35 lines
1.1 KiB
Go
35 lines
1.1 KiB
Go
|
package pixelgl
|
||
|
|
|
||
|
|
// BeginEnder is an interface for manipulating OpenGL state.
|
||
|
|
//
|
||
|
|
// OpenGL is a state machine and as such, it is natural to manipulate it in a begin-end manner.
|
||
|
|
// This interface is intended for all OpenGL objects, that can begin being active and end being active
|
||
|
|
// such as windows, vertex arrays, vertex buffers, textures, shaders, pretty much everything.
|
||
|
|
//
|
||
|
|
// It might seem natural to use BeginEnders this way:
|
||
|
|
//
|
||
|
|
// window.Begin()
|
||
|
|
// shader.Begin()
|
||
|
|
// texture.Begin()
|
||
|
|
// vertexarray.Begin()
|
||
|
|
// vertexarray.Draw()
|
||
|
|
// vertexarray.End()
|
||
|
|
// texture.End()
|
||
|
|
// shader.End()
|
||
|
|
// window.End()
|
||
|
|
//
|
||
|
|
// Don't do this! A better practice is to make a BeginEnder so that it wraps another BeginEnder like this:
|
||
|
|
//
|
||
|
|
// shader = NewShader(window)
|
||
|
|
// texture = NewTexture(shader)
|
||
|
|
// vertexarray = NewVertexArray(texture)
|
||
|
|
// // now, somewhere else in your code, instead of calling numerous Begin/Ends, you just calling
|
||
|
|
// vertexarray.Draw()
|
||
|
|
//
|
||
|
|
// The final single call to draw a vertex array executes all of the Begins and Ends, because the objects are
|
||
|
|
// wrapped around each other.
|
||
|
|
type BeginEnder interface {
|
||
|
|
Begin()
|
||
|
|
End()
|
||
|
|
}
|