package glx

import x11 "vendor:x11/xlib"
foreign import glx "system:GL"

Drawable :: x11.XID

@private
__FBConfigRec :: struct {
	visualType: i32,

	transparentType: i32,
	transparentRed, transparentGreen, transparentBlue, transparentAlpha: i32,
	transparentIndex: i32,

	visualCaveat: i32,

	associatedVisualId: i32,
	screen: i32,

	drawableType: i32,
	renderType: i32,

	maxPbufferWidth, maxPbufferHeight, maxPbufferPixels: i32,
	optimalPbufferWidth, optimalPbufferHeight: i32,  /* for SGIX_pbuffer */

	visualSelectGroup: i32,	/* visuals grouped by select priority */

	id: u32,

	rgbMode: b8,
	colorIndexMode: b8,
	doubleBufferMode: b8,
	stereoMode: b8,
	haveAccumBuffer: b8,
	haveDepthBuffer: b8,
	haveStencilBuffer: b8,

	/* The number of bits present in various buffers */
	accumRedBits, accumGreenBits, accumBlueBits, accumAlphaBits: i32,
	depthBits: i32,
	stencilBits: i32,
	indexBits: i32,
	redBits, greenBits, blueBits, alphaBits: i32,
	redMask, greenMask, blueMask, alphaMask: u32,

	multiSampleSize: u32,/* Number of samples per pixel (0 if no ms) */

	nMultiSampleBuffers: u32,/* Number of available ms buffers */
	maxAuxBuffers: i32,

	/* frame buffer level */
	level: i32,

	/* color ranges (for SGI_color_range) */
	extendedRange: b8,
	minRed, maxRed: f64,
	minGreen, maxGreen: f64,
	minBlue, maxBlue: f64,
	minAlpha, maxAlpha: f64,
}

// apparently this isn't defined anywhere ???
// so we define a minimal one according to this
// https://dri.freedesktop.org/docs/gallium/glxapi_8h-source.html
// see also: https://github.com/Tarnyko/EGLX/blob/b82af86a8a0daf3408fb7a6e7b07b02b01476626/EGLX.h#L280
@private
__ContextRec :: struct {
	currentDpy: ^x11.Display,
	isDirect: b8,
	currentDrawable: Drawable,
	currentReadable: Drawable,
	xid: x11.XID
}

FBConfig :: ^__FBConfigRec
Context :: ^__ContextRec

foreign glx {
	@(link_name = "glXGetProcAddressARB")
	GetProcAddressARB				:: proc(name: ^u8) -> rawptr ---
	@(link_name = "glXSwapBuffers")
	SwapBuffers							:: proc(display: ^x11.Display, drawable: Drawable) ---
	@(link_name = "glXQueryVersion")
	QueryVersion						:: proc(display: ^x11.Display, major: ^i32, minor: ^i32) -> bool ---
	@(link_name = "glXChooseFBConfig")
	ChooseFBConfig					:: proc(display: ^x11.Display, screen: i32, attrib_list: ^i32, nelements: ^i32) -> [^]FBConfig ---
	@(link_name = "glXCreateContextAttribsARB")
	CreateContextAttribsARB	:: proc(display: ^x11.Display, config: FBConfig, share_context: Context, direct: bool, attrib_list: ^i32) -> Context ---
	@(link_name = "glXDestroyContext")
	DestroyContext					:: proc(display: ^x11.Display, ctx: Context) ---
	@(link_name = "glXSwapIntervalEXT")
	SwapIntervalEXT					:: proc(display: ^x11.Display, drawable: Drawable, interval: i32) -> bool ---
	@(link_name = "glXMakeCurrent")
	MakeCurrent							:: proc(display: ^x11.Display, drawable: Drawable, ctx: Context) -> bool ---
}