1 files changed, 135 insertions, 0 deletions
diff --git a/dustParticle.lua b/dustParticle.lua
new file mode 100644
index 0000000..8e7edd4
--- /dev/null
+++ b/dustParticle.lua
@@ -0,0 +1,135 @@
+local DustParticle = {}
+DustParticle.__index = DustParticle
+
+local MAX_DUST = 30
+local DRIFT_SPEED_MIN = 4
+local DRIFT_SPEED_MAX = 12
+local WOBBLE_AMP_MIN = 3
+local WOBBLE_AMP_MAX = 8
+local WOBBLE_FREQ_MIN = 0.8
+local WOBBLE_FREQ_MAX = 2.5
+local GLOW_FREQ_MIN = 1.5
+local GLOW_FREQ_MAX = 4.0
+local GLOW_RADIUS_MIN = 2
+local GLOW_RADIUS_MAX = 5
+local MARGIN = 16
+
+local DUST_COLORS = {
+    {1.0, 0.95, 0.75},
+    {0.85, 0.9, 1.0},
+    {1.0, 0.85, 0.6},
+    {0.75, 0.85, 1.0},
+}
+
+function DustParticle.new(x, y)
+    local self = setmetatable({}, DustParticle)
+    self.x = x
+    self.y = y
+
+    local angle = math.random() * math.pi * 2
+    local speed = DRIFT_SPEED_MIN + math.random() * (DRIFT_SPEED_MAX - DRIFT_SPEED_MIN)
+    self.dx = math.cos(angle) * speed
+    self.dy = math.sin(angle) * speed
+
+    self.perpX = -math.sin(angle)
+    self.perpY = math.cos(angle)
+
+    self.wobbleAmp = WOBBLE_AMP_MIN + math.random() * (WOBBLE_AMP_MAX - WOBBLE_AMP_MIN)
+    self.wobbleFreq = WOBBLE_FREQ_MIN + math.random() * (WOBBLE_FREQ_MAX - WOBBLE_FREQ_MIN)
+    self.wobblePhase = math.random() * math.pi * 2
+
+    self.glowFreq = GLOW_FREQ_MIN + math.random() * (GLOW_FREQ_MAX - GLOW_FREQ_MIN)
+    self.glowPhase = math.random() * math.pi * 2
+
+    self.baseAlpha = 0.15 + math.random() * 0.25
+    self.color = DUST_COLORS[math.random(#DUST_COLORS)]
+    self.time = 0
+    return self
+end
+
+function DustParticle:update(dt)
+    self.time = self.time + dt
+    local wobble = math.sin(self.time * self.wobbleFreq + self.wobblePhase) * self.wobbleAmp
+    self.x = self.x + (self.dx + self.perpX * wobble * 0.3) * dt
+    self.y = self.y + (self.dy + self.perpY * wobble * 0.3) * dt
+end
+
+function DustParticle:draw()
+    local glowT = math.sin(self.time * self.glowFreq + self.glowPhase)
+    local glowRadius = GLOW_RADIUS_MIN + (GLOW_RADIUS_MAX - GLOW_RADIUS_MIN) * (glowT * 0.5 + 0.5)
+    local alpha = self.baseAlpha * (0.6 + 0.4 * (glowT * 0.5 + 0.5))
+
+    love.graphics.setBlendMode("add")
+    love.graphics.setColor(self.color[1], self.color[2], self.color[3], alpha * 0.4)
+    love.graphics.circle("fill", self.x, self.y, glowRadius)
+    love.graphics.setColor(self.color[1], self.color[2], self.color[3], alpha)
+    love.graphics.circle("fill", self.x, self.y, 1)
+    love.graphics.setBlendMode("alpha")
+    love.graphics.setColor(1, 1, 1, 1)
+end
+
+function DustParticle:isOutOfBounds(viewX, viewY, viewW, viewH)
+    return self.x < viewX - MARGIN or self.x > viewX + viewW + MARGIN
+        or self.y < viewY - MARGIN or self.y > viewY + viewH + MARGIN
+end
+
+local DustSystem = {}
+DustSystem.__index = DustSystem
+
+function DustSystem.new()
+    local self = setmetatable({}, DustSystem)
+    self.particles = {}
+    self.spawned = false
+    return self
+end
+
+function DustSystem:update(dt, camX, camY, camW, camH)
+    if not self.spawned then
+        for _ = 1, MAX_DUST do
+            local x = camX + math.random() * camW
+            local y = camY + math.random() * camH
+            table.insert(self.particles, DustParticle.new(x, y))
+        end
+        self.spawned = true
+    end
+
+    for _, p in ipairs(self.particles) do
+        p:update(dt)
+    end
+
+    for i = #self.particles, 1, -1 do
+        local p = self.particles[i]
+        if p:isOutOfBounds(camX, camY, camW, camH) then
+            local edge = math.random(4)
+            local x, y
+            if edge == 1 then
+                x = camX - MARGIN * 0.5
+                y = camY + math.random() * camH
+            elseif edge == 2 then
+                x = camX + camW + MARGIN * 0.5
+                y = camY + math.random() * camH
+            elseif edge == 3 then
+                x = camX + math.random() * camW
+                y = camY - MARGIN * 0.5
+            else
+                x = camX + math.random() * camW
+                y = camY + camH + MARGIN * 0.5
+            end
+            self.particles[i] = DustParticle.new(x, y)
+        end
+    end
+
+    while #self.particles < MAX_DUST do
+        local x = camX + math.random() * camW
+        local y = camY + math.random() * camH
+        table.insert(self.particles, DustParticle.new(x, y))
+    end
+end
+
+function DustSystem:draw()
+    for _, p in ipairs(self.particles) do
+        p:draw()
+    end
+end
+
+return DustSystem