Various playdate optimizations, increasing unused CPU to hopefully drive audio or something. Moved the Lua project into playdate/matrix_lua

2026-04-16 21:39:29 -07:00 · 2022-06-05 00:23:07 -07:00
parent ceb5b03458
commit 551ce132c4
3 changed files with 40 additions and 17 deletions
--- a/playdate/matrix_lua/main.lua
+++ b/playdate/matrix_lua/main.lua
@@ -0,0 +1,120 @@
+local gfx <const> = playdate.graphics
+local floor <const> = math.floor
+local random <const> = math.random
+
+local screenWidth <const> = playdate.display.getWidth()
+local screenHeight <const> = playdate.display.getHeight()
+local glyphWidth <const> = 20
+local numColumns <const> = floor(screenWidth / glyphWidth)
+local numRows <const> = floor(screenHeight / glyphWidth)
+local numCells <const> = numColumns * numRows
+
+local numGlyphs <const> = 133
+local numFades <const> = 16
+local blackImage = gfx.image.new(glyphWidth, glyphWidth, gfx.kColorBlack)
+local glyphTable = gfx.imagetable.new('images/matrix')
+local ditherType = gfx.image.kDitherTypeAtkinson
+local glyphs = {}
+for i = 1, numGlyphs do
+	glyphs[i] = {}
+	local glyph = glyphTable[i]
+	for j = 1, numFades do
+		glyphs[i][j] = glyph:blendWithImage(blackImage, 1 - j / numFades, ditherType)
+	end
+end
+
+local minSpeed <const> = 0.15
+local maxSpeed <const> = 1
+local time = 0
+local speed = maxSpeed
+
+local sineTable = {}
+for i = 1,360 do
+	sineTable[i] = math.sin(math.pi / 180 * i)
+end
+
+-- function fastSin(x)
+-- 	x = x / 360 % 1
+-- 	local sign
+-- 	if x < 0.5 then
+-- 		sign = -1
+-- 	else
+-- 		sign = 1
+-- 	end
+-- 	x = (x % 0.5) * 2 - 0.5
+-- 	return sign * x * x * 4 - 1
+-- end
+
+local wobbleA <const> = math.sqrt(2) / 50
+local wobbleB <const> = math.sqrt(5) / 50
+
+local cells = {}
+for x = 1, numColumns do
+	local columnTimeOffset = random() * 1000
+	local columnSpeedOffset = random() * 0.5 + 0.5
+	for y = 1, numRows do
+		local cell = {}
+		cell.x = x
+		cell.y = y
+		cell.glyphCycle = random()
+		cell.columnTimeOffset = columnTimeOffset
+		cell.columnSpeedOffset = columnSpeedOffset
+		cell.glyphIndex = floor(random() * numGlyphs) + 1
+		cell.fadeIndex = -1
+
+		cells[#cells + 1] = cell
+	end
+end
+
+playdate.display.setRefreshRate(24)
+playdate.resetElapsedTime()
+
+function playdate.update()
+	local delta
+	if playdate.isCrankDocked() then
+		speed = math.min(maxSpeed, speed + 0.07)
+		delta = playdate.getElapsedTime() * speed
+	else
+		speed = math.max(minSpeed, speed - 0.07)
+		delta = playdate.getElapsedTime() * speed + playdate.getCrankChange() * 2 / 360 -- TODO: tune
+	end
+	playdate.resetElapsedTime()
+	time += delta
+
+	for i = 1, numCells do
+		local mustDraw = false
+		local cell = cells[i]
+
+		local cellTime = cell.y * -0.03 + cell.columnTimeOffset + time * cell.columnSpeedOffset
+		local brightness = 4 * (
+			(
+				cellTime
+				+ 0.3 * sineTable[floor((wobbleA * cellTime) % 360) + 1]
+				+ 0.2 * sineTable[floor((wobbleB * cellTime) % 360) + 1]
+			) % 1
+		)
+		local fadeIndex = floor(brightness * numFades)
+		if fadeIndex < 1 then fadeIndex = 1 end
+		if fadeIndex > numFades then fadeIndex = numFades end
+		if cell.fadeIndex ~= fadeIndex then
+			cell.fadeIndex = fadeIndex
+			mustDraw = true
+		end
+
+		cell.glyphCycle = cell.glyphCycle + delta * 2
+		if cell.glyphCycle > 1 then
+			cell.glyphCycle = cell.glyphCycle % 1
+			local glyphIndex = (cell.glyphIndex + random(20)) % numGlyphs + 1
+			if cell.glyphIndex ~= glyphIndex then
+				cell.glyphIndex = glyphIndex
+				if fadeIndex < numFades then
+					mustDraw = true
+				end
+			end
+		end
+
+		if mustDraw then
+			glyphs[cell.glyphIndex][cell.fadeIndex]:draw((cell.x - 1) * glyphWidth, (cell.y - 1) * glyphWidth)
+		end
+	end
+end