LayerBase CurFrame

[v6v]

Alright, if one wants to give SpriteBase an extra value, say:

float zposition;

in SpriteBase.cs;

How would you retrieve the value for that instance of SpriteBase currently being drawn whenever LayerBase uses Draw() (Inside of LayerBase, that is)?


I need to access a SpriteBase value of the current sprite being drawn within LayerBase.Draw()

I have the variable in SpriteBase.cs, and I need to get that value for the specified sprite instance and have it used in the Draw() Method of LayerBase.

Example= m_Mario_1.zposition = 5. Now I need to access the zposition variable that belongs to that instance of Mario in Draw()

I can't seem to find the object that holds the current sprite being drawn..

Can someone help?

[bluemonkmn]

Layers don't draw sprites directly. Instead, the frames within the sprite are "injected" into the layer to be drawn while it is drawing the tiles so that those frames can be drawn between tiles. You probably have a better system worked out with your z-ordering where sprites wouldn't have to worry about drawing in the middle of the tile drawing, but this is how the current implementation works.  LayerBase has an InjectSprites function, which calls InjectFrames and AppendFrames to add items to m_InjectedFrames, which is inspected during the Draw function of the layer, and drawn at the appropriate time to get the tiles and sprite frames to overlap/interleave properly.  So the code you want is in InjectSprites.  You could probably simply copy it into the Draw function if you have a better way to make the sprites draw behind one row of tiles and in front of the above row when necessary.

[v6v]

I still don't fully understand- the functions for injecting tiles, and the functions for injecting sprites, are different right? I can't seem to distinguish the two.

[bluemonkmn]

There is no function for injecting tiles, just for injecting frames of sprites between tiles.  The LayerBase Draw function follows this rough sequence:
1. Check if there are injected frames to process, and if so prepare (get an enumerator) that will be used to process them in sequence as tiles are drawn.  Since the injected frames are sorted, the code only needs to look at the next injected frame to see if any frames need to be drawn during the loop.
2. Begin looping through each row of tiles on the layer
3. If there are any injected frames to draw behind this row of tiles, draw those frames before drawing this row of tiles
4. Begin Loop through each tile on this row
5. Begin loop through through each frame for this tile
6. Draw the tile's frame
7. End the tile frame loop
8. End the tile row loop
9. End all rows loop
10. If there are any sprite frames that remain to be drawn (did not need to be injected between rows of tiles), draw them here after all loops.

[v6v]

Right, I've looked into the InjectedFrame array you mentioned earlier. I added the extra parameter within the class itself.

I can now have the z as an arbitrary value per sprite instance. It retrieves the z from SpriteBase and injects it in the array at the right position, and when the (final, I think) for loop in Draw looks through the frames I can access it through CurFrame.z

Everything works, thanks again bluemonkmn.

It's a shame OpenGL uses floats, and I can't directly access z within the Rule Editor unless I use some form of casting, which might result in precision errors...

[bluemonkmn]

It's a shame OpenGL uses floats, and I can't directly access z within the Rule Editor unless I use some form of casting, which might result in precision errors...

Simple work around -- scale the number by a factor of 100, for example.  There are a number of rule functions that accept parameters in "tenths of a pixel" units and then divide the parameter by 10 before using it.  You could probably do something similar.  Perform all work in 1/100th-pixel units and then divide by 100 only when you need to use it in OpenGL.