marquee scroller

scroller1.p8

@@ -0,0 +1,88 @@
+pico-8 cartridge // http://www.pico-8.com
+version 27
+__lua__
+-- scroller
+-- 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()
+    pal_background = 1
+    pal_text = 13
+    scroller_speed = 5/30
+    scroller_width = 32
+    text_index = 1
+    text = "12345"
+    text = "lorem ipsum dolor sit amet, consectetur... " -- adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua."
+    debug = true
+end
+
+function _update()
+    update_scroller_text()
+    update_colour()
+    update_speed()
+end
+
+function _draw()
+    cls(palsorted[pal_background])
+    print(scroller_text, 0, 60, palsorted[pal_text])
+    if (debug) draw_debug()
+end
+
+-- updates scroller_text and text_index
+function update_scroller_text()
+    scroller_text = ""
+    -- pad to start text from the right edge
+    if (false and text_index < scroller_width) then
+        pad = ""
+        for i = 1,(scroller_width - flr(text_index)) do
+            pad = pad .. "."
+        end
+        scroller_text = pad
+    end
+
+    text_index_end = flr(text_index + scroller_width - 1)
+    scroller_text = scroller_text .. sub(text, text_index, text_index_end)
+
+    -- add a bit from the start
+    if (text_index_end > #text) then
+        scroller_text = scroller_text .. sub(text, 0, text_index_end - #text)
+    end
+
+    -- +1 allows index to work through the last character at scroller_speed increments before going to 0
+    text_index = ((text_index + scroller_speed) % (#text + 1))
+    -- ...and fix % because index starts from 1
+    if (text_index < 1) text_index = 1
+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
+
+-- print debug info
+function draw_debug()
+    print("bkg:"..pal_background..",txt:"..pal_text, 0, 117, pink)
+    print("spd:"..scroller_speed..",i:"..text_index..",end:"..text_index_end, 0, 123, pink)
+end
+__gfx__
+00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
+00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
+00700700000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
+00077000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
+00077000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
+00700700000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000