[Gambas-devel] Interface of gb.opengl.sge

[Tomek]

On 28.03.2013 02:41, Benoît Minisini wrote:
> Hi Tomek,
>
> I took a glance at your code, and I strongly suggest the following
> changes to the gb.opengl.gse interface before you go further.
>
> Why these changes? Mainly because I try to make Gambas components have
> the most similar interfaces as possible, so that the learning curve is
> lower.
>
> By the way, not that there is a design problem too : the MD2 model
> loading routine only works if the endianness of the CPU is the same as
> the endianness of the file. You should ensure that if the endianness is
> different, you swap the binary data accordingly.
>
> Now the old interface :
>
> GB_DESC Md2ModelDesc[] =
> {
>     GB_DECLARE("Md2Model", sizeof(MD2MODEL)),
>     GB_NOT_CREATABLE(),
>     GB_STATIC_METHOD("Load", "Md2Model" , Md2Model_Load, "(Name)s"),
>     GB_METHOD("SetPosition", NULL, Md2Model_SetPosition, "(X)f(Y)f(Z)f" ),
>     GB_METHOD("DrawFrame", NULL, Md2Model_DrawFrame,
> "(Frame_No)i(Texture)i" ),
>     GB_METHOD("DrawInterFrame", NULL, Md2Model_DrawInterFrame,
> "(Frame_No)i(InterFrame)f(Texture)i" ),
>     GB_METHOD("GetFramesNo", "i", Md2Model_GetNoFrames, NULL ),
>     GB_METHOD("GetFrameName", "s", Md2Model_GetFrameName, "(FrameNumber)i" ),
>     GB_METHOD("Scale", NULL, Md2Model_Scale,
> "(Scale_x)f(Scale_y)f(Scale_z)f" ),
>     GB_METHOD("_free", NULL, Md2Model_free, NULL ),
>     GB_END_DECLARE
> };
>
> The new one I suggest:
>
> GB_DESC Md2ModelDesc[] =
> {
>     GB_DECLARE("Md2Model", sizeof(MD2MODEL)),
>     GB_NOT_CREATABLE(),
>     GB_STATIC_METHOD("Load", "Md2Model" , Md2Model_Load, "(Name)s"),
>     // 'SetPosition' renamed to 'Move'
>     GB_METHOD("Move", NULL, Md2Model_SetPosition, "(X)f(Y)f(Z)f" ),
>     // Three properties to get/set the one coordinate
>     GB_PROPERTY("X", "f", Md2Model_X),
>     GB_PROPERTY("Y", "f", Md2Model_X),
>     GB_PROPERTY("Z", "f", Md2Model_X),
>     // A virtual object for accessing frame properties and count
>     GB_PROPERTY_SELF("Frames", ".Md2Model.Frames"),
>     GB_METHOD("Scale", NULL, Md2Model_Scale, "(ScaleX)f(ScaleY)f(ScaleZ)f" ),
>     // Maybe you should add ScaleX, ScaleY and ScaleZ properties too.
>     GB_METHOD("_free", NULL, Md2Model_free, NULL ),
>     GB_END_DECLARE
> };
>
> GB_DESC Md2ModelFramesDesc[] =
> {
>     GB_DECLARE_VIRTUAL(".Md2Model.Frames"),
>     // Was Md2Model_GetNoFrames
>     GB_PROPERTY_READ("Count", "i", Md2Model_Frames_Count)
>     GB_METHOD("_get", ".Md2Model.Frame", Md2Model_Frames_get, "(Frame)i"),
>     GB_END_DECLARE
> }
>
> // The _get method of Md2Model_Frames is implemented that way:
>
> BEGIN_METHOD(Md2Model_Frames_get, GB_INTEGER frame)
>
>     // Store the frame number into the object, it will be used immediately
>     // by the method called on the virtual .Md2Model.Frame object.
>     // Maybe check that the frame number is valid now.
>     // And don't forget to add the 'frame' field into the object
>     // structure.
>     THIS->frame = VARG(frame);
>
> END_METHOD
>
> GB_DESC Md2ModelFrameDesc[] =
> {
>     GB_DECLARE_VIRTUAL(".Md2Model.Frame"),
>     // Was 'Md2Model.DrawFrame'
>     GB_METHOD("Draw", NULL, Md2Model_Frame_Draw, "(Texture)i"),
>     // Was 'Md2Model.DrawInterFrame'
>     GB_METHOD("DrawInterFrame", NULL, Md2Model_Frame_DrawInterFrame,
> "(InterFrame)f(Texture)i"),
>     GB_END_DECLARE
> }
>
> Tell me what you think about that and if you have questions!
>
> Regards,
>
Hi Benoit,

Thanks for your suggestions, I will try to do as much a I can using 
devel-api documentation page. It's the best way to learn I think. When 
I'm stuck, I'll ask for your help, ok?
Question 1 - How do I check endianess of the CPU from component level?
One more question - what would be the best way to make the class 
creatable - Md2Model_new I suppose, but what should be in that function? 
Can it be empty? Without creatable class I can't make an array of it.

Thanks,
Tomek