization of the Polygon parameter and the return value of OutdoorPlugIn_ReadPredictionArea.

1. Based on my understanding, when NumberCorners is set to 2, OutdoorPlugIn_ReadPredictionArea should return two data sets of type COORDPOINT, each containing values for x, y, and z. Furthermore, these two sets of COORDPOINT data should be stored at the address pointed to by Polygon. How should I initialize the address pointed to by Polygon to store the data that will be returned?

2. Assuming I've completed the first step and obtained a pointer Polygon pointing to two sets of COORDPOINT, how can I access the coordinate data stored in these two sets of COORDPOINT and then assign them to other variables?

I've tried various methods and also the code you sent me, but it seems that Polygon consistently only provides me with the x, y, and z values of only one set of coordinates. I would greatly appreciate it if you could help me resolve this issue.

Thank you,

Tianhang Yu

Hi Reinerh,

Thank you for your assistance. Sorry that I'm not often working with C++, so I'm not very familiar with writing this code. I still have some confusion regarding the initialization of the Polygon parameter and the return value of OutdoorPlugIn_ReadPredictionArea.

1. Based on my understanding, when NumberCorners is set to 2, OutdoorPlugIn_ReadPredictionArea should return two data sets of type COORDPOINT, each containing values for x, y, and z. Furthermore, these two sets of COORDPOINT data should be stored at the address pointed to by Polygon. How should I initialize the address pointed to by Polygon to store the data that will be returned?

2. Assuming I've completed the first step and obtained a pointer Polygon pointing to two sets of COORDPOINT, how can I access the coordinate data stored in these two sets of COORDPOINT and then assign them to other variables?

I've tried various methods and also the code you sent me, but it seems that Polygon consistently only provides me with the x, y, and z values of only one set of coordinates. I would greatly appreciate it if you could help me resolve this issue.

Thank you,

Tianhang Yu

Hi Tianhang Yu,

please note NumberCorners and Polygon are set inside the function, no need to allocate memory before, which is also done inside the function.

For an .odb database the NumberCorners will be set to 4 and the Polygon[0], Polygon[1], Polygon[2], Polygon[3] will be set to the LL, LR, UR, UL corners.

I tested this yesterday on my side and it worked with the mentioned code as expected.

Best regards,
Reiner

Hi Tianhang Yu,

please note NumberCorners and Polygon are set inside the function, no need to allocate memory before, which is also done inside the function.

For an .odb database the NumberCorners will be set to 4 and the Polygon[0], Polygon[1], Polygon[2], Polygon[3] will be set to the LL, LR, UR, UL corners.

I tested this yesterday on my side and it worked with the mentioned code as expected.

Best regards,
Reiner

Hi Reinerh,

You're correct. It's working perfectly! You've really helped me out, thank you so much.

Best regards,

Tianhang Yu