LÖVE

Code: Select all

local ImageData = love.image.newImageData("path/file/texture.png")
local Image = love.graphics.newImage("path/file/texture.png")
local MaskData = love.image.newImageData("path/file/mask.png")

function Mask(img, imgData, maskData)
	
    
    local width, height = img:getDimensions()

    for x = 0, width -1 do
        for y = 0, height -1 do 
			--loops through every pixel of the image
            
			local r1, g1, b1 = imgData:getPixel(x, y)
			--gets the RGB values of each pixel of the texture
			
            local r2, g2, b2, a2 = maskData:getPixel(x, y)
			--gets the alpha value for each pixel from the mask,
            
            imgData:setPixel(x, y, r1, g1, b1, a2)
			--[[Reassigns things. 
				The texture keeps all of its original RBG values, 
				but gets the corresponding alpha from the mask.]]
        end
    end
	
    img:replacePixels(imgData)
    --pushes the updated data to the original image.
end

function love.draw()
	
	Mask (Image, ImageData, MaskData)

	love.graphics.draw(Image, 0, 0)
	--[[It works and is fine for a one time call.
		However doing it every frame is too much and tanks the frame rate.]]
end

Code: Select all

local Image = love.graphics.newImage("path/file/texture.png")
local Mask = love.graphics.newImage("path/file/mask.png")

local MaskShader = love.graphics.newShader[[
uniform Image mask;

vec4 effect(vec4 color, Image tex, vec2 texture_coords, vec2 screen_coords)
{
	vec4 tex_color = Texel(tex, texture_coords);
	vec4 mask_color = Texel(mask, texture_coords);
	tex_color.a = mask_color.a;
	return tex_color;
}
]]

function love.draw()
	MaskShader:send("mask", Mask)
	love.graphics.setShader(MaskShader)
	love.graphics.draw(Image, 0, 0)
end