imageviewer.janet

(use ./libs/jaylib)
(ffi/context "tinyfd.dll")

(ffi/defbind tinyfd_selectFolderDialog :string
    [tilte :string defaultpath :string])
(ffi/defbind tinyfd_utf8toMbcs :string
    [instr :string])

#(set-trace-log-level :none)
(init-window 1920 1080 "Image viewer")
(set-target-fps 60)
#(hide-cursor)
(set-window-state :window-resizable)

(var imgpath "E:\\play\\photo\\wp")
(var imgnames @[])
(var bFix false)
(var pos 0)
(var ctexture nil)
(var imgw 0)
(var imgh 0)
(var lastsecond (get-time))
(var offsetx 0)
(var offsety 0)
(var mmovex 0)
(var mmovey 0)

(defn load_image_list []
    (var tmppath (tinyfd_selectFolderDialog "select directory" imgpath))
    (set imgpath (tinyfd_utf8toMbcs tmppath))
    #(pp imgpath)
    (array/clear imgnames)
    (var tmpnames (os/dir imgpath))
    (each fname tmpnames
        (when
            (or (string/has-suffix? ".jpg" fname) (string/has-suffix? ".JPG" fname) (string/has-suffix? ".png" fname) (string/has-suffix? ".PNG" fname))
            (array/push imgnames fname)
        )
    )
)

(defn switch_image []
    (if (not= ctexture nil)
        (do
            (unload-texture ctexture)
            (set ctexture nil)
        )
    )
    (var ciname (string imgpath "\\" (get imgnames pos)))
    (set ctexture (load-texture ciname))
    (set imgw (get ctexture :width))
    (set imgh (get ctexture :height))
    (set offsetx 0)
    (set offsety 0)
)

# main loop
(while (not (window-should-close))
    # mouse drag
    (if (and (mouse-button-pressed? :left) (not bFix))
        (do
            (set mmovex (get-mouse-x))
            (set mmovey (get-mouse-y))
        )
    )
    (if (and (mouse-button-released? :left) (not bFix))
        (when (and (> mmovex 0) (> mmovey 0))
            (set offsetx (+ (- (get-mouse-x) mmovex) offsetx) )
            (set offsety (+ (- (get-mouse-y) mmovey) offsety) )
        )
    )
    # key press
    (var pkey (get-key-pressed))
    (when (= pkey :a)
        (when (> pos 0)
            (set pos (- pos 1))
            (switch_image)
        )
    )
    (when (= pkey :d)
        (when (< pos (- (length imgnames) 1))
            (set pos (+ pos 1))
            (switch_image)
        )
    )
    (when (= pkey :space)
		(set bFix (if bFix false true))
    )
    (when (= pkey :f)
		(toggle-fullscreen)
    )
    (when (= pkey :o)
		(load_image_list)
		(when (> (length imgnames) 0)
            (set pos 0)
            (switch_image)
		)
    )
    # mouse wheel
    (var wheeloff (get-mouse-wheel-move))
    (when (> wheeloff 0)
        (var clockdelta (- (get-time) lastsecond))
        (set lastsecond (get-time))
        (when (> clockdelta 0.2)
            (when (> pos 0)
                (set pos (- pos 1))
                (switch_image)
            )
        )
    )
    (when (< wheeloff 0)
        (var clockdelta (- (get-time) lastsecond))
        (set lastsecond (get-time))
        (when (> clockdelta 0.2)
            (when (< pos (- (length imgnames) 1))
                (set pos (+ pos 1))
                (switch_image)
            )
        )
    )
    # draw
    (begin-drawing)
    (clear-background [0 0 0])
    (if (> imgw 0)
    	(do
    		(var winw (get-screen-width))
    		(var winh (get-screen-height))
	    	(if (= bFix true)
	    		(do
	    			(var fScale (/ winw imgw))
	    			(var neww winw)
	    			(var newh (* imgh fScale))
	    			(when (> newh winh)
	    				(do
	    					(set fScale (/ winh imgh))
	    					(set newh winh)
	    					(set neww (* imgw fScale))
	    				)
	    			)
	    			(draw-texture-ex ctexture [(math/floor (/ (- winw neww) 2)) (math/floor (/ (- winh newh) 2))] 0 fScale :white)
	    		)
	        	(draw-texture ctexture (math/floor (+ (/ (- winw imgw) 2) offsetx)) (math/floor (+ (/ (- winh imgh) 2) offsety)) :white)
	    	)
    	)
    	(do
            (draw-text "No image to show" 50 50 20 :blue)
            (draw-text "A for prev image" 50 80 20 :blue)
            (draw-text "D for next image" 50 110 20 :blue)
            (draw-text "O for change folder" 50 140 20 :blue)
            (draw-text "F for toggle fullscreen" 50 170 20 :blue)
            (draw-text "SPACE for toggle fix image size" 50 200 20 :blue)
        )
    )
    (end-drawing)
)
# release memory
(if (not= ctexture nil) 
    (do
        (unload-texture ctexture)
        (set ctexture nil)
    )
)
(close-window)