more flexible scroller working!

scroller2.p8

@@ -0,0 +1,119 @@
+pico-8 cartridge // http://www.pico-8.com
+version 27
+__lua__
+-- scroller2
+-- by apa
+
+-- consts
+left, right, up, down, fire1, fire2 = 0, 1, 2, 3, 4, 5
+black, dark_blue, dark_purple, dark_green, brown, dark_gray, light_gray, white, red, orange, yellow, green, blue, indigo, pink, peach = 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15
+palsorted = { 0, 5, 6, 7, 15, 14, 8, 2, 4, 9, 10, 11, 3, 12, 13, 1 }
+
+function _init()
+    -- palsorted index
+    pal_background = 2
+    pal_text = 13
+    init_scroller()
+    -- debug print
+    debug = true
+end
+
+function _update()
+    update_scroller()
+    update_colour()
+    update_speed()
+end
+
+function _draw()
+    cls(palsorted[pal_background])
+    draw_scroller(palsorted[pal_text])
+    if (debug) draw_debug()
+end
+
+-->8
+-- ######################## init
+
+function init_scroller()
+    -- scroller contents
+    scroller = {}
+    -- print location
+    scroller.x = 4
+    scroller.y = 60
+    scroller.speed = 3/30
+    scroller.width = 30             -- field width in characters 
+    scroller.pos = scroller.width   -- print start position
+    scroller.text = ""
+    scroller.state = "init"
+    -- text to show
+    text = {}
+    text.t = "12345"
+    text.t = "lorem ipsum dolor sit amet, consectetur... " -- adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua."
+    text.i = 1
+    text.iend = 1
+end
+
+-->8
+-- ###################### update
+
+-- updates scroller pos, text and text i, iend
+function update_scroller()
+    --if (text.iend < scroller.width and text.iend < #text.t) then
+    if (scroller.pos >= 1) then
+        -- scrolling in from right side, not fully visible
+        scroller.state = "coming in"
+        scroller.pos = (scroller.pos - scroller.speed) % (scroller.width + 1)
+        text.i = 1
+        if (text.iend < #text.t) text.iend += scroller.speed
+    elseif (text.i < #text.t + 1) then  -- +1 to allow i to work thru last letter
+        -- text on left edge, decreasing
+        scroller.state = "going out"
+        scroller.pos = 0
+        text.i += scroller.speed
+        -- BUG: with #text.t>scroller.width the last letter will flash outside of width
+        if (text.iend < #text.t) text.iend += scroller.speed
+    else
+        -- reset to restart from state 1
+        scroller.state = "reset"
+        scroller.pos = scroller.width
+        text.iend = 1
+    end
+    scroller.text = sub(text.t, flr(text.i), flr(text.iend))
+end
+
+-- cycle colors with direction keys
+function update_colour()
+    -- add +1 because % gives 0..15 but palsorted index needs to be 1..16
+    if (btnp(right)) pal_text = (pal_text % #palsorted) + 1
+    -- subtract -2 because we add the +1 anyway
+    if (btnp(left)) pal_text = ((pal_text - 2) % #palsorted) + 1
+    if (btnp(up)) pal_background = (pal_background % #palsorted) + 1
+    if (btnp(down)) pal_background = ((pal_background - 2) % #palsorted) + 1
+end
+
+-- cycle speed with fire keys
+function update_speed()
+    if (btnp(fire1)) scroller.speed = ((scroller.speed - 1/60) % 2)
+    if (btnp(fire2)) scroller.speed = ((scroller.speed + 1/60) % 2)
+end
+
+-->8
+-- ######################## draw
+
+function draw_scroller(color)
+    print(scroller.text, scroller.x + flr(scroller.pos)*4, scroller.y, color)
+end
+
+-- print debug info
+function draw_debug()
+    print("state:"..scroller.state,0,111,red)
+    print("bkg:"..pal_background..",txt:"..pal_text..",pos:"..scroller.pos, 0, 117, pink)
+    print("spd:"..scroller.speed..",i:"..text.i..",iend:"..text.iend, 0, 123, pink)
+end
+
+__gfx__
+00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
+00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
+00700700000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
+00077000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
+00077000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
+00700700000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000