glfw3

README

GLFW backend for go.wde

Notes:

• glfw doesn't support icons for the windows (except on the MS Windows platform). To implement this, platform specific code needs to be written. However, the issue is known at glfw, so in the future it will be probably implemented.
• glfw supports clipboard messaging. This is not implemented (yet) in go.wde but IMO it should be part of the event system.
• glfw key numpad works with numbers and go.wde with arrows/ins/del/pageup/etc. So numpad key 5 has no go.wde mapping!
• go.wde has a key called KeyFunction and I don't know what it is. There is no direct glfw counterpart for this AFAIK.
• I have no idea how to get the status of capslock, numlock, pause, scrollock. This means that when the user presses the letter 'a', it is unclear that the output is 'a' or 'A'. This of course US English only.

Open issues:

• Still not all events are handled
• Add Icons to the windows.
• Window.FlushImage(). How to implement "bounds ...image.Rectangle" ?
• Sometimes when exiting, the following error (numbers differ) is displayed:

X Error of failed request:  BadWindow (invalid Window parameter)
  Major opcode of failed request:  3 (X_GetWindowAttributes)
  Resource id in failed request:  0x0
  Serial number of failed request:  963
  Current serial number in output stream:  964

• Only tested on Ubuntu 12.04 64-bit
• I am not sure that glfw.PollEvents() is implemented correctly in combination with multiple windows. Also glfw.SwapInterval() isn't implemented (yet).

Solved issues:

• Where to place glfw3.Init()? go.wde doesn't work with Init(), but glfw3.Init() must be run in the main thread. So placing it in the func wdeglfw3.init() might not solve it. I will test it in the gears app. Answ: Solved.
• How to access OpenGL functions? This is not a real issue for go.wde because only At() is being used. But for the other draw2d functions in go.uik it needs to be fully implemented. Answ: glfw3 is only used as a backend for go.wde. That means the OpenGL functionality is not available in go.uik.
• How to access the buffers of a window? Answ: Don't. Let OpenGL handle the rendering of a window.
• How to implement glfw3.SwapBuffers? go.wde solves this (I guess) with CopyRGBA(), but glfw3 doesn't. Answ: By calling FlushImage() and let this function call SwapBuffers.
• How to properly shutdown the app? Why is this a problem? Because glfw3.Main() is blocking a proper shutdown. Answ:

    wde.BackendStop = func() {
        glfw.Terminate()
        // other cleanup functions
        os.Exit(0)
    }

• The individual window rendering is done by calling glfw.MakeContextCurrent. That means only one window is rendered at a time and kinda ruins the goroutine idea. Let's see how to implement it without modifying wdetest. Answ: Looks like that implementing it in Screen() is the easiest. The blocking is fixed with channels.
• The event system of glfw3 works very different than that of go.wde However the callback functions might/should solve that Answ1: Added Window.C() in package glfw3 to get access of the underlying C structure pointer.
• LockSize() in struct wdeglfw3.Window modifies Window.lockedSize. What is the functionality of this function? Answ: It a switch for window stretching allowment (think dialogs). However, in glfw this switch need to be set before the window initialization.
• Drawing the window buffer on the screen is a serious issue. In OpenGL there are two ways to do this:
  • gl.DrawPixels (deprecated in OpenGL 4.0). Problem is vertical window stretching. Answ: For now, the stretching issue is solved with gl.Viewport. So we stick with gl.DrawPixels. Maybe in the future it is better to switch to gl.TexImage2D.
  • gl.TexImage2D. Problem is that it only shows a white square on the first quadrant (right upper corner)

Documentation

Index

• type OSWindow
  • func NewOSWindow(width, height int) (w *OSWindow, err error)
  • func (w *OSWindow) Close() (err error)
  • func (w *OSWindow) EventChan() (events <-chan interface{})
  • func (w *OSWindow) FlushImage(bounds ...image.Rectangle)
  • func (w *OSWindow) LockSize(lock bool)
  • func (w *OSWindow) Screen() oswin.WinImage
  • func (w *OSWindow) SetCursor(cursor oswin.Cursor)
  • func (w *OSWindow) SetSize(width, height int)
  • func (w *OSWindow) SetTitle(title string)
  • func (w *OSWindow) Show()
  • func (w *OSWindow) Size() (width, height int)
• type WinImage
  • func (buffer WinImage) CopyRGBA(src *image.RGBA, r image.Rectangle)

Types

type OSWindow

type OSWindow struct {
	// contains filtered or unexported fields
}

func NewOSWindow

func NewOSWindow(width, height int) (w *OSWindow, err error)

func (*OSWindow) Close

func (w *OSWindow) Close() (err error)

func (*OSWindow) EventChan

func (w *OSWindow) EventChan() (events <-chan interface{})

func (*OSWindow) FlushImage

func (w *OSWindow) FlushImage(bounds ...image.Rectangle)

func (*OSWindow) LockSize

func (w *OSWindow) LockSize(lock bool)

func (*OSWindow) Screen

func (w *OSWindow) Screen() oswin.WinImage

func (*OSWindow) SetCursor

func (w *OSWindow) SetCursor(cursor oswin.Cursor)

func (*OSWindow) SetSize

func (w *OSWindow) SetSize(width, height int)

func (*OSWindow) SetTitle

func (w *OSWindow) SetTitle(title string)

func (*OSWindow) Show

func (w *OSWindow) Show()

func (*OSWindow) Size

func (w *OSWindow) Size() (width, height int)

type WinImage

type WinImage struct {
	*image.RGBA
}

func (WinImage) CopyRGBA

func (buffer WinImage) CopyRGBA(src *image.RGBA, r image.Rectangle)