Where can I find the document of definition of P_COLOR, P_UV, P_DEFAULT…etc, difference between v_UserData and a_UserData? and explanation how to code the shaders on corona shader playground correctly into lua file for beginners?
Here’s the document in question: Custom Shader Effects.
You should be using the
CoronaVertexUserData name, rather than those internal ones. As for what they are,
a_UserData is the “attribute”, so basically the view of that member of the vertex that got uploaded to the GPU;
v_UserData is a “varying”: the vertex shader puts the attribute into this variable, which is also interpolated (“varies”) across the fragments and visible to the fragment shader.
My bad, found what I need in the document