Implement blend mode code

UI2 support not added yet since I won't be able to test them yet

src/Essentials/Font.lua

@@ -76,10 +76,17 @@ function Font:getTextSize(text)
 	end
 end
 
-function Font:draw(text, pos, align, color, alpha)
+function Font:draw(text, pos, align, color, alpha, blendMode)
 	align = align or Vec2(0.5)
 	color = color or Color()
-	alpha = alpha or 1
+    alpha = alpha or 1
+    blendMode = blendMode or "alpha"
+	-- see Sprite.lua on why this reassigment exists
+	if blendMode == "none" then
+		blendMode = "alpha"
+    end
+	---@diagnostic disable-next-line: param-type-mismatch
+    love.graphics.setBlendMode(blendMode)
 
 	if self.type == "image" then
 		love.graphics.setColor(color.r, color.g, color.b, alpha)

src/Essentials/Sprite.lua

@@ -65,20 +65,40 @@ end
 ---@param color Color? The sprite color.
 ---@param alpha number? Sprite transparency. `0` is fully transparent. `1` is fully opaque.
 ---@param scale Vector2? The scale of this sprite.
-function Sprite:draw(pos, align, state, frame, rot, color, alpha, scale)
+---@param blendMode "none"|"alpha"|"screen"|"add"|"subtract"|"multiply"|"lighten"|"darken"? The blending mode to use.
+function Sprite:draw(pos, align, state, frame, rot, color, alpha, scale, blendMode)
 	align = align or Vec2()
 	state = state or 1
 	frame = frame or Vec2(1)
 	rot = rot or 0
 	color = color or Color()
 	alpha = alpha or 1
-	scale = scale or Vec2(1)
+    scale = scale or Vec2(1)
+    blendMode = blendMode or "alpha"
+    -- this is for convenience reasons so json files can use "none"
+	-- instead of "alpha", but the option is there regardless
+	if blendMode == "none" then
+		blendMode = "alpha"
+    end
 	pos = _PosOnScreen(pos - (align * scale * self.frameSize):rotate(rot))
 	if color.r then -- temporary chunk
 		love.graphics.setColor(color.r, color.g, color.b, alpha)
 	else
 		love.graphics.setColor(unpack(color), alpha)
+    end
+
+	--[[
+	local blendAlphaMode = "alphamultiply"
+    local modesToPremultiply = { "add", "subtract", "multiply", "lighten", "darken" }
+	for _,mode in pairs(modesToPremultiply) do
+		if mode == blendMode then
+			blendAlphaMode = "premultiplied"
+		end
 	end
+	]]
+	---@diagnostic disable-next-line: param-type-mismatch
+    love.graphics.setBlendMode(blendMode)
+
 	self.img:draw(self:getFrame(state, frame), pos.x, pos.y, rot, scale.x * _GetResolutionScale(), scale.y * _GetResolutionScale())
 end
 

src/Particle/Piece.lua

@@ -55,7 +55,8 @@ function ParticlePiece:new(manager, spawner, data)
 	self.lifetime = self.lifespan
 	self.time = 0
 
-	self.sprite = _Game.resourceManager:getSprite(data.sprite)
+    self.sprite = _Game.resourceManager:getSprite(data.sprite)
+	self.blendMode = data.blendMode
 	self.animationSpeed = data.animationSpeed
 	self.animationFrameCount = data.animationFrameCount
 	self.animationLoop = data.animationLoop
@@ -165,7 +166,7 @@ end
 
 function ParticlePiece:draw(layer)
 	if self.layer == layer then
-		self.sprite:draw(self:getPos(), Vec2(0.5), nil, Vec2(math.min(math.floor(self.animationFrame), self.animationFrameCount), 1), nil, self:getColor(), self:getAlpha())
+		self.sprite:draw(self:getPos(), Vec2(0.5), nil, Vec2(math.min(math.floor(self.animationFrame), self.animationFrameCount), 1), nil, self:getColor(), self:getAlpha(), nil, self.blendMode)
 	end
 end
 

