[PyQt] Creating a QSGGeometry.AttributeSet in PyQt5

[Phil Thompson]

On 22-02-2014 2:33 pm, Phil Thompson wrote:
> On 21-02-2014 1:08 pm, pwuertz wrote:
>> Hi,
>> I am trying to add a vertex array to a QSGGeometryNode for a custom 
>> QtQuick
>> Item. Qt5 uses QSGGeometry for that purpose and requires the user to 
>> define
>> a QSGGeometry.AttributeSet that describes structure of a vertex 
>> array. There
>> are a few pre-defined structures like the one from
>> defaultAttributes_Point2D() but I need to create my own as described 
>> in
>> http://qt-project.org/doc/qt-5/qsggeometry.html.
>>
>> QSGGeometry::Attribute MyPoint2D_Attributes[] = {
>>     QSGGeometry::Attribute::create(0, 2, GL_FLOAT, true),
>>     QSGGeometry::Attribute::create(1, 4, GL_FLOAT, false)
>> };
>>
>> QSGGeometry::AttributeSet MyPoint2D_AttributeSet = {
>>     2,
>>     sizeof(MyPoint2D),
>>     MyPoint2D_Attributes
>> };
>>
>> The problem is that I don't know how to create a 
>> QSGGeometry.AttributeSet in
>> PyQt5, which C++ creates by struct initialization. AttributeSet 
>> doesn't have
>> an initializing constructor and naively assigning a list of 
>> Attributes to a
>> default constructed instance fails because AttributeSet.attributes 
>> is
>> read-only. How can I construct a complete AttributeSet in PyQt5?
>
> Tonight's snapshot will have a AttributeSet ctor that takes a stride
> and a sequence of Attributes so that you can do...
>
> attribute_set = QSGGeometry.AttributeSet(24,
>     (QSGGeometry.Attribute.create(0, 2, QSGGeometry.GL_FLOAT, True),
>      QSGGeometry.Attribute.create(1, 4, QSGGeometry.GL_FLOAT, True)))
>
> It's very likely that there are other problems with the QSGGeometry
> API. Please let me know if you find other things that you need to be
> able to do but can't.

This has changed in tonight's snapshot. The stride argument is now the 
second argument and is optional. If not specified then the value is 
calculated automatically.

Phil