'' 
'' gfx_alleg.bas - External graphics functions implemented in Allegro
''
'' part of OHRRPGCE - see elsewhere for license details
''

option explicit

#include "gfx.bi"
#undef Font
#include "allegro.bi"
#include "scancodes.bi"

declare sub debug(s$)

dim shared init_gfx as integer = 0
dim shared screenbuf as BITMAP ptr = null

dim shared mouse_hidden as integer = 0
dim shared baroffset as integer = 0
dim shared windowed as integer = 1
dim shared alpal(255) as RGB

'Translate an allegro scancode into a normal one
dim shared scantrans(0 to 127) as integer => { _
	0, scA, scB, scC, scD, scE, scF, scG, _
	scH, scI, scJ, scK, scL, scM, scN, scO, _
	scP, scQ, scR, scS, scT, scU, scV, scW, _
	scX, scY, scZ, sc0, sc1, sc2, sc3, sc4, _
	sc5, sc6, sc7, sc8, sc9, scNumpad0, scNumpad1, scNumpad2, _
	scNumpad3, scNumpad4, scNumpad5, scNumpad6, scNumpad7, scNumpad8, scNumpad9, scF1, _
	scF2, scF3, scF4, scF5, scF6, scF7, scF8, scF9, _
	scF10, scF11, scF12, scEsc, scTilde, scMinus, scEquals, scBackspace, _
	scTab, scLeftBrace, scRightBrace, scEnter, scColon, scQuote, scBackslash, 0, _
	scComma, scPeriod, scSlash, scSpace, scInsert, scDelete, scHome, scEnd, _
	scPageup, scPagedown, scLeft, scRight, scUp, scDown, scNumpadSlash, scNumpadAsterix, _
	scNumpadMinus, scNumpadPlus, scNumpadPeriod, scNumpadEnter, scPrintScreen, scPause, 0, 0, _
	0, 0, 0, scAtSign, scCircumflex, 0, 0, scLeftShift, _
	scRightShift, scLeftCtrl, scRightCtrl, scLeftAlt, scRightAlt, scLeftWinLogo, scRightWinLogo, scContext, _
	scScrollLock, scNumlock, scCapslock, 0, 0, 0, 0, 0, _
	0, 0, 0, 0, 0, 0, 0, 0 _
}

extern "C"

function gfx_alleg_init(byval terminate_signal_handler as sub cdecl (), byval windowicon as zstring ptr, byval info_buffer as zstring ptr, byval info_buffer_size as integer) as integer
	if init_gfx = 0 then
		allegro_init()
	
		set_color_depth(8)
		if windowed <> 0 then
			set_gfx_mode(GFX_AUTODETECT_WINDOWED, 640, 400, 0, 0)
			baroffset = 0
		else
			set_gfx_mode(GFX_AUTODETECT_FULLSCREEN, 640, 480, 0, 0)
			baroffset = 40
		end if
		clear_bitmap(screen)
		
		install_keyboard
		install_mouse
		unscare_mouse
		set_window_close_hook(@post_terminate_signal)
		
		init_gfx = 1
	end if
	return 1
end function

sub gfx_alleg_close
	if screenbuf <> null then
		destroy_bitmap(screenbuf)
		screenbuf = null
	end if
end sub

function gfx_alleg_getversion() as integer
	return 1
end function

sub gfx_alleg_showpage(byval raw as ubyte ptr, byval w as integer, byval h as integer)
'takes a pointer to raw 8-bit data at 320x200 (w, h ignored)
	dim as integer x, y

	if screenbuf = null then
		'only create this once, to save a bit of time	
		screenbuf = create_bitmap(320, 200)
	end if
	
	for y = 0 to 199
		for x = 0 to 319
			#IFDEF putpixel8
			putpixel8(screenbuf, x, y, *raw)
			#ELSE
			putpixel(screenbuf, x, y, *raw)
			#ENDIF
			raw += 1
		next
	next
	
	stretch_blit(screenbuf, screen, 0, 0, 320, 200, 0, baroffset, 640, 400)
	
end sub

sub gfx_alleg_setpal(byval pal as RGBcolor ptr)
'In 8 bit colour depth, allegro uses 6 bit colour components in the palette
	dim as integer i
	
	for i = 0 to 255
		alpal(i).r = pal[i].r \ 4
		alpal(i).g = pal[i].g \ 4
		alpal(i).b = pal[i].b \ 4
	next
	
	set_palette(@alpal(0))
end sub

function gfx_alleg_screenshot(byval fname as zstring ptr) as integer
	gfx_alleg_screenshot = 0
end function

sub gfx_alleg_setwindowed(byval iswindow as integer)
	if iswindow <> 0 then iswindow = 1 'only 1 "true" value
	if iswindow = windowed then exit sub
	