src/UI/Widget.lua

@@ -77,6 +77,7 @@ function UIWidget:new(name, data, parent)
 			self.children[childN] = UIWidget(childN, child, self)
 		end
 	end
+	self.blendMode = data.blendMode
 
 	self.inheritShow = data.inheritShow
 	self.inheritHide = data.inheritHide

src/UI/WidgetSprite.lua

@@ -17,7 +17,7 @@ end
 
 
 function UIWidgetSprite:draw()
-	self.sprite:draw(self.parent:getPos(), self.parent.align / self.sprite.size, nil, nil, self.parent.angle, nil, self.parent:getAlpha())
+	self.sprite:draw(self.parent:getPos(), self.parent.align / self.sprite.size, nil, nil, self.parent.angle, nil, self.parent:getAlpha(), nil, self.parent.blendMode)
 end
 
 return UIWidgetSprite

src/UI/WidgetSpriteButton.lua

@@ -64,7 +64,7 @@ function UIWidgetSpriteButton:draw()
 		end
 	end
 
-	self.sprite:draw(pos, nil, self:getState(), nil, nil, nil, alpha)
+	self.sprite:draw(pos, nil, self:getState(), nil, nil, nil, alpha, nil, self.parent.blendMode)
 end
 
 function UIWidgetSpriteButton:getState()

src/UI/WidgetSpriteProgress.lua

@@ -39,7 +39,7 @@ function UIWidgetSpriteProgress:draw(variables)
 	local pos = self.parent:getPos()
 	local pos2 = _PosOnScreen(pos)
 	love.graphics.setScissor(pos2.x, pos2.y, self.size.x * _GetResolutionScale() * self.value, self.size.y * _GetResolutionScale())
-	self.sprite:draw(pos, nil, nil, nil, nil, nil, self.parent:getAlpha())
+	self.sprite:draw(pos, nil, nil, nil, nil, nil, self.parent:getAlpha(), nil, self.parent.blendMode)
 	love.graphics.setScissor()
 end
 

src/UI/WidgetSpriteProgressBlitz.lua

@@ -50,7 +50,7 @@ function UIWidgetSpriteProgressBlitz:draw(variables)
 	-- mark only these pixels as the pixels which can be affected
 	love.graphics.setStencilTest("equal", 1)
 	-- draw the circle
-	self.sprite:draw(self.parent:getPos(), nil, nil, nil, nil, nil, self.parent:getAlpha())
+	self.sprite:draw(self.parent:getPos(), nil, nil, nil, nil, nil, self.parent:getAlpha(), nil, self.parent.blendMode)
 	-- reset the mask
 	love.graphics.setStencilTest()
 end

src/UI/WidgetText.lua

@@ -22,7 +22,7 @@ end
 
 
 function UIWidgetText:draw(variables)
-	self.font:draw(self.textTmp, self.parent:getPos(), self.align, nil, self.parent:getAlpha())
+	self.font:draw(self.textTmp, self.parent:getPos(), self.align, nil, self.parent:getAlpha(), nil, self.parent.blendMode)
 end
 
 function UIWidgetText:getSize()

src/UI/WidgetTextInput.lua

@@ -45,11 +45,11 @@ end
 function UIWidgetTextInput:draw(variables)
 	local pos = self.parent:getPos()
 	local alpha = self.parent:getAlpha()
-	self.font:draw(self.text, pos, self.align, nil, alpha)
+	self.font:draw(self.text, pos, self.align, nil, alpha, nil, self.parent.blendMode)
 	if self.cursorSprite then
 		local cpos = pos + Vec2(self:getSize().x * (1 - self.align.x), 0)
 		local frame = math.floor(self.cursorSpriteBlink * 2) + 1
-		self.cursorSprite:draw(cpos, nil, nil, Vec2(frame, 1), nil, nil, alpha)
+		self.cursorSprite:draw(cpos, nil, nil, Vec2(frame, 1), nil, nil, alpha, nil, self.parent.blendMode)
 	end
 end