	windowed = iswindow
	
	if init_gfx = 1 then
		if screenbuf <> null then
			destroy_bitmap(screenbuf)
			screenbuf = null
		end if
		if windowed <> 0 then
			set_gfx_mode(GFX_AUTODETECT_WINDOWED, 640, 400, 0, 0)
			baroffset = 0
		else
			set_gfx_mode(GFX_AUTODETECT_FULLSCREEN, 640, 480, 0, 0)
			baroffset = 40
		end if
		set_palette(@alpal(0))		
	end if
end sub

sub gfx_alleg_windowtitle(byval title as zstring ptr)
	if init_gfx = 1 then
 		set_window_title(title)
 	end if
end sub

function gfx_alleg_getwindowstate() as WindowState ptr
	return 0
end function

function gfx_alleg_setoption(byval opt as zstring ptr, byval arg as zstring ptr) as integer
'handle command-line options in a generic way, so that they
'can be ignored or supported as the library permits.
	'unrecognised
	return 0
end function

function gfx_alleg_describe_options() as zstring ptr
'No options are supported by this backend
 return @""
end function

'------------- IO Functions --------------
sub io_alleg_init
' 	'mostly handled above
' 	if mouse_hidden = 0 then
' 		scare_mouse() 'hide mouse
' 		mouse_hidden = 1
' 	end if
end sub

sub io_alleg_pollkeyevents()
	'not needed by this backend
end sub

sub io_alleg_waitprocessing()
	'not needed by this backend
end sub

sub io_alleg_updatekeys(byval keybd as integer ptr)
	dim a as integer
	for a = 0 to &h7f
		if key(a) then
			keybd[scantrans(a)] = keybd[scantrans(a)] or 8
		end if
	next

	keybd[scShift] or= (keybd[scLeftShift] or keybd[scRightShift]) and 8
	keybd[scUnfilteredAlt] or= (keybd[scLeftAlt] or keybd[scRightAlt]) and 8
	keybd[scCtrl] or= (keybd[scLeftCtrl] or keybd[scRightCtrl]) and 8

	'Note: Pause reports NumLock for me, just like fbgfx

	if key(KEY_ENTER) andalso (key_shifts and KB_ALT_FLAG) then
		if windowed = 0 then
			gfx_alleg_setwindowed(1)
		else
			gfx_alleg_setwindowed(0)
		end if
	end if
end sub

sub io_alleg_setmousevisibility(byval visible as integer)
'who know why this check is here
 	if visible <> 0 and mouse_hidden = 1 then
 		unscare_mouse()
 		mouse_hidden = 0
 	end if
 	if visible = 0 and mouse_hidden = 0 then
 		scare_mouse()
 		mouse_hidden = 1
 	end if
end sub

sub io_alleg_getmouse(mx as integer, my as integer, mwheel as integer, mbuttons as integer)
	mx = mouse_x \ 2		'allegro screen is double res
	my = (mouse_y \ 2) - baroffset	'and centred
	mwheel = mouse_z
	mbuttons = mouse_b
end sub

sub io_alleg_setmouse(byval x as integer, byval y as integer)
	position_mouse(x * 2, y * 2 + baroffset)
end sub

sub io_alleg_mouserect(byval xmin as integer, byval xmax as integer, byval ymin as integer, byval ymax as integer)
'doesn't seem to work fullscreen, no idea why not. Height of mouse cursor?
'FIXME: doesn't seem to restrict to the window at all.
 	set_mouse_range(xmin * 2, ymin * 2 + baroffset, xmax * 2 + 1, ymax * 2 + 1 + baroffset)
end sub

function io_alleg_readjoysane(byval joynum as integer, byref button as integer, byref x as integer, byref y as integer) as integer
	'don't know
	return 0
end function

function gfx_alleg_setprocptrs() as integer
	gfx_init = @gfx_alleg_init
	gfx_close = @gfx_alleg_close
	gfx_getversion = @gfx_alleg_getversion
	gfx_showpage = @gfx_alleg_showpage
	gfx_setpal = @gfx_alleg_setpal
	gfx_screenshot = @gfx_alleg_screenshot
	gfx_setwindowed = @gfx_alleg_setwindowed
	gfx_windowtitle = @gfx_alleg_windowtitle
	gfx_getwindowstate = @gfx_alleg_getwindowstate
	gfx_setoption = @gfx_alleg_setoption
	gfx_describe_options = @gfx_alleg_describe_options
	io_init = @io_alleg_init
	io_pollkeyevents = @io_alleg_pollkeyevents
	io_waitprocessing = @io_alleg_waitprocessing
	io_keybits = @io_amx_keybits
	io_updatekeys = @io_alleg_updatekeys
	io_mousebits = @io_amx_mousebits
	io_setmousevisibility = @io_alleg_setmousevisibility
	io_getmouse = @io_alleg_getmouse
	io_setmouse = @io_alleg_setmouse
	io_mouserect = @io_alleg_mouserect
	io_readjoysane = @io_alleg_readjoysane

	return 1
end function

end extern